2024
Müllers, Johannes; Greß, Hannah; Haaga, Lisa; Krüger, Björn
Sensorik am Krankenbett – Synchrone Datenakquise für Studien in der Epileptologie Conference
62. Jahrestagung der Deutschen Gesellschaft für Epileptologie, 2024.
@conference{muellers2024,
title = {Sensorik am Krankenbett – Synchrone Datenakquise für Studien in der Epileptologie},
author = {Johannes Müllers and Hannah Greß and Lisa Haaga and Björn Krüger},
year = {2024},
date = {2024-06-14},
urldate = {2024-06-14},
booktitle = {62. Jahrestagung der Deutschen Gesellschaft für Epileptologie},
abstract = {Die Möglichkeit der Anfallserkennung oder -vorhersage außerhalb des Krankenhauses kann die Lebensqualität und das Sicherheitsbedürfnis von Epilepsiepatienten erhöhen. Die Überwachung von Vitalparametern, Bewegungen und weiteren Messgrößen kann von einer Vielzahl von Wearables oder sonstigen neuartigen Sensorsystemen gewährleistet werden. Videoüberwachte EEG-Messplätze dienen als Goldstandard und werden für Studien mit solchen Sensoren genutzt, um Korrelationen festzustellen. Hierbei stellen technische Herausforderungen ein wiederkehrendes Problem dar. Neben der Inbetriebnahme der Sensorsysteme, die ohne informationstechnische Kenntnisse oft nur mit proprietären Mitteln möglich ist, ist insbesondere die Synchronizität zur EEG-Aufzeichnung anspruchsvoll. Aktuelle Vorbereitungen einer Studie mit Eye-Tracker Brillen bieten den Anlass, ein neues System zur Datenakquisition aufzubauen. },
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Die Möglichkeit der Anfallserkennung oder -vorhersage außerhalb des Krankenhauses kann die Lebensqualität und das Sicherheitsbedürfnis von Epilepsiepatienten erhöhen. Die Überwachung von Vitalparametern, Bewegungen und weiteren Messgrößen kann von einer Vielzahl von Wearables oder sonstigen neuartigen Sensorsystemen gewährleistet werden. Videoüberwachte EEG-Messplätze dienen als Goldstandard und werden für Studien mit solchen Sensoren genutzt, um Korrelationen festzustellen. Hierbei stellen technische Herausforderungen ein wiederkehrendes Problem dar. Neben der Inbetriebnahme der Sensorsysteme, die ohne informationstechnische Kenntnisse oft nur mit proprietären Mitteln möglich ist, ist insbesondere die Synchronizität zur EEG-Aufzeichnung anspruchsvoll. Aktuelle Vorbereitungen einer Studie mit Eye-Tracker Brillen bieten den Anlass, ein neues System zur Datenakquisition aufzubauen. Schulte-Rüther, Martin; Lemken, Johannes; Krüger, Björn; Greß, Hannah; Stroth, Sanna; Kamp-Becker, Inge; Poustka, Luise
Automated annotation and quantification of non-verbal behavior from eye tracking and accelerometer data during live social interaction Conference
Wissenschaftliche Tagung Autismus-Spektrum (WTAS), 2024.
@conference{schulteruether2024,
title = {Automated annotation and quantification of non-verbal behavior from eye tracking and accelerometer data during live social interaction},
author = {Martin Schulte-Rüther and Johannes Lemken and Björn Krüger and Hannah Greß and Sanna Stroth and Inge Kamp-Becker and Luise Poustka},
year = {2024},
date = {2024-03-21},
booktitle = {Wissenschaftliche Tagung Autismus-Spektrum (WTAS)},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
2023
Krüger, Björn; Weber, Christian; Greß, Hannah; Knaub, Jessica; Pukropski, Jan; Hütwohl, Daniela; Hahn, Kai; Grond, Martin; Jonas, Stephan; Surges, Rainer
Telekonsil zur Verbesserung der Epilepsiediagnostik Conference
Digitalisierung der Gesundheitsversorgung älterer Menschen, 2023.
@conference{krueger2023,
title = {Telekonsil zur Verbesserung der Epilepsiediagnostik},
author = {Björn Krüger and Christian Weber and Hannah Greß and Jessica Knaub and Jan Pukropski and Daniela Hütwohl and Kai Hahn and Martin Grond and Stephan Jonas and Rainer Surges},
year = {2023},
date = {2023-07-01},
booktitle = {Digitalisierung der Gesundheitsversorgung älterer Menschen},
abstract = {Erfolgreiche Diagnose von Epilepsien bedürfen einer engen Zusammenarbeit von Hausärzt:innen, Kinderärzt:innen und neurologischen und epileptologischen Fachärzt:innen sowie den entsprechenden Fachkliniken. Zusätzlich zu der Expertise der Ärzt:innen ist ein fortlaufender Austausch und die kontinuierliche Anreicherung von Fachwissen von Bedeutung. Neben der frühzeitigen Überweisung an Fachkliniken kann die gemeinsame Fall-begleitende und Klinikübergreifende Aufnahme, der Austausch und die Pflege von Falldokumentationen ein wichtiger Baustein für die langfristige und erfolgreiche Begleitung der Patient:innen sein. },
keywords = {},
pubstate = {published},
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}
Erfolgreiche Diagnose von Epilepsien bedürfen einer engen Zusammenarbeit von Hausärzt:innen, Kinderärzt:innen und neurologischen und epileptologischen Fachärzt:innen sowie den entsprechenden Fachkliniken. Zusätzlich zu der Expertise der Ärzt:innen ist ein fortlaufender Austausch und die kontinuierliche Anreicherung von Fachwissen von Bedeutung. Neben der frühzeitigen Überweisung an Fachkliniken kann die gemeinsame Fall-begleitende und Klinikübergreifende Aufnahme, der Austausch und die Pflege von Falldokumentationen ein wichtiger Baustein für die langfristige und erfolgreiche Begleitung der Patient:innen sein. Riedlinger, Dorothee; Krüger, Björn; Sydow, Hanna; Deutschbein, Johannes; Fischer-Rosinský, Antje; Slagman, Anna; Möckel, Martin
Ein Frühwarnsystem für Stürze – Identifikation von sturzgefährdeten Patient:innen durch die kombinierte Analyse von Medikamenten-Verordnungsdaten und Bewegungsprofilen Conference
Digitalisierung der Gesundheitsversorgung älterer Menschen, 2023.
@conference{riedlinger2023,
title = {Ein Frühwarnsystem für Stürze – Identifikation von sturzgefährdeten Patient:innen durch die kombinierte Analyse von Medikamenten-Verordnungsdaten und Bewegungsprofilen},
author = {Dorothee Riedlinger and Björn Krüger and Hanna Sydow and Johannes Deutschbein and Antje Fischer-Rosinský and Anna Slagman and Martin Möckel},
year = {2023},
date = {2023-07-01},
booktitle = {Digitalisierung der Gesundheitsversorgung älterer Menschen},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Schulte-Rüther, Martin; Krüger, Björn; Lemken, Johannes; Greß, Hannah; Stroth, Sanna; Kamp-Becker, Inge; Poustka, Luise
2023.
@conference{schulteruether2023,
title = {Automatic Delineation and Classification of Head Movements Using 3D Accelerometer Data from Live Social Interaction},
author = {Martin Schulte-Rüther and Björn Krüger and Johannes Lemken and Hannah Greß and Sanna Stroth and Inge Kamp-Becker and Luise Poustka},
url = {https://cdn.ymaws.com/www.autism-insar.org/resource/resmgr/docs/annualmeeting/insar_2023_full_abstract_boo.pdf, INSAR 2023 Abstract Book (p. 1246)},
year = {2023},
date = {2023-05-06},
urldate = {2023-05-06},
abstract = {Individuals with autism spectrum disorder (ASD) often show reduced non-verbal communication during social interactive encounters, e.g. facial expressions, deictic and communicative gestures, eye gaze. This includes reduced usage and expression of gestures of the head, such as nodding, shaking the head, and head turning. Diagnostic criteria of ASD suggest that reduced non-verbal communicative behavior is an important symptom, but current diagnostic tools are restricted to subjective, clinical evaluation.
While many tools for automatic delineation and classification of facial expressions and gestures from video data are available, less work has been done with respective to the usage of accelerometer sensor data. Considering the current lack of objective, quantitative measures of non-verbal behavior during social interaction, an automated analysis pipeline for movement annotation from accelerometer data would be helpful for both clinical evaluation and research.
},
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pubstate = {published},
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Individuals with autism spectrum disorder (ASD) often show reduced non-verbal communication during social interactive encounters, e.g. facial expressions, deictic and communicative gestures, eye gaze. This includes reduced usage and expression of gestures of the head, such as nodding, shaking the head, and head turning. Diagnostic criteria of ASD suggest that reduced non-verbal communicative behavior is an important symptom, but current diagnostic tools are restricted to subjective, clinical evaluation.
While many tools for automatic delineation and classification of facial expressions and gestures from video data are available, less work has been done with respective to the usage of accelerometer sensor data. Considering the current lack of objective, quantitative measures of non-verbal behavior during social interaction, an automated analysis pipeline for movement annotation from accelerometer data would be helpful for both clinical evaluation and research.
Lemken, Johannes; Krüger, Björn; Stroth, Sanna; Kamp-Becker, Inge; Gail, A.; Poustka, Luise; Schulte-Rüther, Martin
The relationship between eye gaze and engagement in dyadic conversations – a semi-automatic analysis using unobtrusive eye tracking glasses Conference
Wissenschaftliche Tagung Autismus-Spektrum, 2023.
@conference{lemken2023,
title = {The relationship between eye gaze and engagement in dyadic conversations – a semi-automatic analysis using unobtrusive eye tracking glasses},
author = {Johannes Lemken and Björn Krüger and Sanna Stroth and Inge Kamp-Becker and A. Gail and Luise Poustka and Martin Schulte-Rüther},
year = {2023},
date = {2023-03-03},
booktitle = {Wissenschaftliche Tagung Autismus-Spektrum},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Xu, Jing; Greß, Hannah; Seefried, Sabine; van Drongelen, Stefan; Schween, Raphael; Sommer, Claudia; Endres, Dominik; Krüger, Björn; Stief, Felix
Diagnosing Rare Diseases by Movement Primitive-Based Classification of Kinematic Gait Data Proceedings
Bernstein Conference, 2023.
@proceedings{JingXu2023,
title = {Diagnosing Rare Diseases by Movement Primitive-Based Classification of Kinematic Gait Data},
author = {Jing Xu and Hannah Greß and Sabine Seefried and Stefan van Drongelen and Raphael Schween and Claudia Sommer and Dominik Endres and Björn Krüger and Felix Stief},
url = {https://abstracts.g-node.org/conference/BC23/abstracts#/uuid/31c21041-91a0-46bd-87dc-46271501fdc0},
doi = {10.12751/nncn.bc2023.313},
year = {2023},
date = {2023-01-10},
urldate = {2023-01-10},
booktitle = { Bernstein Conference 2023},
abstract = {Of over 6.000 known rare diseases, a considerable portion involves motor symptoms [1]. Whereas aiding diagnosis by artificial intelligence based on non-motor symptoms has shown promise [2], the potential of using movement data to this purpose has not yet been fully investigated. We therefore aim to implement a machine learning algorithm inspired by biological motor control to aid diagnosis of rare diseases by classifying data from standard kinematic clinical gait analysis.
Starting from 42-degrees-of-freedom time series of joint angles extracted from motion capture data with custom routines [3], we employ a Gaussian process-based temporal movement primitive algorithm [4] in order to reduce the data to sets of movement primitives and weight vectors that capture the essential characteristics of the gait movement. The primitives are participant (and disease) -independent and represent general human gait. The weights are participant-specific and thus contain disease-specific information. A weighted combination of the primitives can thus generate participant specific gait data. We then apply standard classification tools such as Support Vector Machines and Random Forests to the weights to distinguish the disease from the control gait. The primary goal is to reliably differentiate patients from age-matched controls in an existing data set on patients with Legg–Calvé–Perthes disease (LCPD). A secondary goal is to allow the classifier to expand the set of diseases using nonparametric methods such as the Dirichlet process.
Importantly, our movement primitive algorithm is inspired by current theories of biological motor control with a potential edge over standard algorithms in training on small case numbers. The temporal primitives are analogous to central pattern generators in the spinal cord [5], whereas the weights reflect activation of these central patterns by more central mechanisms in a hierarchical control scheme. In such a control scheme, disease-specific changes in weights may be caused directly by disease-specific influences on neural signaling, such as in the Stiff Person Syndrome [6], or indirectly through pain-avoidance in orthopedic conditions such as LCPD.
With further development, our approach holds potential for facilitating early detection and improving treatment strategies across a wide range of rare movement disorders and orthopedic conditions.},
howpublished = {Bernstein Conference},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
Of over 6.000 known rare diseases, a considerable portion involves motor symptoms [1]. Whereas aiding diagnosis by artificial intelligence based on non-motor symptoms has shown promise [2], the potential of using movement data to this purpose has not yet been fully investigated. We therefore aim to implement a machine learning algorithm inspired by biological motor control to aid diagnosis of rare diseases by classifying data from standard kinematic clinical gait analysis.
Starting from 42-degrees-of-freedom time series of joint angles extracted from motion capture data with custom routines [3], we employ a Gaussian process-based temporal movement primitive algorithm [4] in order to reduce the data to sets of movement primitives and weight vectors that capture the essential characteristics of the gait movement. The primitives are participant (and disease) -independent and represent general human gait. The weights are participant-specific and thus contain disease-specific information. A weighted combination of the primitives can thus generate participant specific gait data. We then apply standard classification tools such as Support Vector Machines and Random Forests to the weights to distinguish the disease from the control gait. The primary goal is to reliably differentiate patients from age-matched controls in an existing data set on patients with Legg–Calvé–Perthes disease (LCPD). A secondary goal is to allow the classifier to expand the set of diseases using nonparametric methods such as the Dirichlet process.
Importantly, our movement primitive algorithm is inspired by current theories of biological motor control with a potential edge over standard algorithms in training on small case numbers. The temporal primitives are analogous to central pattern generators in the spinal cord [5], whereas the weights reflect activation of these central patterns by more central mechanisms in a hierarchical control scheme. In such a control scheme, disease-specific changes in weights may be caused directly by disease-specific influences on neural signaling, such as in the Stiff Person Syndrome [6], or indirectly through pain-avoidance in orthopedic conditions such as LCPD.
With further development, our approach holds potential for facilitating early detection and improving treatment strategies across a wide range of rare movement disorders and orthopedic conditions. Yasin, Hashim; Ghani, Saba; Krüger, Björn
An Effective and Efficient Approach for 3D Recovery of Human Motion Capture Data Journal Article
In: Sensors, vol. 23, no. 7, 2023, ISSN: 1424-8220.
@article{s23073664,
title = {An Effective and Efficient Approach for 3D Recovery of Human Motion Capture Data},
author = {Hashim Yasin and Saba Ghani and Björn Krüger},
url = {https://www.mdpi.com/1424-8220/23/7/3664},
doi = {10.3390/s23073664},
issn = {1424-8220},
year = {2023},
date = {2023-01-01},
journal = {Sensors},
volume = {23},
number = {7},
abstract = {In this work, we propose a novel data-driven approach to recover missing or corrupted motion capture data, either in the form of 3D skeleton joints or 3D marker trajectories. We construct a knowledge-base that contains prior existing knowledge, which helps us to make it possible to infer missing or corrupted information of the motion capture data. We then build a kd-tree in parallel fashion on the GPU for fast search and retrieval of this already available knowledge in the form of nearest neighbors from the knowledge-base efficiently. We exploit the concept of histograms to organize the data and use an off-the-shelf radix sort algorithm to sort the keys within a single processor of GPU. We query the motion missing joints or markers, and as a result, we fetch a fixed number of nearest neighbors for the given input query motion. We employ an objective function with multiple error terms that substantially recover 3D joints or marker trajectories in parallel on the GPU. We perform comprehensive experiments to evaluate our approach quantitatively and qualitatively on publicly available motion capture datasets, namely CMU and HDM05. From the results, it is observed that the recovery of boxing, jumptwist, run, martial arts, salsa, and acrobatic motion sequences works best, while the recovery of motion sequences of kicking and jumping results in slightly larger errors. However, on average, our approach executes outstanding results. Generally, our approach outperforms all the competing state-of-the-art methods in the most test cases with different action sequences and executes reliable results with minimal errors and without any user interaction.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work, we propose a novel data-driven approach to recover missing or corrupted motion capture data, either in the form of 3D skeleton joints or 3D marker trajectories. We construct a knowledge-base that contains prior existing knowledge, which helps us to make it possible to infer missing or corrupted information of the motion capture data. We then build a kd-tree in parallel fashion on the GPU for fast search and retrieval of this already available knowledge in the form of nearest neighbors from the knowledge-base efficiently. We exploit the concept of histograms to organize the data and use an off-the-shelf radix sort algorithm to sort the keys within a single processor of GPU. We query the motion missing joints or markers, and as a result, we fetch a fixed number of nearest neighbors for the given input query motion. We employ an objective function with multiple error terms that substantially recover 3D joints or marker trajectories in parallel on the GPU. We perform comprehensive experiments to evaluate our approach quantitatively and qualitatively on publicly available motion capture datasets, namely CMU and HDM05. From the results, it is observed that the recovery of boxing, jumptwist, run, martial arts, salsa, and acrobatic motion sequences works best, while the recovery of motion sequences of kicking and jumping results in slightly larger errors. However, on average, our approach executes outstanding results. Generally, our approach outperforms all the competing state-of-the-art methods in the most test cases with different action sequences and executes reliable results with minimal errors and without any user interaction. Jermann, N.; Krusche, B.; Metag, V.; Afzal, F.; Badea, M.; Beck, R.; Bielefeldt, P.; Bieling, J.; Biroth, M.; Blanke, E.; Borisov, N.; Bornstein, M.; Brinkmann, K. -T.; Ciupka, S.; Crede, V.; Dolzhikov, A.; Drexler, P.; Dutz, H.; Elsner, D.; Fedorov, A.; Frommberger, F.; Gardner, S.; Ghosal, D.; Goertz, S.; Gorodnov, I.; Grüner, M.; Hammann, C.; Hartmann, J.; Hillert, W.; Hoffmeister, P.; Honisch, C.; Jude, T. C.; Kalischewski, F.; Ketzer, B.; Klassen, P.; Klein, F.; Klempt, E.; Knaust, J.; Kolanus, N.; Kreit, J.; Krönert, P.; Lang, M.; Lazarev, A. B.; Livingston, K.; Lutterer, S.; Mahlberg, P.; Meier, C.; Meyer, W.; Mitlasoczki, B.; Müllers, Johannes; Nanova, M.; Neganov, A.; Nikonov, K.; Noël, J. F.; Ostrick, M.; Ottnad, J.; Otto, B.; Penman, G.; Poller, T.; Proft, D.; Reicherz, G.; Reinartz, N.; Richter, L.; Runkel, S.; Salisbury, B.; Sarantsev, A. V.; Schaab, D.; Schmidt, C.; Schmieden, H.; Schultes, J.; Seifen, T.; Spieker, K.; Stausberg, N.; Steinacher, M.; Taubert, F.; Thiel, A.; Thoma, U.; Thomas, A.; Urban, M.; Urff, G.; Usov, Y.; van Pee, H.; Wang, Y. C.; Wendel, C.; Wiedner, U.; Wunderlich, Y.
Measurement of polarization observables T, P, and H in 𝛑⁰ and 𝛈 photoproduction off quasi-free nucleons Journal Article
In: The European Physical Journal A, vol. 59, 2023.
@article{articleb,
title = {Measurement of polarization observables T, P, and H in 𝛑⁰ and 𝛈 photoproduction off quasi-free nucleons},
author = {N. Jermann and B. Krusche and V. Metag and F. Afzal and M. Badea and R. Beck and P. Bielefeldt and J. Bieling and M. Biroth and E. Blanke and N. Borisov and M. Bornstein and K.-T. Brinkmann and S. Ciupka and V. Crede and A. Dolzhikov and P. Drexler and H. Dutz and D. Elsner and A. Fedorov and F. Frommberger and S. Gardner and D. Ghosal and S. Goertz and I. Gorodnov and M. Grüner and C. Hammann and J. Hartmann and W. Hillert and P. Hoffmeister and C. Honisch and T. C. Jude and F. Kalischewski and B. Ketzer and P. Klassen and F. Klein and E. Klempt and J. Knaust and N. Kolanus and J. Kreit and P. Krönert and M. Lang and A. B. Lazarev and K. Livingston and S. Lutterer and P. Mahlberg and C. Meier and W. Meyer and B. Mitlasoczki and Johannes Müllers and M. Nanova and A. Neganov and K. Nikonov and J. F. Noël and M. Ostrick and J. Ottnad and B. Otto and G. Penman and T. Poller and D. Proft and G. Reicherz and N. Reinartz and L. Richter and S. Runkel and B. Salisbury and A. V. Sarantsev and D. Schaab and C. Schmidt and H. Schmieden and J. Schultes and T. Seifen and K. Spieker and N. Stausberg and M. Steinacher and F. Taubert and A. Thiel and U. Thoma and A. Thomas and M. Urban and G. Urff and Y. Usov and H. van Pee and Y. C. Wang and C. Wendel and U. Wiedner and Y. Wunderlich},
doi = {10.1140/epja/s10050-023-01134-0},
year = {2023},
date = {2023-01-01},
urldate = {2023-01-01},
journal = {The European Physical Journal A},
volume = {59},
abstract = {The target asymmetry T , recoil asymmetry P, and beam-target double polarization observable H were determined in exclusive π0 and η photoproduction off quasi-
free protons and, for the first time, off quasi-free neutrons. The experiment was performed at the electron stretcher accelerator ELSA in Bonn, Germany, with the Crystal Barrel/TAPS detector setup, using a linearly polarized photon beam and a transversely polarized deuterated butanol target. Effects from the Fermi motion of the nucleons within deuterium were removed by a full kinematic reconstruction of the final state invariant mass. A comparison of the data obtained on the proton and on the neutron provides new insight into the isospin structure of the electromagnetic excitation of the nucleon. Earlier measurements of polarization observables in the γ p → π0 p and γ p → ηp reactions are confirmed. The data obtained on the neutron are of particular relevance for clarifying the origin of the narrow structure in the ηn system at W = 1.68 GeV. A comparison with recent partial wave analyses favors the interpretation of this structure as arising from interference of the S11(1535) and S11(1650) resonances within the S11 -partial wave.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The target asymmetry T , recoil asymmetry P, and beam-target double polarization observable H were determined in exclusive π0 and η photoproduction off quasi-
free protons and, for the first time, off quasi-free neutrons. The experiment was performed at the electron stretcher accelerator ELSA in Bonn, Germany, with the Crystal Barrel/TAPS detector setup, using a linearly polarized photon beam and a transversely polarized deuterated butanol target. Effects from the Fermi motion of the nucleons within deuterium were removed by a full kinematic reconstruction of the final state invariant mass. A comparison of the data obtained on the proton and on the neutron provides new insight into the isospin structure of the electromagnetic excitation of the nucleon. Earlier measurements of polarization observables in the γ p → π0 p and γ p → ηp reactions are confirmed. The data obtained on the neutron are of particular relevance for clarifying the origin of the narrow structure in the ηn system at W = 1.68 GeV. A comparison with recent partial wave analyses favors the interpretation of this structure as arising from interference of the S11(1535) and S11(1650) resonances within the S11 -partial wave.2022
Honisch, C.; Klassen, P.; Müllers, Johannes; Urban, M.; Afzal, F.; Bieling, J.; Ciupka, S.; Hartmann, J.; Hoffmeister, P.; Lang, M.; Schaab, D.; Schmidt, C.; Steinacher, M.; Walther, D.; Beck, R.; Brinkmann, K. -T.; Crede, V.; Dutz, H.; Elsner, D.; Erni, W.; Fix, E.; Frommberger, F.; Grüner, M.; Jude, T.; Kalischewski, F.; Keshelashvili, I.; Krönert, P.; Krusche, B.; Mahlberg, P.; Metag, V.; Meyer, W.; Müller, F.; Nanova, M.; Otto, B.; Richter, L.; Runkel, S.; Salisbury, B.; Schmieden, H.; Schultes, J.; Seifen, T.; Stausberg, N.; Taubert, F.; Thiel, A.; Thoma, U.; Urff, G.; Wendel, C.; Wiedner, U.; Wunderlich, Y.; Zaunick, H. -G.
The new APD-Based Readout of the Crystal Barrel Calorimeter – An Overview Working paper
2022, (Momentan im Review).
@workingpaper{newapdreadout,
title = {The new APD-Based Readout of the Crystal Barrel Calorimeter – An Overview},
author = {C. Honisch and P. Klassen and Johannes Müllers and M. Urban and F. Afzal and J. Bieling and S. Ciupka and J. Hartmann and P. Hoffmeister and M. Lang and D. Schaab and C. Schmidt and M. Steinacher and D. Walther and R. Beck and K. -T. Brinkmann and V. Crede and H. Dutz and D. Elsner and W. Erni and E. Fix and F. Frommberger and M. Grüner and T. Jude and F. Kalischewski and I. Keshelashvili and P. Krönert and B. Krusche and P. Mahlberg and V. Metag and W. Meyer and F. Müller and M. Nanova and B. Otto and L. Richter and S. Runkel and B. Salisbury and H. Schmieden and J. Schultes and T. Seifen and N. Stausberg and F. Taubert and A. Thiel and U. Thoma and G. Urff and C. Wendel and U. Wiedner and Y. Wunderlich and H. -G. Zaunick},
doi = {10.48550/arXiv.2212.12364},
year = {2022},
date = {2022-12-23},
urldate = {2022-12-23},
abstract = {The Crystal Barrel is an electromagnetic calorimeter consisting of 1380 CsI(Tl) scintillators, and is currently installed at the CBELSA/TAPS experiment where it is used to detect decay products from photoproduction of mesons. The readout of the Crystal Barrel has been upgraded in order to integrate the detector into the first level of the trigger and to increase its sensitivity for neutral final states. The new readout uses avalanche photodiodes in the front-end and a dual back-end with branches optimized for energy and time measurement, respectively. An FPGA-based cluster finder processes the whole hit pattern within less than 100 ns. The important downside of APDs -- the temperature dependence of their gain -- is handled with a temperature stabilization and a compensating bias voltage supply. Additionally, a light pulser system allows the APDs' gains to be measured during beamtimes. },
note = {Momentan im Review},
keywords = {},
pubstate = {published},
tppubtype = {workingpaper}
}
The Crystal Barrel is an electromagnetic calorimeter consisting of 1380 CsI(Tl) scintillators, and is currently installed at the CBELSA/TAPS experiment where it is used to detect decay products from photoproduction of mesons. The readout of the Crystal Barrel has been upgraded in order to integrate the detector into the first level of the trigger and to increase its sensitivity for neutral final states. The new readout uses avalanche photodiodes in the front-end and a dual back-end with branches optimized for energy and time measurement, respectively. An FPGA-based cluster finder processes the whole hit pattern within less than 100 ns. The important downside of APDs -- the temperature dependence of their gain -- is handled with a temperature stabilization and a compensating bias voltage supply. Additionally, a light pulser system allows the APDs' gains to be measured during beamtimes. 2021
Gottschall, M.; Afzal, F.; Anisovich, A. V.; Bayadilov, D.; Beck, R.; Bichow, M.; Brinkmann, K. Th.; Crede, V.; Dieterle, M.; Dietz, F.; Dutz, H.; Eberhardt, H.; Elsner, D.; Ewald, R.; Fornet-Ponse, K.; Friedrich, St.; Frommberger, F.; Gridnev, A.; Grüner, M.; Gutz, E.; Hammann, Ch.; Hannappel, J.; Hartmann, J.; Hillert, W.; Hoffmeister, Ph.; Honisch, Ch.; Jude, T.; Kammer, S.; Kalinowsky, H.; Keshelashvili, I.; Klassen, P.; Klein, F.; Klempt, E.; Koop, K.; Krusche, B.; Kube, M.; Lang, M.; Lopatin, I.; Mahlberg, P.; Makonyi, K.; Metag, V.; Meyer, W.; Müller, J.; Müllers, Johannes; Nanova, M.; Nikonov, V.; Novotny, R.; Piontek, D.; Reicherz, G.; Rostomyan, T.; Sarantsev, A.; Schmidt, Ch.; Schmieden, H.; Seifen, T.; Sokhoyan, V.; Spieker, K.; Thiel, A.; Thoma, U.; Urban, M.; Pee, H.; Walther, D.; Wendel, Ch.; Werthmüller, D.; Wiedner, U.; Wilson, A.; Winnebeck, A.; Witthauer, L.; Wunderlich, Y.
Measurement of the helicity asymmetry E for the reaction γp→π0p Journal Article
In: The European Physical Journal A, vol. 57, pp. 40, 2021.
@article{articlec,
title = {Measurement of the helicity asymmetry E for the reaction γp→π0p},
author = {M. Gottschall and F. Afzal and A. V. Anisovich and D. Bayadilov and R. Beck and M. Bichow and K. Th. Brinkmann and V. Crede and M. Dieterle and F. Dietz and H. Dutz and H. Eberhardt and D. Elsner and R. Ewald and K. Fornet-Ponse and St. Friedrich and F. Frommberger and A. Gridnev and M. Grüner and E. Gutz and Ch. Hammann and J. Hannappel and J. Hartmann and W. Hillert and Ph. Hoffmeister and Ch. Honisch and T. Jude and S. Kammer and H. Kalinowsky and I. Keshelashvili and P. Klassen and F. Klein and E. Klempt and K. Koop and B. Krusche and M. Kube and M. Lang and I. Lopatin and P. Mahlberg and K. Makonyi and V. Metag and W. Meyer and J. Müller and Johannes Müllers and M. Nanova and V. Nikonov and R. Novotny and D. Piontek and G. Reicherz and T. Rostomyan and A. Sarantsev and Ch. Schmidt and H. Schmieden and T. Seifen and V. Sokhoyan and K. Spieker and A. Thiel and U. Thoma and M. Urban and H. Pee and D. Walther and Ch. Wendel and D. Werthmüller and U. Wiedner and A. Wilson and A. Winnebeck and L. Witthauer and Y. Wunderlich},
doi = {10.1140/epja/s10050-020-00334-2},
year = {2021},
date = {2021-01-28},
urldate = {2021-01-28},
journal = {The European Physical Journal A},
volume = {57},
pages = {40},
abstract = {A measurement of the double-polarization observable E for the reaction γp→π0p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C 4 H 9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from Eγ=600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses. },
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pubstate = {published},
tppubtype = {article}
}
A measurement of the double-polarization observable E for the reaction γp→π0p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C 4 H 9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from Eγ=600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses. Yasin, Hashim; Krüger, Björn
An Efficient 3D Human Pose Retrieval and Reconstruction from 2D Image-Based Landmarks Journal Article
In: Sensors, vol. 21, no. 7, 2021, ISSN: 1424-8220.
@article{yasin-2021a,
title = {An Efficient 3D Human Pose Retrieval and Reconstruction from 2D Image-Based Landmarks},
author = {Hashim Yasin and Björn Krüger},
url = {https://www.mdpi.com/1424-8220/21/7/2415
https://digital-health-bonn.de/wp-content/uploads/2024/03/sensors-21-02415.pdf, Paper},
doi = {10.3390/s21072415},
issn = {1424-8220},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Sensors},
volume = {21},
number = {7},
abstract = {We propose an efficient and novel architecture for 3D articulated human pose retrieval and reconstruction from 2D landmarks extracted from a 2D synthetic image, an annotated 2D image, an in-the-wild real RGB image or even a hand-drawn sketch. Given 2D joint positions in a single image, we devise a data-driven framework to infer the corresponding 3D human pose. To this end, we first normalize 3D human poses from Motion Capture (MoCap) dataset by eliminating translation, orientation, and the skeleton size discrepancies from the poses and then build a knowledge-base by projecting a subset of joints of the normalized 3D poses onto 2D image-planes by fully exploiting a variety of virtual cameras. With this approach, we not only transform 3D pose space to the normalized 2D pose space but also resolve the 2D-3D cross-domain retrieval task efficiently. The proposed architecture searches for poses from a MoCap dataset that are near to a given 2D query pose in a definite feature space made up of specific joint sets. These retrieved poses are then used to construct a weak perspective camera and a final 3D posture under the camera model that minimizes the reconstruction error. To estimate unknown camera parameters, we introduce a nonlinear, two-fold method. We exploit the retrieved similar poses and the viewing directions at which the MoCap dataset was sampled to minimize the projection error. Finally, we evaluate our approach thoroughly on a large number of heterogeneous 2D examples generated synthetically, 2D images with ground-truth, a variety of real in-the-wild internet images, and a proof of concept using 2D hand-drawn sketches of human poses. We conduct a pool of experiments to perform a quantitative study on PARSE dataset. We also show that the proposed system yields competitive, convincing results in comparison to other state-of-the-art methods.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We propose an efficient and novel architecture for 3D articulated human pose retrieval and reconstruction from 2D landmarks extracted from a 2D synthetic image, an annotated 2D image, an in-the-wild real RGB image or even a hand-drawn sketch. Given 2D joint positions in a single image, we devise a data-driven framework to infer the corresponding 3D human pose. To this end, we first normalize 3D human poses from Motion Capture (MoCap) dataset by eliminating translation, orientation, and the skeleton size discrepancies from the poses and then build a knowledge-base by projecting a subset of joints of the normalized 3D poses onto 2D image-planes by fully exploiting a variety of virtual cameras. With this approach, we not only transform 3D pose space to the normalized 2D pose space but also resolve the 2D-3D cross-domain retrieval task efficiently. The proposed architecture searches for poses from a MoCap dataset that are near to a given 2D query pose in a definite feature space made up of specific joint sets. These retrieved poses are then used to construct a weak perspective camera and a final 3D posture under the camera model that minimizes the reconstruction error. To estimate unknown camera parameters, we introduce a nonlinear, two-fold method. We exploit the retrieved similar poses and the viewing directions at which the MoCap dataset was sampled to minimize the projection error. Finally, we evaluate our approach thoroughly on a large number of heterogeneous 2D examples generated synthetically, 2D images with ground-truth, a variety of real in-the-wild internet images, and a proof of concept using 2D hand-drawn sketches of human poses. We conduct a pool of experiments to perform a quantitative study on PARSE dataset. We also show that the proposed system yields competitive, convincing results in comparison to other state-of-the-art methods.2020
Afzal, F.; Wunderlich, Y.; Anisovich, A. V.; Bayadilov, D.; Beck, R.; Becker, M.; Blanke, E.; Brinkmann, K. -Th.; Ciupka, S.; Crede, V.; Dieterle, M.; Dutz, H.; Elsner, D.; Friedrich, S.; Frommberger, F.; Gridnev, A.; Gottschall, M.; Grüner, M.; Gutz, E.; Hammann, C.; Hannappel, J.; Hartmann, J.; Hillert, W.; Hoff, J.; Hoffmeister, P.; Honisch, C.; Jude, T.; Kalinowsky, H.; Kalischewski, F.; Keshelashvili, I.; Klassen, P.; Klein, F.; Klempt, E.; Koop, K.; Kroenert, P.; Krusche, B.; Lang, M.; Lopatin, I.; Mahlberg, P.; Meißner, U. -G.; Messi, F.; Metag, V.; Meyer, W.; Mitlasóczki, B.; Müller, J.; Müllers, Johannes; Nanova, M.; Nikonov, K.; Nikonov, V.; Novinskiy, V.; Novotny, R.; Piontek, D.; Reicherz, G.; Richter, L.; Rönchen, D.; Rostomyan, T.; Salisbury, B.; Sarantsev, A.; Schaab, D.; Schmidt, C.; Schmieden, H.; Schultes, J.; Seifen, T.; Sokhoyan, V.; Sowa, C.; Spieker, K.; Stausberg, N.; Thiel, A.; Thoma, U.; Triffterer, T.; Urban, M.; Urff, G.; Pee, H.; Walther, D.; Wendel, Ch.; Wiedner, U.; Wilson, A.; Winnebeck, A.; Witthauer, L.
Observation of the p𝛈' Cusp in the New Precise Beam Asymmetry 𝛴 Data for 𝛾 p → p 𝜂 Journal Article
In: Phys. Rev. Lett., vol. 125, iss. 15, pp. 152002, 2020.
@article{PhysRevLett.125.152002,
title = {Observation of the p𝛈' Cusp in the New Precise Beam Asymmetry 𝛴 Data for 𝛾 p → p 𝜂},
author = {F. Afzal and Y. Wunderlich and A. V. Anisovich and D. Bayadilov and R. Beck and M. Becker and E. Blanke and K. -Th. Brinkmann and S. Ciupka and V. Crede and M. Dieterle and H. Dutz and D. Elsner and S. Friedrich and F. Frommberger and A. Gridnev and M. Gottschall and M. Grüner and E. Gutz and C. Hammann and J. Hannappel and J. Hartmann and W. Hillert and J. Hoff and P. Hoffmeister and C. Honisch and T. Jude and H. Kalinowsky and F. Kalischewski and I. Keshelashvili and P. Klassen and F. Klein and E. Klempt and K. Koop and P. Kroenert and B. Krusche and M. Lang and I. Lopatin and P. Mahlberg and U. -G. Meißner and F. Messi and V. Metag and W. Meyer and B. Mitlasóczki and J. Müller and Johannes Müllers and M. Nanova and K. Nikonov and V. Nikonov and V. Novinskiy and R. Novotny and D. Piontek and G. Reicherz and L. Richter and D. Rönchen and T. Rostomyan and B. Salisbury and A. Sarantsev and D. Schaab and C. Schmidt and H. Schmieden and J. Schultes and T. Seifen and V. Sokhoyan and C. Sowa and K. Spieker and N. Stausberg and A. Thiel and U. Thoma and T. Triffterer and M. Urban and G. Urff and H. Pee and D. Walther and Ch. Wendel and U. Wiedner and A. Wilson and A. Winnebeck and L. Witthauer},
url = {https://link.aps.org/doi/10.1103/PhysRevLett.125.152002},
doi = {10.1103/PhysRevLett.125.152002},
year = {2020},
date = {2020-10-09},
urldate = {2020-10-09},
journal = {Phys. Rev. Lett.},
volume = {125},
issue = {15},
pages = {152002},
publisher = {American Physical Society},
abstract = {Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748 MeV to W=2045 MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη′ threshold [Eγ=1447 MeV (W=1896 MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)12− nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748 MeV to W=2045 MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη′ threshold [Eγ=1447 MeV (W=1896 MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)12− nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters. Müller, J.; Hartmann, J.; Grüner, M.; Afzal, F.; Anisovich, A. V.; Bantes, B.; Bayadilov, D.; Beck, R.; Becker, M.; Beloglazov, Y.; Berlin, A.; Bichow, M.; Böse, S.; Brinkmann, K. -T.; Challand, T.; Crede, V.; Dietz, F.; Dieterle, M.; Drexler, P.; Dutz, H.; Eberhardt, H.; Elsner, D.; Ewald, R.; Fornet-Ponse, K.; Friedrich, S.; Frommberger, F.; Funke, C.; Gottschall, M.; Gridnev, A.; Goertz, S.; Gutz, E.; Hammann, C.; Hannen, V.; Hannappel, J.; Herick, J.; Hillert, W.; Hoffmeister, P.; Honisch, C.; Jahn, O.; Jude, T.; Jaegle, I.; Käser, A.; Kaiser, D.; Kalinowsky, H.; Kalischewski, F.; Kammer, S.; Keshelashvili, I.; Klassen, P.; Kleber, V.; Klein, F.; Klempt, E.; Koop, K.; Krusche, B.; Kube, M.; Lang, M.; Lopatin, I.; Maghrbi, Y.; Mahlberg, P.; Makonyi, K.; Messi, F.; Metag, V.; Meyer, W.; Müllers, Johannes; Nanova, M.; Nikonov, V.; Novinski, D.; Novotny, R.; Piontek, D.; Reicherz, G.; Rosenbaum, C.; Rostomyan, T.; Roth, B.; Sarantsev, A.; Schmidt, C.; Schmieden, H.; Schmitz, R.; Seifen, T.; Sokhoyan, V.; Thiel, A.; Thoma, U.; Urban, M.; Pee, H.; Walther, D.; Wendel, C.; Wiedner, U.; Wilson, A.; Winnebeck, A.; Witthauer, L.
New data on γp→ηp with polarized photons and protons and their implications for N⁎ → Nη decays Journal Article
In: Physics Letters B, vol. 803, pp. 135323, 2020, ISSN: 0370-2693.
@article{2020135323,
title = {New data on γp→ηp with polarized photons and protons and their implications for N⁎ → Nη decays},
author = {J. Müller and J. Hartmann and M. Grüner and F. Afzal and A. V. Anisovich and B. Bantes and D. Bayadilov and R. Beck and M. Becker and Y. Beloglazov and A. Berlin and M. Bichow and S. Böse and K. -T. Brinkmann and T. Challand and V. Crede and F. Dietz and M. Dieterle and P. Drexler and H. Dutz and H. Eberhardt and D. Elsner and R. Ewald and K. Fornet-Ponse and S. Friedrich and F. Frommberger and C. Funke and M. Gottschall and A. Gridnev and S. Goertz and E. Gutz and C. Hammann and V. Hannen and J. Hannappel and J. Herick and W. Hillert and P. Hoffmeister and C. Honisch and O. Jahn and T. Jude and I. Jaegle and A. Käser and D. Kaiser and H. Kalinowsky and F. Kalischewski and S. Kammer and I. Keshelashvili and P. Klassen and V. Kleber and F. Klein and E. Klempt and K. Koop and B. Krusche and M. Kube and M. Lang and I. Lopatin and Y. Maghrbi and P. Mahlberg and K. Makonyi and F. Messi and V. Metag and W. Meyer and Johannes Müllers and M. Nanova and V. Nikonov and D. Novinski and R. Novotny and D. Piontek and G. Reicherz and C. Rosenbaum and T. Rostomyan and B. Roth and A. Sarantsev and C. Schmidt and H. Schmieden and R. Schmitz and T. Seifen and V. Sokhoyan and A. Thiel and U. Thoma and M. Urban and H. Pee and D. Walther and C. Wendel and U. Wiedner and A. Wilson and A. Winnebeck and L. Witthauer},
url = {https://www.sciencedirect.com/science/article/pii/S0370269320301271},
doi = {https://doi.org/10.1016/j.physletb.2020.135323},
issn = {0370-2693},
year = {2020},
date = {2020-04-10},
urldate = {2020-04-10},
journal = {Physics Letters B},
volume = {803},
pages = {135323},
abstract = {The polarization observables T,E,P,H, and G in photoproduction of η mesons off protons are measured for photon energies from threshold to W=2400 MeV (T), 2280 MeV (E), 1620 MeV (P,H), or 1820 MeV (G), covering nearly the full solid angle. The data are compared to predictions from the SAID, MAID, JüBo, and BnGa partial-wave analyses. A refit within the BnGa approach including further data yields precise branching ratios for the Nη decay of nucleon resonances. A Nη-branching ratio of 0.33±0.04 for N(1650)1/2− is found, which reduces the large and controversially discussed Nη-branching ratio difference of the two lowest mass JP=1/2−-resonances significantly.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The polarization observables T,E,P,H, and G in photoproduction of η mesons off protons are measured for photon energies from threshold to W=2400 MeV (T), 2280 MeV (E), 1620 MeV (P,H), or 1820 MeV (G), covering nearly the full solid angle. The data are compared to predictions from the SAID, MAID, JüBo, and BnGa partial-wave analyses. A refit within the BnGa approach including further data yields precise branching ratios for the Nη decay of nucleon resonances. A Nη-branching ratio of 0.33±0.04 for N(1650)1/2− is found, which reduces the large and controversially discussed Nη-branching ratio difference of the two lowest mass JP=1/2−-resonances significantly. Peper, Erik; Krüger, Björn; Gokhale, Esther; Harvey, Richard
Comparing Muscle Activity and Spine Shape in Various Sitting Styles Journal Article
In: Biofeedback, vol. 48, no. 3, pp. 62–67, 2020, ISSN: 1081-5937.
@article{peper-2020-a,
title = {Comparing Muscle Activity and Spine Shape in Various Sitting Styles},
author = {Erik Peper and Björn Krüger and Esther Gokhale and Richard Harvey},
doi = {10.5298/1081-5937-48.3.03},
issn = {1081-5937},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
journal = {Biofeedback},
volume = {48},
number = {3},
pages = {62–67},
abstract = {Back problems affect 80% of the population in the U.S. at some time during their lives, and each year 32 million Americans experience lower back pain at an estimated economic cost of $560-$635 billion. One contributing factor for back pain is posture, and more particularly, lack of awareness of dysfunctional posture. For example, many people may sit in a slouched or forward-bent position, exacerbated by poor ergonomics while sitting or, extended use of handheld digital devices while standing such as looking down at a smartphone for long periods of time. This report describes a ‘stacksitting’ technique which is one of the components of the Gokhale Method® for healthy, relaxed sitting and increased awareness of posture. The stacksitting process is illustrated with a case study where the shape of the spine and the muscle activity is analyzed in parallel during three sitting styles: slouching, arched, and stacksitting. The spine curvature was characterized by the Gokhale SpineTracker™ wearable, which consists of five sensor-units attached along the subjects’ spines that are used to plot the spinal curve on a digital device such as a smartphone, tablet or computer. SEMG recordings were made from the right upper trapezius, left upper trapezius, right mid-back, and left mid-back with a second device (Myoscan Pro sensors recorded with Biograph Procomp Infinity) while participants were seated in three postures: a slouched (forward-bent) position, an upright ‘arched’ position, and an upright ‘stacksitting’ position as trained by a Gokhale Method teacher. The case observations showed no significant difference in trapezius SEMG activity during each of the three positions. There was a slight increase in SEMG activity of the mid-back during stacksitting (1.1 µV) as compared to when slouched (0.64 µV) and, a significant increase in SEMG activity when sitting arched (4.9 µV). As expected, the spinal activity tracking device showed significant straightening of the lower spine during the stacksitting position as compared to the slouched and arched positions. The observations suggest that the stacksitting position can be taught to others in a way that allows the vertebrae to be parallel to each other with very low levels of corresponding muscle activity. In contrast, sitting in an arched or slouched position would increase asymmetrical pressures on the disks, contributing to vertebral wedging which could also contribute to spinal disk-bulging and eventual back injury. The observations suggest that proper coaching may foster a stacksitting position of the spine, which would foster a healthier posture than a slouched or arched spinal positions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Back problems affect 80% of the population in the U.S. at some time during their lives, and each year 32 million Americans experience lower back pain at an estimated economic cost of $560-$635 billion. One contributing factor for back pain is posture, and more particularly, lack of awareness of dysfunctional posture. For example, many people may sit in a slouched or forward-bent position, exacerbated by poor ergonomics while sitting or, extended use of handheld digital devices while standing such as looking down at a smartphone for long periods of time. This report describes a ‘stacksitting’ technique which is one of the components of the Gokhale Method® for healthy, relaxed sitting and increased awareness of posture. The stacksitting process is illustrated with a case study where the shape of the spine and the muscle activity is analyzed in parallel during three sitting styles: slouching, arched, and stacksitting. The spine curvature was characterized by the Gokhale SpineTracker™ wearable, which consists of five sensor-units attached along the subjects’ spines that are used to plot the spinal curve on a digital device such as a smartphone, tablet or computer. SEMG recordings were made from the right upper trapezius, left upper trapezius, right mid-back, and left mid-back with a second device (Myoscan Pro sensors recorded with Biograph Procomp Infinity) while participants were seated in three postures: a slouched (forward-bent) position, an upright ‘arched’ position, and an upright ‘stacksitting’ position as trained by a Gokhale Method teacher. The case observations showed no significant difference in trapezius SEMG activity during each of the three positions. There was a slight increase in SEMG activity of the mid-back during stacksitting (1.1 µV) as compared to when slouched (0.64 µV) and, a significant increase in SEMG activity when sitting arched (4.9 µV). As expected, the spinal activity tracking device showed significant straightening of the lower spine during the stacksitting position as compared to the slouched and arched positions. The observations suggest that the stacksitting position can be taught to others in a way that allows the vertebrae to be parallel to each other with very low levels of corresponding muscle activity. In contrast, sitting in an arched or slouched position would increase asymmetrical pressures on the disks, contributing to vertebral wedging which could also contribute to spinal disk-bulging and eventual back injury. The observations suggest that proper coaching may foster a stacksitting position of the spine, which would foster a healthier posture than a slouched or arched spinal positions. Mezzarobba, Susanna; Grassi, Michele; Pellegrini, Lorella; Catalan, Mauro; Krüger, Björn; Stragapede, Lara; Manganotti, Paolo; Bernardis, Paolo
In: Parkinsonism & Related Disorders, vol. 80, pp. 133–137, 2020.
@article{Mezzarobba2020,
title = {Action Observation Plus Sonification. Biomechanical Analysis of Sit-To-Walk Performance in Patients with Parkinson's Disease and Freezing of Gait},
author = {Susanna Mezzarobba and Michele Grassi and Lorella Pellegrini and Mauro Catalan and Björn Krüger and Lara Stragapede and Paolo Manganotti and Paolo Bernardis},
doi = {https://doi.org/10.1016/j.parkreldis.2020.09.029},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
journal = {Parkinsonism & Related Disorders},
volume = {80},
pages = {133–137},
abstract = {Introduction. Freezing of gait (FoG) is one of the most disabling gait disorders in Parkinson's disease (PD) reflecting motor and cognitive impairments, mainly related to dopamine deficiency. Recent studies, investigating kinematic and kinetic factors affecting gait in these patients, showed a postural instability characterized by disturbed weight-shifting, inappropriate anticipatory postural adjustment, worse reactive postural control, and a difficulty to execute complex motor task (i.e. sit-to-walk). Symptoms that are difficult to alleviate and not much responsive to Levodopa. For this reason, additional therapeutic actions based on specific therapeutic protocols may help patients in daily life. Methods. In 2018, we conducted a randomized control trial aimed to test two clinical protocols for PD patients with FoG. Protocols, conceived to improve gait, were based on learning motor exercises with the Action Observation plus Sonification (AOS) technique, and with a standard protocol centered on cue use. We found a significant improvement in the FoG questionnaire and the UPDRS III clinical scale for the AOS protocol only. We also collected biomechanical data, using the sit-to-walk task as a measure of motor performance. Results. Here we report kinetic and kinematic analysis of data showing that, when treatment effects consolidate, patients treated with AOS protocol are more efficient in merging subsequent motor tasks (sit-tostand and gait initiation) with a better dynamic balance control during the sit-to-stand. Conclusion. Promising results of the AOS protocol in reducing FoG confirm that a mobility training focused on improving weight-shifting and motor switching abilities, may have benefits for Parkinson patients with FoG.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Introduction. Freezing of gait (FoG) is one of the most disabling gait disorders in Parkinson's disease (PD) reflecting motor and cognitive impairments, mainly related to dopamine deficiency. Recent studies, investigating kinematic and kinetic factors affecting gait in these patients, showed a postural instability characterized by disturbed weight-shifting, inappropriate anticipatory postural adjustment, worse reactive postural control, and a difficulty to execute complex motor task (i.e. sit-to-walk). Symptoms that are difficult to alleviate and not much responsive to Levodopa. For this reason, additional therapeutic actions based on specific therapeutic protocols may help patients in daily life. Methods. In 2018, we conducted a randomized control trial aimed to test two clinical protocols for PD patients with FoG. Protocols, conceived to improve gait, were based on learning motor exercises with the Action Observation plus Sonification (AOS) technique, and with a standard protocol centered on cue use. We found a significant improvement in the FoG questionnaire and the UPDRS III clinical scale for the AOS protocol only. We also collected biomechanical data, using the sit-to-walk task as a measure of motor performance. Results. Here we report kinetic and kinematic analysis of data showing that, when treatment effects consolidate, patients treated with AOS protocol are more efficient in merging subsequent motor tasks (sit-tostand and gait initiation) with a better dynamic balance control during the sit-to-stand. Conclusion. Promising results of the AOS protocol in reducing FoG confirm that a mobility training focused on improving weight-shifting and motor switching abilities, may have benefits for Parkinson patients with FoG.2019
Müllers, Johannes
An FPGA-based Sampling ADC for the Crystal Barrel Calorimeter PhD Thesis
Rheinische Friedrich-Wilhelms-Universität Bonn, 2019.
@phdthesis{handle:20.500.11811/8118,
title = {An FPGA-based Sampling ADC for the Crystal Barrel Calorimeter},
author = {Johannes Müllers},
url = {https://hdl.handle.net/20.500.11811/8118},
year = {2019},
date = {2019-12-01},
urldate = {2019-12-01},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
abstract = {The CBELSA/TAPS experiment in Bonn investigates the excitation spectra of protons and neutrons through meson-photoproduction. With its ability to polarize the target nucleons and the incident photon beam, the experiment has contributed significantly to a better understanding of the baryon excitation spectrum, and with that also to the understanding of the strong interaction in the non-perturbative regime. Since a recent upgrade, the experiment's main electromagnetic calorimeter, the Crystal Barrel, is read out by avalanche photo-diodes. Their signal is digitized by integrating Fastbus ADCs, providing a value proportional to the energy deposited in the calorimeter crystals. As a result of long conversion and transfer times, those ADCs have become the limiting factor in the data acquisition, with possible readout rates of less than 2 kHz. Moreover, the possibility to identify pile-up, i.e. quickly-succeeding energy deposits that overlap in the integration window, is presently missing.
Already years ago, it has been investigated whether this readout system could be replaced by faster and more modern sampling ADCs, which offer access to the waveform representation for a more sophisticated analysis, but the investigations were limited to commercially available digitizers with high cost and low channel densities. In addition, the firmware (operating system) of such digitizers is usually closed-source, which does not allow for the implementation of experiment-specific algorithms. Due to the above reasons, the investigations had not led to a satisfactory solution, and the Fastbus ADCs are still in operation today.
In this thesis, the development and test of a custom (non-commercial) FPGA-based sampling ADC, which will replace the Fastbus ADC, has been driven forward. This so-called CB-SADC (Crystal Barrel Sampling Analog-to-Digital Converter) has been adapted from a prototype of the PANDA experiment in such a way that it is suited to operate within the specific conditions of the CBELSA/TAPS experiment.
Apart from the hardware development, the firmware for the FPGA, which processes the digitized data, was designed and tested extensively. Specific algorithms allow not only the determination of the deposited energy and the timestamps of each event, but also an event-wise baseline determination and the detection of pile-up events. An online correction of pileup events, which occur with significant frequency in the forward region of the calorimeter, leads to a higher data quality and improved efficiency and statistics.
Apart from the hardware development, the firmware for the FPGA, which processes the digitized data, was designed and tested extensively. Specific algorithms allow not only the determination of the deposited energy and the timestamps of each event, but also an event-wise baseline determination and the detection of pile-up events. An online correction of pileup events, which occur with significant frequency in the forward region of the calorimeter, leads to a higher data quality and improved efficiency and statistics.
Two prototype iterations of the CB-SADC have been produced and were tested thoroughly in the laboratory and in connection with the CBELSA/TAPS experiment. The results of those tests, and preliminary analyses of production beam times with 50% of the calorimeter's forward half being read out by the CB-SADCs, showed an improvement of the data quality. The timestamp determination of the CB-SADCs in the energy regime below 10MeV has provided data where the experiment's TDC (Time-to-Digital Converter) either has worse resolution or cannot provide timestamps at all. In addition, standalone tests in the laboratory and tests with the data acquisition system have confirmed a much higher readout speed compared to the integrating Fastbus ADCs. Based on the achieved results, it was finally decided to equip the whole calorimeter with the new CB-SADC readout.
At the time of finalizing this thesis, all CB-SADCs have been produced and are prepared for installation in the experimental hall. They will be running in parallel with the integrating Fastbus ADCs during the next production beam times, offering an opportunity to test the CB-SADC readout system as a whole. As soon as it is proven that the new readout works reliably, the limiting integrating Fastbus ADCs will be decommissioned and the CBELSA/TAPS experiment can start taking data with an increased readout rate.},
keywords = {},
pubstate = {published},
tppubtype = {phdthesis}
}
The CBELSA/TAPS experiment in Bonn investigates the excitation spectra of protons and neutrons through meson-photoproduction. With its ability to polarize the target nucleons and the incident photon beam, the experiment has contributed significantly to a better understanding of the baryon excitation spectrum, and with that also to the understanding of the strong interaction in the non-perturbative regime. Since a recent upgrade, the experiment's main electromagnetic calorimeter, the Crystal Barrel, is read out by avalanche photo-diodes. Their signal is digitized by integrating Fastbus ADCs, providing a value proportional to the energy deposited in the calorimeter crystals. As a result of long conversion and transfer times, those ADCs have become the limiting factor in the data acquisition, with possible readout rates of less than 2 kHz. Moreover, the possibility to identify pile-up, i.e. quickly-succeeding energy deposits that overlap in the integration window, is presently missing.
Already years ago, it has been investigated whether this readout system could be replaced by faster and more modern sampling ADCs, which offer access to the waveform representation for a more sophisticated analysis, but the investigations were limited to commercially available digitizers with high cost and low channel densities. In addition, the firmware (operating system) of such digitizers is usually closed-source, which does not allow for the implementation of experiment-specific algorithms. Due to the above reasons, the investigations had not led to a satisfactory solution, and the Fastbus ADCs are still in operation today.
In this thesis, the development and test of a custom (non-commercial) FPGA-based sampling ADC, which will replace the Fastbus ADC, has been driven forward. This so-called CB-SADC (Crystal Barrel Sampling Analog-to-Digital Converter) has been adapted from a prototype of the PANDA experiment in such a way that it is suited to operate within the specific conditions of the CBELSA/TAPS experiment.
Apart from the hardware development, the firmware for the FPGA, which processes the digitized data, was designed and tested extensively. Specific algorithms allow not only the determination of the deposited energy and the timestamps of each event, but also an event-wise baseline determination and the detection of pile-up events. An online correction of pileup events, which occur with significant frequency in the forward region of the calorimeter, leads to a higher data quality and improved efficiency and statistics.
Apart from the hardware development, the firmware for the FPGA, which processes the digitized data, was designed and tested extensively. Specific algorithms allow not only the determination of the deposited energy and the timestamps of each event, but also an event-wise baseline determination and the detection of pile-up events. An online correction of pileup events, which occur with significant frequency in the forward region of the calorimeter, leads to a higher data quality and improved efficiency and statistics.
Two prototype iterations of the CB-SADC have been produced and were tested thoroughly in the laboratory and in connection with the CBELSA/TAPS experiment. The results of those tests, and preliminary analyses of production beam times with 50% of the calorimeter's forward half being read out by the CB-SADCs, showed an improvement of the data quality. The timestamp determination of the CB-SADCs in the energy regime below 10MeV has provided data where the experiment's TDC (Time-to-Digital Converter) either has worse resolution or cannot provide timestamps at all. In addition, standalone tests in the laboratory and tests with the data acquisition system have confirmed a much higher readout speed compared to the integrating Fastbus ADCs. Based on the achieved results, it was finally decided to equip the whole calorimeter with the new CB-SADC readout.
At the time of finalizing this thesis, all CB-SADCs have been produced and are prepared for installation in the experimental hall. They will be running in parallel with the integrating Fastbus ADCs during the next production beam times, offering an opportunity to test the CB-SADC readout system as a whole. As soon as it is proven that the new readout works reliably, the limiting integrating Fastbus ADCs will be decommissioned and the CBELSA/TAPS experiment can start taking data with an increased readout rate. Peper, Erik; Krüger, Björn; Gokhale, Esther
Comparing Muscle Activity and Spine Shape in Various Sitting Positions Proceedings
Association for Applied Psychophysiology and Biofeedback’s 2019 Annual Scientific Meeting, Denver, Colorado, 2019.
@proceedings{2019-peper,
title = {Comparing Muscle Activity and Spine Shape in Various Sitting Positions},
author = {Erik Peper and Björn Krüger and Esther Gokhale},
url = {https://digital-health-bonn.de/wp-content/uploads/2024/03/190401StacksittingPoster.pdf, Poster},
year = {2019},
date = {2019-01-01},
urldate = {2019-01-01},
booktitle = {Association for Applied Psychophysiology and Biofeedback’s 2019 Annual Scientific Meeting},
address = {Denver, Colorado},
howpublished = {Association for Applied Psychophysiology and Biofeedback’s 2019 Annual Scientific Meeting},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
Khandelwal, Icxa; Stollenwerk, Katharina; Krüger, Björn; Weber, Andreas
Posture Classification based on a Spine Shape Monitoring System Proceedings Article
In: Computational Science and Its Applications – ICCSA 2019, 2019.
@inproceedings{Khandelwal-2019,
title = {Posture Classification based on a Spine Shape Monitoring System},
author = {Icxa Khandelwal and Katharina Stollenwerk and Björn Krüger and Andreas Weber},
url = {https://digital-health-bonn.de/wp-content/uploads/2024/03/KSKW19_preprint.pdf, Paper},
year = {2019},
date = {2019-01-01},
urldate = {2019-01-01},
booktitle = {Computational Science and Its Applications – ICCSA 2019},
abstract = {Lower back pain is one of the leading causes for musculoskeletal disability throughout the world. A large percentage of the population suffers from lower back pain at some point in their life. One noninvasive approach to reduce back pain is postural modification which can be learned through training. In this context, wearables are becoming more and more prominent since they are capable of providing feedback about the user’s posture in real-time. Optimal, healthy posture depends on the position (sitting, standing, hinging) the user is in. Meaningful feedback needs to adapt to the current position and, in the best case, identify the position automatically to minimize necessary interactions from the user. In this work, we present results of classifying the positions of users based on the readings of the Gokhale SpineTracker device. We computed various features and evaluated the performance of K-Nearest Neighbors, Extra Trees, Artificial Neural Networks and AdaBoost for global inter-subject classification as well as for personalized subject specific classification.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Lower back pain is one of the leading causes for musculoskeletal disability throughout the world. A large percentage of the population suffers from lower back pain at some point in their life. One noninvasive approach to reduce back pain is postural modification which can be learned through training. In this context, wearables are becoming more and more prominent since they are capable of providing feedback about the user’s posture in real-time. Optimal, healthy posture depends on the position (sitting, standing, hinging) the user is in. Meaningful feedback needs to adapt to the current position and, in the best case, identify the position automatically to minimize necessary interactions from the user. In this work, we present results of classifying the positions of users based on the readings of the Gokhale SpineTracker device. We computed various features and evaluated the performance of K-Nearest Neighbors, Extra Trees, Artificial Neural Networks and AdaBoost for global inter-subject classification as well as for personalized subject specific classification. Stollenwerk, Katharina; Müller, Jonas; Hinkenjann, André; Krüger, Björn
Analyzing Spinal Shape Changes During Posture Training Using a Wearable Device Journal Article
In: Sensors, 2019.
@article{stollenwerk-2019a,
title = {Analyzing Spinal Shape Changes During Posture Training Using a Wearable Device},
author = {Katharina Stollenwerk and Jonas Müller and André Hinkenjann and Björn Krüger},
url = {https://digital-health-bonn.de/wp-content/uploads/2024/03/sensors-19-03625.pdf, Paper},
doi = {https://doi.org/10.3390/s19163625},
year = {2019},
date = {2019-01-01},
urldate = {2019-01-01},
journal = {Sensors},
abstract = {Lower back pain is one of the most prevalent diseases in Western societies. A large percentage of European and American populations suffer from back pain at some point in their lives. One successful approach to address lower back pain is postural training, which can be supported by wearable devices, providing real-time feedback about the user’s posture. In this work, we analyze the changes in posture induced by postural training. To this end, we compare snapshots before and after training, as measured by the Gokhale SpineTracker™. Considering pairs of before and after snapshots in different positions (standing, sitting, and bending), we introduce a feature space, that allows for unsupervised clustering. We show that resulting clusters represent certain groups of postural changes, which are meaningful to professional posture trainers.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Lower back pain is one of the most prevalent diseases in Western societies. A large percentage of European and American populations suffer from back pain at some point in their lives. One successful approach to address lower back pain is postural training, which can be supported by wearable devices, providing real-time feedback about the user’s posture. In this work, we analyze the changes in posture induced by postural training. To this end, we compare snapshots before and after training, as measured by the Gokhale SpineTracker™. Considering pairs of before and after snapshots in different positions (standing, sitting, and bending), we introduce a feature space, that allows for unsupervised clustering. We show that resulting clusters represent certain groups of postural changes, which are meaningful to professional posture trainers.2018
Mezzarobba, Susanna; Grassi, Michele; Pellegrini, Lorella; Catalan, Mauro; Krüger, Björn; Furlanis, Giovanni; Manganotti, Paolo; Bernardis, Paolo
Action observation plus sonification. A novel therapeutic protocol for Parkinson’s patient with freezing of gait Journal Article
In: Frontiers in Neurology, vol. 8, 2018, ISSN: 1664-2295, (accepted for Publication).
@article{mezzarobba2018a,
title = {Action observation plus sonification. A novel therapeutic protocol for Parkinson’s patient with freezing of gait},
author = {Susanna Mezzarobba and Michele Grassi and Lorella Pellegrini and Mauro Catalan and Björn Krüger and Giovanni Furlanis and Paolo Manganotti and Paolo Bernardis},
url = {https://www.frontiersin.org/article/10.3389/fneur.2017.00723},
doi = {10.3389/fneur.2017.00723},
issn = {1664-2295},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
journal = {Frontiers in Neurology},
volume = {8},
abstract = {Freezing of gait (FoG) is a disabling symptom associated to falls, with little or no responsiveness to pharmacological treatment. Current protocols used for rehabilitation are based on the use of external sensory cues. However, cued strategies might generate an important dependence on the environment. Teaching motor strategies without cues (i.e. action observation - AO - plus sonification) could represent an alternative/innovative approach to rehabilitation that matters most on appropriate allocation of attention and lightening cognitive load. We aimed to test the effects of a novel experimental protocol to treat patients with Parkinson disease (PD) and freezing of gait, using functional, and clinical scales. The experimental protocol was based on action observation plus sonification. 12 patients were treated with 8 motor gestures. They watched 8 videos showing an actor performing the same 8 gestures, and then tried to repeat each gesture. Each video was composed by images and sounds of the gestures. By means of the sonification technique, the sounds of gestures were obtained by transforming kinematic data (velocity) recorded during gesture execution, into pitch variations. The same 8 motor gestures were also used in a second group of 10 patients; which were treated with a standard protocol based on a common sensory stimulation method. All patients were tested with functional and clinical scales before, after, at 1 month, and 3 months after the treatment. Data showed that the experimental protocol have positive effects on functional and clinical tests. In comparison with the baseline evaluations, significant performance improvements were seen in the N-FOG questionnaire, and the UPDRS (part 3 and 2). Importantly, all these improvements were consistently observed at the end, 1 month, and 3 months after treatment. No improvements effects were found in the group of patients treated with the standard protocol. These data suggest that a multisensory approach based on action observation plus sonification, with the two stimuli semantically related, could help PD patients with FoG to re-learn gait movements, to reduce freezing episodes, and that these effects could be prolonged over time.},
note = {accepted for Publication},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Freezing of gait (FoG) is a disabling symptom associated to falls, with little or no responsiveness to pharmacological treatment. Current protocols used for rehabilitation are based on the use of external sensory cues. However, cued strategies might generate an important dependence on the environment. Teaching motor strategies without cues (i.e. action observation - AO - plus sonification) could represent an alternative/innovative approach to rehabilitation that matters most on appropriate allocation of attention and lightening cognitive load. We aimed to test the effects of a novel experimental protocol to treat patients with Parkinson disease (PD) and freezing of gait, using functional, and clinical scales. The experimental protocol was based on action observation plus sonification. 12 patients were treated with 8 motor gestures. They watched 8 videos showing an actor performing the same 8 gestures, and then tried to repeat each gesture. Each video was composed by images and sounds of the gestures. By means of the sonification technique, the sounds of gestures were obtained by transforming kinematic data (velocity) recorded during gesture execution, into pitch variations. The same 8 motor gestures were also used in a second group of 10 patients; which were treated with a standard protocol based on a common sensory stimulation method. All patients were tested with functional and clinical scales before, after, at 1 month, and 3 months after the treatment. Data showed that the experimental protocol have positive effects on functional and clinical tests. In comparison with the baseline evaluations, significant performance improvements were seen in the N-FOG questionnaire, and the UPDRS (part 3 and 2). Importantly, all these improvements were consistently observed at the end, 1 month, and 3 months after treatment. No improvements effects were found in the group of patients treated with the standard protocol. These data suggest that a multisensory approach based on action observation plus sonification, with the two stimuli semantically related, could help PD patients with FoG to re-learn gait movements, to reduce freezing episodes, and that these effects could be prolonged over time. Iqbal, Umar; Doering, Andreas; Yasin, Hashim; Krüger, Björn; Weber, Andreas; Gall, Juergen
A Dual-Source Approach for 3D Human Pose Estimation from Single Images Journal Article
In: Computer Vision and Image Understanding, vol. 172, pp. 37–49, 2018, ISSN: 1077-3142.
@article{iqbal-2018,
title = {A Dual-Source Approach for 3D Human Pose Estimation from Single Images},
author = {Umar Iqbal and Andreas Doering and Hashim Yasin and Björn Krüger and Andreas Weber and Juergen Gall},
url = {http://www.sciencedirect.com/science/article/pii/S1077314218300511},
doi = {https://doi.org/10.1016/j.cviu.2018.03.007},
issn = {1077-3142},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
journal = {Computer Vision and Image Understanding},
volume = {172},
pages = {37–49},
abstract = {In this work we address the challenging problem of 3D human pose estimation from single images. Recent approaches learn deep neural networks to regress 3D pose directly from images. One major challenge for such methods, however, is the collection of large amounts of training data. Particularly, collecting a large number of unconstrained images that are annotated with accurate 3D poses is impractical. We therefore propose to use two independent training sources. The first source consists of accurate 3D motion capture data, and the second source consists of unconstrained images with annotated 2D poses. To incorporate both sources, we propose a dual-source approach that combines 2D pose estimation with efficient 3D pose retrieval. To this end, we first convert the motion capture data into a normalized 2D pose space, and separately learn a 2D pose estimation model from the image data. During inference, we estimate the 2D pose and efficiently retrieve the nearest 3D poses. We then jointly estimate a mapping from the 3D pose space to the image and reconstruct the 3D pose. We provide a comprehensive evaluation of the proposed method and experimentally demonstrate the effectiveness of our approach, even when the skeleton structures of the two sources differ substantially.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work we address the challenging problem of 3D human pose estimation from single images. Recent approaches learn deep neural networks to regress 3D pose directly from images. One major challenge for such methods, however, is the collection of large amounts of training data. Particularly, collecting a large number of unconstrained images that are annotated with accurate 3D poses is impractical. We therefore propose to use two independent training sources. The first source consists of accurate 3D motion capture data, and the second source consists of unconstrained images with annotated 2D poses. To incorporate both sources, we propose a dual-source approach that combines 2D pose estimation with efficient 3D pose retrieval. To this end, we first convert the motion capture data into a normalized 2D pose space, and separately learn a 2D pose estimation model from the image data. During inference, we estimate the 2D pose and efficiently retrieve the nearest 3D poses. We then jointly estimate a mapping from the 3D pose space to the image and reconstruct the 3D pose. We provide a comprehensive evaluation of the proposed method and experimentally demonstrate the effectiveness of our approach, even when the skeleton structures of the two sources differ substantially. Zsoldos, Rebeka; Vögele, Anna; Krüger, Björn; Schröder, Ulrike; Weber, Andreas; Licka, Theresia
Long term consistency and locationspecificity of equine gluteus medius muscleactivity during locomotion on the treadmill Journal Article
In: BMC Veterinary Research, vol. 14, no. 126, pp. 1–10, 2018.
@article{Zsoldos2018,
title = {Long term consistency and locationspecificity of equine gluteus medius muscleactivity during locomotion on the treadmill},
author = {Rebeka Zsoldos and Anna Vögele and Björn Krüger and Ulrike Schröder and Andreas Weber and Theresia Licka},
doi = {10.1186/s12917-018-1443-y},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
journal = {BMC Veterinary Research},
volume = {14},
number = {126},
pages = {1–10},
abstract = {Background: The equine m. gluteus medius (GM) is the largest muscle of the horse, its main movement function is the extension of the hip joint. The objective of the present study was to measure equine GM activity in three adjacent locations on GM during walk and trot on a treadmill, in order to document potential differences. Fourteen Haflinger mares were measured using surface electromyography and kinematic markers to identify the motion cycles on three occasions over 16 weeks. The electrodes were placed on left and right gluteus medius muscle over the middle of its widest part and 5 cm lateral and medial of it. For data processing, electrical activity was normalised to its maximum value and timing was normalised to the motion cycle. A Gaussian distribution approach was used to determine up to 10 modes of focussed activity, and results were analysed separately for stance and swing phase of the ipsilateral hindlimb. Results: Fair reliability was found for mean mode values (Cronbach’s alpha = 0.66) and good reliability was found for mean mode locations (Cronbach’s alpha = 0.71) over the three data collection days. The magnitude of muscle activity identified as mean mode value was much larger at trot than at walk, and mean mode value was significantly different between stance phases of walk and trot for all electrode positions (p < 0.01). The pattern of muscle activity identified as mean mode location was significantly different for walk and trot at all electrode positions, both during stance and swing phases (p < 0.001). This indicates the different timing pattern between the gaits. Results of the three electrode positions on the same muscle during each gait were not significantly different when comparing the same measurement. Conclusions: The middle of the equine GM does not show any indication of functional differentiation during walk and trot on a treadmill; this might be due to lack of segmentation as such, or due to lack of need for segmented use for these very basic main tasks of the muscle. The reliability of the sEMG measurements over several weeks was fair to good, an indication for the robustness of the methodology.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: The equine m. gluteus medius (GM) is the largest muscle of the horse, its main movement function is the extension of the hip joint. The objective of the present study was to measure equine GM activity in three adjacent locations on GM during walk and trot on a treadmill, in order to document potential differences. Fourteen Haflinger mares were measured using surface electromyography and kinematic markers to identify the motion cycles on three occasions over 16 weeks. The electrodes were placed on left and right gluteus medius muscle over the middle of its widest part and 5 cm lateral and medial of it. For data processing, electrical activity was normalised to its maximum value and timing was normalised to the motion cycle. A Gaussian distribution approach was used to determine up to 10 modes of focussed activity, and results were analysed separately for stance and swing phase of the ipsilateral hindlimb. Results: Fair reliability was found for mean mode values (Cronbach’s alpha = 0.66) and good reliability was found for mean mode locations (Cronbach’s alpha = 0.71) over the three data collection days. The magnitude of muscle activity identified as mean mode value was much larger at trot than at walk, and mean mode value was significantly different between stance phases of walk and trot for all electrode positions (p < 0.01). The pattern of muscle activity identified as mean mode location was significantly different for walk and trot at all electrode positions, both during stance and swing phases (p < 0.001). This indicates the different timing pattern between the gaits. Results of the three electrode positions on the same muscle during each gait were not significantly different when comparing the same measurement. Conclusions: The middle of the equine GM does not show any indication of functional differentiation during walk and trot on a treadmill; this might be due to lack of segmentation as such, or due to lack of need for segmented use for these very basic main tasks of the muscle. The reliability of the sEMG measurements over several weeks was fair to good, an indication for the robustness of the methodology. Stollenwerk, Katharina; Müllers, Johannes; Müller, Jonas; Hinkenjann, André; Krüger, Björn
Evaluating an Accelerometer-based System for Spine Shape Monitoring Proceedings Article
In: Computational Science and Its Applications – ICCSA 2018, 2018.
@inproceedings{stollenwerk-2018a,
title = {Evaluating an Accelerometer-based System for Spine Shape Monitoring},
author = {Katharina Stollenwerk and Johannes Müllers and Jonas Müller and André Hinkenjann and Björn Krüger},
url = {https://digital-health-bonn.de/wp-content/uploads/2024/03/2018_ICCSA_PostureSensei_Preprint.pdf, Paper},
doi = {10.1007/978-3-319-95171-3_58},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
booktitle = {Computational Science and Its Applications – ICCSA 2018},
abstract = {In western societies a huge percentage of the population suffers from some kind of back pain at least once in their life. There are several approaches addressing back pain by postural modifications. Postural training and activity can be tracked by various wearable devices most of which are based on accelerometers. We present research on the accuracy of accelerometer-based posture measurements. To this end, we took simultaneous recordings using an optical motion capture system and a system consisting of five accelerometers in three different settings: On a test robot, in a template, and on actual human backs. We compare the accelerometer-based spine curve reconstruction against the motion capture data. Results show that tilt values from the accelerometers are captured highly accurate, and the spine curve reconstruction works well.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
In western societies a huge percentage of the population suffers from some kind of back pain at least once in their life. There are several approaches addressing back pain by postural modifications. Postural training and activity can be tracked by various wearable devices most of which are based on accelerometers. We present research on the accuracy of accelerometer-based posture measurements. To this end, we took simultaneous recordings using an optical motion capture system and a system consisting of five accelerometers in three different settings: On a test robot, in a template, and on actual human backs. We compare the accelerometer-based spine curve reconstruction against the motion capture data. Results show that tilt values from the accelerometers are captured highly accurate, and the spine curve reconstruction works well. Müllers, Johannes; Marciniewski, Pawel; Poller, Timo; Schmidt, Christoph; Schultes, Jan; Thoma, Ulrike
Adaption of an FPGA-based Sampling-ADC for the Crystal Barrel Calorimeter Proceedings Article
In: Proceedings of Science, pp. 052, 2018.
@inproceedings{inproceedings,
title = {Adaption of an FPGA-based Sampling-ADC for the Crystal Barrel Calorimeter},
author = {Johannes Müllers and Pawel Marciniewski and Timo Poller and Christoph Schmidt and Jan Schultes and Ulrike Thoma},
doi = {10.22323/1.313.0052},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
booktitle = {Proceedings of Science},
volume = {313},
pages = {052},
series = {Topical Workshop on Electronics for Particle Physics (TWEPP-17)},
abstract = {The digitization stage of the main electromagnetic calorimeter of the CBELSA/TAPS experiment in Bonn (Germany) is being equipped with 80MS/s, 14 bit sampling-ADCs (SADCs), which were adapted from a prototype for the PANDA experiment. Onboard data processing with FPGAs allows determination of the signal characteristics, reducing the data volume substantially. The optional readout of the unprocessed sampled waveforms allows offline analysis and refinement of the FPGA algorithms.
A partial setup has shown promising results during a photoproduction-beamtime. It has been demonstrated that the readout-rate limitation of the current QDC readout can be overcome. The full setup is planned to be commissioned within the next year.
This paper will present an overview of the SADC project. After an introduction of the CBELSA/TAPS experiment, the new SADC readout will be motivated, followed by its technical specifications and the setup in the experiment. An outline of the firmware and findings from first tests conclude the paper.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
The digitization stage of the main electromagnetic calorimeter of the CBELSA/TAPS experiment in Bonn (Germany) is being equipped with 80MS/s, 14 bit sampling-ADCs (SADCs), which were adapted from a prototype for the PANDA experiment. Onboard data processing with FPGAs allows determination of the signal characteristics, reducing the data volume substantially. The optional readout of the unprocessed sampled waveforms allows offline analysis and refinement of the FPGA algorithms.
A partial setup has shown promising results during a photoproduction-beamtime. It has been demonstrated that the readout-rate limitation of the current QDC readout can be overcome. The full setup is planned to be commissioned within the next year.
This paper will present an overview of the SADC project. After an introduction of the CBELSA/TAPS experiment, the new SADC readout will be motivated, followed by its technical specifications and the setup in the experiment. An outline of the firmware and findings from first tests conclude the paper.
2024
Müllers, Johannes; Greß, Hannah; Haaga, Lisa; Krüger, Björn
Sensorik am Krankenbett – Synchrone Datenakquise für Studien in der Epileptologie Conference
62. Jahrestagung der Deutschen Gesellschaft für Epileptologie, 2024.
@conference{muellers2024,
title = {Sensorik am Krankenbett – Synchrone Datenakquise für Studien in der Epileptologie},
author = {Johannes Müllers and Hannah Greß and Lisa Haaga and Björn Krüger},
year = {2024},
date = {2024-06-14},
urldate = {2024-06-14},
booktitle = {62. Jahrestagung der Deutschen Gesellschaft für Epileptologie},
abstract = {Die Möglichkeit der Anfallserkennung oder -vorhersage außerhalb des Krankenhauses kann die Lebensqualität und das Sicherheitsbedürfnis von Epilepsiepatienten erhöhen. Die Überwachung von Vitalparametern, Bewegungen und weiteren Messgrößen kann von einer Vielzahl von Wearables oder sonstigen neuartigen Sensorsystemen gewährleistet werden. Videoüberwachte EEG-Messplätze dienen als Goldstandard und werden für Studien mit solchen Sensoren genutzt, um Korrelationen festzustellen. Hierbei stellen technische Herausforderungen ein wiederkehrendes Problem dar. Neben der Inbetriebnahme der Sensorsysteme, die ohne informationstechnische Kenntnisse oft nur mit proprietären Mitteln möglich ist, ist insbesondere die Synchronizität zur EEG-Aufzeichnung anspruchsvoll. Aktuelle Vorbereitungen einer Studie mit Eye-Tracker Brillen bieten den Anlass, ein neues System zur Datenakquisition aufzubauen. },
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Die Möglichkeit der Anfallserkennung oder -vorhersage außerhalb des Krankenhauses kann die Lebensqualität und das Sicherheitsbedürfnis von Epilepsiepatienten erhöhen. Die Überwachung von Vitalparametern, Bewegungen und weiteren Messgrößen kann von einer Vielzahl von Wearables oder sonstigen neuartigen Sensorsystemen gewährleistet werden. Videoüberwachte EEG-Messplätze dienen als Goldstandard und werden für Studien mit solchen Sensoren genutzt, um Korrelationen festzustellen. Hierbei stellen technische Herausforderungen ein wiederkehrendes Problem dar. Neben der Inbetriebnahme der Sensorsysteme, die ohne informationstechnische Kenntnisse oft nur mit proprietären Mitteln möglich ist, ist insbesondere die Synchronizität zur EEG-Aufzeichnung anspruchsvoll. Aktuelle Vorbereitungen einer Studie mit Eye-Tracker Brillen bieten den Anlass, ein neues System zur Datenakquisition aufzubauen.
Schulte-Rüther, Martin; Lemken, Johannes; Krüger, Björn; Greß, Hannah; Stroth, Sanna; Kamp-Becker, Inge; Poustka, Luise
Automated annotation and quantification of non-verbal behavior from eye tracking and accelerometer data during live social interaction Conference
Wissenschaftliche Tagung Autismus-Spektrum (WTAS), 2024.
@conference{schulteruether2024,
title = {Automated annotation and quantification of non-verbal behavior from eye tracking and accelerometer data during live social interaction},
author = {Martin Schulte-Rüther and Johannes Lemken and Björn Krüger and Hannah Greß and Sanna Stroth and Inge Kamp-Becker and Luise Poustka},
year = {2024},
date = {2024-03-21},
booktitle = {Wissenschaftliche Tagung Autismus-Spektrum (WTAS)},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
2023
Krüger, Björn; Weber, Christian; Greß, Hannah; Knaub, Jessica; Pukropski, Jan; Hütwohl, Daniela; Hahn, Kai; Grond, Martin; Jonas, Stephan; Surges, Rainer
Telekonsil zur Verbesserung der Epilepsiediagnostik Conference
Digitalisierung der Gesundheitsversorgung älterer Menschen, 2023.
@conference{krueger2023,
title = {Telekonsil zur Verbesserung der Epilepsiediagnostik},
author = {Björn Krüger and Christian Weber and Hannah Greß and Jessica Knaub and Jan Pukropski and Daniela Hütwohl and Kai Hahn and Martin Grond and Stephan Jonas and Rainer Surges},
year = {2023},
date = {2023-07-01},
booktitle = {Digitalisierung der Gesundheitsversorgung älterer Menschen},
abstract = {Erfolgreiche Diagnose von Epilepsien bedürfen einer engen Zusammenarbeit von Hausärzt:innen, Kinderärzt:innen und neurologischen und epileptologischen Fachärzt:innen sowie den entsprechenden Fachkliniken. Zusätzlich zu der Expertise der Ärzt:innen ist ein fortlaufender Austausch und die kontinuierliche Anreicherung von Fachwissen von Bedeutung. Neben der frühzeitigen Überweisung an Fachkliniken kann die gemeinsame Fall-begleitende und Klinikübergreifende Aufnahme, der Austausch und die Pflege von Falldokumentationen ein wichtiger Baustein für die langfristige und erfolgreiche Begleitung der Patient:innen sein. },
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Erfolgreiche Diagnose von Epilepsien bedürfen einer engen Zusammenarbeit von Hausärzt:innen, Kinderärzt:innen und neurologischen und epileptologischen Fachärzt:innen sowie den entsprechenden Fachkliniken. Zusätzlich zu der Expertise der Ärzt:innen ist ein fortlaufender Austausch und die kontinuierliche Anreicherung von Fachwissen von Bedeutung. Neben der frühzeitigen Überweisung an Fachkliniken kann die gemeinsame Fall-begleitende und Klinikübergreifende Aufnahme, der Austausch und die Pflege von Falldokumentationen ein wichtiger Baustein für die langfristige und erfolgreiche Begleitung der Patient:innen sein.
Riedlinger, Dorothee; Krüger, Björn; Sydow, Hanna; Deutschbein, Johannes; Fischer-Rosinský, Antje; Slagman, Anna; Möckel, Martin
Ein Frühwarnsystem für Stürze – Identifikation von sturzgefährdeten Patient:innen durch die kombinierte Analyse von Medikamenten-Verordnungsdaten und Bewegungsprofilen Conference
Digitalisierung der Gesundheitsversorgung älterer Menschen, 2023.
@conference{riedlinger2023,
title = {Ein Frühwarnsystem für Stürze – Identifikation von sturzgefährdeten Patient:innen durch die kombinierte Analyse von Medikamenten-Verordnungsdaten und Bewegungsprofilen},
author = {Dorothee Riedlinger and Björn Krüger and Hanna Sydow and Johannes Deutschbein and Antje Fischer-Rosinský and Anna Slagman and Martin Möckel},
year = {2023},
date = {2023-07-01},
booktitle = {Digitalisierung der Gesundheitsversorgung älterer Menschen},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Schulte-Rüther, Martin; Krüger, Björn; Lemken, Johannes; Greß, Hannah; Stroth, Sanna; Kamp-Becker, Inge; Poustka, Luise
2023.
@conference{schulteruether2023,
title = {Automatic Delineation and Classification of Head Movements Using 3D Accelerometer Data from Live Social Interaction},
author = {Martin Schulte-Rüther and Björn Krüger and Johannes Lemken and Hannah Greß and Sanna Stroth and Inge Kamp-Becker and Luise Poustka},
url = {https://cdn.ymaws.com/www.autism-insar.org/resource/resmgr/docs/annualmeeting/insar_2023_full_abstract_boo.pdf, INSAR 2023 Abstract Book (p. 1246)},
year = {2023},
date = {2023-05-06},
urldate = {2023-05-06},
abstract = {Individuals with autism spectrum disorder (ASD) often show reduced non-verbal communication during social interactive encounters, e.g. facial expressions, deictic and communicative gestures, eye gaze. This includes reduced usage and expression of gestures of the head, such as nodding, shaking the head, and head turning. Diagnostic criteria of ASD suggest that reduced non-verbal communicative behavior is an important symptom, but current diagnostic tools are restricted to subjective, clinical evaluation.
While many tools for automatic delineation and classification of facial expressions and gestures from video data are available, less work has been done with respective to the usage of accelerometer sensor data. Considering the current lack of objective, quantitative measures of non-verbal behavior during social interaction, an automated analysis pipeline for movement annotation from accelerometer data would be helpful for both clinical evaluation and research.
},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Individuals with autism spectrum disorder (ASD) often show reduced non-verbal communication during social interactive encounters, e.g. facial expressions, deictic and communicative gestures, eye gaze. This includes reduced usage and expression of gestures of the head, such as nodding, shaking the head, and head turning. Diagnostic criteria of ASD suggest that reduced non-verbal communicative behavior is an important symptom, but current diagnostic tools are restricted to subjective, clinical evaluation.
While many tools for automatic delineation and classification of facial expressions and gestures from video data are available, less work has been done with respective to the usage of accelerometer sensor data. Considering the current lack of objective, quantitative measures of non-verbal behavior during social interaction, an automated analysis pipeline for movement annotation from accelerometer data would be helpful for both clinical evaluation and research.
While many tools for automatic delineation and classification of facial expressions and gestures from video data are available, less work has been done with respective to the usage of accelerometer sensor data. Considering the current lack of objective, quantitative measures of non-verbal behavior during social interaction, an automated analysis pipeline for movement annotation from accelerometer data would be helpful for both clinical evaluation and research.
Lemken, Johannes; Krüger, Björn; Stroth, Sanna; Kamp-Becker, Inge; Gail, A.; Poustka, Luise; Schulte-Rüther, Martin
The relationship between eye gaze and engagement in dyadic conversations – a semi-automatic analysis using unobtrusive eye tracking glasses Conference
Wissenschaftliche Tagung Autismus-Spektrum, 2023.
@conference{lemken2023,
title = {The relationship between eye gaze and engagement in dyadic conversations – a semi-automatic analysis using unobtrusive eye tracking glasses},
author = {Johannes Lemken and Björn Krüger and Sanna Stroth and Inge Kamp-Becker and A. Gail and Luise Poustka and Martin Schulte-Rüther},
year = {2023},
date = {2023-03-03},
booktitle = {Wissenschaftliche Tagung Autismus-Spektrum},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Xu, Jing; Greß, Hannah; Seefried, Sabine; van Drongelen, Stefan; Schween, Raphael; Sommer, Claudia; Endres, Dominik; Krüger, Björn; Stief, Felix
Diagnosing Rare Diseases by Movement Primitive-Based Classification of Kinematic Gait Data Proceedings
Bernstein Conference, 2023.
@proceedings{JingXu2023,
title = {Diagnosing Rare Diseases by Movement Primitive-Based Classification of Kinematic Gait Data},
author = {Jing Xu and Hannah Greß and Sabine Seefried and Stefan van Drongelen and Raphael Schween and Claudia Sommer and Dominik Endres and Björn Krüger and Felix Stief},
url = {https://abstracts.g-node.org/conference/BC23/abstracts#/uuid/31c21041-91a0-46bd-87dc-46271501fdc0},
doi = {10.12751/nncn.bc2023.313},
year = {2023},
date = {2023-01-10},
urldate = {2023-01-10},
booktitle = { Bernstein Conference 2023},
abstract = {Of over 6.000 known rare diseases, a considerable portion involves motor symptoms [1]. Whereas aiding diagnosis by artificial intelligence based on non-motor symptoms has shown promise [2], the potential of using movement data to this purpose has not yet been fully investigated. We therefore aim to implement a machine learning algorithm inspired by biological motor control to aid diagnosis of rare diseases by classifying data from standard kinematic clinical gait analysis.
Starting from 42-degrees-of-freedom time series of joint angles extracted from motion capture data with custom routines [3], we employ a Gaussian process-based temporal movement primitive algorithm [4] in order to reduce the data to sets of movement primitives and weight vectors that capture the essential characteristics of the gait movement. The primitives are participant (and disease) -independent and represent general human gait. The weights are participant-specific and thus contain disease-specific information. A weighted combination of the primitives can thus generate participant specific gait data. We then apply standard classification tools such as Support Vector Machines and Random Forests to the weights to distinguish the disease from the control gait. The primary goal is to reliably differentiate patients from age-matched controls in an existing data set on patients with Legg–Calvé–Perthes disease (LCPD). A secondary goal is to allow the classifier to expand the set of diseases using nonparametric methods such as the Dirichlet process.
Importantly, our movement primitive algorithm is inspired by current theories of biological motor control with a potential edge over standard algorithms in training on small case numbers. The temporal primitives are analogous to central pattern generators in the spinal cord [5], whereas the weights reflect activation of these central patterns by more central mechanisms in a hierarchical control scheme. In such a control scheme, disease-specific changes in weights may be caused directly by disease-specific influences on neural signaling, such as in the Stiff Person Syndrome [6], or indirectly through pain-avoidance in orthopedic conditions such as LCPD.
With further development, our approach holds potential for facilitating early detection and improving treatment strategies across a wide range of rare movement disorders and orthopedic conditions.},
howpublished = {Bernstein Conference},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
Of over 6.000 known rare diseases, a considerable portion involves motor symptoms [1]. Whereas aiding diagnosis by artificial intelligence based on non-motor symptoms has shown promise [2], the potential of using movement data to this purpose has not yet been fully investigated. We therefore aim to implement a machine learning algorithm inspired by biological motor control to aid diagnosis of rare diseases by classifying data from standard kinematic clinical gait analysis.
Starting from 42-degrees-of-freedom time series of joint angles extracted from motion capture data with custom routines [3], we employ a Gaussian process-based temporal movement primitive algorithm [4] in order to reduce the data to sets of movement primitives and weight vectors that capture the essential characteristics of the gait movement. The primitives are participant (and disease) -independent and represent general human gait. The weights are participant-specific and thus contain disease-specific information. A weighted combination of the primitives can thus generate participant specific gait data. We then apply standard classification tools such as Support Vector Machines and Random Forests to the weights to distinguish the disease from the control gait. The primary goal is to reliably differentiate patients from age-matched controls in an existing data set on patients with Legg–Calvé–Perthes disease (LCPD). A secondary goal is to allow the classifier to expand the set of diseases using nonparametric methods such as the Dirichlet process.
Importantly, our movement primitive algorithm is inspired by current theories of biological motor control with a potential edge over standard algorithms in training on small case numbers. The temporal primitives are analogous to central pattern generators in the spinal cord [5], whereas the weights reflect activation of these central patterns by more central mechanisms in a hierarchical control scheme. In such a control scheme, disease-specific changes in weights may be caused directly by disease-specific influences on neural signaling, such as in the Stiff Person Syndrome [6], or indirectly through pain-avoidance in orthopedic conditions such as LCPD.
With further development, our approach holds potential for facilitating early detection and improving treatment strategies across a wide range of rare movement disorders and orthopedic conditions.
Starting from 42-degrees-of-freedom time series of joint angles extracted from motion capture data with custom routines [3], we employ a Gaussian process-based temporal movement primitive algorithm [4] in order to reduce the data to sets of movement primitives and weight vectors that capture the essential characteristics of the gait movement. The primitives are participant (and disease) -independent and represent general human gait. The weights are participant-specific and thus contain disease-specific information. A weighted combination of the primitives can thus generate participant specific gait data. We then apply standard classification tools such as Support Vector Machines and Random Forests to the weights to distinguish the disease from the control gait. The primary goal is to reliably differentiate patients from age-matched controls in an existing data set on patients with Legg–Calvé–Perthes disease (LCPD). A secondary goal is to allow the classifier to expand the set of diseases using nonparametric methods such as the Dirichlet process.
Importantly, our movement primitive algorithm is inspired by current theories of biological motor control with a potential edge over standard algorithms in training on small case numbers. The temporal primitives are analogous to central pattern generators in the spinal cord [5], whereas the weights reflect activation of these central patterns by more central mechanisms in a hierarchical control scheme. In such a control scheme, disease-specific changes in weights may be caused directly by disease-specific influences on neural signaling, such as in the Stiff Person Syndrome [6], or indirectly through pain-avoidance in orthopedic conditions such as LCPD.
With further development, our approach holds potential for facilitating early detection and improving treatment strategies across a wide range of rare movement disorders and orthopedic conditions.
Yasin, Hashim; Ghani, Saba; Krüger, Björn
An Effective and Efficient Approach for 3D Recovery of Human Motion Capture Data Journal Article
In: Sensors, vol. 23, no. 7, 2023, ISSN: 1424-8220.
@article{s23073664,
title = {An Effective and Efficient Approach for 3D Recovery of Human Motion Capture Data},
author = {Hashim Yasin and Saba Ghani and Björn Krüger},
url = {https://www.mdpi.com/1424-8220/23/7/3664},
doi = {10.3390/s23073664},
issn = {1424-8220},
year = {2023},
date = {2023-01-01},
journal = {Sensors},
volume = {23},
number = {7},
abstract = {In this work, we propose a novel data-driven approach to recover missing or corrupted motion capture data, either in the form of 3D skeleton joints or 3D marker trajectories. We construct a knowledge-base that contains prior existing knowledge, which helps us to make it possible to infer missing or corrupted information of the motion capture data. We then build a kd-tree in parallel fashion on the GPU for fast search and retrieval of this already available knowledge in the form of nearest neighbors from the knowledge-base efficiently. We exploit the concept of histograms to organize the data and use an off-the-shelf radix sort algorithm to sort the keys within a single processor of GPU. We query the motion missing joints or markers, and as a result, we fetch a fixed number of nearest neighbors for the given input query motion. We employ an objective function with multiple error terms that substantially recover 3D joints or marker trajectories in parallel on the GPU. We perform comprehensive experiments to evaluate our approach quantitatively and qualitatively on publicly available motion capture datasets, namely CMU and HDM05. From the results, it is observed that the recovery of boxing, jumptwist, run, martial arts, salsa, and acrobatic motion sequences works best, while the recovery of motion sequences of kicking and jumping results in slightly larger errors. However, on average, our approach executes outstanding results. Generally, our approach outperforms all the competing state-of-the-art methods in the most test cases with different action sequences and executes reliable results with minimal errors and without any user interaction.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work, we propose a novel data-driven approach to recover missing or corrupted motion capture data, either in the form of 3D skeleton joints or 3D marker trajectories. We construct a knowledge-base that contains prior existing knowledge, which helps us to make it possible to infer missing or corrupted information of the motion capture data. We then build a kd-tree in parallel fashion on the GPU for fast search and retrieval of this already available knowledge in the form of nearest neighbors from the knowledge-base efficiently. We exploit the concept of histograms to organize the data and use an off-the-shelf radix sort algorithm to sort the keys within a single processor of GPU. We query the motion missing joints or markers, and as a result, we fetch a fixed number of nearest neighbors for the given input query motion. We employ an objective function with multiple error terms that substantially recover 3D joints or marker trajectories in parallel on the GPU. We perform comprehensive experiments to evaluate our approach quantitatively and qualitatively on publicly available motion capture datasets, namely CMU and HDM05. From the results, it is observed that the recovery of boxing, jumptwist, run, martial arts, salsa, and acrobatic motion sequences works best, while the recovery of motion sequences of kicking and jumping results in slightly larger errors. However, on average, our approach executes outstanding results. Generally, our approach outperforms all the competing state-of-the-art methods in the most test cases with different action sequences and executes reliable results with minimal errors and without any user interaction.
Jermann, N.; Krusche, B.; Metag, V.; Afzal, F.; Badea, M.; Beck, R.; Bielefeldt, P.; Bieling, J.; Biroth, M.; Blanke, E.; Borisov, N.; Bornstein, M.; Brinkmann, K. -T.; Ciupka, S.; Crede, V.; Dolzhikov, A.; Drexler, P.; Dutz, H.; Elsner, D.; Fedorov, A.; Frommberger, F.; Gardner, S.; Ghosal, D.; Goertz, S.; Gorodnov, I.; Grüner, M.; Hammann, C.; Hartmann, J.; Hillert, W.; Hoffmeister, P.; Honisch, C.; Jude, T. C.; Kalischewski, F.; Ketzer, B.; Klassen, P.; Klein, F.; Klempt, E.; Knaust, J.; Kolanus, N.; Kreit, J.; Krönert, P.; Lang, M.; Lazarev, A. B.; Livingston, K.; Lutterer, S.; Mahlberg, P.; Meier, C.; Meyer, W.; Mitlasoczki, B.; Müllers, Johannes; Nanova, M.; Neganov, A.; Nikonov, K.; Noël, J. F.; Ostrick, M.; Ottnad, J.; Otto, B.; Penman, G.; Poller, T.; Proft, D.; Reicherz, G.; Reinartz, N.; Richter, L.; Runkel, S.; Salisbury, B.; Sarantsev, A. V.; Schaab, D.; Schmidt, C.; Schmieden, H.; Schultes, J.; Seifen, T.; Spieker, K.; Stausberg, N.; Steinacher, M.; Taubert, F.; Thiel, A.; Thoma, U.; Thomas, A.; Urban, M.; Urff, G.; Usov, Y.; van Pee, H.; Wang, Y. C.; Wendel, C.; Wiedner, U.; Wunderlich, Y.
Measurement of polarization observables T, P, and H in 𝛑⁰ and 𝛈 photoproduction off quasi-free nucleons Journal Article
In: The European Physical Journal A, vol. 59, 2023.
@article{articleb,
title = {Measurement of polarization observables T, P, and H in 𝛑⁰ and 𝛈 photoproduction off quasi-free nucleons},
author = {N. Jermann and B. Krusche and V. Metag and F. Afzal and M. Badea and R. Beck and P. Bielefeldt and J. Bieling and M. Biroth and E. Blanke and N. Borisov and M. Bornstein and K.-T. Brinkmann and S. Ciupka and V. Crede and A. Dolzhikov and P. Drexler and H. Dutz and D. Elsner and A. Fedorov and F. Frommberger and S. Gardner and D. Ghosal and S. Goertz and I. Gorodnov and M. Grüner and C. Hammann and J. Hartmann and W. Hillert and P. Hoffmeister and C. Honisch and T. C. Jude and F. Kalischewski and B. Ketzer and P. Klassen and F. Klein and E. Klempt and J. Knaust and N. Kolanus and J. Kreit and P. Krönert and M. Lang and A. B. Lazarev and K. Livingston and S. Lutterer and P. Mahlberg and C. Meier and W. Meyer and B. Mitlasoczki and Johannes Müllers and M. Nanova and A. Neganov and K. Nikonov and J. F. Noël and M. Ostrick and J. Ottnad and B. Otto and G. Penman and T. Poller and D. Proft and G. Reicherz and N. Reinartz and L. Richter and S. Runkel and B. Salisbury and A. V. Sarantsev and D. Schaab and C. Schmidt and H. Schmieden and J. Schultes and T. Seifen and K. Spieker and N. Stausberg and M. Steinacher and F. Taubert and A. Thiel and U. Thoma and A. Thomas and M. Urban and G. Urff and Y. Usov and H. van Pee and Y. C. Wang and C. Wendel and U. Wiedner and Y. Wunderlich},
doi = {10.1140/epja/s10050-023-01134-0},
year = {2023},
date = {2023-01-01},
urldate = {2023-01-01},
journal = {The European Physical Journal A},
volume = {59},
abstract = {The target asymmetry T , recoil asymmetry P, and beam-target double polarization observable H were determined in exclusive π0 and η photoproduction off quasi-
free protons and, for the first time, off quasi-free neutrons. The experiment was performed at the electron stretcher accelerator ELSA in Bonn, Germany, with the Crystal Barrel/TAPS detector setup, using a linearly polarized photon beam and a transversely polarized deuterated butanol target. Effects from the Fermi motion of the nucleons within deuterium were removed by a full kinematic reconstruction of the final state invariant mass. A comparison of the data obtained on the proton and on the neutron provides new insight into the isospin structure of the electromagnetic excitation of the nucleon. Earlier measurements of polarization observables in the γ p → π0 p and γ p → ηp reactions are confirmed. The data obtained on the neutron are of particular relevance for clarifying the origin of the narrow structure in the ηn system at W = 1.68 GeV. A comparison with recent partial wave analyses favors the interpretation of this structure as arising from interference of the S11(1535) and S11(1650) resonances within the S11 -partial wave.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The target asymmetry T , recoil asymmetry P, and beam-target double polarization observable H were determined in exclusive π0 and η photoproduction off quasi-
free protons and, for the first time, off quasi-free neutrons. The experiment was performed at the electron stretcher accelerator ELSA in Bonn, Germany, with the Crystal Barrel/TAPS detector setup, using a linearly polarized photon beam and a transversely polarized deuterated butanol target. Effects from the Fermi motion of the nucleons within deuterium were removed by a full kinematic reconstruction of the final state invariant mass. A comparison of the data obtained on the proton and on the neutron provides new insight into the isospin structure of the electromagnetic excitation of the nucleon. Earlier measurements of polarization observables in the γ p → π0 p and γ p → ηp reactions are confirmed. The data obtained on the neutron are of particular relevance for clarifying the origin of the narrow structure in the ηn system at W = 1.68 GeV. A comparison with recent partial wave analyses favors the interpretation of this structure as arising from interference of the S11(1535) and S11(1650) resonances within the S11 -partial wave.
free protons and, for the first time, off quasi-free neutrons. The experiment was performed at the electron stretcher accelerator ELSA in Bonn, Germany, with the Crystal Barrel/TAPS detector setup, using a linearly polarized photon beam and a transversely polarized deuterated butanol target. Effects from the Fermi motion of the nucleons within deuterium were removed by a full kinematic reconstruction of the final state invariant mass. A comparison of the data obtained on the proton and on the neutron provides new insight into the isospin structure of the electromagnetic excitation of the nucleon. Earlier measurements of polarization observables in the γ p → π0 p and γ p → ηp reactions are confirmed. The data obtained on the neutron are of particular relevance for clarifying the origin of the narrow structure in the ηn system at W = 1.68 GeV. A comparison with recent partial wave analyses favors the interpretation of this structure as arising from interference of the S11(1535) and S11(1650) resonances within the S11 -partial wave.
2022
Honisch, C.; Klassen, P.; Müllers, Johannes; Urban, M.; Afzal, F.; Bieling, J.; Ciupka, S.; Hartmann, J.; Hoffmeister, P.; Lang, M.; Schaab, D.; Schmidt, C.; Steinacher, M.; Walther, D.; Beck, R.; Brinkmann, K. -T.; Crede, V.; Dutz, H.; Elsner, D.; Erni, W.; Fix, E.; Frommberger, F.; Grüner, M.; Jude, T.; Kalischewski, F.; Keshelashvili, I.; Krönert, P.; Krusche, B.; Mahlberg, P.; Metag, V.; Meyer, W.; Müller, F.; Nanova, M.; Otto, B.; Richter, L.; Runkel, S.; Salisbury, B.; Schmieden, H.; Schultes, J.; Seifen, T.; Stausberg, N.; Taubert, F.; Thiel, A.; Thoma, U.; Urff, G.; Wendel, C.; Wiedner, U.; Wunderlich, Y.; Zaunick, H. -G.
The new APD-Based Readout of the Crystal Barrel Calorimeter – An Overview Working paper
2022, (Momentan im Review).
@workingpaper{newapdreadout,
title = {The new APD-Based Readout of the Crystal Barrel Calorimeter – An Overview},
author = {C. Honisch and P. Klassen and Johannes Müllers and M. Urban and F. Afzal and J. Bieling and S. Ciupka and J. Hartmann and P. Hoffmeister and M. Lang and D. Schaab and C. Schmidt and M. Steinacher and D. Walther and R. Beck and K. -T. Brinkmann and V. Crede and H. Dutz and D. Elsner and W. Erni and E. Fix and F. Frommberger and M. Grüner and T. Jude and F. Kalischewski and I. Keshelashvili and P. Krönert and B. Krusche and P. Mahlberg and V. Metag and W. Meyer and F. Müller and M. Nanova and B. Otto and L. Richter and S. Runkel and B. Salisbury and H. Schmieden and J. Schultes and T. Seifen and N. Stausberg and F. Taubert and A. Thiel and U. Thoma and G. Urff and C. Wendel and U. Wiedner and Y. Wunderlich and H. -G. Zaunick},
doi = {10.48550/arXiv.2212.12364},
year = {2022},
date = {2022-12-23},
urldate = {2022-12-23},
abstract = {The Crystal Barrel is an electromagnetic calorimeter consisting of 1380 CsI(Tl) scintillators, and is currently installed at the CBELSA/TAPS experiment where it is used to detect decay products from photoproduction of mesons. The readout of the Crystal Barrel has been upgraded in order to integrate the detector into the first level of the trigger and to increase its sensitivity for neutral final states. The new readout uses avalanche photodiodes in the front-end and a dual back-end with branches optimized for energy and time measurement, respectively. An FPGA-based cluster finder processes the whole hit pattern within less than 100 ns. The important downside of APDs -- the temperature dependence of their gain -- is handled with a temperature stabilization and a compensating bias voltage supply. Additionally, a light pulser system allows the APDs' gains to be measured during beamtimes. },
note = {Momentan im Review},
keywords = {},
pubstate = {published},
tppubtype = {workingpaper}
}
The Crystal Barrel is an electromagnetic calorimeter consisting of 1380 CsI(Tl) scintillators, and is currently installed at the CBELSA/TAPS experiment where it is used to detect decay products from photoproduction of mesons. The readout of the Crystal Barrel has been upgraded in order to integrate the detector into the first level of the trigger and to increase its sensitivity for neutral final states. The new readout uses avalanche photodiodes in the front-end and a dual back-end with branches optimized for energy and time measurement, respectively. An FPGA-based cluster finder processes the whole hit pattern within less than 100 ns. The important downside of APDs -- the temperature dependence of their gain -- is handled with a temperature stabilization and a compensating bias voltage supply. Additionally, a light pulser system allows the APDs' gains to be measured during beamtimes.
2021
Gottschall, M.; Afzal, F.; Anisovich, A. V.; Bayadilov, D.; Beck, R.; Bichow, M.; Brinkmann, K. Th.; Crede, V.; Dieterle, M.; Dietz, F.; Dutz, H.; Eberhardt, H.; Elsner, D.; Ewald, R.; Fornet-Ponse, K.; Friedrich, St.; Frommberger, F.; Gridnev, A.; Grüner, M.; Gutz, E.; Hammann, Ch.; Hannappel, J.; Hartmann, J.; Hillert, W.; Hoffmeister, Ph.; Honisch, Ch.; Jude, T.; Kammer, S.; Kalinowsky, H.; Keshelashvili, I.; Klassen, P.; Klein, F.; Klempt, E.; Koop, K.; Krusche, B.; Kube, M.; Lang, M.; Lopatin, I.; Mahlberg, P.; Makonyi, K.; Metag, V.; Meyer, W.; Müller, J.; Müllers, Johannes; Nanova, M.; Nikonov, V.; Novotny, R.; Piontek, D.; Reicherz, G.; Rostomyan, T.; Sarantsev, A.; Schmidt, Ch.; Schmieden, H.; Seifen, T.; Sokhoyan, V.; Spieker, K.; Thiel, A.; Thoma, U.; Urban, M.; Pee, H.; Walther, D.; Wendel, Ch.; Werthmüller, D.; Wiedner, U.; Wilson, A.; Winnebeck, A.; Witthauer, L.; Wunderlich, Y.
Measurement of the helicity asymmetry E for the reaction γp→π0p Journal Article
In: The European Physical Journal A, vol. 57, pp. 40, 2021.
@article{articlec,
title = {Measurement of the helicity asymmetry E for the reaction γp→π0p},
author = {M. Gottschall and F. Afzal and A. V. Anisovich and D. Bayadilov and R. Beck and M. Bichow and K. Th. Brinkmann and V. Crede and M. Dieterle and F. Dietz and H. Dutz and H. Eberhardt and D. Elsner and R. Ewald and K. Fornet-Ponse and St. Friedrich and F. Frommberger and A. Gridnev and M. Grüner and E. Gutz and Ch. Hammann and J. Hannappel and J. Hartmann and W. Hillert and Ph. Hoffmeister and Ch. Honisch and T. Jude and S. Kammer and H. Kalinowsky and I. Keshelashvili and P. Klassen and F. Klein and E. Klempt and K. Koop and B. Krusche and M. Kube and M. Lang and I. Lopatin and P. Mahlberg and K. Makonyi and V. Metag and W. Meyer and J. Müller and Johannes Müllers and M. Nanova and V. Nikonov and R. Novotny and D. Piontek and G. Reicherz and T. Rostomyan and A. Sarantsev and Ch. Schmidt and H. Schmieden and T. Seifen and V. Sokhoyan and K. Spieker and A. Thiel and U. Thoma and M. Urban and H. Pee and D. Walther and Ch. Wendel and D. Werthmüller and U. Wiedner and A. Wilson and A. Winnebeck and L. Witthauer and Y. Wunderlich},
doi = {10.1140/epja/s10050-020-00334-2},
year = {2021},
date = {2021-01-28},
urldate = {2021-01-28},
journal = {The European Physical Journal A},
volume = {57},
pages = {40},
abstract = {A measurement of the double-polarization observable E for the reaction γp→π0p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C 4 H 9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from Eγ=600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses. },
keywords = {},
pubstate = {published},
tppubtype = {article}
}
A measurement of the double-polarization observable E for the reaction γp→π0p is reported. The data were taken with the CBELSA/TAPS experiment at the ELSA facility in Bonn using the Bonn frozen-spin butanol (C 4 H 9 OH) target, which provided longitudinally-polarized protons. Circularly-polarized photons were produced via bremsstrahlung of longitudinally-polarized electrons. The data cover the photon energy range from Eγ=600 to 2310 MeV and nearly the complete angular range. The results are compared to and have been included in recent partial wave analyses.
Yasin, Hashim; Krüger, Björn
An Efficient 3D Human Pose Retrieval and Reconstruction from 2D Image-Based Landmarks Journal Article
In: Sensors, vol. 21, no. 7, 2021, ISSN: 1424-8220.
@article{yasin-2021a,
title = {An Efficient 3D Human Pose Retrieval and Reconstruction from 2D Image-Based Landmarks},
author = {Hashim Yasin and Björn Krüger},
url = {https://www.mdpi.com/1424-8220/21/7/2415
https://digital-health-bonn.de/wp-content/uploads/2024/03/sensors-21-02415.pdf, Paper},
doi = {10.3390/s21072415},
issn = {1424-8220},
year = {2021},
date = {2021-01-01},
urldate = {2021-01-01},
journal = {Sensors},
volume = {21},
number = {7},
abstract = {We propose an efficient and novel architecture for 3D articulated human pose retrieval and reconstruction from 2D landmarks extracted from a 2D synthetic image, an annotated 2D image, an in-the-wild real RGB image or even a hand-drawn sketch. Given 2D joint positions in a single image, we devise a data-driven framework to infer the corresponding 3D human pose. To this end, we first normalize 3D human poses from Motion Capture (MoCap) dataset by eliminating translation, orientation, and the skeleton size discrepancies from the poses and then build a knowledge-base by projecting a subset of joints of the normalized 3D poses onto 2D image-planes by fully exploiting a variety of virtual cameras. With this approach, we not only transform 3D pose space to the normalized 2D pose space but also resolve the 2D-3D cross-domain retrieval task efficiently. The proposed architecture searches for poses from a MoCap dataset that are near to a given 2D query pose in a definite feature space made up of specific joint sets. These retrieved poses are then used to construct a weak perspective camera and a final 3D posture under the camera model that minimizes the reconstruction error. To estimate unknown camera parameters, we introduce a nonlinear, two-fold method. We exploit the retrieved similar poses and the viewing directions at which the MoCap dataset was sampled to minimize the projection error. Finally, we evaluate our approach thoroughly on a large number of heterogeneous 2D examples generated synthetically, 2D images with ground-truth, a variety of real in-the-wild internet images, and a proof of concept using 2D hand-drawn sketches of human poses. We conduct a pool of experiments to perform a quantitative study on PARSE dataset. We also show that the proposed system yields competitive, convincing results in comparison to other state-of-the-art methods.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We propose an efficient and novel architecture for 3D articulated human pose retrieval and reconstruction from 2D landmarks extracted from a 2D synthetic image, an annotated 2D image, an in-the-wild real RGB image or even a hand-drawn sketch. Given 2D joint positions in a single image, we devise a data-driven framework to infer the corresponding 3D human pose. To this end, we first normalize 3D human poses from Motion Capture (MoCap) dataset by eliminating translation, orientation, and the skeleton size discrepancies from the poses and then build a knowledge-base by projecting a subset of joints of the normalized 3D poses onto 2D image-planes by fully exploiting a variety of virtual cameras. With this approach, we not only transform 3D pose space to the normalized 2D pose space but also resolve the 2D-3D cross-domain retrieval task efficiently. The proposed architecture searches for poses from a MoCap dataset that are near to a given 2D query pose in a definite feature space made up of specific joint sets. These retrieved poses are then used to construct a weak perspective camera and a final 3D posture under the camera model that minimizes the reconstruction error. To estimate unknown camera parameters, we introduce a nonlinear, two-fold method. We exploit the retrieved similar poses and the viewing directions at which the MoCap dataset was sampled to minimize the projection error. Finally, we evaluate our approach thoroughly on a large number of heterogeneous 2D examples generated synthetically, 2D images with ground-truth, a variety of real in-the-wild internet images, and a proof of concept using 2D hand-drawn sketches of human poses. We conduct a pool of experiments to perform a quantitative study on PARSE dataset. We also show that the proposed system yields competitive, convincing results in comparison to other state-of-the-art methods.
2020
Afzal, F.; Wunderlich, Y.; Anisovich, A. V.; Bayadilov, D.; Beck, R.; Becker, M.; Blanke, E.; Brinkmann, K. -Th.; Ciupka, S.; Crede, V.; Dieterle, M.; Dutz, H.; Elsner, D.; Friedrich, S.; Frommberger, F.; Gridnev, A.; Gottschall, M.; Grüner, M.; Gutz, E.; Hammann, C.; Hannappel, J.; Hartmann, J.; Hillert, W.; Hoff, J.; Hoffmeister, P.; Honisch, C.; Jude, T.; Kalinowsky, H.; Kalischewski, F.; Keshelashvili, I.; Klassen, P.; Klein, F.; Klempt, E.; Koop, K.; Kroenert, P.; Krusche, B.; Lang, M.; Lopatin, I.; Mahlberg, P.; Meißner, U. -G.; Messi, F.; Metag, V.; Meyer, W.; Mitlasóczki, B.; Müller, J.; Müllers, Johannes; Nanova, M.; Nikonov, K.; Nikonov, V.; Novinskiy, V.; Novotny, R.; Piontek, D.; Reicherz, G.; Richter, L.; Rönchen, D.; Rostomyan, T.; Salisbury, B.; Sarantsev, A.; Schaab, D.; Schmidt, C.; Schmieden, H.; Schultes, J.; Seifen, T.; Sokhoyan, V.; Sowa, C.; Spieker, K.; Stausberg, N.; Thiel, A.; Thoma, U.; Triffterer, T.; Urban, M.; Urff, G.; Pee, H.; Walther, D.; Wendel, Ch.; Wiedner, U.; Wilson, A.; Winnebeck, A.; Witthauer, L.
Observation of the p𝛈' Cusp in the New Precise Beam Asymmetry 𝛴 Data for 𝛾 p → p 𝜂 Journal Article
In: Phys. Rev. Lett., vol. 125, iss. 15, pp. 152002, 2020.
@article{PhysRevLett.125.152002,
title = {Observation of the p𝛈' Cusp in the New Precise Beam Asymmetry 𝛴 Data for 𝛾 p → p 𝜂},
author = {F. Afzal and Y. Wunderlich and A. V. Anisovich and D. Bayadilov and R. Beck and M. Becker and E. Blanke and K. -Th. Brinkmann and S. Ciupka and V. Crede and M. Dieterle and H. Dutz and D. Elsner and S. Friedrich and F. Frommberger and A. Gridnev and M. Gottschall and M. Grüner and E. Gutz and C. Hammann and J. Hannappel and J. Hartmann and W. Hillert and J. Hoff and P. Hoffmeister and C. Honisch and T. Jude and H. Kalinowsky and F. Kalischewski and I. Keshelashvili and P. Klassen and F. Klein and E. Klempt and K. Koop and P. Kroenert and B. Krusche and M. Lang and I. Lopatin and P. Mahlberg and U. -G. Meißner and F. Messi and V. Metag and W. Meyer and B. Mitlasóczki and J. Müller and Johannes Müllers and M. Nanova and K. Nikonov and V. Nikonov and V. Novinskiy and R. Novotny and D. Piontek and G. Reicherz and L. Richter and D. Rönchen and T. Rostomyan and B. Salisbury and A. Sarantsev and D. Schaab and C. Schmidt and H. Schmieden and J. Schultes and T. Seifen and V. Sokhoyan and C. Sowa and K. Spieker and N. Stausberg and A. Thiel and U. Thoma and T. Triffterer and M. Urban and G. Urff and H. Pee and D. Walther and Ch. Wendel and U. Wiedner and A. Wilson and A. Winnebeck and L. Witthauer},
url = {https://link.aps.org/doi/10.1103/PhysRevLett.125.152002},
doi = {10.1103/PhysRevLett.125.152002},
year = {2020},
date = {2020-10-09},
urldate = {2020-10-09},
journal = {Phys. Rev. Lett.},
volume = {125},
issue = {15},
pages = {152002},
publisher = {American Physical Society},
abstract = {Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748 MeV to W=2045 MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη′ threshold [Eγ=1447 MeV (W=1896 MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)12− nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Data on the beam asymmetry Σ in the photoproduction of η mesons off protons are reported for tagged photon energies from 1130 to 1790 MeV (mass range from W=1748 MeV to W=2045 MeV). The data cover the full solid angle that allows for a precise moment analysis. For the first time, a strong cusp effect in a polarization observable has been observed that is an effect of a branch-point singularity at the pη′ threshold [Eγ=1447 MeV (W=1896 MeV)]. The latest BnGa partial wave analysis includes the new beam asymmetry data and yields a strong indication for the N(1895)12− nucleon resonance, demonstrating the importance of including all singularities for a correct determination of partial waves and resonance parameters.
Müller, J.; Hartmann, J.; Grüner, M.; Afzal, F.; Anisovich, A. V.; Bantes, B.; Bayadilov, D.; Beck, R.; Becker, M.; Beloglazov, Y.; Berlin, A.; Bichow, M.; Böse, S.; Brinkmann, K. -T.; Challand, T.; Crede, V.; Dietz, F.; Dieterle, M.; Drexler, P.; Dutz, H.; Eberhardt, H.; Elsner, D.; Ewald, R.; Fornet-Ponse, K.; Friedrich, S.; Frommberger, F.; Funke, C.; Gottschall, M.; Gridnev, A.; Goertz, S.; Gutz, E.; Hammann, C.; Hannen, V.; Hannappel, J.; Herick, J.; Hillert, W.; Hoffmeister, P.; Honisch, C.; Jahn, O.; Jude, T.; Jaegle, I.; Käser, A.; Kaiser, D.; Kalinowsky, H.; Kalischewski, F.; Kammer, S.; Keshelashvili, I.; Klassen, P.; Kleber, V.; Klein, F.; Klempt, E.; Koop, K.; Krusche, B.; Kube, M.; Lang, M.; Lopatin, I.; Maghrbi, Y.; Mahlberg, P.; Makonyi, K.; Messi, F.; Metag, V.; Meyer, W.; Müllers, Johannes; Nanova, M.; Nikonov, V.; Novinski, D.; Novotny, R.; Piontek, D.; Reicherz, G.; Rosenbaum, C.; Rostomyan, T.; Roth, B.; Sarantsev, A.; Schmidt, C.; Schmieden, H.; Schmitz, R.; Seifen, T.; Sokhoyan, V.; Thiel, A.; Thoma, U.; Urban, M.; Pee, H.; Walther, D.; Wendel, C.; Wiedner, U.; Wilson, A.; Winnebeck, A.; Witthauer, L.
New data on γp→ηp with polarized photons and protons and their implications for N⁎ → Nη decays Journal Article
In: Physics Letters B, vol. 803, pp. 135323, 2020, ISSN: 0370-2693.
@article{2020135323,
title = {New data on γp→ηp with polarized photons and protons and their implications for N⁎ → Nη decays},
author = {J. Müller and J. Hartmann and M. Grüner and F. Afzal and A. V. Anisovich and B. Bantes and D. Bayadilov and R. Beck and M. Becker and Y. Beloglazov and A. Berlin and M. Bichow and S. Böse and K. -T. Brinkmann and T. Challand and V. Crede and F. Dietz and M. Dieterle and P. Drexler and H. Dutz and H. Eberhardt and D. Elsner and R. Ewald and K. Fornet-Ponse and S. Friedrich and F. Frommberger and C. Funke and M. Gottschall and A. Gridnev and S. Goertz and E. Gutz and C. Hammann and V. Hannen and J. Hannappel and J. Herick and W. Hillert and P. Hoffmeister and C. Honisch and O. Jahn and T. Jude and I. Jaegle and A. Käser and D. Kaiser and H. Kalinowsky and F. Kalischewski and S. Kammer and I. Keshelashvili and P. Klassen and V. Kleber and F. Klein and E. Klempt and K. Koop and B. Krusche and M. Kube and M. Lang and I. Lopatin and Y. Maghrbi and P. Mahlberg and K. Makonyi and F. Messi and V. Metag and W. Meyer and Johannes Müllers and M. Nanova and V. Nikonov and D. Novinski and R. Novotny and D. Piontek and G. Reicherz and C. Rosenbaum and T. Rostomyan and B. Roth and A. Sarantsev and C. Schmidt and H. Schmieden and R. Schmitz and T. Seifen and V. Sokhoyan and A. Thiel and U. Thoma and M. Urban and H. Pee and D. Walther and C. Wendel and U. Wiedner and A. Wilson and A. Winnebeck and L. Witthauer},
url = {https://www.sciencedirect.com/science/article/pii/S0370269320301271},
doi = {https://doi.org/10.1016/j.physletb.2020.135323},
issn = {0370-2693},
year = {2020},
date = {2020-04-10},
urldate = {2020-04-10},
journal = {Physics Letters B},
volume = {803},
pages = {135323},
abstract = {The polarization observables T,E,P,H, and G in photoproduction of η mesons off protons are measured for photon energies from threshold to W=2400 MeV (T), 2280 MeV (E), 1620 MeV (P,H), or 1820 MeV (G), covering nearly the full solid angle. The data are compared to predictions from the SAID, MAID, JüBo, and BnGa partial-wave analyses. A refit within the BnGa approach including further data yields precise branching ratios for the Nη decay of nucleon resonances. A Nη-branching ratio of 0.33±0.04 for N(1650)1/2− is found, which reduces the large and controversially discussed Nη-branching ratio difference of the two lowest mass JP=1/2−-resonances significantly.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The polarization observables T,E,P,H, and G in photoproduction of η mesons off protons are measured for photon energies from threshold to W=2400 MeV (T), 2280 MeV (E), 1620 MeV (P,H), or 1820 MeV (G), covering nearly the full solid angle. The data are compared to predictions from the SAID, MAID, JüBo, and BnGa partial-wave analyses. A refit within the BnGa approach including further data yields precise branching ratios for the Nη decay of nucleon resonances. A Nη-branching ratio of 0.33±0.04 for N(1650)1/2− is found, which reduces the large and controversially discussed Nη-branching ratio difference of the two lowest mass JP=1/2−-resonances significantly.
Peper, Erik; Krüger, Björn; Gokhale, Esther; Harvey, Richard
Comparing Muscle Activity and Spine Shape in Various Sitting Styles Journal Article
In: Biofeedback, vol. 48, no. 3, pp. 62–67, 2020, ISSN: 1081-5937.
@article{peper-2020-a,
title = {Comparing Muscle Activity and Spine Shape in Various Sitting Styles},
author = {Erik Peper and Björn Krüger and Esther Gokhale and Richard Harvey},
doi = {10.5298/1081-5937-48.3.03},
issn = {1081-5937},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
journal = {Biofeedback},
volume = {48},
number = {3},
pages = {62–67},
abstract = {Back problems affect 80% of the population in the U.S. at some time during their lives, and each year 32 million Americans experience lower back pain at an estimated economic cost of $560-$635 billion. One contributing factor for back pain is posture, and more particularly, lack of awareness of dysfunctional posture. For example, many people may sit in a slouched or forward-bent position, exacerbated by poor ergonomics while sitting or, extended use of handheld digital devices while standing such as looking down at a smartphone for long periods of time. This report describes a ‘stacksitting’ technique which is one of the components of the Gokhale Method® for healthy, relaxed sitting and increased awareness of posture. The stacksitting process is illustrated with a case study where the shape of the spine and the muscle activity is analyzed in parallel during three sitting styles: slouching, arched, and stacksitting. The spine curvature was characterized by the Gokhale SpineTracker™ wearable, which consists of five sensor-units attached along the subjects’ spines that are used to plot the spinal curve on a digital device such as a smartphone, tablet or computer. SEMG recordings were made from the right upper trapezius, left upper trapezius, right mid-back, and left mid-back with a second device (Myoscan Pro sensors recorded with Biograph Procomp Infinity) while participants were seated in three postures: a slouched (forward-bent) position, an upright ‘arched’ position, and an upright ‘stacksitting’ position as trained by a Gokhale Method teacher. The case observations showed no significant difference in trapezius SEMG activity during each of the three positions. There was a slight increase in SEMG activity of the mid-back during stacksitting (1.1 µV) as compared to when slouched (0.64 µV) and, a significant increase in SEMG activity when sitting arched (4.9 µV). As expected, the spinal activity tracking device showed significant straightening of the lower spine during the stacksitting position as compared to the slouched and arched positions. The observations suggest that the stacksitting position can be taught to others in a way that allows the vertebrae to be parallel to each other with very low levels of corresponding muscle activity. In contrast, sitting in an arched or slouched position would increase asymmetrical pressures on the disks, contributing to vertebral wedging which could also contribute to spinal disk-bulging and eventual back injury. The observations suggest that proper coaching may foster a stacksitting position of the spine, which would foster a healthier posture than a slouched or arched spinal positions.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Back problems affect 80% of the population in the U.S. at some time during their lives, and each year 32 million Americans experience lower back pain at an estimated economic cost of $560-$635 billion. One contributing factor for back pain is posture, and more particularly, lack of awareness of dysfunctional posture. For example, many people may sit in a slouched or forward-bent position, exacerbated by poor ergonomics while sitting or, extended use of handheld digital devices while standing such as looking down at a smartphone for long periods of time. This report describes a ‘stacksitting’ technique which is one of the components of the Gokhale Method® for healthy, relaxed sitting and increased awareness of posture. The stacksitting process is illustrated with a case study where the shape of the spine and the muscle activity is analyzed in parallel during three sitting styles: slouching, arched, and stacksitting. The spine curvature was characterized by the Gokhale SpineTracker™ wearable, which consists of five sensor-units attached along the subjects’ spines that are used to plot the spinal curve on a digital device such as a smartphone, tablet or computer. SEMG recordings were made from the right upper trapezius, left upper trapezius, right mid-back, and left mid-back with a second device (Myoscan Pro sensors recorded with Biograph Procomp Infinity) while participants were seated in three postures: a slouched (forward-bent) position, an upright ‘arched’ position, and an upright ‘stacksitting’ position as trained by a Gokhale Method teacher. The case observations showed no significant difference in trapezius SEMG activity during each of the three positions. There was a slight increase in SEMG activity of the mid-back during stacksitting (1.1 µV) as compared to when slouched (0.64 µV) and, a significant increase in SEMG activity when sitting arched (4.9 µV). As expected, the spinal activity tracking device showed significant straightening of the lower spine during the stacksitting position as compared to the slouched and arched positions. The observations suggest that the stacksitting position can be taught to others in a way that allows the vertebrae to be parallel to each other with very low levels of corresponding muscle activity. In contrast, sitting in an arched or slouched position would increase asymmetrical pressures on the disks, contributing to vertebral wedging which could also contribute to spinal disk-bulging and eventual back injury. The observations suggest that proper coaching may foster a stacksitting position of the spine, which would foster a healthier posture than a slouched or arched spinal positions.
Mezzarobba, Susanna; Grassi, Michele; Pellegrini, Lorella; Catalan, Mauro; Krüger, Björn; Stragapede, Lara; Manganotti, Paolo; Bernardis, Paolo
In: Parkinsonism & Related Disorders, vol. 80, pp. 133–137, 2020.
@article{Mezzarobba2020,
title = {Action Observation Plus Sonification. Biomechanical Analysis of Sit-To-Walk Performance in Patients with Parkinson's Disease and Freezing of Gait},
author = {Susanna Mezzarobba and Michele Grassi and Lorella Pellegrini and Mauro Catalan and Björn Krüger and Lara Stragapede and Paolo Manganotti and Paolo Bernardis},
doi = {https://doi.org/10.1016/j.parkreldis.2020.09.029},
year = {2020},
date = {2020-01-01},
urldate = {2020-01-01},
journal = {Parkinsonism & Related Disorders},
volume = {80},
pages = {133–137},
abstract = {Introduction. Freezing of gait (FoG) is one of the most disabling gait disorders in Parkinson's disease (PD) reflecting motor and cognitive impairments, mainly related to dopamine deficiency. Recent studies, investigating kinematic and kinetic factors affecting gait in these patients, showed a postural instability characterized by disturbed weight-shifting, inappropriate anticipatory postural adjustment, worse reactive postural control, and a difficulty to execute complex motor task (i.e. sit-to-walk). Symptoms that are difficult to alleviate and not much responsive to Levodopa. For this reason, additional therapeutic actions based on specific therapeutic protocols may help patients in daily life. Methods. In 2018, we conducted a randomized control trial aimed to test two clinical protocols for PD patients with FoG. Protocols, conceived to improve gait, were based on learning motor exercises with the Action Observation plus Sonification (AOS) technique, and with a standard protocol centered on cue use. We found a significant improvement in the FoG questionnaire and the UPDRS III clinical scale for the AOS protocol only. We also collected biomechanical data, using the sit-to-walk task as a measure of motor performance. Results. Here we report kinetic and kinematic analysis of data showing that, when treatment effects consolidate, patients treated with AOS protocol are more efficient in merging subsequent motor tasks (sit-tostand and gait initiation) with a better dynamic balance control during the sit-to-stand. Conclusion. Promising results of the AOS protocol in reducing FoG confirm that a mobility training focused on improving weight-shifting and motor switching abilities, may have benefits for Parkinson patients with FoG.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Introduction. Freezing of gait (FoG) is one of the most disabling gait disorders in Parkinson's disease (PD) reflecting motor and cognitive impairments, mainly related to dopamine deficiency. Recent studies, investigating kinematic and kinetic factors affecting gait in these patients, showed a postural instability characterized by disturbed weight-shifting, inappropriate anticipatory postural adjustment, worse reactive postural control, and a difficulty to execute complex motor task (i.e. sit-to-walk). Symptoms that are difficult to alleviate and not much responsive to Levodopa. For this reason, additional therapeutic actions based on specific therapeutic protocols may help patients in daily life. Methods. In 2018, we conducted a randomized control trial aimed to test two clinical protocols for PD patients with FoG. Protocols, conceived to improve gait, were based on learning motor exercises with the Action Observation plus Sonification (AOS) technique, and with a standard protocol centered on cue use. We found a significant improvement in the FoG questionnaire and the UPDRS III clinical scale for the AOS protocol only. We also collected biomechanical data, using the sit-to-walk task as a measure of motor performance. Results. Here we report kinetic and kinematic analysis of data showing that, when treatment effects consolidate, patients treated with AOS protocol are more efficient in merging subsequent motor tasks (sit-tostand and gait initiation) with a better dynamic balance control during the sit-to-stand. Conclusion. Promising results of the AOS protocol in reducing FoG confirm that a mobility training focused on improving weight-shifting and motor switching abilities, may have benefits for Parkinson patients with FoG.
2019
Müllers, Johannes
An FPGA-based Sampling ADC for the Crystal Barrel Calorimeter PhD Thesis
Rheinische Friedrich-Wilhelms-Universität Bonn, 2019.
@phdthesis{handle:20.500.11811/8118,
title = {An FPGA-based Sampling ADC for the Crystal Barrel Calorimeter},
author = {Johannes Müllers},
url = {https://hdl.handle.net/20.500.11811/8118},
year = {2019},
date = {2019-12-01},
urldate = {2019-12-01},
school = {Rheinische Friedrich-Wilhelms-Universität Bonn},
abstract = {The CBELSA/TAPS experiment in Bonn investigates the excitation spectra of protons and neutrons through meson-photoproduction. With its ability to polarize the target nucleons and the incident photon beam, the experiment has contributed significantly to a better understanding of the baryon excitation spectrum, and with that also to the understanding of the strong interaction in the non-perturbative regime. Since a recent upgrade, the experiment's main electromagnetic calorimeter, the Crystal Barrel, is read out by avalanche photo-diodes. Their signal is digitized by integrating Fastbus ADCs, providing a value proportional to the energy deposited in the calorimeter crystals. As a result of long conversion and transfer times, those ADCs have become the limiting factor in the data acquisition, with possible readout rates of less than 2 kHz. Moreover, the possibility to identify pile-up, i.e. quickly-succeeding energy deposits that overlap in the integration window, is presently missing.
Already years ago, it has been investigated whether this readout system could be replaced by faster and more modern sampling ADCs, which offer access to the waveform representation for a more sophisticated analysis, but the investigations were limited to commercially available digitizers with high cost and low channel densities. In addition, the firmware (operating system) of such digitizers is usually closed-source, which does not allow for the implementation of experiment-specific algorithms. Due to the above reasons, the investigations had not led to a satisfactory solution, and the Fastbus ADCs are still in operation today.
In this thesis, the development and test of a custom (non-commercial) FPGA-based sampling ADC, which will replace the Fastbus ADC, has been driven forward. This so-called CB-SADC (Crystal Barrel Sampling Analog-to-Digital Converter) has been adapted from a prototype of the PANDA experiment in such a way that it is suited to operate within the specific conditions of the CBELSA/TAPS experiment.
Apart from the hardware development, the firmware for the FPGA, which processes the digitized data, was designed and tested extensively. Specific algorithms allow not only the determination of the deposited energy and the timestamps of each event, but also an event-wise baseline determination and the detection of pile-up events. An online correction of pileup events, which occur with significant frequency in the forward region of the calorimeter, leads to a higher data quality and improved efficiency and statistics.
Apart from the hardware development, the firmware for the FPGA, which processes the digitized data, was designed and tested extensively. Specific algorithms allow not only the determination of the deposited energy and the timestamps of each event, but also an event-wise baseline determination and the detection of pile-up events. An online correction of pileup events, which occur with significant frequency in the forward region of the calorimeter, leads to a higher data quality and improved efficiency and statistics.
Two prototype iterations of the CB-SADC have been produced and were tested thoroughly in the laboratory and in connection with the CBELSA/TAPS experiment. The results of those tests, and preliminary analyses of production beam times with 50% of the calorimeter's forward half being read out by the CB-SADCs, showed an improvement of the data quality. The timestamp determination of the CB-SADCs in the energy regime below 10MeV has provided data where the experiment's TDC (Time-to-Digital Converter) either has worse resolution or cannot provide timestamps at all. In addition, standalone tests in the laboratory and tests with the data acquisition system have confirmed a much higher readout speed compared to the integrating Fastbus ADCs. Based on the achieved results, it was finally decided to equip the whole calorimeter with the new CB-SADC readout.
At the time of finalizing this thesis, all CB-SADCs have been produced and are prepared for installation in the experimental hall. They will be running in parallel with the integrating Fastbus ADCs during the next production beam times, offering an opportunity to test the CB-SADC readout system as a whole. As soon as it is proven that the new readout works reliably, the limiting integrating Fastbus ADCs will be decommissioned and the CBELSA/TAPS experiment can start taking data with an increased readout rate.},
keywords = {},
pubstate = {published},
tppubtype = {phdthesis}
}
The CBELSA/TAPS experiment in Bonn investigates the excitation spectra of protons and neutrons through meson-photoproduction. With its ability to polarize the target nucleons and the incident photon beam, the experiment has contributed significantly to a better understanding of the baryon excitation spectrum, and with that also to the understanding of the strong interaction in the non-perturbative regime. Since a recent upgrade, the experiment's main electromagnetic calorimeter, the Crystal Barrel, is read out by avalanche photo-diodes. Their signal is digitized by integrating Fastbus ADCs, providing a value proportional to the energy deposited in the calorimeter crystals. As a result of long conversion and transfer times, those ADCs have become the limiting factor in the data acquisition, with possible readout rates of less than 2 kHz. Moreover, the possibility to identify pile-up, i.e. quickly-succeeding energy deposits that overlap in the integration window, is presently missing.
Already years ago, it has been investigated whether this readout system could be replaced by faster and more modern sampling ADCs, which offer access to the waveform representation for a more sophisticated analysis, but the investigations were limited to commercially available digitizers with high cost and low channel densities. In addition, the firmware (operating system) of such digitizers is usually closed-source, which does not allow for the implementation of experiment-specific algorithms. Due to the above reasons, the investigations had not led to a satisfactory solution, and the Fastbus ADCs are still in operation today.
In this thesis, the development and test of a custom (non-commercial) FPGA-based sampling ADC, which will replace the Fastbus ADC, has been driven forward. This so-called CB-SADC (Crystal Barrel Sampling Analog-to-Digital Converter) has been adapted from a prototype of the PANDA experiment in such a way that it is suited to operate within the specific conditions of the CBELSA/TAPS experiment.
Apart from the hardware development, the firmware for the FPGA, which processes the digitized data, was designed and tested extensively. Specific algorithms allow not only the determination of the deposited energy and the timestamps of each event, but also an event-wise baseline determination and the detection of pile-up events. An online correction of pileup events, which occur with significant frequency in the forward region of the calorimeter, leads to a higher data quality and improved efficiency and statistics.
Apart from the hardware development, the firmware for the FPGA, which processes the digitized data, was designed and tested extensively. Specific algorithms allow not only the determination of the deposited energy and the timestamps of each event, but also an event-wise baseline determination and the detection of pile-up events. An online correction of pileup events, which occur with significant frequency in the forward region of the calorimeter, leads to a higher data quality and improved efficiency and statistics.
Two prototype iterations of the CB-SADC have been produced and were tested thoroughly in the laboratory and in connection with the CBELSA/TAPS experiment. The results of those tests, and preliminary analyses of production beam times with 50% of the calorimeter's forward half being read out by the CB-SADCs, showed an improvement of the data quality. The timestamp determination of the CB-SADCs in the energy regime below 10MeV has provided data where the experiment's TDC (Time-to-Digital Converter) either has worse resolution or cannot provide timestamps at all. In addition, standalone tests in the laboratory and tests with the data acquisition system have confirmed a much higher readout speed compared to the integrating Fastbus ADCs. Based on the achieved results, it was finally decided to equip the whole calorimeter with the new CB-SADC readout.
At the time of finalizing this thesis, all CB-SADCs have been produced and are prepared for installation in the experimental hall. They will be running in parallel with the integrating Fastbus ADCs during the next production beam times, offering an opportunity to test the CB-SADC readout system as a whole. As soon as it is proven that the new readout works reliably, the limiting integrating Fastbus ADCs will be decommissioned and the CBELSA/TAPS experiment can start taking data with an increased readout rate.
Already years ago, it has been investigated whether this readout system could be replaced by faster and more modern sampling ADCs, which offer access to the waveform representation for a more sophisticated analysis, but the investigations were limited to commercially available digitizers with high cost and low channel densities. In addition, the firmware (operating system) of such digitizers is usually closed-source, which does not allow for the implementation of experiment-specific algorithms. Due to the above reasons, the investigations had not led to a satisfactory solution, and the Fastbus ADCs are still in operation today.
In this thesis, the development and test of a custom (non-commercial) FPGA-based sampling ADC, which will replace the Fastbus ADC, has been driven forward. This so-called CB-SADC (Crystal Barrel Sampling Analog-to-Digital Converter) has been adapted from a prototype of the PANDA experiment in such a way that it is suited to operate within the specific conditions of the CBELSA/TAPS experiment.
Apart from the hardware development, the firmware for the FPGA, which processes the digitized data, was designed and tested extensively. Specific algorithms allow not only the determination of the deposited energy and the timestamps of each event, but also an event-wise baseline determination and the detection of pile-up events. An online correction of pileup events, which occur with significant frequency in the forward region of the calorimeter, leads to a higher data quality and improved efficiency and statistics.
Apart from the hardware development, the firmware for the FPGA, which processes the digitized data, was designed and tested extensively. Specific algorithms allow not only the determination of the deposited energy and the timestamps of each event, but also an event-wise baseline determination and the detection of pile-up events. An online correction of pileup events, which occur with significant frequency in the forward region of the calorimeter, leads to a higher data quality and improved efficiency and statistics.
Two prototype iterations of the CB-SADC have been produced and were tested thoroughly in the laboratory and in connection with the CBELSA/TAPS experiment. The results of those tests, and preliminary analyses of production beam times with 50% of the calorimeter's forward half being read out by the CB-SADCs, showed an improvement of the data quality. The timestamp determination of the CB-SADCs in the energy regime below 10MeV has provided data where the experiment's TDC (Time-to-Digital Converter) either has worse resolution or cannot provide timestamps at all. In addition, standalone tests in the laboratory and tests with the data acquisition system have confirmed a much higher readout speed compared to the integrating Fastbus ADCs. Based on the achieved results, it was finally decided to equip the whole calorimeter with the new CB-SADC readout.
At the time of finalizing this thesis, all CB-SADCs have been produced and are prepared for installation in the experimental hall. They will be running in parallel with the integrating Fastbus ADCs during the next production beam times, offering an opportunity to test the CB-SADC readout system as a whole. As soon as it is proven that the new readout works reliably, the limiting integrating Fastbus ADCs will be decommissioned and the CBELSA/TAPS experiment can start taking data with an increased readout rate.
Peper, Erik; Krüger, Björn; Gokhale, Esther
Comparing Muscle Activity and Spine Shape in Various Sitting Positions Proceedings
Association for Applied Psychophysiology and Biofeedback’s 2019 Annual Scientific Meeting, Denver, Colorado, 2019.
@proceedings{2019-peper,
title = {Comparing Muscle Activity and Spine Shape in Various Sitting Positions},
author = {Erik Peper and Björn Krüger and Esther Gokhale},
url = {https://digital-health-bonn.de/wp-content/uploads/2024/03/190401StacksittingPoster.pdf, Poster},
year = {2019},
date = {2019-01-01},
urldate = {2019-01-01},
booktitle = {Association for Applied Psychophysiology and Biofeedback’s 2019 Annual Scientific Meeting},
address = {Denver, Colorado},
howpublished = {Association for Applied Psychophysiology and Biofeedback’s 2019 Annual Scientific Meeting},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
Khandelwal, Icxa; Stollenwerk, Katharina; Krüger, Björn; Weber, Andreas
Posture Classification based on a Spine Shape Monitoring System Proceedings Article
In: Computational Science and Its Applications – ICCSA 2019, 2019.
@inproceedings{Khandelwal-2019,
title = {Posture Classification based on a Spine Shape Monitoring System},
author = {Icxa Khandelwal and Katharina Stollenwerk and Björn Krüger and Andreas Weber},
url = {https://digital-health-bonn.de/wp-content/uploads/2024/03/KSKW19_preprint.pdf, Paper},
year = {2019},
date = {2019-01-01},
urldate = {2019-01-01},
booktitle = {Computational Science and Its Applications – ICCSA 2019},
abstract = {Lower back pain is one of the leading causes for musculoskeletal disability throughout the world. A large percentage of the population suffers from lower back pain at some point in their life. One noninvasive approach to reduce back pain is postural modification which can be learned through training. In this context, wearables are becoming more and more prominent since they are capable of providing feedback about the user’s posture in real-time. Optimal, healthy posture depends on the position (sitting, standing, hinging) the user is in. Meaningful feedback needs to adapt to the current position and, in the best case, identify the position automatically to minimize necessary interactions from the user. In this work, we present results of classifying the positions of users based on the readings of the Gokhale SpineTracker device. We computed various features and evaluated the performance of K-Nearest Neighbors, Extra Trees, Artificial Neural Networks and AdaBoost for global inter-subject classification as well as for personalized subject specific classification.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Lower back pain is one of the leading causes for musculoskeletal disability throughout the world. A large percentage of the population suffers from lower back pain at some point in their life. One noninvasive approach to reduce back pain is postural modification which can be learned through training. In this context, wearables are becoming more and more prominent since they are capable of providing feedback about the user’s posture in real-time. Optimal, healthy posture depends on the position (sitting, standing, hinging) the user is in. Meaningful feedback needs to adapt to the current position and, in the best case, identify the position automatically to minimize necessary interactions from the user. In this work, we present results of classifying the positions of users based on the readings of the Gokhale SpineTracker device. We computed various features and evaluated the performance of K-Nearest Neighbors, Extra Trees, Artificial Neural Networks and AdaBoost for global inter-subject classification as well as for personalized subject specific classification.
Stollenwerk, Katharina; Müller, Jonas; Hinkenjann, André; Krüger, Björn
Analyzing Spinal Shape Changes During Posture Training Using a Wearable Device Journal Article
In: Sensors, 2019.
@article{stollenwerk-2019a,
title = {Analyzing Spinal Shape Changes During Posture Training Using a Wearable Device},
author = {Katharina Stollenwerk and Jonas Müller and André Hinkenjann and Björn Krüger},
url = {https://digital-health-bonn.de/wp-content/uploads/2024/03/sensors-19-03625.pdf, Paper},
doi = {https://doi.org/10.3390/s19163625},
year = {2019},
date = {2019-01-01},
urldate = {2019-01-01},
journal = {Sensors},
abstract = {Lower back pain is one of the most prevalent diseases in Western societies. A large percentage of European and American populations suffer from back pain at some point in their lives. One successful approach to address lower back pain is postural training, which can be supported by wearable devices, providing real-time feedback about the user’s posture. In this work, we analyze the changes in posture induced by postural training. To this end, we compare snapshots before and after training, as measured by the Gokhale SpineTracker™. Considering pairs of before and after snapshots in different positions (standing, sitting, and bending), we introduce a feature space, that allows for unsupervised clustering. We show that resulting clusters represent certain groups of postural changes, which are meaningful to professional posture trainers.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Lower back pain is one of the most prevalent diseases in Western societies. A large percentage of European and American populations suffer from back pain at some point in their lives. One successful approach to address lower back pain is postural training, which can be supported by wearable devices, providing real-time feedback about the user’s posture. In this work, we analyze the changes in posture induced by postural training. To this end, we compare snapshots before and after training, as measured by the Gokhale SpineTracker™. Considering pairs of before and after snapshots in different positions (standing, sitting, and bending), we introduce a feature space, that allows for unsupervised clustering. We show that resulting clusters represent certain groups of postural changes, which are meaningful to professional posture trainers.
2018
Mezzarobba, Susanna; Grassi, Michele; Pellegrini, Lorella; Catalan, Mauro; Krüger, Björn; Furlanis, Giovanni; Manganotti, Paolo; Bernardis, Paolo
Action observation plus sonification. A novel therapeutic protocol for Parkinson’s patient with freezing of gait Journal Article
In: Frontiers in Neurology, vol. 8, 2018, ISSN: 1664-2295, (accepted for Publication).
@article{mezzarobba2018a,
title = {Action observation plus sonification. A novel therapeutic protocol for Parkinson’s patient with freezing of gait},
author = {Susanna Mezzarobba and Michele Grassi and Lorella Pellegrini and Mauro Catalan and Björn Krüger and Giovanni Furlanis and Paolo Manganotti and Paolo Bernardis},
url = {https://www.frontiersin.org/article/10.3389/fneur.2017.00723},
doi = {10.3389/fneur.2017.00723},
issn = {1664-2295},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
journal = {Frontiers in Neurology},
volume = {8},
abstract = {Freezing of gait (FoG) is a disabling symptom associated to falls, with little or no responsiveness to pharmacological treatment. Current protocols used for rehabilitation are based on the use of external sensory cues. However, cued strategies might generate an important dependence on the environment. Teaching motor strategies without cues (i.e. action observation - AO - plus sonification) could represent an alternative/innovative approach to rehabilitation that matters most on appropriate allocation of attention and lightening cognitive load. We aimed to test the effects of a novel experimental protocol to treat patients with Parkinson disease (PD) and freezing of gait, using functional, and clinical scales. The experimental protocol was based on action observation plus sonification. 12 patients were treated with 8 motor gestures. They watched 8 videos showing an actor performing the same 8 gestures, and then tried to repeat each gesture. Each video was composed by images and sounds of the gestures. By means of the sonification technique, the sounds of gestures were obtained by transforming kinematic data (velocity) recorded during gesture execution, into pitch variations. The same 8 motor gestures were also used in a second group of 10 patients; which were treated with a standard protocol based on a common sensory stimulation method. All patients were tested with functional and clinical scales before, after, at 1 month, and 3 months after the treatment. Data showed that the experimental protocol have positive effects on functional and clinical tests. In comparison with the baseline evaluations, significant performance improvements were seen in the N-FOG questionnaire, and the UPDRS (part 3 and 2). Importantly, all these improvements were consistently observed at the end, 1 month, and 3 months after treatment. No improvements effects were found in the group of patients treated with the standard protocol. These data suggest that a multisensory approach based on action observation plus sonification, with the two stimuli semantically related, could help PD patients with FoG to re-learn gait movements, to reduce freezing episodes, and that these effects could be prolonged over time.},
note = {accepted for Publication},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Freezing of gait (FoG) is a disabling symptom associated to falls, with little or no responsiveness to pharmacological treatment. Current protocols used for rehabilitation are based on the use of external sensory cues. However, cued strategies might generate an important dependence on the environment. Teaching motor strategies without cues (i.e. action observation - AO - plus sonification) could represent an alternative/innovative approach to rehabilitation that matters most on appropriate allocation of attention and lightening cognitive load. We aimed to test the effects of a novel experimental protocol to treat patients with Parkinson disease (PD) and freezing of gait, using functional, and clinical scales. The experimental protocol was based on action observation plus sonification. 12 patients were treated with 8 motor gestures. They watched 8 videos showing an actor performing the same 8 gestures, and then tried to repeat each gesture. Each video was composed by images and sounds of the gestures. By means of the sonification technique, the sounds of gestures were obtained by transforming kinematic data (velocity) recorded during gesture execution, into pitch variations. The same 8 motor gestures were also used in a second group of 10 patients; which were treated with a standard protocol based on a common sensory stimulation method. All patients were tested with functional and clinical scales before, after, at 1 month, and 3 months after the treatment. Data showed that the experimental protocol have positive effects on functional and clinical tests. In comparison with the baseline evaluations, significant performance improvements were seen in the N-FOG questionnaire, and the UPDRS (part 3 and 2). Importantly, all these improvements were consistently observed at the end, 1 month, and 3 months after treatment. No improvements effects were found in the group of patients treated with the standard protocol. These data suggest that a multisensory approach based on action observation plus sonification, with the two stimuli semantically related, could help PD patients with FoG to re-learn gait movements, to reduce freezing episodes, and that these effects could be prolonged over time.
Iqbal, Umar; Doering, Andreas; Yasin, Hashim; Krüger, Björn; Weber, Andreas; Gall, Juergen
A Dual-Source Approach for 3D Human Pose Estimation from Single Images Journal Article
In: Computer Vision and Image Understanding, vol. 172, pp. 37–49, 2018, ISSN: 1077-3142.
@article{iqbal-2018,
title = {A Dual-Source Approach for 3D Human Pose Estimation from Single Images},
author = {Umar Iqbal and Andreas Doering and Hashim Yasin and Björn Krüger and Andreas Weber and Juergen Gall},
url = {http://www.sciencedirect.com/science/article/pii/S1077314218300511},
doi = {https://doi.org/10.1016/j.cviu.2018.03.007},
issn = {1077-3142},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
journal = {Computer Vision and Image Understanding},
volume = {172},
pages = {37–49},
abstract = {In this work we address the challenging problem of 3D human pose estimation from single images. Recent approaches learn deep neural networks to regress 3D pose directly from images. One major challenge for such methods, however, is the collection of large amounts of training data. Particularly, collecting a large number of unconstrained images that are annotated with accurate 3D poses is impractical. We therefore propose to use two independent training sources. The first source consists of accurate 3D motion capture data, and the second source consists of unconstrained images with annotated 2D poses. To incorporate both sources, we propose a dual-source approach that combines 2D pose estimation with efficient 3D pose retrieval. To this end, we first convert the motion capture data into a normalized 2D pose space, and separately learn a 2D pose estimation model from the image data. During inference, we estimate the 2D pose and efficiently retrieve the nearest 3D poses. We then jointly estimate a mapping from the 3D pose space to the image and reconstruct the 3D pose. We provide a comprehensive evaluation of the proposed method and experimentally demonstrate the effectiveness of our approach, even when the skeleton structures of the two sources differ substantially.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work we address the challenging problem of 3D human pose estimation from single images. Recent approaches learn deep neural networks to regress 3D pose directly from images. One major challenge for such methods, however, is the collection of large amounts of training data. Particularly, collecting a large number of unconstrained images that are annotated with accurate 3D poses is impractical. We therefore propose to use two independent training sources. The first source consists of accurate 3D motion capture data, and the second source consists of unconstrained images with annotated 2D poses. To incorporate both sources, we propose a dual-source approach that combines 2D pose estimation with efficient 3D pose retrieval. To this end, we first convert the motion capture data into a normalized 2D pose space, and separately learn a 2D pose estimation model from the image data. During inference, we estimate the 2D pose and efficiently retrieve the nearest 3D poses. We then jointly estimate a mapping from the 3D pose space to the image and reconstruct the 3D pose. We provide a comprehensive evaluation of the proposed method and experimentally demonstrate the effectiveness of our approach, even when the skeleton structures of the two sources differ substantially.
Zsoldos, Rebeka; Vögele, Anna; Krüger, Björn; Schröder, Ulrike; Weber, Andreas; Licka, Theresia
Long term consistency and locationspecificity of equine gluteus medius muscleactivity during locomotion on the treadmill Journal Article
In: BMC Veterinary Research, vol. 14, no. 126, pp. 1–10, 2018.
@article{Zsoldos2018,
title = {Long term consistency and locationspecificity of equine gluteus medius muscleactivity during locomotion on the treadmill},
author = {Rebeka Zsoldos and Anna Vögele and Björn Krüger and Ulrike Schröder and Andreas Weber and Theresia Licka},
doi = {10.1186/s12917-018-1443-y},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
journal = {BMC Veterinary Research},
volume = {14},
number = {126},
pages = {1–10},
abstract = {Background: The equine m. gluteus medius (GM) is the largest muscle of the horse, its main movement function is the extension of the hip joint. The objective of the present study was to measure equine GM activity in three adjacent locations on GM during walk and trot on a treadmill, in order to document potential differences. Fourteen Haflinger mares were measured using surface electromyography and kinematic markers to identify the motion cycles on three occasions over 16 weeks. The electrodes were placed on left and right gluteus medius muscle over the middle of its widest part and 5 cm lateral and medial of it. For data processing, electrical activity was normalised to its maximum value and timing was normalised to the motion cycle. A Gaussian distribution approach was used to determine up to 10 modes of focussed activity, and results were analysed separately for stance and swing phase of the ipsilateral hindlimb. Results: Fair reliability was found for mean mode values (Cronbach’s alpha = 0.66) and good reliability was found for mean mode locations (Cronbach’s alpha = 0.71) over the three data collection days. The magnitude of muscle activity identified as mean mode value was much larger at trot than at walk, and mean mode value was significantly different between stance phases of walk and trot for all electrode positions (p < 0.01). The pattern of muscle activity identified as mean mode location was significantly different for walk and trot at all electrode positions, both during stance and swing phases (p < 0.001). This indicates the different timing pattern between the gaits. Results of the three electrode positions on the same muscle during each gait were not significantly different when comparing the same measurement. Conclusions: The middle of the equine GM does not show any indication of functional differentiation during walk and trot on a treadmill; this might be due to lack of segmentation as such, or due to lack of need for segmented use for these very basic main tasks of the muscle. The reliability of the sEMG measurements over several weeks was fair to good, an indication for the robustness of the methodology.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Background: The equine m. gluteus medius (GM) is the largest muscle of the horse, its main movement function is the extension of the hip joint. The objective of the present study was to measure equine GM activity in three adjacent locations on GM during walk and trot on a treadmill, in order to document potential differences. Fourteen Haflinger mares were measured using surface electromyography and kinematic markers to identify the motion cycles on three occasions over 16 weeks. The electrodes were placed on left and right gluteus medius muscle over the middle of its widest part and 5 cm lateral and medial of it. For data processing, electrical activity was normalised to its maximum value and timing was normalised to the motion cycle. A Gaussian distribution approach was used to determine up to 10 modes of focussed activity, and results were analysed separately for stance and swing phase of the ipsilateral hindlimb. Results: Fair reliability was found for mean mode values (Cronbach’s alpha = 0.66) and good reliability was found for mean mode locations (Cronbach’s alpha = 0.71) over the three data collection days. The magnitude of muscle activity identified as mean mode value was much larger at trot than at walk, and mean mode value was significantly different between stance phases of walk and trot for all electrode positions (p < 0.01). The pattern of muscle activity identified as mean mode location was significantly different for walk and trot at all electrode positions, both during stance and swing phases (p < 0.001). This indicates the different timing pattern between the gaits. Results of the three electrode positions on the same muscle during each gait were not significantly different when comparing the same measurement. Conclusions: The middle of the equine GM does not show any indication of functional differentiation during walk and trot on a treadmill; this might be due to lack of segmentation as such, or due to lack of need for segmented use for these very basic main tasks of the muscle. The reliability of the sEMG measurements over several weeks was fair to good, an indication for the robustness of the methodology.
Stollenwerk, Katharina; Müllers, Johannes; Müller, Jonas; Hinkenjann, André; Krüger, Björn
Evaluating an Accelerometer-based System for Spine Shape Monitoring Proceedings Article
In: Computational Science and Its Applications – ICCSA 2018, 2018.
@inproceedings{stollenwerk-2018a,
title = {Evaluating an Accelerometer-based System for Spine Shape Monitoring},
author = {Katharina Stollenwerk and Johannes Müllers and Jonas Müller and André Hinkenjann and Björn Krüger},
url = {https://digital-health-bonn.de/wp-content/uploads/2024/03/2018_ICCSA_PostureSensei_Preprint.pdf, Paper},
doi = {10.1007/978-3-319-95171-3_58},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
booktitle = {Computational Science and Its Applications – ICCSA 2018},
abstract = {In western societies a huge percentage of the population suffers from some kind of back pain at least once in their life. There are several approaches addressing back pain by postural modifications. Postural training and activity can be tracked by various wearable devices most of which are based on accelerometers. We present research on the accuracy of accelerometer-based posture measurements. To this end, we took simultaneous recordings using an optical motion capture system and a system consisting of five accelerometers in three different settings: On a test robot, in a template, and on actual human backs. We compare the accelerometer-based spine curve reconstruction against the motion capture data. Results show that tilt values from the accelerometers are captured highly accurate, and the spine curve reconstruction works well.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
In western societies a huge percentage of the population suffers from some kind of back pain at least once in their life. There are several approaches addressing back pain by postural modifications. Postural training and activity can be tracked by various wearable devices most of which are based on accelerometers. We present research on the accuracy of accelerometer-based posture measurements. To this end, we took simultaneous recordings using an optical motion capture system and a system consisting of five accelerometers in three different settings: On a test robot, in a template, and on actual human backs. We compare the accelerometer-based spine curve reconstruction against the motion capture data. Results show that tilt values from the accelerometers are captured highly accurate, and the spine curve reconstruction works well.
Müllers, Johannes; Marciniewski, Pawel; Poller, Timo; Schmidt, Christoph; Schultes, Jan; Thoma, Ulrike
Adaption of an FPGA-based Sampling-ADC for the Crystal Barrel Calorimeter Proceedings Article
In: Proceedings of Science, pp. 052, 2018.
@inproceedings{inproceedings,
title = {Adaption of an FPGA-based Sampling-ADC for the Crystal Barrel Calorimeter},
author = {Johannes Müllers and Pawel Marciniewski and Timo Poller and Christoph Schmidt and Jan Schultes and Ulrike Thoma},
doi = {10.22323/1.313.0052},
year = {2018},
date = {2018-01-01},
urldate = {2018-01-01},
booktitle = {Proceedings of Science},
volume = {313},
pages = {052},
series = {Topical Workshop on Electronics for Particle Physics (TWEPP-17)},
abstract = {The digitization stage of the main electromagnetic calorimeter of the CBELSA/TAPS experiment in Bonn (Germany) is being equipped with 80MS/s, 14 bit sampling-ADCs (SADCs), which were adapted from a prototype for the PANDA experiment. Onboard data processing with FPGAs allows determination of the signal characteristics, reducing the data volume substantially. The optional readout of the unprocessed sampled waveforms allows offline analysis and refinement of the FPGA algorithms.
A partial setup has shown promising results during a photoproduction-beamtime. It has been demonstrated that the readout-rate limitation of the current QDC readout can be overcome. The full setup is planned to be commissioned within the next year.
This paper will present an overview of the SADC project. After an introduction of the CBELSA/TAPS experiment, the new SADC readout will be motivated, followed by its technical specifications and the setup in the experiment. An outline of the firmware and findings from first tests conclude the paper.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
The digitization stage of the main electromagnetic calorimeter of the CBELSA/TAPS experiment in Bonn (Germany) is being equipped with 80MS/s, 14 bit sampling-ADCs (SADCs), which were adapted from a prototype for the PANDA experiment. Onboard data processing with FPGAs allows determination of the signal characteristics, reducing the data volume substantially. The optional readout of the unprocessed sampled waveforms allows offline analysis and refinement of the FPGA algorithms.
A partial setup has shown promising results during a photoproduction-beamtime. It has been demonstrated that the readout-rate limitation of the current QDC readout can be overcome. The full setup is planned to be commissioned within the next year.
This paper will present an overview of the SADC project. After an introduction of the CBELSA/TAPS experiment, the new SADC readout will be motivated, followed by its technical specifications and the setup in the experiment. An outline of the firmware and findings from first tests conclude the paper.
A partial setup has shown promising results during a photoproduction-beamtime. It has been demonstrated that the readout-rate limitation of the current QDC readout can be overcome. The full setup is planned to be commissioned within the next year.
This paper will present an overview of the SADC project. After an introduction of the CBELSA/TAPS experiment, the new SADC readout will be motivated, followed by its technical specifications and the setup in the experiment. An outline of the firmware and findings from first tests conclude the paper.