@inproceedings{PereiraPereiradaSilvaetal., author = {Pereira, Clayton R. and Pereira, Danilo R. and da Silva, Francisco A. and Hook, Christian and Weber, Silke A. T. and Pereira, Luis A. M. and Papa, Jo{\~a}o Paulo}, title = {A Step Towards the Automated Diagnosis of Parkinson's Disease: Analyzing Handwriting Movements}, series = {2015 IEEE 28th International Symposium on Computer-Based Medical Systems, 22.-25.06.2015, Sao Carlos, Brazil}, booktitle = {2015 IEEE 28th International Symposium on Computer-Based Medical Systems, 22.-25.06.2015, Sao Carlos, Brazil}, publisher = {IEEE}, isbn = {978-1-4673-6775-2}, issn = {2372-9198}, doi = {10.1109/cbms.2015.34}, pages = {171 -- 176}, abstract = {Parkinson's disease (PD) has affected millions of people world-wide, being its major problem the loss of movements and, consequently, the ability of working and locomotion. Although we can find several works that attempt at dealing with this problem out there, most of them make use of datasets composed by a few subjects only. In this work, we present some results toward the automated diagnosis of PD by means of computer vision-based techniques in a dataset composed by dozens of patients, which is one of the main contributions of this work. The dataset is part of a joint research project that aims at extracting both visual and signal-based information from healthy and PD patients in order to go forward the early diagnosis of PD patients. The dataset is composed by handwriting clinical exams that are analyzed by means of image processing and machine learning techniques, being the preliminary results encouraging and promising. Additionally, a new quantitative feature to measure the amount of tremor of an individual's handwritten trace called Mean Relative Tremor is also presented.}, language = {en} } @article{VoellnerWeberWeberetal., author = {V{\"o}llner, Florian and Weber, Tim A. and Weber, Markus and Renkawitz, Tobias and Dendorfer, Sebastian and Grifka, Joachim and Craiovan, Benjamin}, title = {A simple method for determining ligament stiffness during total knee arthroplasty in vivo}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, publisher = {Nature}, doi = {10.1038/s41598-019-41732-x}, pages = {1 -- 8}, abstract = {A key requirement in both native knee joints and total knee arthroplasty is a stable capsular ligament complex. However, knee stability is highly individual and ranges from clinically loose to tight. So far, hardly any in vivo data on the intrinsic mechanical of the knee are available. This study investigated if stiffness of the native ligament complex may be determined in vivo using a standard knee balancer. Measurements were obtained with a commercially available knee balancer, which was initially calibrated in vitro. 5 patients underwent reconstruction of the force-displacement curves of the ligament complex. Stiffness of the medial and lateral compartments were calculated to measure the stability of the capsular ligament complex. All force-displacement curves consisted of a non-linear section at the beginning and of a linear section from about 80 N onwards. The medial compartment showed values of 28.4 ± 1.2 N/mm for minimum stiffness and of 39.9 ± 1.1 N/mm for maximum stiffness; the respective values for the lateral compartment were 19.9 ± 0.9 N/mm and 46.6 ± 0.8 N/mm. A commercially available knee balancer may be calibrated for measuring stiffness of knee ligament complex in vivo, which may contribute to a better understanding of the intrinsic mechanical behaviour of knee joints.}, subject = {Biomechanische Analyse}, language = {en} } @article{RenkawitzWeberDullienetal., author = {Renkawitz, Tobias and Weber, Tim A. and Dullien, Silvia and Woerner, Michael and Dendorfer, Sebastian and Grifka, Joachim and Weber, Markus}, title = {Leg length and offset differences above 5 mm after total hip arthroplasty are associated with altered gait kinematics}, series = {Gait \& Posture}, volume = {vol. 49}, journal = {Gait \& Posture}, doi = {10.1016/j.gaitpost.2016.07.011}, pages = {196 -- 201}, abstract = {We aimed to investigate the relationship between postoperative leg length/offset (LL/OS) reconstruction and gait performance after total hip arthroplasty (THA). In the course of a prospective randomized controlled trial, 60 patients with unilateral hip arthrosis received cementless THA through a minimally-invasive anterolateral surgical approach. One year post-operatively, LL and global OS restoration were analyzed and compared to the contralateral hip on AP pelvic radiographs. The combined postoperative limb length/OS reconstruction of the operated hip was categorized as restored (within 5 mm) or non-restored (more than 5 mm reduction or more than 5 mm increment). The acetabular component inclination, anteversion and femoral component anteversion were evaluated using CT scans of the pelvis and the femur. 3D gait analysis of the lower extremity and patient related outcome measures (HHS, HOOS, EQ-5D) were obtained pre-operatively, six months and twelve months post-operatively by an observer blinded to radiographic results. Component position of cup and stem was comparable between the restored and non-restored group. Combined LL and OS restoration within 5 mm resulted in higher Froude number (p < 0.001), normalized walking speed (p < 0.001) and hip range-of-motion (ROM) (p = 0.004) during gait twelve months postoperatively, whereas gait symmetry was comparable regardless of LL and OS reconstruction at both examinations. Clinical scores did not show any relevant association between the accuracy of LL or OS reconstruction and gait six/twelve months after THA. In summary, postoperative LL/OS discrepancies larger than 5 mm relate to unphysiological gait kinematics within the first year after THA. DRKS00000739, German Clinical Trials Register.}, language = {en} } @article{WeberWeberWoerneretal., author = {Weber, Markus and Weber, Tim A. and Woerner, Michael and Craiovan, Benjamin and Worlicek, Michael and Winkler, Sebastian and Grifka, Joachim and Renkawitz, Tobias}, title = {The impact of standard combined anteversion definitions on gait and clinical outcome within one year after total hip arthroplasty}, series = {International Orthopaedics}, volume = {39}, journal = {International Orthopaedics}, number = {12}, doi = {10.1007/s00264-015-2777-8}, pages = {2323 -- 2333}, abstract = {Different target areas within the concept of combined cup and stem anteversion have been published for total hip arthroplasty (THA). We asked whether component positioning according to eight standard combined anteversion rules is associated with (1) more physiological gait patterns, (2) higher improvement of gait variables and (3) better clinical outcome after THA.In a prospective clinical study, 60 patients received cementless THA through an anterolateral MIS approach in a lateral decubitus position. Six weeks postoperatively, implant position was analysed using 3D-CT by an independent external institute. Preoperatively, six and 12 months postoperatively range of motion, normalized walking speed and hip flexion symmetry index were measured using 3D motion-capture gait analysis. Patient-related outcome measures (HHS, HOOS, EQ-5D) were obtained by an observer blinded to 3D-CT results. Eight combined anteversion definitions and Lewinnek's "safe zone" were evaluated regarding their impact on gait patterns and clinical outcome.Combined cup and stem anteversion according to standard combined anteversion definitions as well as cup placement within Lewinnek's "safe zone" did not influence range of motion, normalized walking speed and/or hip flexion symmetry index six and 12 months after THA. Similarly, increase of gait parameters within the first year after THA was comparable between all eight combined anteversion rules. Clinical outcome measures like HHS, HOOS and EQ-5D did not show any benefit for either of the combined anteversion definitions.Standard combined cup and stem anteversion rules do not improve postoperative outcome as measured by gait analysis and clinical scores within one year after THA.}, subject = {H{\"u}ftgelenkprothese}, language = {en} } @misc{ScharfenbergMottokArtmannetal., author = {Scharfenberg, Georg and Mottok, J{\"u}rgen and Artmann, Christina and Hobelsberger, Martin and Paric, Ivan and Großmann, Benjamin and Pohlt, Clemens and Wackerbarth, Alena and Pausch, Uli and Heidrich, Christiane and Fadanelli, Martin and Elsner, Michael and P{\"o}cher, Daniel and Pittroff, Lenz and Beer, Stefan and Br{\"u}ckl, Oliver and Haslbeck, Matthias and Sterner, Michael and Thema, Martin and Muggenthaler, Nicole and Lenck, Thorsten and G{\"o}tz, Philipp and Eckert, Fabian and Deubzer, Michael and Stingl, Armin and Simsek, Erol and Kr{\"a}mer, Stefan and Großmann, Benjamin and Schlegl, Thomas and Niedersteiner, Sascha and Berlehner, Thomas and Joblin, Mitchell and Mauerer, Wolfgang and Apel, Sven and Siegmund, Janet and Riehle, Dirk and Weber, Joachim and Palm, Christoph and Zobel, Martin and Al-Falouji, Ghassan and Prestel, Dietmar and Scharfenberg, Georg and Mandl, Roland and Deinzer, Arnulf and Halang, W. and Margraf-Stiksrud, Jutta and Sick, Bernhard and Deinzer, Renate and Scherzinger, Stefanie and Klettke, Meike and St{\"o}rl, Uta and Wiech, Katharina and Kubata, Christoph and Sindersberger, Dirk and Monkman, Gareth J. and Dollinger, Markus and Dembianny, Sven and K{\"o}lbl, Andreas and Welker, Franz and Meier, Matthias and Thumann, Philipp and Swidergal, Krzysztof and Wagner, Marcus and Haug, Sonja and Vernim, Matthias and Seidenst{\"u}cker, Barbara and Weber, Karsten and Arsan, Christian and Schone, Reinhold and M{\"u}nder, Johannes and Schroll-Decker, Irmgard and Dillinger, Andrea Elisabeth and Fuchshofer, Rudolf and Monkman, Gareth J. and Shamonin (Chamonine), Mikhail and Geith, Markus A. and Koch, Fabian and {\"U}hlin, Christian and Schratzenstaller, Thomas and Saßmannshausen, Sean Patrick and Auchter, Eberhard and Kriz, Willy and Springer, Othmar and Thumann, Maria and Kusterle, Wolfgang and Obermeier, Andreas and Udalzow, Anton and Schmailzl, Anton and Hierl, Stefan and Langer, Christoph and Schreiner, Rupert}, title = {Forschungsbericht 2015}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, isbn = {978-3-00-048589-3}, doi = {10.35096/othr/pub-1386}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-13867}, language = {de} } @incollection{PereiraPassosLopesetal., author = {Pereira, Clayton R. and Passos, Leandro A. and Lopes, Ricardo R. and Weber, Silke A. T. and Hook, Christian and Papa, Joao Paulo}, title = {Parkinson's Disease Identification Using Restricted Boltzmann Machines}, series = {Computer Analysis of Images and Patterns, 17th International Conference, CAIP 2017, Ystad, Sweden, August 22-24, 2017, Proceedings, Part II}, volume = {10425}, booktitle = {Computer Analysis of Images and Patterns, 17th International Conference, CAIP 2017, Ystad, Sweden, August 22-24, 2017, Proceedings, Part II}, publisher = {Springer}, isbn = {978-3-319-64697-8}, doi = {10.1007/978-3-319-64698-5_7}, pages = {70 -- 80}, abstract = {Currently, Parkinson's Disease (PD) has no cure or accurate diagnosis, reaching approximately 60, 000 new cases yearly and worldwide, being more often in the elderly population. Its main symptoms can not be easily uncorrelated with other illness, being way more difficult to be identified at the early stages. As such, computer-aided tools have been recently used to assist in this task, but the challenge in the automatic identification of Parkinson's Disease still persists. In order to cope with this problem, we propose to employ Restricted Boltzmann Machines (RBMs) to learn features in an unsupervised fashion by analyzing images from handwriting exams, which aim at assessing the writing skills of potential individuals. These are one of the main symptoms of PD-prone people, since such kind of ability ends up being severely affected. We show that RBMs can learn proper features that help supervised classifiers in the task of automatic identification of PD patients, as well as one can obtain a more compact representation of the exam for the sake of storage and computational load purposes.}, language = {en} } @article{PereiraPereiraSilvaetal., author = {Pereira, Clayton R. and Pereira, Danilo R. and Silva, Francisco A. and Masieiro, Joao P. and Weber, Silke A. T. and Hook, Christian and Papa, Jo{\~a}o Paulo}, title = {A new computer vision-based approach to aid the diagnosis of Parkinson's disease}, series = {Computer Methods and Programs in Biomedicine}, volume = {136}, journal = {Computer Methods and Programs in Biomedicine}, publisher = {Elsevier}, doi = {10.1016/j.cmpb.2016.08.005}, pages = {79 -- 88}, abstract = {Background and Objective: Even today, pointing out an exam that can diagnose a patient with Parkinson's disease (PD) accurately enough is not an easy task. Although a number of techniques have been used in search for a more precise method, detecting such illness and measuring its level of severity early enough to postpone its side effects are not straightforward. In this work, after reviewing a considerable number of works, we conclude that only a few techniques address the problem of PD recognition by means of micrography using computer vision techniques. Therefore, we consider the problem of aiding automatic PD diagnosis by means of spirals and meanders filled out in forms, which are then compared with the template for feature extraction. Methods: In our work, both the template and the drawings are identified and separated automatically using image processing techniques, thus needing no user intervention. Since we have no registered images, the idea is to obtain a suitable representation of both template and drawings using the very same approach for all images in a fast and accurate approach. Results: The results have shown that we can obtain very reasonable recognition rates (around approximate to 67\%), with the most accurate class being the one represented by the patients, which outnumbered the control individuals in the proposed dataset. Conclusions: The proposed approach seemed to be suitable for aiding in automatic PD diagnosis by means of computer vision and machine learning techniques. Also, meander images play an important role, leading to higher accuracies than spiral images. We also observed that the main problem in detecting PD is the patients in the early stages, who can draw near-perfect objects, which are very similar to the ones made by control patients. (C) 2016 Elsevier Ireland Ltd. All rights reserved.}, language = {en} } @article{HoelscherWeberLazarevetal., author = {H{\"o}lscher, Thomas and Weber, Tim A. and Lazarev, Igor A. and Englert, Carsten and Dendorfer, Sebastian}, title = {The influence of rotator cuff tears on glenohumeral stability during abduction tasks}, series = {Journal of Orthopaedic Research}, volume = {34}, journal = {Journal of Orthopaedic Research}, number = {9}, doi = {10.1002/jor.23161}, pages = {1628 -- 1635}, abstract = {One of the main goals in reconstructing rotator cuff tears is the restoration of glenohumeral joint stability, which is subsequently of utmost importance in order to prevent degenerative damage such as superior labral anterior posterior (SLAP) lesion, arthrosis, and malfunction. The goal of the current study was to facilitate musculoskeletal models in order to estimate glenohumeral instability introduced by muscle weakness due to cuff lesions. Inverse dynamics simulations were used to compute joint reaction forces for several static abduction tasks with different muscle weakness. Results were compared with the existing literature in order to ensure the model validity. Further arm positions taken from activities of daily living, requiring the rotator cuff muscles were modeled and their contribution to joint kinetics computed. Weakness of the superior rotator cuff muscles (supraspinatus; infraspinatus) leads to a deviation of the joint reaction force to the cranial dorsal rim of the glenoid. Massive rotator cuff defects showed higher potential for glenohumeral instability in contrast to single muscle ruptures. The teres minor muscle seems to substitute lost joint torque during several simulated muscle tears to maintain joint stability. Joint instability increases with cuff tear size. Weakness of the upper part of the rotator cuff leads to a joint reaction force closer to the upper glenoid rim. This indicates the comorbidity of cuff tears with SLAP lesions. The teres minor is crucial for maintaining joint stability in case of massive cuff defects and should be uprated in clinical decision-making.}, subject = {Rotatorenmanschettenriss}, language = {en} } @article{WeberDendorferBulstraetal., author = {Weber, Tim A. and Dendorfer, Sebastian and Bulstra, Sjoerd K. and Grifka, Joachim and Verkerke, Gijsbertus Jacob and Renkawitz, Tobias}, title = {Gait six month and one-year after computer assisted Femur First THR vs. conventional THR. Results of a patient- and observer- blinded randomized controlled trial}, series = {Gait \& Posture}, volume = {vol. 49}, journal = {Gait \& Posture}, doi = {10.1016/j.gaitpost.2016.06.035}, pages = {418 -- 425}, abstract = {A prospective randomized controlled trial is presented that is used to compare gait performance between the computer assisted Femur First (CAS FF) operation method and conventional THR (CON). 60 patients underwent a 3D gait analysis of the lower extremity at pre-operative, 6 months post-operative and twelve months post-operative. Detailed verification experiments were facilitated to ensure the quality of data as well as to avoid over-interpreting of the data. The results confirm a similar data-quality as reported in the literature. Walking speed, range of motion and symmetry thereof improved over the follow-up period, without significant differences between the groups. While all parameters do significantly increase over the follow-up period for both groups, there were no significant differences between them at any given time-point. Patients undergoing CAS FF showed a trend to improved hip flexion angle indicating a possible long-term benefit.}, language = {en} } @article{WeberDendorferGrifkaetal., author = {Weber, Tim A. and Dendorfer, Sebastian and Grifka, Joachim and Verkerke, Gijsbertus Jacob and Renkawitz, Tobias}, title = {Does Computer-Assisted Femur First THR Improve Musculoskeletal Loading Conditions?}, series = {BioMed Research International}, volume = {2015}, journal = {BioMed Research International}, editor = {Takagi, Michiaki}, doi = {10.1155/2015/625317}, pages = {ID 625317}, abstract = {We have developed a novel, computer-assisted operation method for minimal-invasive total hip replacement (THR) following the concept of "femur first/combined anteversion," which incorporates various aspects of performing a functional optimization of the prosthetic stem and cup position (CAS FF). The purpose of this study is to assess whether the hip joint reaction forces and patient's gait parameters are being improved by CAS FF in relation to conventional THR (CON). We enrolled 60 patients (28 CAS FF/32 CON) and invited them for gait analysis at three time points (preoperatively, postop six months, and postop 12 months). Data retrieved from gait analysis was processed using patient-specific musculoskeletal models. The target parameters were hip reaction force magnitude (hrf), symmetries, and orientation with respect to the cup. Hrf in the CAS FF group were closer to a young healthy normal. Phase-shift symmetry showed an increase in the CAS FF group. Hrf orientation in the CAS FF group was closer to optimum, though no edge or rim-loading occurred in the CON group as well. The CAS FF group showed an improved hrf orientation in an early stage and a trend to an improved long-term outcome.}, subject = {H{\"u}ftgelenkprothese}, language = {en} } @inproceedings{WeberDendorferDullienetal., author = {Weber, Tim A. and Dendorfer, Sebastian and Dullien, Silvia and Grifka, Joachim and Verkerke, Gijsbertus Jacob and Renkawitz, Tobias}, title = {Measuring functional outcome after total hip replacement with subject-specific hip joint loading}, series = {Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine}, volume = {226}, booktitle = {Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine}, number = {12}, doi = {10.1177/0954411912447728}, pages = {939 -- 946}, abstract = {Total hip replacement is an often-performed orthopedic surgical procedure; the amount of procedures undertaken will increase since our life expectancy is growing. In order to optimize function, hip biomechanics should be restored to as near normal as possible. The goal of this pilot study was to determine whether or not it is feasible to compute the vectorial hip reaction force pathways on the head of the prosthesis and the force angles relative to the cup of the prosthesis that occur during gait in total hip replacement patients, serving as an objective measurement of the functional outcome following hip replacement. A three-dimensional gait analysis, measuring ground reaction forces and kinematics, was performed. The data retrieved from the gait analysis was used as the input for the musculoskeletal model to compute vectorial joint reaction forces for data processing. To evaluate the position and orientation of the joint reaction forces, the force path, as well as the force angles for the operated and non-operated joint, has been calculated during the stance phase of the specific leg. The force path for subject 2 on the non-operated side is only located in the posterior-lateral quarter, as is the force path for subject 1. In contrast to this subject, the force path for subject 2 at the operated hip joint can be found only within the anterior quarter of the head of the implant, where it is nearly equally distributed in the medio-lateral half of the prosthesis head. The force-inclination angles on the cup of subject 1, with respect to the plane of the socket face, indicates that the force vector is mainly positioned in the same quadrant when compared with subject 2 (in a cup-fixed coordinate system). The force-anteversion angle behaves similarly to the force-inclination angle, even when the effects are not as pronounced. The proposed methods in this article are aiming to define two functional outcomes of total hip replacement that are related to wear and rim loading. It is accepted that wear is not only a function of time, but a function of use. Owing to the methods listed in this article, we are able to determine a) the applied force and b) the sliding distance (force pathway) in a subject-specific manner. The computed hip-reaction force angles and the distance to the rim cup are a measurement for cup or rim loading, and occurs in the so-called safe-zones. This method may well give us insight into the biomechanical situation during gait, after receiving total hip replacement, that we need to fully understand the mechanisms acting on a hip joint and to prove a possible increase of functional outcome after receiving total hip replacement.}, subject = {H{\"u}ftgelenkprothese}, language = {en} } @inproceedings{BillingGoetzWeberetal., author = {Billing, A. and G{\"o}tz, J. and Weber, Tim and Dendorfer, Sebastian}, title = {Positionsanalyse von winkelstabilen Plattenosteosynthesesystemen zur Versorgung von Metatarsalfrakturen mit Hilfe von patientenspezifischen biomechanischen Modellen}, series = {Vereinigung S{\"u}ddeutscher Orthop{\"a}den und Unfallchirurgen Jahrestagung 2015, Baden-Baden, Germany}, booktitle = {Vereinigung S{\"u}ddeutscher Orthop{\"a}den und Unfallchirurgen Jahrestagung 2015, Baden-Baden, Germany}, language = {de} } @incollection{RolfesBittnerSonaretal., author = {Rolfes, Vasilija and Bittner, Uta and Sonar, A. and Weber, Karsten}, title = {Stigmatisierung {\"u}bergewichtiger und adip{\"o}ser Patient*innen in der digitalisierten Medizin}, series = {Menschenrechte im Gesundheitswesen. Vom Krankenhaus zur Landesebene}, booktitle = {Menschenrechte im Gesundheitswesen. Vom Krankenhaus zur Landesebene}, editor = {Hack, L. and Bergemann, Lutz and Bielefeldt, H. and Frewer, Andreas}, publisher = {K{\"o}nigshausen \& Neumann}, address = {W{\"u}rzburg}, isbn = {978-3-8260-6902-4}, pages = {121 -- 143}, language = {de} } @article{KrugScharfWeberetal., author = {Krug, Henriette and Scharf, Anna and Weber, Karsten and K{\"u}hn, Andrea A. and Krause, Patricia and Haug, Sonja}, title = {Herzschrittmacher, Organ oder Gehstock? Vorher-Nachher-Befragung zur subjektiven Wahrnehmung eines Ger{\"a}tes zur Tiefen Hirnstimulation}, series = {Fortschritte der Neurologie-Psychiatrie}, journal = {Fortschritte der Neurologie-Psychiatrie}, publisher = {Thieme}, doi = {10.1055/a-2202-9772}, abstract = {AIM OF THE STUDY This study was conducted in a pre-post design with a survey of patients who had undergone deep brain stimulation (DBS) as treatment for a neurological movement disorder. The aim of the study was to compare patients' expectations and beliefs before a DBS intervention with patients' subjective experience of this intervention. METHODOLOGY The longitudinal study of patients (n=132) with an indication for DBS therapy was based on a written survey at the time points of preoperative screening (pre-op) and one-year follow-up (post-op). RESULTS Preoperatively, a clear majority of respondents believed DSB to be similar to a pacemaker intervention, but one year after the intervention less than one third did so, as they compared DBS to using a walking stick or glasses. CONCLUSION The experience of DBS in the patient's own body seems to be comparable by means of individually different associations, whereby the comparison with non-invasive aids predominates postoperatively. The discussion of these descriptions in the educational interview can contribute to a realistic horizon of patients' expectations before DBS. ZIEL DER STUDIE Es wird eine Studie im Pr{\"a}-Post-Design mit einer Befragung von Patient*innen vorgestellt, bei denen zur Therapie einer neurologischen Bewegungsst{\"o}rung die Indikation f{\"u}r eine Tiefe Hirnstimulation (THS) gegeben war. Die Patient*innen wurden vor und nach der THS-Operation zu ihren pr{\"a}operativen Assoziationen bzw. postoperativen Wahrnehmungen im Umgang mit einem Hirnschrittmacher befragt. Ziel der Untersuchung ist, die bisherige Praxis der {\"a}rztlichen Aufkl{\"a}rung vor einer THS-Intervention um Angaben zur subjektiven Erlebnisqualit{\"a}t dieser Intervention erg{\"a}nzen zu k{\"o}nnen. METHODIK Es wurde eine L{\"a}ngsschnittstudie mit Patient*innen (n=132) durchgef{\"u}hrt, in der die Teilnehmenden zweizeitig schriftlich zu Imaginationen zu ihrer subjektiven Erlebnisqualit{\"a}t von THS befragt wurden. Die Untersuchungen erfolgten beim pr{\"a}operativen Screening (Pr{\"a}-OP) sowie beim Ein-Jahres-Follow-Up (Post-OP). ERGEBNISSE Pr{\"a}operativ gab die Mehrheit der Befragten die Assoziation Herzschrittmacher an. Postoperativ w{\"a}hlten nur weniger als ein Drittel diese Option, gleich h{\"a}ufig wie die Assoziationen Gehstock oder Brille. SCHLUSSFOLGERUNG Die Erlebnisqualit{\"a}t von THS im eigenen K{\"o}rper scheint sich mittels individuell verschiedener Assoziationen vergleichen zu lassen, wobei postoperativ der Vergleich mit nicht invasiven Hilfsmitteln {\"u}berwiegt. Im Aufkl{\"a}rungsgespr{\"a}ch kann die Thematisierung dieser Beschreibungen bei den Patient*innen zu einem realit{\"a}tsnahen Erwartungshorizont vor THS beitragen.}, language = {de} } @article{SonarWeber, author = {Sonar, A. and Weber, Karsten}, title = {Ein Vergleich von Implementierungsdebatten als Evaluierungsbasis von Stakeholderperspektiven auf KI-gest{\"u}tzte Diagnostik}, series = {Gesundheitswesen}, volume = {81}, journal = {Gesundheitswesen}, number = {8/9}, publisher = {Thieme}, doi = {10.1055/s-0039-1694541}, pages = {723 -- 724}, abstract = {Einleitung: Die ubiquit{\"a}re Durchdringung mit digitaltechnischen Applikationen und den damit einhergehenden Einfl{\"u}ssen auf organisationale Strukturen, f{\"u}hrt insbesondere im hochsensiblen medizinischen Anwendungsbereich zur Notwendigkeit, einer aktiven Implementierungsgestaltung. Das zwischen den omnipr{\"a}senten Schlagw{\"o}rtern Big Data (Analytics), Smart Technologies, Internet of Things oder K{\"u}nstliche Intelligenz (KI) bestehende und f{\"u}r etwaige Implementierungsabw{\"a}gungen bedeutsame korrelative Verh{\"a}ltnis, ist dabei nicht immer offensichtlich: Viele konzeptionelle {\"U}berlegungen aus fr{\"u}heren Ans{\"a}tzen der KI manifestieren sich in den verschiedenen Digitalisierungstrends und Entwicklungstendenzen. Methode: Die intensive theoretische Auseinandersetzung mit Entwicklungslinien und inhaltlicher Reflektion von begleitenden Diskursen, kann im Rahmen der Auseinandersetzung mit KI-basierten Anwendungen und den An- wie auch Herausforderungen an deren Implementierung einen Weg er{\"o}ffnen, ethische und soziale Aspekte heutiger KI-Entwicklungen (im Vortrag am Beispiel der KI-Nutzung in der medizinischen Diagnostik) zumindest teilweise daraus abzuleiten, besser zu verstehen und gegebenenfalls um neue Faktoren zu erg{\"a}nzen. Ergebnisse: Die Gegen{\"u}berstellung fr{\"u}herer und heutiger KI-Debatten leistet dabei einen grundlegenden Beitrag zur Identifikation relevanter Wertebereiche, sowie zur Entwicklung erster vorl{\"a}ufiger Empfehlungen f{\"u}r die Gestaltung und den Einsatz von KI-Systemen in der Praxis und derart deren konstruktive Einbettung in existierende Organisationsstrukturen. Diskussion: Neben der Identifikation potentieller Stakeholder und m{\"o}glicher Interessenslagen, er{\"o}ffnet ein derart empirisch orientierter Zugang erste Einblicke in die, f{\"u}r die Hervorbringung und Implementierung medizintechnischer Applikationen notwendige normative Landschaft. Um hieraus jedoch, wie im Projekt „KI \& Ethik" angedacht, eine tentative ethische Leitlinien als Rahmengef{\"u}ge des Einsatzes einer medizintechnischen Anwendung abzuleiten, gilt es ein solches Fundament um jeweilige, aus Stakeholder-Interviews gewonnene Perspektiven auf etwaige An- und Herausforderungen an eine Implementierung, aber auch hinsichtlich deren Nutzungserwartungen zu erweitern.}, language = {de} } @article{PereiraPereiraRosaetal., author = {Pereira, Clayton R. and Pereira, Danilo R. and Rosa, Gustavo H. and Albuquerque, Victor Hugo C. and Weber, Silke A. T. and Hook, Christian and Papa, Jo{\~a}o Paulo}, title = {Handwritten dynamics assessment through convolutional neural networks}, series = {Artificial Intelligence in Medicine}, volume = {37}, journal = {Artificial Intelligence in Medicine}, number = {May}, publisher = {Elsevier}, doi = {10.1016/j.artmed.2018.04.001}, pages = {67 -- 77}, abstract = {Background and objective Parkinson's disease (PD) is considered a degenerative disorder that affects the motor system, which may cause tremors, micrography, and the freezing of gait. Although PD is related to the lack of dopamine, the triggering process of its development is not fully understood yet. Methods In this work, we introduce convolutional neural networks to learn features from images produced by handwritten dynamics, which capture different information during the individual's assessment. Additionally, we make available a dataset composed of images and signal-based data to foster the research related to computer-aided PD diagnosis. Results The proposed approach was compared against raw data and texture-based descriptors, showing suitable results, mainly in the context of early stage detection, with results nearly to 95\%. Conclusions The analysis of handwritten dynamics using deep learning techniques showed to be useful for automatic Parkinson's disease identification, as well as it can outperform handcrafted features.}, language = {en} } @article{AfonsoRosaPereiraetal., author = {Afonso, Luis Claudio Sugi and Rosa, Gustavo H. and Pereira, Clayton R. and Weber, Silke A. T. and Hook, Christian and Albuquerque, Victor Hugo C. and Papa, Joao Paulo}, title = {A recurrence plot-based approach for Parkinson's disease identification}, series = {Future generation computer systems - The international journal of escience}, volume = {94}, journal = {Future generation computer systems - The international journal of escience}, number = {May}, publisher = {Elsevier}, doi = {10.1016/j.future.2018.11.054}, pages = {282 -- 292}, abstract = {Parkinson's disease (PD) is a neurodegenerative disease that affects millions of people worldwide, causing mental and mainly motor dysfunctions. The negative impact on the patient's daily routine has moved the science in search of new techniques that can reduce its negative effects and also identify the disease in individuals. One of the main motor characteristics of PD is the hand tremor faced by patients, which turns out to be a crucial information to be used towards a computer-aided diagnosis. In this context, we make use of handwriting dynamics data acquired from individuals when submitted to some tasks that measure abilities related to writing skills. This work proposes the application of recurrence plots to map the signals onto the image domain, which are further used to feed a Convolutional Neural Network for learning proper information that can help the automatic identification of PD. The proposed approach was assessed in a public dataset under several scenarios that comprise different combinations of deep-based architectures, image resolutions, and training set sizes. Experimental results showed significant accuracy improvement compared to our previous work with an average accuracy of over 87\%. Moreover, it was observed an improvement in accuracy concerning the classification of patients (i.e., mean recognition rates above to 90\%). The promising results showed the potential of the proposed approach towards the automatic identification of Parkinson's disease.}, language = {en} } @article{PereiraPereiraWeberetal., author = {Pereira, Clayton R. and Pereira, Danilo R. and Weber, Silke A. T. and Hook, Christian}, title = {A survey on computer-assisted Parkinson's Disease diagnosis}, series = {Artificial intelligence in medicine}, volume = {95}, journal = {Artificial intelligence in medicine}, number = {April}, publisher = {Elsevier}, doi = {10.1016/j.artmed.2018.08.007}, pages = {48 -- 63}, abstract = {Background and objective: In this work, we present a systematic review concerning the recent enabling technologies as a tool to the diagnosis, treatment and better quality of life of patients diagnosed with Parkinson's Disease (PD), as well as an analysis of future trends on new approaches to this end. Methods: In this review, we compile a number of works published at some well-established databases, such as Science Direct, IEEEXplore, PubMed, Plos One, Multidisciplinary Digital Publishing Institute (MDPI), Association for Computing Machinery (ACM), Springer and Hindawi Publishing Corporation. Each selected work has been carefully analyzed in order to identify its objective, methodology and results. Results: The review showed the majority of works make use of signal-based data, which are often acquired by means of sensors. Also, we have observed the increasing number of works that employ virtual reality and e-health monitoring systems to increase the life quality of PD patients. Despite the different approaches found in the literature, almost all of them make use of some sort of machine learning mechanism to aid the automatic PD diagnosis. Conclusions: The main focus of this survey is to consider computer-assisted diagnosis, and how effective they can be when handling the problem of PD identification. Also, the main contribution of this review is to consider very recent works only, mainly from 2015 and 2016.}, language = {en} } @article{AfonsoPereiraWeberetal., author = {Afonso, Luis Claudio Sugi and Pereira, Clayton R. and Weber, Silke A. T. and Hook, Christian and Falc{\~a}o, Alexandre X. and Papa, Joao Paulo}, title = {Hierarchical learning using deep optimum-path forest}, series = {Journal of Visual Communication and Image Representation}, volume = {71}, journal = {Journal of Visual Communication and Image Representation}, number = {August}, publisher = {Elsevier}, doi = {10.1016/j.jvcir.2020.102823}, abstract = {Bag-of-Visual Words (BoVW) and deep learning techniques have been widely used in several domains, which include computer-assisted medical diagnoses. In this work, we are interested in developing tools for the automatic identification of Parkinson's disease using machine learning and the concept of BoVW. The proposed approach concerns a hierarchical-based learning technique to design visual dictionaries through the Deep Optimum-Path Forest classifier. The proposed method was evaluated in six datasets derived from data collected from individuals when performing handwriting exams. Experimental results showed the potential of the technique, with robust achievements.}, language = {en} } @article{ErbWeinmannAhlborgetal., author = {Erb, Wolfgang and Weinmann, Andreas and Ahlborg, Mandy and Brandt, Christina and Bringout, Gael and Buzug, Thorsten M. and Frikel, J{\"u}rgen and Kaethner, C. and Knopp, Tobias and M{\"a}rz, T. and Moddel, Martin and Storath, Martin and Weber, A.}, title = {Mathematical analysis of the 1D model and reconstruction schemes for magnetic particle imaging}, series = {Inverse Problems}, volume = {34}, journal = {Inverse Problems}, number = {5}, publisher = {IOP Publishing}, doi = {10.1088/1361-6420/aab8d1}, abstract = {Magnetic particle imaging (MPI) is a promising new in vivo medical imaging modality in which distributions of super-paramagnetic nanoparticles are tracked based on their response in an applied magnetic field. In this paper we provide a mathematical analysis of the modeled MPI operator in the univariate situation. We provide a Hilbert space setup, in which the MPI operator is decomposed into simple building blocks and in which these building blocks are analyzed with respect to their mathematical properties. In turn, we obtain an analysis of the MPI forward operator and, in particular, of its ill-posedness properties. We further get that the singular values of the MPI core operator decrease exponentially. We complement our analytic results by some numerical studies which, in particular, suggest a rapid decay of the singular values of the MPI operator.}, language = {en} } @misc{BeimlerLeisslEbneretal., author = {Beimler, Josef and Leißl, Caroline and Ebner, Lena and Elsner, Michael and M{\"u}hlbauer, Gerhard and Kohlert, Dieter and Schubert, Martin J. W. and Weiß, Andreas P. and Sterner, Michael and Raith, Thomas and Afranseder, Martin and Krapf, Tobias and Mottok, J{\"u}rgen and Siemers, Christian and Großmann, Benjamin and H{\"o}cherl, Johannes and Schlegl, Thomas and Schneider, Ralph and Milaev, Johannes and Rampelt, Christina and Roduner, Christian and Glowa, Christoph and Bachl, Christoph and Schliekmann, Claus and Gnan, Alfons and Grill, Martin and Ruhland, Karl and Piehler, Thomas and Friers, Daniel and Wels, Harald and Pflug, Kenny and Kucera, Markus and Waas, Thomas and Schlachetzki, Felix and Boy, Sandra and Pemmerl, Josef and Leis, Alexander and Welsch, Andreas F.X. and Graf, Franz and Zenger, Gerhard and Volbert, Klaus and Waas, Thomas and Scherzinger, Stefanie and Klettke, Meike and St{\"o}rl, Uta and Heyl, C. and Boldenko, A. and Monkman, Gareth J. and Kujat, Richard and Briem, Ulrich and Hierl, Stefan and Talbot, Sebastian and Schmailzl, Anton and Ławrowski, Robert Damian and Prommesberger, Christian and Langer, Christoph and Dams, Florian and Schreiner, Rupert and Valentino, Piergiorgio and Romano, Marco and Ehrlich, Ingo and Furgiuele, Franco and Gebbeken, Norbert and Eisenried, Michael and Jungbauer, Bastian and Hutterer, Albert and Bauhuber, Michael and Mikrievskij, Andreas and Argauer, Monika and Hummel, Helmut and Lechner, Alfred and Liebetruth, Thomas and Schumm, Michael and Joseph, Saskia and Reschke, Michael and Soska, Alexander and Schroll-Decker, Irmgard and Putzer, Michael and Rasmussen, John and Dendorfer, Sebastian and Weber, Tim and Al-Munajjed, Amir Andreas and Verkerke, Gijsbertus Jacob and Renkawitz, Tobias and Haug, Sonja and Rudolph, Clarissa and Zeitler, Annika and Schaubeck, Simon and Steffens, Oliver and Rechenauer, Christian and Schulz-Brize, Thekla and Fleischmann, Florian and Kusterle, Wolfgang and Beer, Anne and Wagner, Bernd and Neidhart, Thomas}, title = {Forschungsbericht 2013}, editor = {Baier, Wolfgang}, address = {Regensburg}, organization = {Ostbayerische Technische Hochschule Regensburg}, doi = {10.35096/othr/pub-799}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-7990}, pages = {80}, language = {de} }