Burg bei Magdeburg, Germany
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Schliessmann D.,University of Heidelberg | Schuld C.,University of Heidelberg | Schneiders M.,University of Heidelberg | Derlien S.,University Hospital Jena | And 4 more authors.
Frontiers in Human Neuroscience | Year: 2014

Background: Incomplete spinal cord injury (iSCI) leads to motor and sensory deficits. Even in ambulatory persons with good motor function an impaired proprioception may result in an insecure gait. Limited internal afferent feedback (FB) can be compensated by provision of external FB by therapists or technical systems. Progress in computational power of motion analysis systems allows for implementation of instrumented real-time FB. The aim of this study was to test if individuals with iSCI can normalize their gait kinematics during FB and more importantly maintain an improvement after therapy. Methods: Individuals with chronic iSCI had to complete 6 days (1 day per week) of treadmill-based FB training with a 2 weeks pause after 3 days of training. Each day consists of an initial gait analysis followed by 2 blocks with FB/no-FB. During FB the deviation of the mean knee angle during swing from a speed matched reference (norm distance, ND) is visualized as a number. The task consists of lowering the ND, which was updated after every stride. Prior to the tests in patients the in-house developed FB implementation was tested in healthy subjects with an artificial movement task. Results: Four of five study participants benefited from FB in the short and medium term. Decrease of mean ND was highest during the first 3 sessions (from 3.93 ± 1.54 to 2.18 ± 1.04). After the pause mean ND stayed in the same range than before. In the last 3 sessions the mean ND decreased slower (2.40 ± 1.18 to 2.20 ± 0.90). Direct influences of FB ranged from 60 to 15% of reduction in mean ND compared to initial gait analysis and from 20 to 1% compared to no-FB sessions. Conclusions: Instrumented kinematic real-time FB may serve as an effective adjunct to established gait therapies in normalizing the gait pattern after incomplete spinal cord injury. Further studies with larger patient groups need to prove long term learning and the successful transfer of newly acquired skills to activities of daily living. © 2014 Schließmann, Schuld, Schneiders, Derlien, Glöckner, Gladow, Weidnerand Rupp.


PubMed | HASOMED GmbH, University of Heidelberg and University Hospital Jena Jena
Type: | Journal: Frontiers in human neuroscience | Year: 2014

Incomplete spinal cord injury (iSCI) leads to motor and sensory deficits. Even in ambulatory persons with good motor function an impaired proprioception may result in an insecure gait. Limited internal afferent feedback (FB) can be compensated by provision of external FB by therapists or technical systems. Progress in computational power of motion analysis systems allows for implementation of instrumented real-time FB. The aim of this study was to test if individuals with iSCI can normalize their gait kinematics during FB and more importantly maintain an improvement after therapy.Individuals with chronic iSCI had to complete 6 days (1 day per week) of treadmill-based FB training with a 2 weeks pause after 3 days of training. Each day consists of an initial gait analysis followed by 2 blocks with FB/no-FB. During FB the deviation of the mean knee angle during swing from a speed matched reference (norm distance, ND) is visualized as a number. The task consists of lowering the ND, which was updated after every stride. Prior to the tests in patients the in-house developed FB implementation was tested in healthy subjects with an artificial movement task.Four of five study participants benefited from FB in the short and medium term. Decrease of mean ND was highest during the first 3 sessions (from 3.93 1.54 to 2.18 1.04). After the pause mean ND stayed in the same range than before. In the last 3 sessions the mean ND decreased slower (2.40 1.18 to 2.20 0.90). Direct influences of FB ranged from 60 to 15% of reduction in mean ND compared to initial gait analysis and from 20 to 1% compared to no-FB sessions.Instrumented kinematic real-time FB may serve as an effective adjunct to established gait therapies in normalizing the gait pattern after incomplete spinal cord injury. Further studies with larger patient groups need to prove long term learning and the successful transfer of newly acquired skills to activities of daily living.


Shalaby R.,TU Berlin | Schauer T.,TU Berlin | Liedecke W.,HASOMED GmbH | Raisch J.,TU Berlin | Raisch J.,Max Planck Institute for Dynamics of Complex Technical Systems
Biomedizinische Technik | Year: 2011

Functional electrical stimulation leg cycle ergometry (FES-LCE), which is often used as exercise for people with spinal cord injury (SCI), has recently been applied in the motor rehabilitation of stroke patients. Recently completed studies show controversial results, but with a tendency to positive training effects. Current technology is identical to that used in FES-LCE for SCI, whereas the pathology of stroke differs strongly. Most stroke patients with hemiparesis are able to drive an ergometer independently. Depending on the degree of spasticity, the paretic leg will partially support or hinder movements. Electrical stimulation increases muscle force and endurance and both are prerequisites for restoring gait. However, the effect of FES-LCE on improving impaired motor coordination is unclear. To measure motor coordination during FES-LCE, an EMG-amplifier design has been investigated which suppresses stimulation artifacts and allows detection of volitional or reflex induced muscle activity. Direct measurement of EMG from stimulation electrodes between stimulation pulses is an important asset of this amplifier. Photo-MOS switches in front of the preamplifier are utilized to achieve this. The technology presented here can be used to monitor the effects of FES-LCE to adapt the stimulation strategy or to realize EMG-biofeedback training. © 2011 by Walter de Gruyter Berlin New York.


PubMed | University of Tübingen, The Cure Parkinsons Trust, AbilityNet, University of Tromsø and 3 more.
Type: Journal Article | Journal: Journal of Parkinson's disease | Year: 2015

Parkinsons disease (PD) is a neurodegenerative disorder with fluctuating symptoms. To aid the development of a system to evaluate people with PD (PwP) at home (SENSE-PARK system) there was a need to define parameters and tools to be applied in the assessment of 6 domains: gait, bradykinesia/hypokinesia, tremor, sleep, balance and cognition.To identify relevant parameters and assessment tools of the 6 domains, from the perspective of PwP, caregivers and movement disorders specialists.A 2-round Delphi study was conducted to select a core of parameters and assessment tools to be applied. This process included PwP, caregivers and movement disorders specialists.Two hundred and thirty-three PwP, caregivers and physicians completed the first round questionnaire, and 50 the second. Results allowed the identification of parameters and assessment tools to be added to the SENSE-PARK system. The most consensual parameters were: Falls and Near Falls; Capability to Perform Activities of Daily Living; Interference with Activities of Daily Living; Capability to Process Tasks; and Capability to Recall and Retrieve Information. The most cited assessment strategies included Walkers; the Evaluation of Performance Doing Fine Motor Movements; Capability to Eat; Assessment of Sleep Quality; Identification of Circumstances and Triggers for Loose of Balance and Memory Assessment.An agreed set of measuring parameters, tests, tools and devices was achieved to be part of a system to evaluate PwP at home. A pattern of different perspectives was identified for each stakeholder.


PubMed | University of Tübingen, The Cure Parkinsons Trust, AbilityNet, University of Tromsø and 3 more.
Type: | Journal: BMC neurology | Year: 2015

Currently, assessment of symptoms associated with Parkinsons disease is mainly performed in the clinic. However, these assessments have limitations because they provide only a snapshot of the condition.The feasibility and usability of an objective, continuous and relatively unobtrusive system (SENSE-PARK System), which consists of wearable sensors (three worn during the day and one worn at night), a smartphone-based App, a balance board and computer software, was tested 24/7 over 12weeks in a study including 22 PD patients. During the first four weeks of the study, patients did not get feedback about their performance, during the last eight weeks they did. The study included seven clinical visits with standardized interviews, and regular phone contact. The primary outcome was the number of drop-outs during the study. As secondary outcomes, the Post-Study System Usability Questionnaire (PSSUQ), score and information obtained from the standardized interviews were used to evaluate the usability of the system.All patients completed the study. The participants rated the usability of the SENSE-PARK System with a mean score of 2.67 (0.49) on the PSSUQ. The interviews revealed that most participants liked using the system and appreciated that it signaled changes in their health condition.This 12week controlled study demonstrates that the acceptance level of PD patients using the SENSE-PARK System as a home-based 24/7 assessment is very good. Particular emphasis should be given to a user-friendly design. Motivation to wear such a system can be increased by providing direct feedback about the individual health condition.


Serrano J.A.,University of Tromsø | Serrano J.A.,Health Science University | Thoms A.,HASOMED GmbH | Weber P.,HASOMED GmbH
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

The reality of a Parkinson's Disease patient involves coping with the condition 24 hours a day for the rest of her or his life. A continuous decay of physical and sometimes cognitive functions makes activities of daily life progressively more difficult to accomplish. Many keep a diary where they take note of feelings, relevant events related to the daily routines, reaction to the medication, etc. Such diaries may prove extremely useful for a better understanding of the disease progression, both by the patient and by the doctor. The SENSE-PARK project went a step forward: it combines the patient diary notes (self-reported) with information gathered from movement sensors (automatic measurement) and a visualization mechanism combining the two. A system has been designed, prototyped and tested. Parkinson's medical specialists, user experience experts, technologists and most important the patients themselves, were involved in this process. © 2014 Springer International Publishing Switzerland.


Valtin M.,TU Berlin | Kociemba K.,HASOMED GmbH | Behling C.,HASOMED GmbH | Kuberski B.,HASOMED GmbH | And 2 more authors.
Biomedizinische Technik | Year: 2014

Functional Electrical Stimulation (FES) is a commonly used method in clinical rehabilitation and research to trigger muscle contractions by electrical stimuli, e.g. applied via self-adhesive surface electrodes. A variety of stimulation systems is commercially available which all offer limited control over the stimulation waveform and timing. In this work, a stimulation system is presented, which allows extensive control over the stimulation waveform and the stimulation timing. Additionally, the stimulator supports array electrodes and enables surface electromyography (sEMG) measurements. The waveform is entirely user defined by declaration of characteristic points of the waveform which will be piecewise constant interpolated. Up to 16 points can be declared, each with a duration ranging from 10 μs up to 4095 μs and a current of up to +/- 150 mA. A symmetric, balanced biphasic waveform as well as a balanced triangular waveform were used to validate the waveform generation. To validate the stimulation timing, which is also entirely user defined, a realtime operating system was used. Recording of sEMG signals from the stimulation electrodes is possible even during active stimulation because of the high voltage protection of the EMG analogue frontend. To demonstrate the use in advanced FES applications, a drop foot stimulation experiment was conducted using a novel stimulation waveform. The designed waveform enables almost independent control of the muscle fibularis longus and the muscle tibialis anterior with only a single stimulation channel. © 2014 by Walter de Gruyter Berlin Boston.


Valtin M.,TU Berlin | Valtin M.,HASOMED GmbH | Schauer T.,TU Berlin | Behling C.,HASOMED GmbH | And 2 more authors.
BIODEVICES 2012 - Proceedings of the International Conference on Biomedical Electronics and Devices | Year: 2012

Array electrodes have the potential to significantly advance Functional Electrical Stimulation (FES) performance and patient compliance by optimizing the electrode position. To evaluate the potentials and for research purposes, an universal stimulation system for array electrodes has been developed. The system additionally features volitional EMG recording from the array electrodes during active stimulation. Multiple devices, one stimulator and at least one demultiplexer, are synchronized to deliver up to 10 stimulation pulses per stimulation cycle at a frequency of ≈ 420Hz. A typical stimulation cycle period is 50 ms. The real-time controllable array electrode can include up to 60 elements for the active electrode and up to 4 elements for the indifferent electrode. A small switch module permits placement near the array electrode, eliminating extensive wiring. The stimulation system is fully controllable from a PC via USB interfaces.


PubMed | TU Berlin and HASOMED GmbH
Type: Journal Article | Journal: European journal of translational myology | Year: 2016

Functional Electrical Stimulation is a commonly used method in clinical rehabilitation and research to trigger useful muscle contractions by electrical stimuli. In this work, we present a stimulation system for transcutaneous electrical stimulation that gives extensive control over the stimulation waveform and the stimulation timing. The system supports electrode arrays, which have been suggested to achieve better selectivity and to simplify electrode placement. Electromyography (EMG) measurements are obtained from the active stimulation electrodes (between the stimulation pulses) or from separate surface EMG electrodes. The modular design enables the implementation of sophisticated stimulation control systems including external triggers or wireless sensors. This is demonstrated by the standalone implementation of a feedback-controlled drop foot neuroprosthesis, which uses a wireless inertial sensor for realtime gait phase detection and foot orientation measurement.


Schwesig R.,Martin Luther University of Halle Wittenberg | Kauert R.,HASOMED GmbH | Wust S.,HASOMED GmbH | Becker S.,III. Orthopadische Abteilung | Leuchte S.,Martin Luther University of Halle Wittenberg
Biomedizinische Technik | Year: 2010

Quantitative gait analysis plays an important role in neurological and orthopedic rehabilitation regarding the evaluation of rehabilitation progress. However, most of the currently available gait analysis systems share the disadvantage of being expensive, time-consuming, and complex. A promising alternative is the portable gait analysis system RehaWatch. It is based on inertial sensors that allow the quantitative measurement of the important kinemetric variables acceleration and angular velocity. The associated software analyzes the sensor signals and calculates temporal (e.g., stride duration, gait phases) and spatial (e.g., stride length, foot angle) parameters on this basis. The aim of this study was to investigate the intraobserver reliability of RehaWatch. A total of 44 healthy subjects (age: 27.7±4.2 years) were included in the study. Each participant underwent three measurements (walking distance: 20 m) for each of the three sessions with a time interval of 48 h in-between. Variance analysi (General Linear Model) revealed no significant differences between gait parameters at different measuring points. ICCs (Average Measure Intraclass Correlations) were between 0.691 and 0.959. In addition to the results of the variance and correlation analysis the Bland-Altman plots suggest high reliability. © 2010 by Walter de Gruyter.

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