Comparison of stimulation patterns for FES-cycling using measures of oxygen cost and stimulation cost

<b>Aim</b><p></p> The energy efficiency of FES-cycling in spinal cord injured subjects is very much lower than that of normal cycling, and efficiency is dependent upon the parameters of muscle stimulation. We investigated measures which can be used to evaluate the effect on cycling performance of changes in stimulation parameters, and which might therefore be used to optimise them. We aimed to determine whether oxygen cost and stimulation cost measurements are sensitive enough to allow discrimination between the efficacy of different activation ranges for stimulation of each muscle group during constant-power cycling. <p></p> <b>Methods</b><p></p> We employed a custom FES-cycling ergometer system, with accurate control of cadence and stimulated exercise workrate. Two sets of muscle activation angles (“stimulation patterns”), denoted “P1” and “P2”, were applied repeatedly (eight times each) during constant-power cycling, in a repeated measures design with a single paraplegic subject. Pulmonary oxygen uptake was measured in real time and used to determine the oxygen cost of the exercise. A new measure of stimulation cost of the exercise is proposed, which represents the total rate of stimulation charge applied to the stimulated muscle groups during cycling. A number of energy-efficiency measures were also estimated. <p></p> <b>Results</b><p></p> Average oxygen cost and stimulation cost of P1 were found to be significantly lower than those for P2 (paired <i>t</i>-test, <i>p</i> < 0.05): oxygen costs were 0.56 ± 0.03 l min<sup>−1</sup> and 0.61 ± 0.04 l min<sup>−1</sup>(mean ± S.D.), respectively; stimulation costs were 74.91 ± 12.15 mC min<sup>−1</sup> and 100.30 ± 14.78 mC min<sup>−1</sup> (mean ± S.D.), respectively. Correspondingly, all efficiency estimates for P1 were greater than those for P2. <p></p> <b>Conclusion</b><p></p> Oxygen cost and stimulation cost measures both allow discrimination between the efficacy of different muscle activation patterns during constant-power FES-cycling. However, stimulation cost is more easily determined in real time, and responds more rapidly and with greatly improved signal-to-noise properties than the ventilatory oxygen uptake measurements required for estimation of oxygen cost. These measures may find utility in the adjustment of stimulation patterns for achievement of optimal cycling performance. <p></p&gt

ADJUSTMENT OF FUNCTIONAL ELECTRICAL STIMULATION (FES) ACCORDING TO KNEE FLEXION ANGLE

To clarify the different results of our simulation and FES-cycling tests, measurements on a knee dynamometer were made. The m. quadriceps of 16 healthy test persons was activated both by FES and voluntary contraction. Stimulated with the same level of intensity in a knee flexion angle range from 5° to 105°, the diagrams showed a very unusual course. The knee torque shows its maximum at the knee flexion angle of approx. 30°. Additional isometric measurements using stimulation intensity on constant on-verge-to pain levels for different knee angles were made. The measured courses of the resulting knee torque as a function of the knee angle are much closer to the results of physiologically activated muscle. These measurements show that for optimum power release, the stimulation intensity must be regulated depending on the knee flexion angle

Rechtliche Aspekte der Vogel- und Geflügelhaltung in Österreich

In den Jahren 2005 bzw. 2006 trat in Europa und auch in Österreich erstmals das H5N1 – Vogelgrippevirus auf. Im Zuge der damals wie heute geführten Diskussion und der durchaus begründeten Angst vor einem Übergreifen des Virus auf den Menschen (Stichwort Pandemie), ist es Intention der Dissertation, einen umfassenden Überblick über die aktuelle Gesetzeslage der Vogel- und Geflügelhaltung bzw. Zucht in Österreich darzustellen. Aktualität erhält dieser Themenbereich auch dadurch, dass am 1.1.2005 das neue österreichische Tierschutzgesetz (TSchG) in Kraft trat. Dieses Regelwerk bedeutete für den Vogel- und Geflügelhalter einen tiefen Einschnitt in die bisherigen Methoden bezüglich Haltung und Zucht dieser Tiere. Der erste Teil der gegenständlichen Arbeit beleuchtet die Anforderungen an die Haltung von Vögeln und Geflügel gemäß dem TSchG und beschäftigt sich mit verwandten Randthemen wie der Abhaltung von Tierausstellungen und Tierbörsen, der Schlachtung von Tieren, dem Transport von Tieren, der gewerblichen Tierhaltung, der Vollziehung der Bestimmungen des TSchG, etc, die vor allem in den Durchführungsverordnungen zum TSchG geregelt werden. Der zweite Teil der Arbeit thematisiert die generelle Einbettung der Vogel- und Geflügelhaltung in die österreichische Rechtsordnung, besonders im Hinblick auf die gewerberechtliche Einordnung der Vogel- und Geflügelhaltung, eine allfällige Einkommenssteuerpflicht sowie eine allfällige Kammerzugehörigkeit und Sozialversicherungspflicht des Halters. Der dritte Teil der Arbeit behandelt völkerrechtliche und gemeinschaftsrechtliche Handelsbeschränkungen und deren Umsetzung. Der vierte Teil der Arbeit befasst sich schlussendlich mit den Maßnahmen und rechtlichen Bestimmungen zur Bekämpfung der aviären Influenza. Ein wesentlicher, kapitelübergreifender Teil dieser Arbeit ist auch die Prüfung, ob durch Haltungs- und/oder Handelsbeschränkungen sachlich ungerechtfertigt in einzelne Grundrechte der Halter eingegriffen wird. Insbesondere werden auch die unterschiedlichen Anforderungen an die Vogel- und Geflügelhaltung im Rahmen einer gewerblichen Haltung oder Haltung im Rahmen der Land- und Forstwirtschaft einerseits und einer Hobby- oder Liebhabertierhaltung andererseits aufgezeigt. Anhand des Gleichheitsgrundsatzes wird diskutiert, ob für aufgezeigte Ungleichbehandlungen eine sachliche Rechtfertigung gegeben ist

Passive Light-Weight Arm Exoskeleton: Possible Applications

Upper extremity exoskeletons are useful for humans in different ways: for motor rehabilitation, as assistive devices, or for the reduction of workrelated loads on the musculoskeletal system. This paper describes the design of a passive modular and light-weight arm exoskeleton with gravity support and discusses possible fields of application. Tests, carried out with enabled gravity support show reduced muscle activations and forces compared to the same movements with disabled gravity support, indicting the effectiveness of the design

Feedback control of arm movements using Neuro-Muscular Electrical Stimulation (NMES) combined with a lockable, passive exoskeleton for gravity compensation

Within the European project MUNDUS, an assistive framework was developed for the support of arm and hand functions during daily life activities in severely impaired people. This contribution aims at designing a feedback control system for Neuro-Muscular Electrical Stimulation (NMES) to enable reaching functions in people with no residual voluntary control of the arm and shoulder due to high level spinal cord injury. NMES is applied to the deltoids and the biceps muscles and integrated with a three degrees of freedom (DoFs) passive exoskeleton, which partially compensates gravitational forces and allows to lock each DOF. The user is able to choose the target hand position and to trigger actions using an eyetracker system. The target position is selected by using the eyetracker and determined by a marker-based tracking system using Microsoft Kinect. A central controller, i.e., a finite state machine, issues a sequence of basic movement commands to the real-time arm controller. The NMES control algorithm sequentially controls each joint angle while locking the other DoFs. Daily activities, such as drinking, brushing hair, pushing an alarm button, etc., can be supported by the system. The robust and easily tunable control approach was evaluated with five healthy subjects during a drinking task. Subjects were asked to remain passive and to allow NMES to induce the movements. In all of them, the controller was able to perform the task, and a mean hand positioning error of less than five centimeters was achieved. The average total time duration for moving the hand from a rest position to a drinking cup, for moving the cup to the mouth and back, and for finally returning the arm to the rest position was 71 s.EC/FP7/248326/EU/MUltimodal Neuroprostesis for Daily Upper limb Support/MUNDU

Feedback control of arm movements using Neuro-Muscular Electrical Stimulation (NMES) combined with a lockable, passive exoskeleton for gravity compensation.

Within the European project MUNDUS, an assistive framework was developed for the support of arm and hand functions during daily life activities in severely impaired people. This contribution aims at designing a feedback control system for Neuro-Muscular Electrical Stimulation (NMES) to enable reaching functions in people with no residual voluntary control of the arm and shoulder due to high level spinal cord injury. NMES is applied to the deltoids and the biceps muscles and integrated with a three degrees of freedom (DoFs) passive exoskeleton, which partially compensates gravitational forces and allows to lock each DOE The user is able to choose the target hand position and to trigger actions using an eyetracker system. The target position is selected by using the eyetracker and determined by a marker-based tracking system using Microsoft Kinect. A central controller, i.e., a finite state machine, issues a sequence of basic movement commands to the real-time arm controller. The NMES control algorithm sequentially controls each joint angle while locking the other DoFs. Daily activities, such as drinking, brushing hair, pushing an alarm button, etc., can be supported by the system. The robust and easily tunable control approach was evaluated with five healthy subjects during a drinking task. Subjects were asked to remain passive and to allow NMES to induce the movements. In all of them, the controller was able to perform the task, and a mean hand positioning error of less than five centimeters was achieved. The average total time duration for moving the hand from a rest position to a drinking cup, for moving the cup to the mouth and back, and for finally returning the arm to the rest position was 71 s

Functional and usability assessment of a robotic exoskeleton arm to support activities of daily life

An assistive device for upper limb support was developed and evaluated in terms of usability, user satisfaction and motor performance on six end-users affected by neuro-motor disorders (three spinal cord injury; one multiple sclerosis; two Friedreich's ataxia). The system consisted of a lightweight 3-degrees-of-freedom robotic exoskeleton arm for weight relief, equipped with electromagnetic brakes. Users could autonomously control the brakes using a USB-button or residual electromyogram activations. The system functionally supported all of the potential users in performing reaching and drinking tasks. For three of them, time, smoothness, straightness and repeatability were also comparable to healthy subjects. An overall high level of usability (system usability score, median value of 90/100) and user satisfaction (Tele-healthcare Satisfaction Questionnaire - Wearable Technology, median value of 104/120) were obtained for all subject

MUNDUS project : MUltimodal neuroprosthesis for daily upper limb support

Background: MUNDUS is an assistive framework for recovering direct interaction capability of severely motor impaired people based on arm reaching and hand functions. It aims at achieving personalization, modularity and maximization of the user’s direct involvement in assistive systems. To this, MUNDUS exploits any residual control of the end-user and can be adapted to the level of severity or to the progression of the disease allowing the user to voluntarily interact with the environment. MUNDUS target pathologies are high-level spinal cord injury (SCI) and neurodegenerative and genetic neuromuscular diseases, such as amyotrophic lateral sclerosis, Friedreich ataxia, and multiple sclerosis (MS). The system can be alternatively driven by residual voluntary muscular activation, head/eye motion, and brain signals. MUNDUS modularly combines an antigravity lightweight and non-cumbersome exoskeleton, closed-loop controlled Neuromuscular Electrical Stimulation for arm and hand motion, and potentially a motorized hand orthosis, for grasping interactive objects. Methods: The definition of the requirements and of the interaction tasks were designed by a focus group with experts and a questionnaire with 36 potential end-users. Five end-users (3 SCI and 2 MS) tested the system in the configuration suitable to their specific level of impairment. They performed two exemplary tasks: reaching different points in the working volume and drinking. Three experts evaluated over a 3-level score (from 0, unsuccessful, to 2, completely functional) the execution of each assisted sub-action. Results: The functionality of all modules has been successfully demonstrated. User’s intention was detected with a 100% success. Averaging all subjects and tasks, the minimum evaluation score obtained was 1.13 ± 0.99 for the release of the handle during the drinking task, whilst all the other sub-actions achieved a mean value above 1.6. All users, but one, subjectively perceived the usefulness of the assistance and could easily control the system. Donning time ranged from 6 to 65 minutes, scaled on the configuration complexity. Conclusions: The MUNDUS platform provides functional assistance to daily life activities; the modules integration depends on the user’s need, the functionality of the system have been demonstrated for all the possible configurations, and preliminary assessment of usability and acceptance is promising

Archetypen der Führung im Unternehmenslebenszyklus - Lernerfahrungen von GründerInnen und Führungskräften an der Unternehmensspitze

Die einzelnen Phasen im Lebenszyklus eines Unternehmens erfordern unterschiedliche Typen von FÃhrungskrÃ$ften oder FÃhrungskrÃ$fte mit Kompetenzen, die den unterschiedlichen Anforderungen in den einzelnen Phasen gerecht werden. Der Autor hat dafÃr ein eigenes integriertes Unternehmenslebenszyklusmodell (iULZM) entwickelt, das die Phasen von der GrÃndung eines Unternehmens bis zum hochentwickelten GroÃkonzern systematisch erfasst. Mit einem speziellen Testverfahren, das das Entscheidungs- und ProblemlÃsungsverhalten von FÃhrungskrÃ$ften misst, werden die einzelnen FÃhrungsarchetypen unterscheidbar gemacht und den Phasen im Unternehmenslebenszyklus gegenÃbergestellt. Dabei kann nachgewiesen werden, dass nach der Typologisierung des Autors EntrepreneurInnen und LeaderInnen in Pionier- bis Reifephasen in Klein- und Mittelbetrieben und ManagerInnen und AdministratorInnen dominieren. Dazu wurden dreiÃig UnternehmensgrÃnderInnen und SpitzenfÃhrungskrÃ$fte getestet und interviewt. Aus den Lernerfahrungen der interviewten SpitzenfÃhrungskrÃ$fte, den Erkenntnissen Ãber die Archetypen und die Phasen des Unternehmenszyklus sowie den GrundsÃ$tzen Ãber nachhaltige FÃhrung hat der Autor ein Trainingsprogramm fÃr phasen-transformierende Unternehmenssteuerung entwickelt.The various stages in the life cycle of an enterprise require different types of top executives or top executives with skills that meet the different requirements at each stage. The author has developed its own integrated corporate life cycle model (iCLCM) that systematically captures the phases from founding an enterprise up to the highly developed enterprise. Using a special test procedure that measures the decision-making and problem-solving behavior of top-executives, the individual leadership archetypes are made distinguishable and contrasted with the phases of the corporate life cycle. It can be shown that after the typology of the author entrepreneurs and leaders dominate in start-up and mature phases of small and medium enterprises and managers and administrators in growth and stable phases. Thirty entrepreneurs and top executives have been tested and interviewed. From the learning experience of the interviewed top executives, the findings about the archetypes, the phases of the corporate life cycle and the principles on sustainable management, the author has developed a training program for phase transforming corporate management.Willibald GföhlerAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersZsfassung in engl. SpracheKlagenfurt, Alpen-Adria-Univ., Diss., 2013OeBB(VLID)241186