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Session: Prostheses
Session starts: Thursday 24 January, 13:30
Presentation starts: 14:00
Room: Lecture room 558

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Dick Plettenburg (TU-Delft)
Gerwin Smit (TU-Delft)
Mona Hichert (TU-Delft)

Abstract:
In order to meet the needs of a person with an arm defect, many, sometimes conflicting, requirements have to be fulfilled. These requirements can be summarized into three basic demands: cosmesis, comfort, and control [1, 2]. In the control domain natural, intuitive, subconscious control is strived for. To achieve this type of control proper feedback needs to be present [3]. This implies control according to the voluntary closing principle. In body-powered, body-controlled prostheses voluntary closing control enables proprioceptive feedback of position, velocity, and force to the user through the bodies own proprioceptive system, comparable to the way we use a tool, e.g. a tennis racket [4, 5]. The Delft Institute of Prosthetics and Orthotics has started several projects to develop body-powered, body-controlled voluntary closing prostheses. Current projects include: - a voluntary closing hand for toddlers, with an emphasize on the reduction of glove forces acting. Recently a master thesis project has started; - a voluntary closing prehensor similar in looks to the already existing and successful appealing prehensor [6], where the main challenge is a variable advantage mechanism to promote fast sizing of powerful grasps. Recently a master thesis project has started; - a wrist-operated voluntary closing prehensor, which will incorporate novel hydraulics. In a master thesis project very interesting initial results have been obtained [7]; - a study into the psychophysical properties of shoulder harnesses, where the main challenge is to identify the optimal force and excursion windows. Initial experiments [8, 9] indicate that the currently available body powered prostheses require too large operating forces. A PhD-project is started to further investigate the optimal range for operating forces and displacements. Ultimately, we aim at voluntary closing hands that provide adaptive grasp patterns. Adaptivity enhances the natural appearance [cosmesis], and at the same time reduces the need for high pinch forces [comfort, control]. A PhD-project has resulted in a very promising first prototype [10]. REFERENCES [1] D.H. Plettenburg, “Basic requirements for upper extremity prostheses: the WILMER approach.” In: Proceedings of the 20th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, October 29 – November 1, 1998, Hong Kong SAR, China. Chang H.K., Zhang Y.T. [eds.], Vol.5/6, ISBN 0-7803-5164-9, pp. 2276 – 2281, 1998 [2] D.H. Plettenburg, Upper extremity prosthetics. Current status and evaluation. VSSD, The Netherlands, ISBN-13: 978-90-71301-75-9, 133 + 8 pp., 2006 [3] N. Wiener, Cybernetics, or control and communication in the animal and the machine. John Wiley & Sons, Inc., New York, USA, 1948 [4] D. Simpson, “The choice of control system for the multimovement prosthesis: extended physiological proprioception.” In: The control of upper-extremity prostheses and orthoses. Herberts P., Kadefors R., Magnusson R, Petersen I. [eds.], Charles C. Thomas, Springfield, Illinois, ISBN 0-398-02869-9, pp. 146 – 150, 1974 [5] J.A. Doubler, D.S. Childress, “An analysis of extended physiological proprioception as a prosthesis-control technique.” Journal of Rehabilitation Research and Development, Vol. 21, No. 1. BPR 10-38, pp. 5 – 18, 1984 [6] D.H. Plettenburg, “The WILMER Appealing Prehensor” Journal of Prosthetics and Orthotics, Vol. 18, No. 2, pp. 43 – 45, 2006 [7] D.H. Plettenburg, J. Nieuwendijk, G. Smit, “A new voluntary closing hook prosthesis” In: Proceedings of the University of New Brunswick’s International Conference on Advanced Limb Prosthetics, August 14-19, 2011, Fredericton, NB, Canada, ISBN 978-1-55131-160-91, pp. 110-113 [8] D.H. Plettenburg, M. Hichert, G. Smit, “Feedback in voluntary closing arm prostheses” In: Proceedings of the University of New Brunswick’s International Conference on Advanced Limb Prosthetics, August 14-19, 2011, Fredericton, NB, Canada, ISBN 978-1-55131-160-91, pp. 74-78 [9] M.L. Valk, “Towards better perception. A first pterspective on the perception of operating force and cable displacement in shoulder harness controlled body powered prostheses”. MSc-Thesis, Delft University of Technology, 2012 [10] G. Smit, D.H. Plettenburg, “Design of a hydraulic hand prosthesis with articulating fingers” In: Proceedings of the University of New Brunswick’s International Conference on Advanced Limb Prosthetics, August 14-19, 2011, Fredericton, NB, Canada, ISBN 978-1-55131-160-91, pp. 24-26