THE HANDMASTER NMS1: AN UPPER LIMB EXTERNAL NEUROPROSTHESIS
R.H. Nathan-1,2, H. Weingarden-1,3, A. Dar-1, D. Katz-1
(1-NESS Ltd., Raanana, Israel, 2-Ben Gurion University of the Negev, Beer Sheva, Israel, 3-Sheba Medical Center, Tel Hashomer, Israel)
The Device: The Handmaster NMS1 system comprises a control box delivering microprocessor- controlled stimulation through 5 surface electrodes arrayed on the inside surface of a hand/forearm splint. The system is designed to be fitted in a single session to the limb of the patient and after a short training program, to be used unsupervised by the patient at home. The device is intended for therapeutic use in CVA, TBI, CP, MS, and in orthopaedics (hand/forearm, post-surgery/post-trauma). It is also intended for functional use in restoration of active prehension - release to the paralyzed hand. SCI patients at C5 and C6 lesion levels can benefit functionally from using the device in addition to certain CVA and TBI patients.
The Technology: The technology addresses problems of conventional surface stimulation of the upper limb: the problems of positioning and anchoring the electrode array to allow the patient to don and doff the system fast, and to allow unimpeded arm movements. The aesthetics of the system are addressed, and the phasing of the prehension-release patterns to optimize functionality. Five therapeutic exercise protocols, two functional hand grasp - release programs, and one functional hand posture are programmed into the device.
Future Developments: Technological enhancements in the pipeline include activation of the proximal upper limb: the elbow joint for function and therapy, and the shoulder joint therapeutically for prevention of sublaxation. An MP-block is under development for prevention of finger MP joint hyperextension. Patient/device interfaces such as voice input will enable the device to be used by patient groups unable to operate the present touch buttons on the control box, such as C4 lesion-level SCI patients.
FUNCTIONAL ELECTRICAL STIMULATION FOR PARAPLEGIC AMBULATION
Maarten J. IJzerman (Roessingh Research and Development, Enschede, the Netherlands)
Purpose: This presentation gives an overview of the use of electrical stimulation in the Netherlands. Besides the use of FES to improve upper limb function in the tetraplegic patient, a major part of this presentation deals with the development of a hybrid system for paraplegic locomotion.
Methods: An extensive research program on development of a new hybrid walking system for paraplegic ambulation is carried out by Roessingh Research and Development, Rehabilitation centre "Het Roessingh" and University of Twente (institute for biomedical technology). The program comprises research on both the orthotic as well as electrical component.
Results: A new orthosis has been developed based on clinical experience in the last 10 years. It comprises a mechanism to obtain knee flexion during swing phase and a built in reciprocal cable. The legs are slightly aligned in abduction in the frontal plane. The electrical stimulation part comprises a 4 channel surface muscle stimulator with an external intention detection system. The intention detection combines the sensor information of accelerometers on the thigh and a crutch force threshold in order to start a specific stimulation pattern.
Conclusion: A new orthoses and electrical stimulation control strategies are developed and have shown to be reliable. A clinical evaluation of the hybrid system in four users is ongoing.