Adaptive hand neuroprosthesis using inertial sensors for real-time motion tracking [article]

Christina Salchow-Hömmen, Technische Universität Berlin, Thomas Schauer, Jörg Raisch
People suffering from upper limb impairments after a stroke or spinal cord injury are not only restricted in their independence but also in their inclusion in professional and social life. The increasing number of patients and the resulting rise in timely and monetary rehabilitation expenses lead to strong demands for new, effective therapies. Neuroprostheses based on functional electrical stimulation (FES) have been found to influence motor recovery positively. Electrical pulses are applied to
more » ... peripheral nerves in the forearm and hand to generate functional hand motions. However, noninvasive hand neuroprostheses (HNPs) for rehabilitation face several challenges in clinical practice. The limited selectivity of transcutaneous FES yields difficulties in achieving fine hand movements by stimulating the muscle-rich forearm. Intersubject variability in neuroanatomy and tolerance of the FES make an individual adjustment of spatial and temporal stimulation parameters obligatory. Furthermore, strategies are required for a quick and easy adaptation of stimulation parameters in real-time, as the neuromuscular system is subject to time-variant changes. In this thesis, new concepts and methods are presented on the road to a novel, adaptive HNP based on automation, closed-loop control, and user-centered design. The HNP features a new, modular hand sensor system for accurate real-time motion tracking of FES-induced movements. In contrast to glove-based approaches, the proposed solution maintains the sense of touch. Algorithms for measuring segment orientations, wrist and finger joint angles, and fingertip positions from up to 17 micro inertial sensors were developed for application in patients with severe motor impairment of the hand. The methods avoid extensive calibration movements performed by the patients and work robustly in magnetically disturbed environments, i.e., indoors. The sensor system was evaluated with four healthy subjects in different validation settings before it was applied in clinical studies. Selective and [...]
doi:10.14279/depositonce-10136 fatcat:5vwxwbbdk5fdhlrbj2rqrhl3sq