A PC-based system for evaluating the efficacy of the NESS Handmaster orthosis

Functional electrical stimulation (FES) is a viable alternative to conventional treatments aimed at restoring function and mobility following central nervous system (CNS) damage. Muscle contractions are converted into functional activity, thus, its wide range of clinical applications. Research efforts are currently focused on the development of programmable stimulators that enable the patient to perform tasks related to activities of daily living. Herein, we present a PC-based surface stimulator that enables the user to vary the stimulus waveform and the activation sequence of different muscle groups within a wide range of options. This instrumentation is not only a development platform for other, more sophisticated neuroprostheses, but an essential tool for evaluating the rehabilitative efficacy of the NESS Handmaster (NESS Ltd., Israel). Our PC-based stimulator reproduces Handmaster motor tasks by selectively activating the five muscle groups that control the hand, palmar, and lateral grasps. The stimulator is entirely controlled by the plegic patient with the push of a button. The ancillary software permits acquisition of up to sixteen analog channels, so that feedback signals for closed-loop control of the grasp function can be measured.