A unit to provide a capability for programmable real-time adjustment of stimulus intensity to a hand-held stimulator for drop foot correction applications

This paper describes the design of an intelligent drop foot stimulator unit for use in conjunction with a commercial NMES unit, the NT2000. The developed micro-controller unit interfaces to a PC and a GUI allows the clinician to graphically specify the shape of the stimulation intensity envelope required for subject undergoing drop foot correction. The developed unit is based on the ADuC812S micro-controller evaluation board from analog devices and uses two FSR-based foot-switches to control application of stimulus. The unit has the ability to display diagnostic data to clinician indicating how the stimulus intensity envelope is being delivered during walking using a data capture capability. The developed system has a built-in algorithm to adjust the deliver of stimulus to reflect changes in gait cycle time.