System and method for multifunctional control of upper limb prosthesis

Abstract

A system for controlling the operation of an electrically powered prosthetic appliance which replaces an amputee's missing limb. The method employed consists of conducting electromyographic (EMG) signals from the stump of the missing limb and processing the signals so as to reduce them to a near minimum number of linear time series model parameters effective to differentiate between each of the several functions performed by the missing limb from each other function thereof. A filter array carried by the amputee subsequently employs the identified parameters such that each individual filter of the array is tuned according to a set of parameters related to one of the limb functions considered. The myoelectric (EMG or ME) signal as obtained at a surface electrode worn by the amputee is fed to each filter of the above array of filters, and the outputs of these various filters are used for a decision by the system as to which limb function should be actuated. In another realization, identification of partial correlation coefficients of the ME signal is performed. These coefficients are stored in memory per each limb function, and during normal operation the partial correlation parameters for the current ME signal are compared with those in memory to determine which limb function is to be actuated.