Implantable MyoElectric Sensors (IMES) for Prosthetic Control in Transhumeral Amputees

Implantable Myoelectric Sensors (IMES), the surgical tools implantation, and the external equipment used to control an electromechanical prosthetic device, together comprise the IMES System (investigational product, medical device).

Each IMES acts as an independent differential amplifier consisting of custom electronics housed within a biocompatible, hermetically sealed ceramic cylinder with metal end caps. The end caps serve as electrodes for picking up EMG activity during muscle contraction. Reverse telemetry (via a coil around the arm) is used to transfer data from the implanted sensor, and forward telemetry is used to transmit power and configuration settings to the sensors. The coil and associated electronics are housed within the frame of a prosthesis. A control system that sends data associated with muscle contraction to the motors of the prosthetic joints is housed in a belt-worn, battery-powered device. A cable attaches the control unit to the prosthetic frame.

An IMES is implanted into each targeted muscle that will be used to control a function of the prosthetic arm. Two IMES devices are needed for each DOF. For example, one device would control fingers opening and another device would control fingers closing.