Abstract: Muscle stimulation devices are used to restore or maintain the muscle activity of paralyzed patients who suffer from musculoskeletal injuries for several decades. In this paper, a portable and low-cost versatile muscle stimulator for two channel TES applications is described. The microcontroller-based programmable stimulator with two bipolar output channels send arbitrarily specified electrical pulses to the element in the electrode array for enabling the complex schemes of muscles. The amplitude and phase of each pulse in the stimulus sequence are in-dependently variable, and the two channels are independently programmable, al-lowing a wide variety of stimulus patterns. We also designed an output circuit that can provide bi-phasic, voltage-regulated, charge-balanced outputs while avoiding the electrochemical erosion of electrode due to charge accumulation, the electrodes are electrically isolated from one another to effect regional (Selective) stimulation. Selective stimulation offers greater control over the spatial pattern of muscle stimulation and may allow for increased muscle efficiency. The proposed stimulator has provided an opportunity for further study of a potential novel electrical stimulator with closed-loop stimulation paradigm suitable for a variety of FES (Functional electrical stimulation) applications, both for experimental and clinical studies.

Keywords: Muscle stimulation; microcontroller; medical device; FES applications.