Towards a Low-Cost Non-Invasive Patient Operated Electric Muscle Stimulator for People with Spinal Cord Injuries

Road accidents, violence and terrorism have resulted in an increasing number of people with spinal cord injuries. This paper presents a programmable portable low-cost non-invasive electric muscle stimulator for the sake of muscle pace making. Using off-shelve components, the device is designed to generate a biphasic stimulation signal with controllable stimulation parameters. The device is operated using only one 3.7V Li-ion battery. The device is capable of delivering a stimulation current up to 50mA to a load impedance of 1.2 k Ω. Lower stimulation current can be delivered to a higher load impedance. The simulation as well as the measurement results clearly show the effectiveness of the control knobs in delivering the stimulation signal with the required timing parameters including pulse width, burst on and off times. The device can be used as either a standalone device in the rehabilitation units or to be part of a completely patient-operated system.