Integrated Design of Functional Electrical Stimulator and Transcutaneous Electrical Nerve Stimulator on a Single Prototype

This study proposed a novel system with an integrated design of functional electrical stimulator (FES) and transcutaneous electrical nerve stimulator (TENS) on a single prototype. The novel component of the device involves two modes of operation – the FES and TENS, with controllable frequency, pulse-width, stimulation intensity, and multi-shape pulses on a single device. A boost converter controls the stimulation intensity; an Arduino Uno microcontroller controls the frequency and pulse width; an H-bridge produces square pulses, a toggle switch monitors the mode of operation, and RC filters generate multiple shape pulses. The FES and TENS modes of the device were analyzed with variable parameters and multiple shape pulses. This new design realized a low cost (less than 50 $), low inputs (9 V), and multi-shape stimulation pulses for the FES and TENS, with variable frequency control, controllable pulse-width, and smaller size of the device on a single prototype. This design makes the FES and TENS more practically switched and safer with lower voltage outputs (less than 35 V) than the single-mode stimulators.