A Wearable Multi-Channel Electrical Stimulator for Tremor Suppression

Abstract Pathological wrist and finger tremors can be mitigated by out-of-phase stimulation of the sensory nerves in the flexor and extensor muscles. This study endeavors to develop a portable, multi-channel electrical stimulator designed to deliver high-frequency, low-intensity, biphasic charge-balanced current pulses within a practical load range to effectively suppress wrist and finger tremors. The circuit architecture integrates an Arduino Nano microcontroller, a 4-channel digital potentiometer, and four Howland current pumps. The Howland current pump, employing an operational amplifier, generates bipolar currents by accepting bipolar voltages, whereas the digital potentiometer offers programmable bipolar voltages via its wiper terminals. Experimental results indicate that the pulse frequency can be adjusted between 50 Hz and 200 Hz, and the current level can be modulated within a range of -10 mA to +10 mA, with load resistance spanning 100O to 1.3kO. This portable and multi-channel device is effective in delivering high-frequency, low-intensity sensory nerve stimulation through programmable biphasic charge-balanced current pulses. The proposed stimulator has the potential to enable adaptive muscle activation, thereby initiating, promoting, and generating movements, and facilitating interactive in-home neurorehabilitation for disabled patients. The portability and programmability of this device make it a promising tool for personalized tremor management and rehabilitation, enhancing the quality of life for individuals with motor impairments.