Microcontroller based switch inverter for controlling assistive technology devices

A practical device for switching needs has been constructed to take advantage of limited index finger abduction in a person with paralysis. The device utilizes a microcontroller to handle mechanical switch debouncing, convert normally closed switch to normally open switch, turn on an audible output for cueing, control an external device, and be tolerant of spasms. A simple time window technique is developed to prevent involuntary switching due to spasms. The switch activates a relay controlled, isolated output for interfacing with any external assistive technology device that can be operated with a single switch.