Design of an Assistive Technology Adaptive Switch using an Inertial Measurement Unit.

摘要

A new assistive technology switch for people with disabilities was developed utilizing an Inertial Measurement Unit (IMU) as the sensor technology. The hardware can be customized through firmware to provide custom switch activations on a person by person basis. The firmware is customized to recognize specific data features in the IMU data which identify the desired switch activation movement performed by the user. In this way, the switch can be adapted to activate based on the movements of the user. During this research, the generic hardware platform, including the IMU sensor technology and Bluetooth communications, was designed and tested. An Android application was developed to communicate with the Bluetooth enabled switch to acquire the IMU sensory data for analysis.;A case study was performed to recognize thumb and pinky movements as individual switch activations. This experiment tested the feasibility of using the designed switch with an InvoTek client. A training session was performed to acquire movement data of the thumb and pinky. The acquired data was analyzed in MATLAB and a unique data feature was identified. The switch firmware was updated with the necessary algorithm to recognize and differentiate the thumb and pinky movements. Lastly, the switch was tested with 100 repetitive access movements in which the switch accurately characterized and differentiated 100% of the movements.