A novel force sensitive resistor wheatstone bridge for prosthesis control

Control of prosthetic devices should be robust and intuitive. In this work a simple, robust, and intuitive method for opening and closing a prosthetic hand for transradial amputations is proposed. The method utilizes force sensitive resistors (FSR) in a sleeve around the residual forearm. Contracting the muscles to open or close the hand changes the shape of the forearm and the force on the FSR sensors. A novel Wheatstone bridge configuration of the sensors simplifies and expediates the calibration. Using all four FSRs as the resistors of the Wheatstone bridge, the system is relatively insensitive to sensor location. To calibrate the sensor, the user opens and closes the hand a few times. The method was demonstrated in simulation on two unamputated individuals opening and closing the hand. To demonstrate the robustness of the method, the sleeve was removed and replaced so that the FSR locations and the calibration is different, but the system is still functional.