Development of a Limb prosthesis by reverse mechanotransduction

Abstract

Recent developments in the field of limb prosthesis have focused on the use of body signals of the user to generate the desired motion in the prosthesis. Unlike earlier designs, this approach is more effective and less stressful for the amputee. The signals that have been used up till now are EMG signals, EEG signals and neural signals. Another possible source of body signal is the pH value of the neuromuscular junction, which depends upon the ion movements across the muscle tissue. Hence, it is safe to assume that changes in the pH can accurately mimic the intended changes in the amputated limb muscles, and therefore can be used to turn the user’s desired motion into actual motion of the limb prosthesis. In the current model, this is achieved through the means of a pH-to-voltage converter that converts the pH value into voltage that is in turn used to drive the motor. The direction of movement is controlled by a microcontroller-based circuit. Further improvements can be made upon the model presented in this thesis, if the pH values could be more accurately read and employed to determine the direction of the movement of the finger too. Also, attempts can be made to apply the same working principle on more complex models of hand prosthesis, thus producing more applicable results.