Differential measure of matched linear accelerometers as a sensing strategy for the development of a vestibular prosthesis

We propose using a matched pair of linear diaphragm accelerometers in order to capture angular velocity data for use in a vestibular prosthesis. Each sensor transduces linear acceleration into deflection of the membrane. This deflection changes the distance between the plates and concordantly their capacitance. Through analytic equations of motion and finite element analysis we show that such a sensor design will allow for sufficient sensitivity for a vestibular prosthesis. By placing two accelerometers in such a way that they are parallel, within the same plane, and share a perpendicular axis, we can derive angular acceleration, and through signal processing, angular velocity. In such a configuration, linear accelerations will be rejected by taking the difference between the measured capacitances, while angular acceleration data will be accepted. Physical analysis shows that this scheme will generate the requisite data.