FPGA-Based tactile sensory feedback system with optical fiber data communication link for prosthetic applications

Tactile sensory feedback systems could enable the prosthetic system to convey touch information to the amputee. Employing sensor arrays with a high number of sensors gives high-resolution tactile information but imposes challenges on the embedded electronics in processing and transmitting a large number of tactile data to the prosthetic user. This work proposes the design of a FPGA-based approach for tactile sensory feedback systems that employs an optical fiber data communication link for prosthetic applications. The system consists of an interface electronics to manage the data acquisition from the tactile sensor array, a digital coding unit, an optical fiber-based communication link, a digital decoding unit and a further interface electronics to communicate with external apparatus. The data acquisition process followed by a UWB-based optical modulation allows for the transmission of pulsed coded tactile data through the optical fiber to a final user by means of, for example, an electrotactile stimulator combined with flexible electrodes. The transmitter and receiver systems have been implemented on two different FPGA boards with the optical communication channel connecting the two boards. The designed system functionality was demonstrated by employing an experimental setup where sequence of sensor data, emulating an array of 32 sensors sampled at 2kHz, were employed to verify the correctness of the data transmission at 100Mbps data rate through the optical fiber. Experimental results validated the functionality of the proposed design and demonstrated that the optical communication link highly improves the robustness to electromagnetic disturbances, the transmission data rate as well as the power consumption.