A custom signal processor based neuroprosthesis intended to recover urinary bladder functions

This paper concerns a custom digital signal processor (CDSP) dedicated to evaluate a sensory feedback from a neuroprosthetic implant that is intended to restore the storage and voiding functions of the urinary bladder. The proposed CDSP executes the neural source identification through an on-the-fly spike-sorting process followed by neural decoding of the bladder volume. In addition to in situ measurement of the urine volume, its wireless transmission to a base station, and informing user about the bladder status, this sensory information is intended for a closed-loop electrical stimulation interface dedicated to tune up the stimulation parameters to ensure continence and bladder voiding. To assess feasibility, the CDSP prototype was deployed in a low-power FPGA (Actel Igloo). The results of the tests performed using synthetic realistic signals and real signals recorded from rats´ bladder during acute experiments, show the feasibility of the proposed device.