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.