A new bladder stimulator--hand-held controller and miniaturized implant: preliminary results in dogs.

A new urinary-tract stimulator that is intended to restore normal bladder function to patients who have spinal-cord injuries is described. The system is composed of two principal parts. The first, which is external, consists of a hand-held device based on an inductive-coupling technique. This controller incorporates all the circuitry necessary to transmit data transdermally. The second, a fully programmable implantable device, includes a complementary metal oxide semiconductor gate-array integrated circuit controlling eight monopolar (or four bipolar) stimulation channels. To protect the tissues and the device, three different biocompatible polymers encapsulate the implant. In the experimental phase, the authors investigated the effect of early electrical stimulation of the bladder during the spinal-shock phase in paraplegic dogs. In addition, using the stimulator, they localized the parameters of stimulation that give the best results in terms of effective bladder pressure and voiding a high volume of urine.