A new implantable microstimulator dedicated to selective stimulation of the bladder

Presents a new implantable functional electrical stimulation (FES) system specially designed for the purpose of selective stimulation of the bladder in spinal cord injured patients. This system, composed of an external controller and an implantable microstimulator (implant), is used to induce low-pressure micturition. After receiving both energy and the stimulation parameters via radio-frequency coupling from the controller, the implant starts stimulation of the S₂ sacral nerve. The stimulation, composed of two independent frequencies, mainly stimulates the detrusor while blocking the stimulation of the sphincter even thought both muscles are linked to the S₂ nerve. A computer controlled controller is used by the physician to determine the best parameters for the patient. These parameters are then stored in a portable handheld unit that is used by the medical staff or patient. Acute studies in dogs were carried out to validate the authors´ technique and chronic studies started five months ago