New stimulation strategy to improve the bladder function in paraplegics: chronic experiments in dogs

A neural electrical stimulation strategy, intended to recover the bladder functions, is proposed. Restoring urinary functions allows voluntary bladder voiding, and reduces or even suppresses hyperreflexia. The preliminary stimulation system is composed of subcutaneous implantable stimulators (an implant) and an external device. The implant includes the selective stimulation for bladder voiding, in addition to a new permanent stimulation technique to reduce (or cancel) the bladder hyperreflexia and so cures other related diseases. Permanent stimulation is a low frequency, low amplitude and all day long stimulation that needs to be battery powered. On the other hand, selective stimulation is a bi-frequency, punctual, precise and at a higher amplitude stimulation that is well controlled and powered from the outside. Eight prototypes of the stimulator have been used in an experimental evaluation in dogs to characterize the reliability and functionality of the new implant in-a real application environment. Preliminary results of the study show that the proposed stimulation system and the stimulation strategy provide significant improvement for bladder hyperreflexia curing while it confirmed the efficiency of the selective stimulation by means or high frequency blockage.