Closed-Loop Bladder Neuromodulation Therapy in Spinal Cord Injury Rat Model

Poor bladder management is a common and potentially life-threatening dysfunction among spinal cord injury (SCI) patients. In this condition, sensation from the bladder and voluntary control of micturition are lost, which might result in high post-void residual urine volume in the bladder, leading to renal impairment. Micturition can be driven using the sacral anterior root stimulator (SARS). However, commercially available SARS devices are not equipped with a closed-loop regulator for adaptive and automated control of bladder contractions. In our previous study, we developed a closed-loop control strategy for bladder emptying. In this paper we demonstrate the closed-loop neuromodulation feasibility in a SCI rat. The closed-loop strategy in this model achieved 71% voiding efficiency, higher than 40% efficiency obtained using open-loop stimulation. Our results provide a basis for developing an implantable closed-loop neural bladder prosthesis for SCI patients in the future.