Abstract

Overactive bladder patients suffer from a frequent and uncontrollable urge to urinate, which can lead to a poor quality of life. Current sacral neuromodulation therapy uses open-loop electrical stimulation to alleviate symptoms, which limits battery life and can lead to neural habituation. In this study, we aim to improve therapy by developing a conditional stimulation paradigm using neural recordings from dorsal root ganglia (DRG) as sensory feedback. Experiments were performed in 5 non-survival, anesthetized felines, in which the sacral-level DRG and spinal roots were exposed bilaterally. A bipolar cuff electrode was placed on a S1 root distal to the DRG for stimulation. Microelectrode arrays were implanted in the same or opposite S1 and/or S2 DRG. We implemented a Kalman filter-based algorithm to estimate the bladder pressure in real-time using DRG neural recordings. The Medtronic Summit Research Development Kit was used to control sacral root stimulation when the algorithm detected an increase in bladder pressure. Closed-loop neuromodulation was performed during continuous cystometry and compared to bladder fills with continuous and no stimulation. Overall, closed-loop stimulation with DRG sensory feedback increased bladder capacity by 13.8% over no stimulation (p