Overactive bladder (OAB) is a significant global health issue. The standard percutaneous tibial nerve stimulation (PTNS) protocol uses maximal-tolerance stimulation and causes discomfort and other side effects. This study aimed to optimize stimulation intensity using a motion capture (MoCap) system, thereby enhancing therapy safety and personalization.
In a single short-term stimulation session, the stimulator was fixed to the cat's (four males and four females) medial malleolus and the inertial measurement unit (IMU) sensor to the ipsilateral paw dorsum. Threshold intensity T was established conventionally by visual observation of toe flexion, and t was established through MoCap. The effects of PTNS on the micturition reflex were assessed using serial cystometrograms (CMGs) during infusion of normal saline (NS) or acetic acid (AA).
During NS infusion, PTNS at 2T increased bladder capacity (BC) to 143.60% ± 4.96% of control (9.89 ± 3.20 mL) and at 2t increased it to 143.10% ± 5.81% (both p < 0.01). During AA infusion, BC decreased to 56.43% ± 1.59% of control (p < 0.01); subsequent PTNS at 2T and at 2t restored it to 77.99% ± 4.80% and 78.08% ± 4.65%, respectively (both p < 0.01). MoCap t was significantly lower than T (p < 0.05). Both intensities prolonged contraction duration relative to the AA group (p < 0.05), whereas contraction amplitude and area under the curve did not differ among conditions (p > 0.05). Angular velocity and linear acceleration across all three orthogonal axes showed moderately to highly significant positive correlations with stimulation intensity.
The IMU-based MoCap system used angular velocity and linear acceleration as measures and identified a markedly lower stimulation threshold that produced therapeutic outcomes equivalent to conventional protocols. Although this single-session short-term study differs from standard longitudinal clinical application, this approach reduces stimulation intensity and may enable safer and more individualized PTNS for OAB.
Neuromodulation : journal of the International Neuromodulation Society. 2026 Jul 15 [Epub ahead of print]
Linquan Jin, Dongsheng Shang, Han Deng, Chen Li, Ziyu Wang, Hao Li, Limin Liao, Yun Guo, Xing Li
Department of Rehabilitation, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China; Department of Urology, Rehabilitation School of Capital Medical University, China Rehabilitation Research Center, Beijing, China., Department of Urology, Rehabilitation School of Capital Medical University, China Rehabilitation Research Center, Beijing, China., INFURO Biotechnology, Hangzhou, China., Department of Rehabilitation Medicine, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua Medicine, Tsinghua University, Beijing, China., Department of Rehabilitation, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China; Department of Urology, Rehabilitation School of Capital Medical University, China Rehabilitation Research Center, Beijing, China. Electronic address: .