Optimization of a wearable pudendal nerve stimulator using computational models.

After spinal cord injury, lower urinary tract functions may be disrupted. Trans-rectal stimulation of the pudendal nerve may enable patients to regain these functions via minimally invasive means. Using a finite element model of a wearable trans-rectal stimulator in the pelvic region, and a computational model of mammalian nerve fiber, various electrode configurations and the corresponding required current levels were studied. A configuration requiring considerably lower current level than previously reported was identified. For this configuration, the strength-duration curve was simulated and the effect of different stimulus waveforms on the required current was studied. In addition, the study examined whether a multi-electrode device could selectively activate different terminal branches of the pudendal nerve.