An Enhanced Method of Transcutaneously Stimulating the Tibial Nerve for the Treatment of Overactive Bladder

Transcutaneous electrical nerve stimulation (TENS) can be used to electrically stimulate the tibial nerve for the purpose of treating overactive bladder. Although clinical benefits can be achieved, the overall therapeutic efficacy of TENS is limited. Inconsistent activation of the intended neural target and co-activation of cutaneous sensory fibers are considered key limiting factors. In this study, we propose a novel approach that combines TENS with an implanted, electrically-conductive nerve cuff to reduce the stimulation amplitude needed to activate the tibial nerve. This enhanced version of TENS (called eTENS) was designed using a computational model of the rat tibial nerve and subsequently tested in anesthetized rats. Our computational model showed that eTENS can reduce the nerve activation threshold by a factor of up to 2.6. Similar effects were also achieved by in vivo experiments (1.4 ± 0.1-fold decrease, n = 5). Among various design parameters, spatial alignment between the surface electrode and the nerve cuff was identified as an important factor. Our results show that eTENS can improve the selective activation of the rat tibial nerve, but further work is needed to evaluate its use in clinical therapies.