A Combined Interfascicular-Cuff Electrode (ICE) for Selective Recruitment of Polyfascicular Peripheral Nerves Using Transversal Stimulation

Selective electrical stimulation of peripheral nerves has shown potential in reducing symptoms of Phantom Limb Pain (PLP). The cuff electrode design is used in clinical applications, however, it is not able to selectively activate deeper fascicles of large human sized nerves. This work investigates the effects of combining an Interfascicular and a Cuff Electrode (ICE). An ICE was constructed, consisting of an eight contact cuff (two full ring contact sites in each end, six contact sites in a center ring configuration) and an interfascicular wire electrode, which was placed in the center of the nerve. In vitro experiments were conducted on three pig median nerves. During in vitro experiments transversal stimulation was performed using the cuff alone or in combination with the interfascicular electrode. The evoked Compound Action Potentials (eCAP) were recorded from 26-30 individual fascicles and used to quantify the selectivity performance of the different stimulation configurations. Device selectivity was 0.25 +/- 0.10 for the ICE and 0.20 +/- 0.11 for the cuff. This is an improvement of 22.08% +/- 13.60% for the ICE over the cuff. The ICE could therefore prove to be a simple and effective improvement over existing cuff electrodes, which could see potential use in treatment of PLP and other areas where selective stimulation is required.