18polar Hybrid Cuff Electrodes for Stimulation of Peripheral Nerves

For restoration of neuro-muscular functions in disabled people, cuff type electrodes have been used for several 10 years. A lot of experiences were collected using 12polar electrodes, which consisted of silicone tubes, carrying 4 stimulation tripoles, each tripole orientated longitudinally to the nerve. The tripoles were at 0°, 90°, 180°, and 270° position around the nerve. It is obvious that the success of fascicle selective stimulation strongly depends on the position of the tripoles relatively to the nerve and its inner fascicles. It appears to be nearly impossible to selectively excite only the aimed few in a compound of about 40 fascicles of e.g. a radial nerve using a "traditional" 12polar cuff electrode. Higher numbers of stimulation sites seem to be recommendable. Here, we describe the development of a new cuff electrode with 6 tripoles.