A spiral nerve cuff electrode for peripheral nerve stimulation

A novel type of nerve cuff electrode consisting of conductive segments embedded within a self-curling sheath of biocompatible insulation has been developed. This spiral nerve cuff is biased to self-wrap around peripheral nerves and possesses a ´self-sizing´ property, presenting an alternative to present commercially available, fixed-size nerve cuffs that are manually wrapped around nerves and sutured shut (´split-cylinder´ cuffs). Spiral cuff design and manufacture are described. The authors hypothesize that unlike traditional cuffs, the spiral cuff potentially can be implanted safely when sized to fit peripheral nerves snugly. Theoretical pressure analyzes of traditional and spiral cuffs that support this hypothesis are presented. These analyses are designed to predict the minimum CNR (cuff diameter/nerve diameter ratio) at which there is no interference with intraneural blood flow. Results of a preliminary experiment in which snug spiral cuffs were implanted on feline peripheral nerve support the prediction that they may be safe.