New easy to install nerve cuff electrode using shape memory alloy armature.

This paper presents an easy to install nerve cuff electrode dedicated to functional electrical stimulation (FES). In this new device, a shape memory alloy (SMA) armature is used to perform the closing of the electrode. This technique makes the electrode installation around the nerve much easier, quicker, and safer. Both remarkable mechanical properties of SMA materials, namely, shape memory effect and superelasticity, can be used to obtain the desired mode of electrode closing. The fabrication procedure of the new electrode is described. It does not require any expensive or complex techniques. Bipolar and tripolar electrodes have been manufactured with an inner diameter of 1.6 mm and a cuff wall thickness of 0.8 mm. These electrodes are to be used for FES of the bladder in spinal cord injured patients. Acute studies in dogs are being carried out to validate the device and the implantation procedure.