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

This paper presents an easy to install nerve cuff electrode dedicated to fu nctional electrical stimulation (FES). In this new device, a shape memory a lloy (SMA) armature is used to perform the closing of the electrode. This t echnique makes the electrode installation around the nerve much easier, qui cker, and safer. Both remarkable mechanical properties of SMA materials, na mely, shape memory effect and superelasticity, can be used to obtain the de sired mode of electrode closing. The fabrication procedure of the new elect rode is described. It does not require any expensive or complex techniques. Bipolar and tripolar electrodes have been manufactured with an inner diame ter 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 studi es in dogs are being carried out to validate the device and the implantatio n procedure.