Verification and validation of an electrode array for a blink prosthesis for facial paralysis patients

We are developing an implantable functional electrical stimulation (FES) system to restore eye blink activity in patients with unilateral paralysis. This implantable system will record blink from the contralateral, neurally-intact eyelid to use as a timing signal for stimulation of the paretic eyelid. An implantable electrode array for stimulating the paralyzed eyelid should be both thin and highly flexible. We have developed a novel conductive polymer electrode array by depositing a platinum-doped ink on a nonconductive polymer substrate. To test the mechanical stability of this structure we conducted an in vitro study to flex the test structure over a bend radius while monitoring electrode impedance over 25 million cycles so far. The size of device was validated by implanting the device in a cadaveric eyelid to assess surgical access questions. In addition, we have conducted preliminary in vivo studies in animal subjects to validate this engineering approach. This chronic study has validated the stability of the array to withstand the mechanical rigors of surgical implantation.