Bringing sensation to prosthetic hands—chronic assessment of implanted thin-film electrodes in humans

Direct stimulation of peripheral nerves with implantable electrodes successfully provided sensory feedback to amputees while using hand prostheses. Longevity of the electrodes is key to success, which we have improved for the polyimide-based transverse intrafascicular multichannel electrode (TIME). The TIMEs were implanted in the median and ulnar nerves of three trans-radial amputees for up to six months. We present a comprehensive assessment of the electrical properties of the thin-film metallization as well as material status post explantationem. The TIMEs stayed within the electrochemical safe limits while enabling consistent and precise amplitude modulation. This lead to a reliable performance in terms of eliciting sensation. No signs of corrosion or morphological change to the thin-film metallization of the probes was observed by means of electrochemical and optical analysis. The presented longevity demonstrates that thin-film electrodes are applicable in permanent implant systems

Advanced 56 channels stimulation system to drive intrafascicular electrodes

International audienceA wearable, 56-channel stimulator was developed and successfully tested to drive multichannel intrafascicular electrodes. It is able to safely elicit sensory afferent signals through the activation of 4 Time-4H intrafascicular electrodes. The STIMEP embeds not only the pulse generator but also a software that ensures: i) real time control by a hand-prosthesis, ii) embedded procedures for sensation mapping interfaced with a PC software, iii) impedance follow-up, iv) real-time safety management