| Many chronic EMG and neural recording situations are hampered by interference, signal crosstalk, and noise. Shielding is not always practical, and low-noise cables are difficult to work with.;The goal of this project is the development of encapsulation and design techniques which facilitate the construction of miniature, active bioelectric sensors suitable for chronic implantable use in humans.;A stable, low-noise, bioelectric interface could increase the capabilities of many prosthetic devices by providing numerous independent control sites. Increasing the selectivity and number of control sites is often crucial to enhancing the usefulness of the device. Other uses include biofeedback and motor-link systems.;Using a dual monolithic J-FET follower, a sensor of this type has been developed and tested. Although intended for implanted EMG use, with minimal alteration it can be adapted to a variety of electrodes. Silicone resins and elastomers have been used to protect the electronic device and provide biocompatibility. The 1200um diameter of this bipolar sensor has been achieved through the use of non-standard hybrid techniques in conjunction with applications of state-of-the-art encapsulants.;The primary cause of these recording problems is the high impedance of many electrodes. An implantable active unity gain buffer located at the electrode site can virtually eliminate most common recording problems. |
