Implantable multichannel wireless electromyography for prosthesis control

We have developed a prototype implantable device for recording multiple independent channels of EMG and sending those signals wirelessly to an external receiver. This design records multichannel EMG signals for providing simultaneous multi-axis control of prosthetic limbs. This proof-of-concept study demonstrates benchtop performance of the bioamplifier in dry and soaked in saline configurations, as well as system performance in a short-term in vivo study in six dogs. The amplifier was shown to have an input-referred noise of 2.2 μV_RMS, a common mode rejection ratio greater than 55 dB, and neighboring channel isolation averaging 66 dB. The prototype devices were constructed of an amplifier ASIC along with discrete components for wireless function. These devices were coated in silicone and implanted for at least one week in each dog. EMG recorded from each animal as it walked down a hallway had very low noise and swing/stance phases of gait were clearly shown. This study demonstrates this device design can be used to amplify and transmit muscle signals.