It has long been suspected that tethering forces between a peripheral nerve interface device and a connector mounted on the skin can cause... Show moreIt has long been suspected that tethering forces between a peripheral nerve interface device and a connector mounted on the skin can cause wire breakage and device failure in a relatively short time. This has been confirmed by our own experimental observations. Devices and methods have been developed that eliminate the need for a wire tether by replacing it with a wireless power and data transmission system based on mutual induction. Wireless systems, however, require the use of electronic components placed directly on the nerve being interfaced, which could be an alternate source of trauma to the tissue. An additional difficulty with wireless devices is their placement within the body. Wireless power and data transfer often depend on the successful coupling of inductive coils in the transmitter and receiver. The strength of this coupling changes with the distance, alignment, and size difference between the two coils. This creates practical limits on where implanted devices can be placed within the body. Typically, implantable wireless devices utilizing mutual induction approach this problem by making their inductive coils larger. The relationship between on-nerve device size and damage to the interfaced tissue has not been thoroughly studied for implantable peripheral nerve interface devices. Two experimental phases were devised to investigate the biological impact in-vivo of wired versus wireless devices and increasing the size of wireless devices. First, a 14-month study was performed to assess the chronic usability of this type of interface. Next, a 10-week study was performed to closely investigate the tissue response to implanted devices. The conclusion of this work is that for wireless modules integrated with peripheral nerve cu s, there is not a correlation between electronics package size and overall nerve health as based upon histological and functional assays. This suggests that use of untethered wireless, rather than tethered wired, interfaces may be better for the health of the nerve interface even when utilizing a broad range of wireless electronic package sizes. Ph.D. in Biomedical Engineering, May 2018 Show less
