A Bluetooth Low Energy (BLE)-enabled Microdevice for Activity-dependent Stimulation in Nonhuman Primates

Abstract

This paper reports on the design, fabrication, and assembly of a Bluetooth low energy (BLE)-enabled microdevice for activity-dependent stimulation (ADS) in nonhuman primates (NHPs). The microdevice is partitioned into two miniaturized head-mounted and backpack units with compact enclosures. The head-mounted unit houses a previously developed application-specific integrated circuit (ASIC) for ADS along with all the requisite peripheral hardware. The backpack unit houses power-management electronics and a BLE module for bidirectional wireless communication between the head-mounted unit and a BLE-enabled user base station. The overall microdevice weighs ~48g and consumes ~618µW from a lithium-ion battery (3.6V, 1.6Ah) placed in the backpack unit. Moreover, the overall functionality of the microdevice is experimentally demonstrated in vitro in saline via recording and discriminating neural spike waveforms as well as performing spike-triggered stimulation. The microdevice is envisioned for use in longitudinal experiments assessing the effects of ADS on facilitating functional recovery in an NHP model of traumatic brain injury.