Wireless Neural Stimulation in Freely Behaving Small Animals

Abstract

We introduce a novel wireless, low-power neural stimulation system for use in freely behaving animals. The system consists of an external transmitter and a miniature, implantable wireless receiver-stimulator. The implant uses a custom integrated chip to deliver biphasic current pulses to four addressable bipolar electrodes at 32 selectable current levels (10 microA to 1 mA). To achieve maximal battery life, the chip enters a sleep mode when not needed and can be awakened remotely when required. To test our device, we implanted bipolar stimulating electrodes into the songbird motor nucleus HVC (formerly called the high vocal center) of zebra finches. Single-neuron recordings revealed that wireless stimulation of HVC led to a strong increase of spiking activity in its downstream target, the robust nucleus of the arcopallium. When we used this device to deliver biphasic pulses of current randomly during singing, singing activity was prematurely terminated in all birds tested. Thus our device is highly effective for remotely modulating a neural circuit and its corresponding behavior in an untethered, freely behaving animal.

Silicon-Integrated High-Density Electrocortical Interfaces

“…One of the most straightforward strategies is to employ serial dcblocking capacitors, inherently forcing the net dc to be zero all the time. This method has been employed for neural stimulation applications [97]- [99] due to its intrinsic safety when area permits. However, the required blocking capacitance is often prohibitively large for onchip integration, and is thus inadequate for high-density and/or miniaturized implants.…”

Self-Tracking Energy Transfer for Neural Stimulation in Untethered Mice

“…Wireless systems for neural modulation have been developed in order to eliminate tethers [5][6][7][8][9][10][11][12]. Most systems for mice need to be wirelessly powered due to the substantial size and weight of batteries relative to that of the animal [6,13].…”

Closed loop deep brain stimulation: an evolving technology

“…Recently, numerous articles on wireless telemetry for neural stimulation and recording system have been published. Among many of these reported works Arfin et al [60] developed a wireless neural stimulation system. The system consisted of an external transmitter which is controllable through a computer interface, and a miniature, implantable wireless receiver-stimulator as well as four addressable bipolar electrodes.…”

“…The transmitter transmited commands to the implantable system for delivering biphasic current pulses to electrodes at 32 selectable current levels (10 lA-1 mA). However, the system is battery dependent and an open loop system [60]. Another wireless implantable microelectronic device for transmitting cortical signals transcutaneously to interface a cortical microelectrode array to an external computer for neural control applications was developed by Song et al [61].…”