RESUMO
Deeply implanted bioelectronic devices that selectively record and stimulate peripheral nerves have the potential to revolutionize healthcare by delivering on-demand, personalized therapy. A key barrier to this goal is the lack of a miniaturized, robust, and energy-efficient wireless link capable of transmitting data from multiple sensing channels. To address this issue, we present a wireless galvanic impulse link that uses two 500µm diameter planar electrodes on the outside of a nerve cuff to transmit data to a wearable receiver on the skin's surface at rates greater than 1Mbps. To achieve an energy-efficient, high data rate link, our protocol encodes information in the timing of narrow biphasic pulses that is reconstructed by the wearable receiver. We use a combination of modeling and in vivo and in vitro experimentation to demonstrate the viability of the link. We demonstrate losses lower than 60dB even with significant, 50mm lateral misalignment, ensuring a sufficient signal-to-noise ratio for robust operation. Using a custom, flexible nerve cuff, we demonstrate data transmission in a 14mm-thick rodent animal model and in a 42mm-thick heterogeneous human tissue phantom.
Assuntos
Próteses e Implantes , Tecnologia sem Fio , Animais , Humanos , Desenho de Equipamento , Nervos Periféricos/fisiologia , EletrodosRESUMO
Selective neuromodulation of peripheral nerves is an emerging treatment for neurological diseases that are resistant to traditional drug therapy. While nerve cuffs with multichannel stimulation can be made by many varied methods, they usually require specialized microfabrication or additive manufacturing equipment. A truly low-cost and effective method of creating a custom cuff has not been accessible to researchers to prototype new methodologies and therapies in acute studies. Here, we present an inexpensive, highly repeatable method to create multi-contact nerve cuffs that require a simple postproduction PEDOT:PSS coating to improve the tissue/electrode interface. We demonstrate spatially selective neuromodulation with the proposed cuff design on the rat sciatic by preferentially activating the tibialis anterior (TA) and the lateral gastrocnemius (LG) in longitudinal and transverse stimulation patterns. This demonstrates that the proposed cuff fabrication method was not only effective for selective neuromodulation, but it is also significantly lower in cost, fully-customizable, and easily manufactured for future selective neuromodulation studies.
Assuntos
Músculo Esquelético , Nervo Isquiático , Ratos , Animais , Nervo Isquiático/fisiologia , Eletrodos Implantados , Músculo Esquelético/fisiologia , Estimulação Elétrica , Desenho de EquipamentoRESUMO
We present a small (43mm x 24mm x 15mm), off-the-shelf wireless neurostimulator for rodent deep brain stimulation research. Our device enables researchers to wirelessly configure stimulator settings, such as amplitude, pulse width, channel selection, and frequency, via a phone app. The system uses impedance-independent current-mode stimulation and steers current to a selected channel. In addition to monophasic and biphasic stimulation, the system also supports arbitrary waveform stimulation using pre-stored lookup tables. The system uses a configurable grounding phase to clear residual charge and a stimulation compliance monitor to ensure safe operation. The compliance monitor wirelessly reports the current during stimulation, the amount of passive recharge current, and the DC voltage of the electrode interface. The 400mAh battery is easy to replace and can go over 40 hours between charges. The system can be built for less than $50 using easy-to-source components to support inexpensive, highly-parallel research applications.