Sub-millimeter precision wireless neuromodulation using a microwave split ring resonator

项目摘要 亚毫米空间分辨率的微创神经调制仍然是一个关键但尚未满足的 生物医学的需要。研究人员已经探索了广泛的电磁波， 无线神经调节方法。由于其长波长，经颅磁刺激不 提供足够的空间分辨率以瞄准功能单元，例如在视觉系统中的单个眼优势柱。 视觉皮层或周围神经病变。另一方面，光子由于波长短， 微米级的空间精度，但几乎不能穿透几百微米到组织中， 提到人类头骨频率在300 MHz和300 GHz之间的微波（MW）填补了差距 然而，光波和磁波之间的差异很少被探索用于神经调节。我们提出了一个 利用微波开口环谐振器（SRR）的微创神经调节装置 设计SRR的周长约为MW波长的一半，因此充当谐振腔。 天线它无线耦合微波并将微波集中在差距处，产生 空间中的局部电场约为100 μm。我们的科学前提是基于非热神经 微波的抑制效应和SRR的共振效应。SRR生产浓缩的 微波，并允许超过微波衍射极限的神经调节，达到~100 μm的空间 精度本研究将设计并制作一种植入式钛合金SRR，其上级 生物相容性然后，我们将在体外使用原代神经元验证SRR在神经抑制中的潜力， 一种小鼠体内癫痫模型。通过完成拟议的研究，我们将制定一个 生物相容性和可植入神经调节装置。厘米级穿透深度由 SRR提供的微波和亚毫米空间精度保证了广泛的生物医学应用。 对于中枢神经系统，我们的技术允许微创经颅神经调制， 脑内活动和临床治疗癫痫。一个多学科的团队， 为执行拟议的活动汇集了专门知识。

Project Summary Minimally invasive neural modulation at sub-millimeter spatial resolution remains a critical yet unmet biomedical need. Researchers have explored a broad spectrum of electromagnetic wave and developed wireless neuromodulation methods. Due to its long wavelength, transcranial magnetic stimulation does not provide sufficient spatial resolution to target a functional unit such as a single ocular dominance column in the visual cortex or a diseased peripheral nerve. On the other hand, photons, with their short wavelength, offer micrometer-scale spatial precision but can barely penetrate couple hundred micrometers into the tissue, not to mention the human skull. Microwave (MW), with frequencies between 300 MHz and 300 GHz, fills the gap between optical wave and magnetic wave, yet, has rarely been explored for neuromodulation. We propose a minimally invasive neuromodulation device by taking advantage of a microwave split ring resonator (SRR) design. The SRR has a perimeter of approximately one half of MW wavelength, thus acting as a resonant antenna. It couples the microwave wirelessly and concentrates the microwave at the gap, producing a localized electrical field of ~100 μm in space. Our scientific premise is based on the nonthermal neural inhibitory effect of microwave and the resonance effect of the SRR. The SRR produces concentrated microwave and allows for neuromodulation beyond the microwave diffraction limit, reaching ~100 μm spatial precision. In the proposed work, we will design and fabricate an implantable SRR with titanium for its superior biocompatibility. We will then validate the SRR’s potential in neural inhibition using primary neurons in vitro and a mouse epilepsy model in vivo. By accomplishing the proposed studies, we will have developed a biocompatible and implantable neuromodulation device. The centimeter-scale penetration depth provided by microwave and the sub-millimeter spatial precision provided by SRR promises broad biomedical applications. For central nervous system, our technology allows minimally invasive transcranial modulation of neural activities inside brain and for clinical treatment of epilepsy. A multi-disciplinary team with complementary expertise is assembled to implement the proposed activities.