The ability to safely monitor neuropotentials is essential in establishing methods to study the brain. Current research focuses on the wireless telemetry aspect of implantable sensors in order to make these devices ubiquitous and safe. Chronic implants necessitate superior reliability and durability of the integrated electronics. The power consumption of implanted electronics must also be limited to within several milliwatts to microwatts to minimize heat trauma in the human body. In order to address these severe requirements, we developed an entirely passive and wireless microsystem for recording neuropotentials. An external interrogator supplies a fundamental microwave carrier to the microsystem. The microsystem comprises varactors that perform nonlinear mixing of neuropotential and fundamental carrier signals. The varactors generate third-order mixing products that are wirelessly backscattered to the external interrogator where the original neuropotential signals are recovered. Performance of the neurorecording microsystem was demonstrated by wireless recording of emulated and in vivo neuropotentials. The obtained results were wireless recovery of neuropotentials as low as approximately 500 microvolts peak-to-peak (μVpp) with a bandwidth of 10 Hz to 3 kHz (for emulated signals) and with 128 epoch signal averaging of repetitive signals (for in vivo signals).

中文翻译：

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使用射频反向散射方法记录神经电位的全无源无线微系统

安全监测神经电位的能力对于建立研究大脑的方法至关重要。当前的研究集中在可植入传感器的无线遥测方面，以使这些设备无处不在且安全。慢性植入物需要集成电子设备具有卓越的可靠性和耐用性。植入电子设备的功耗也必须限制在几毫瓦到几微瓦之间，以最大限度地减少人体热损伤。为了满足这些严格的要求，我们开发了一个完全被动的无线微系统来记录神经电势。外部询问器为微系统提供基本的微波载波。微系统包括执行神经电势和基本载波信号的非线性混合的变容二极管。变容二极管产生三阶混合产物，这些产物无线反向散射到外部询问器，在那里恢复原始神经电势信号。神经记录微系统的性能通过模拟和体内神经电位的无线记录来证明。获得的结果是神经电势的无线恢复低至约 500 微伏峰峰值 (μVpp)，带宽为 10 Hz 至 3 kHz（对于模拟信号）和重复信号的 128 epoch 信号平均（对于体内信号） ）。