Ultra-low power wireless neural recording implant: novel pulse representation

描述(申请人提供)：该项目的总体目标是设计新一代完全可植入的柔性衬底微电极阵列探头，以记录表现良好的啮齿动物的神经活动。在现有的方法中，行为正常的啮齿动物要么被绑在身上的外部设备拴住，要么被束缚住。一个完全可植入的单元将通过在不受限制的条件下对大鼠的神经记录来改进对大脑功能的表征。建议的设备是电池供电的电子芯片，利用最先进的集成和点火(IF)表示和经过验证的协议：微线阵列、柔性基板和无线通信。使这种可植入规范成为可能的是能够降低功耗和传输高分辨率数据所需带宽的新的中频采样原理。我们预计有可能建造一种植入物，它使用不到2 mW的总功率来记录、放大、编码和无线传输16个通道的场电位和细胞外活动，持续72-96小时，具体取决于数据速率。外部信号重建算法将以20 kHz的采样率输出至少40dB精度的神经数据(在高幅度信号区域更好)。为了设计、表征、制造和在体测试佛罗里达无线可植入记录电极(FWIRE)，我们特别提出：1.基于新型积分点火采样方案，对超低功耗16通道脉冲输出放大器进行设计、VLSI制作、在体测试和制定系统指标。该子系统的总体功耗将低于1 mW。2.设计了一种超功率(1 MW)、低带宽(500K脉冲/秒)的无线链路，并使用柔性基板将多个模块(电极、集成和发射放大器、通信链路)集成到可植入的封装中。3.体内研究可植入探头发育全过程中的FWIRE特征。将预测、发现并纠正设计中的瓶颈；系统性能将得到充分表征。

DESCRIPTION (provided by applicant): The overall goal of this project is to design a new generation of fully implantable flexible substrate microelectrode array probes to record neural activity from behaving rodents. In existing approaches, the behaving rodents are either tethered or encumbered by external devices strapped to their bodies. A fully implantable unit would allow improved characterization of brain function via neural recordings in rats in an unrestrained condition. The proposed device is a battery powered electronic chip that utilizes the state-of- the-art integrate-and-fire (IF) representation and proven protocols: microwire array, flexible substrate, and wireless communication. What makes this implantable specification possible is anew IF sampling principle that is able to reduce both the power dissipation and the necessary bandwidth to transmit high-resolution data. We anticipate that it is possible to build an implant that uses less than 2mW of total power dissipation to record, amplify, encode and transmit wirelessly 16 channels of field potentials and extracellular action for 72-96 hours depending on the data rates. An external signal reconstruction algorithm will output neural data with at least 40dB accuracy (better on high amplitude signal regions) at a 20 kHz sampling rate. In order to design, characterize, build and test in vivo the Florida Wireless Implantable Recording Electrodes (FWIRE), we specifically propose: 1. To design, fabricate in VLSI, test in vivo and formulate system specifications for an ultra low power 16- channel amplifier with pulsed output based on the novel integrate-and-fire sampling scheme. The overall power consumption of this subsystem will be below 1mW. 2. To design an ultra-power (1mW), low-bandwidth (500Kpulses/sec) wireless link and integrate the multiple modules (electrodes, integrate-and-fire amplifiers, communication link) into an implantable package using a flexible substrate. 3. To study in vivo the characteristics of FWIRE during the full duration of the implantable probe development. Bottlenecks in the design will be anticipated, found, and corrected; system performance will be fully characterized.