Microelectronic neural bridge for signal regeneration and function rebuilding over two separate nerves

According to the feature of neural signals,a micro-electronic neural bridge(MENB)has been designed. It consists of two electrode arrays for neural signal detection and functional electrical stimulation(FES),and a microelectronic circuit for signal amplifying,processing,and FES driving.The core of the system is realized in 0.5-μm CMOS technology and used in animal experiments.A special experimental strategy has been designed to demonstrate the feasibility of the system.With the help of the MENB,the withdrawal reflex function of the left/right leg of one spinal toad has been rebuilt in the corresponding leg of another spinal toad.According to the coherence analysis between the source and regenerated neural signals,the controlled spinal toad’s sciatic nerve signal is delayed by 0.72 ms in relation to the sciatic nerve signal of the source spinal toad and the cross-correlation function reaches a value of 0.73.This shows that the regenerated signal is correlated with the source sciatic signal significantly and the neural activities involved in reflex function have been regenerated.The experiment demonstrates that the MENB is useful in rebuilding the neural function between nerves of different bodies.     

单片集成低功耗神经信号检测CMOS放大器

采用CSMC 0.6μm CMOS工艺设计了可用于植入式神经信号检测的放大器芯片.电路适用于卡肤电极系统,包括低噪声前置放大级、由电流模仪表放大器构成的主放大级、输出缓冲级和恒跨导偏置级.电路工作于2.5V/±1.25V,功耗180μW.为满足体内植入式神经信号检测的要求,通过电路改进以避免使用片外元件,实现了单片集成.根据神经信号的特点,电路频率响应带宽设计为59Hz～12.8kHz,增益80dB.采用时域方法测试,芯片达到设计目标,有望用于体内神经信号检测.依据测试结果分析了电路特性并提出改进方法.     

单片集成低功耗神经信号检测CMOS放大器

采用CSMC 0.6μm CMOS工艺设计了可用于植入式神经信号检测的放大器芯片.电路适用于卡肤电极系统,包括低噪声前置放大级、由电流模仪表放大器构成的主放大级、输出缓冲级和恒跨导偏置级.电路工作于2.5V/±1.25V,功耗180μW.为满足体内植入式神经信号检测的要求,通过电路改进以避免使用片外元件,实现了单片集成.根据神经信号的特点,电路频率响应带宽设计为59Hz～12.8kHz,增益80dB.采用时域方法测试,芯片达到设计目标,有望用于体内神经信号检测.依据测试结果分析了电路特性并提出改进方法.     

一种用于中枢神经信号再生的四通道微电子系统

This paper presents a microelectronic system which is capable of making a signal record and functional electric stimulation of an injured spinal cord. As a requirement of implantable engineering for the regeneration microelectronic system, the system is of low noise, low power, small size and high performance. A front-end circuit and two high performance OPAs （operational amplifiers） have been designed for the system with different functions, and the two OPAs are a low-noise low-power two-stage OPA and a constant-gm RTR input and output OPA. The system has been realized in CSMC 0.5-μm CMOS technology. The test results show that the system satisfies the demands of neuron signal regeneration.     

A multi-channel analog IC for in vitro neural recording

Recent work in the field of neurophysiology has demonstrated that, by observing the firing characteristic of action potentials (AP) and the exchange pattern of signals between neurons, it is possible to reveal the nature of "memory" and "thinking" and help humans to understand how the brain works. To address these needs, we developed a prototype fully integrated circuit (IC) with micro-electrode array (MEA) for neural recording. In this scheme, the microelectrode array is composed by 64 detection electrodes and 2 reference electrodes. The proposed IC consists of 8 recording channels with an area of 5 × 5 mm². Each channel can operate independently to process the neural signal by amplifying, filtering, etc. The chip is fabricated in 0.5-μ m CMOS technology. The simulated and measured results show the system provides an effective device for recording feeble signal such as neural signals.     

实现分离神经间信号再生和功能重建用的微电子神经桥

根据神经信号的特性设计了微电子神经桥。微电子神经桥包括神经信号探测电极、功能电激励电极和神经信号放大、处理及功能电激励驱动电路,其核心电路采用集成电路0.5μm CMOS工艺实现,已经通过电学测试并应用于动物实验。文中设计了一个特别的实验方案以验证微电子神经桥的可行性。在微电子神经桥辅助下,脊蟾蜍的缩腿反射可以在另外一只脊蟾蜍对应腿上重建。经过相关性分析,受控脊蟾蜍的坐骨神经信号相对于信源脊蟾蜍的坐骨神经信号延迟0.72ms,而且互相干函数值达到0.73,所以受控坐骨神经信号与信源坐骨神经信号显著相关,与反射相关的神经功能得到再生。实验证明微电子神经桥可以在异体神经间实现功能重建。