Design of a low-noise, low-power amplifier for multichannel neural recording

• Main Authors: Wang, Zong Ye, 王宗曄
• Other Authors: Chen, Hsin
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/82968911428517065950

碩士 === 國立清華大學 === 電機工程學系 === 102 === In recent years, with the development of CMOS technology and the improvement of process, a number of integrated circuits have been used in biomedical applications. For instance, implantable brain-machine interfaces for treating Parkinson’s disease, epilepsy, and other diseases have attracted more and more attentions and research resources. This thesis aims to study the frontend biomedical amplifier used in the brain-machine interface for studying the mechanism of deep brain stimulation (DBS) and the therapy for the Parkinson’s disease. The continuous, periodic DBS not only inhibits abnormal neuron activities but also suppresses some normal physiological activities. Therefore, a low-noise, frontend amplifier able to record multi-channel local field potentials (LFPs) is demanded. The LFP recordings are not only crucial for positioning the stimulation electrodes optimally but also for controlling stimulation in a closed-loop manner. This thesis uses a chopper technique to achieve the low-noise performance, and eight chopper amplifiers are employed for multi-channel recording. Three versions of amplifiers are designed and tested. While the first version required external capacitors, the second version investigates the feasibility of sharing embedded capacitors among different channels. The main purpose is to minimize the area and power consumption, and the feasibility is discussed according to both simulation and electrical measurement results. In addition, fast-settling control is added to eliminate the stimulation artifact. With the help from the life and science department, we use the second version amplifier to do biological experiment and get some data from the Parkinson’s disease rat successfully, including abnormal neuron potentials. However, the second version is found to exhibit some hardware non-idealities, including the slew rate, the linearity, and VDD noise resistibility. Therefore, we summarize the drawbacks and design the third version of the low-noise amplifier. According to the testing of the three versions of amplifiers, the design guidelines and considerations will be concluded in the thesis.