High-Density Wireless Neural Recording System
This thesis focuses on integrated and miniaturized wireless neural recording systems for bio-instruments for the in-depth understanding on animal behavior, human brain activities, and complex neuroprosthetic devices to treat various neurological diseases. The interdisciplinary nature of the system requires a wide range of knowledge in biology and electronics to build such systems. A unique environment where the system should operate imposes challenging design constraints and system-level issues, which can be solved only by considering both biology and electronics. Fundamental building circuits including amplifiers, filters, analog-to- digital converters (ADCs) are addressed first. Then sub-systems, which consist of those basic circuits, are analyzed with an emphasis on trade-offs, which should be carefully considered to achieve optimal design. Specifically, an ultra wideband communication system for biomedical applications is proposed to overcome the limitation of the data bandwidth and power consumption existing in current conventional systems. Several ICs are designed and fabricated in 0.35um CMOS process to verify the proposed concepts and ideas. Prototype systems are implemented using those fabricated chips, and their test results from the bench top and in animal implantation are presented.