Some Recent Developments in the Design of Biopotential Amplifiers for ENG Recording Systems

This paper describes some recent progress in the development of amplifiers and other signal acquisition and signal conditioning systems for biopotential recording. The discussion will be based on two contrasting applications. The first concerns the connection of implantable amplifiers to arrays of nerve cuff electrodes which requires very low noise design due to the inherently poor signal to noise ratio of the interface. The second example deals with the interface between cultured neurons and standard CMOS technology. In this case the interface impedance is difficult to quantify accurately and is potentially time varying, requiring a different approach to amplifier design, which is tolerant to these parameter uncertainties