Analogue/digital interface and communications aspects in a multi-channel ENG recording asic

The detection and classification of afferent nerve signals presents a challenge due to the very low amplitude of the Electro-Neurogram (ENG) signals compared to background interference and the large number of neural signals, both afferent and efferent that are generally present in a single nerve. One approach to the solution of these problems employs velocity selective recording (VSR). However, the implementation of a practical VSR system places significant bandwidth requirements on the specification of the various implanted system components and the cables used to interconnect them. In this paper we discuss the important parameters of a conventional VSR system and suggest an alternative solution which we refer to as period matching. The effect of the use of this method is to ease the overall bandwidth constraints of the system.