Ultra-Low-Power Low-Noise Neural Recording System

The human brain is a collection of millions of neurons that form the basis of perception, recognition and control by simultaneous neuronal activities. Neuronal activities are also associated with several brain related diseases such as epilepsy, perkinson’s, migraine, distonia, etc. To unveil the abnormal activities of neurons in real time fashion, a multielectrode neural recording system (Fig. 1) is essential where the bioamplifiers play a vital role of amplifying the neuronal signals extracted by the neural electrodes. The noise contribution of the bioamplifiers to the entire system must be minimized to improve the system performance. In addition, for an implantable system, the power consumption by the large array of bioamplifiers must be monitored to prevent tissue damage by excessive heating. For reliable operation of an implantable neural recording system, our on-going research focuses on the design of an ultra-low-power low-noise bioamplifier (Fig. 2) structure using standard RF-CMOS technology. The self-biased structure obviates the biasing circuitry and an inverter based gain stage results in improved bioamplifier structure with a minimum number of transistors. We are at present working for the development of an efficient neural recording system for better diagnosis of the neuronal activities.

Fig. 1: Multi-electrode Neural Recording System. Fig. 2: Circuit Schematic of the Ultra-Low-Power Low-Noise Bioamplifier.