A Review of Microelectronic Systems and Circuit Techniques for Electrical Neural Recording Aimed at Closed-Loop Epilepsy Control

Abstract

Closed-loop implantable electronics offer a new trend in therapeutic systems aimed at controlling some neurological diseases such as epilepsy. Seizures are detected and electrical stimulation applied to the brain or groups of nerves. To this aim, the signal recording chain must be very carefully designed so as to operate in low-power and low-latency, while enhancing the probability of correct event detection. This paper reviews the electrical characteristics of the target brain signals pertaining to epilepsy detection. Commercial systems are presented and discussed. Finally, the major blocks of the signal acquisition chain are presented with a focus on the circuit architecture and a careful attention to solutions to issues related to data acquisition from multi-channel arrays of cortical sensors.

Toward a personalized closed-loop stimulation of the visual cortex: Advances and challenges

“…This procedures allow an improved control of some neurological conditions such as epilepsy ( Ranjandish and Schmid, 2020 ; Farkhondeh Tale Navi et al, 2022 ), and can also be used for better control of obsessive-compulsive disorders and depression ( Figee et al, 2022 ; Visser-Vandewalle et al, 2022 ). Furthermore, it has been shown that the outcome of brain stimulation to treat Parkinson’s disease can be improved by recording brain activity and stimulating only when the local field potentials collected by electrodes inserted in the subthalamic nucleus exceed a certain threshold ( Little et al, 2013 ), or by associating the brain stimulation to specific phases of patients’ tremor activity ( Cagnan et al, 2017 ).…”

Directions of Deep Brain Stimulation for Epilepsy and Parkinson’s Disease

“…There are two main functions of IPG devices: neural recording and stimulation. Owing to the extremely low amplitude of EEG signals, low-noise and low-power electronic design are necessary for recording and analysis ( Ranjandish and Schmid, 2020 ). Subsequently, we introduce DBS electrodes technology, neural recording amplifier and electrical stimulation system in the following paragraphs.…”

“…Electroencephalogram (EEG), electrocorticogram (ECoG), local field potential or action potential is often used in the closed-loop design of an DBS. Because the extremely low amplitude of EEG signals, recording system with low-noise, low-offset, high CMRR and low-power characteristics is necessary for further analysis ( Ranjandish and Schmid, 2020 ). Two principal categories of chopping schemes with instrumentation amplifier are designed.…”