Novel Methods for Measuring Depth of Anesthesia by Quantifying Dominant Information Flow in Multichannel EEGs.

Kab-Mun Cha,Hyun-Chool Shin,Gyu-Jeong Noh,Byung-Moon Choi

doi:10.1155/2017/3521261

Kab-Mun Cha, Hyun-Chool Shin + Show 2 more

Open Access

https://doi.org/10.1155/2017/3521261

Copy DOI

Abstract

In this paper, we propose novel methods for measuring depth of anesthesia (DOA) by quantifying dominant information flow in multichannel EEGs. Conventional methods mainly use few EEG channels independently and most of multichannel EEG based studies are limited to specific regions of the brain. Therefore the function of the cerebral cortex over wide brain regions is hardly reflected in DOA measurement. Here, DOA is measured by the quantification of dominant information flow obtained from principle bipartition. Three bipartitioning methods are used to detect the dominant information flow in entire EEG channels and the dominant information flow is quantified by calculating information entropy. High correlation between the proposed measures and the plasma concentration of propofol is confirmed from the experimental results of clinical data in 39 subjects. To illustrate the performance of the proposed methods more easily we present the results for multichannel EEG on a two-dimensional (2D) brain map.

Highlights

Depth of anesthesia (DOA) should be accurately and adequately maintained in order to prevent potential intraoperative side effects such as hypertension, tachycardia, sweating, lacrimation, increased skeletal muscle tone, and spontaneous movement [1]
The change in consciousness level before and after anesthesia was examined by quantification of information flow of a multichannel EEG
the minimum (Tmin), and the mean (Tmean) were suggested as the indices for the three bipartitions

Summary

Introduction

Depth of anesthesia (DOA) should be accurately and adequately maintained in order to prevent potential intraoperative side effects such as hypertension, tachycardia, sweating, lacrimation, increased skeletal muscle tone, and spontaneous movement [1]. Several DOA measurements use the features of anesthesia mentioned earlier, including the autonomic nervous systembased methods such as degree of muscle relaxation, hemodynamics, perspiration, and lacrimation [6], as well as the heart rate variability- (HRV-) based method reflecting change in brainstem function [7, 8]. Little correlation between these parameters and the function of the cerebral cortex, which hardly reflects change in DOA [9, 10], might cause intraoperative awareness. The function of the cerebral cortex should be considered in indices for DOA monitoring

Objectives

Methods

Results

Conclusion