Abstract: The present invention relates to a more accurate method for measuring anesthetic depth compared to existing methods for measuring anesthetic depth by using a cepstrum technique, thereby providing an anesthetic depth at an appropriate time even during sudden changes in anesthetic states.

Abstract: The present invention rapidly reacts to changes in the degree of anesthesia to provide an accurate and timely anesthetic depth measurement result, and a method for measuring anesthetic depth comprises the steps of: an epoch dividing portion generating an epoch signal by dividing a EEG signal into a plurality of numbers based on time units, a coefficient portion extracting a CAI calculation value (CAI) by calculating the number of points in an epoch having a value higher than an established critical value, a Shannon entropy calculating portion extracting a Shannon entropy calculation value (ShEn) by conducting a Shannon entropy-calculation from the EEG signal, and a spectra entropy calculating portion extracting a spectra entropy value (SpEn) by conducting a spectra entropy calculation; an improved Shannon entropy extracting portion extracting an improved Shannon entropy calculation value (MshEn) by multiplying the Shannon entropy calculation value (ShEn) and the spectra entropy calculation value (SpEn); and a