Patent Document ID: 7920914
Application ID: 12372666
Patent Flag: 1

Claim One:
1. A method for predicting the depth of anesthesia, comprising steps of: attaching measuring patch on the center, ground, and right of the brow of a human subject and using an electroencephalography monitor to measure electroencephalogram from the human subject being tested; recording the electroencephalography data from the electroencephalography monitor in the induction phase of anesthesia course; calculating an approximate entropy value from the recorded electroencephalogram signal by using the formula: Approximate Entropy=Φ m (r)−Φ m+1 (r); Φ m ⁡ ( r ) = ( N - m + 1 ) - 1 · ∑ i = 1 N - m + 1 ⁢ ln ⁢ ⁢ C i m ⁡ ( r ) ; wherein C i m (r)=(number of x(j) such that d[x(i),x(j)]≦r)/(N−m+1); x(i)=[u(i),. .. , u(i=m−1)]; x(j)=[u(j),. .. , u(j=m−1)]; u(i),u(2). .. u(N) are time sequence data; u(i),u(2). .. u(N) are time sequence data; wherein N is the length of data cycle; m is the number of data comparison; r is a noise filtering coefficient; computing a corrected approximate entropy value by multiplying the approximate entropy value and 1000/17; displaying the corrected approximate entropy value on a monitor as the subject's the depth of anesthesia state, wherein the displayed entropy value of 70-100 indicates that the subject is in a conscious state or slightly tranquilized state; the displayed entropy value of 60-70 indicates that the subject is in a slight non-conscious state; the displayed entropy value of 40-60 indicates that the subject is in a non-conscious state; and the displayed entropy value of 0-40 indicates that the subject is in an excessively non-conscious state.