Patent Document ID: 20090177108
Application ID: 12372666
Patent Flag: 0

Claim One:
1. A method for predicting the depth of anesthesia, comprising steps of: Step 1: attaching measuring patch on the center, ground, and right of the brow of the subject and using electroencephalography (EEG) monitor to measure electroencephalogram (EEG) from the subject being tested; Step 2: a computer records the electroencephalography (EEG) data from electroencephalography (EEG) monitor in the induction phase of anesthesia course; Step 3: using a computer to calculate the approximate entropy value from the recorded electroencephalogram (EEG) signal using the formula 
 Approximat Entropy=Φ m ( r )−Φ m+1 ( r ); wherein Φ m ( r ) = ( N - m + 1 ) - 1 · ∑ i = 1 N - m + 1 ln C i m ( r ) ; 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; wherein N is the length of data cycle; m is the number of data comparison; r is a noise filtering coefficient; Step 4: using a computer to compute corrected approximate entropy value by multiplying the approximate entropy value obtained in step 2 to 1000/17; Step 5: displaying calculated corrected approximate entropy value on a monitor as the subject's the depth of anesthesia state.