Patent ID: 7470231

Claim:
A fatigue degree measurement device, comprising: a living body signal peak value detecting means for detecting the peak value in each cycle of an original waveform of the living body signal data collected by a living body signal measurement device; a power value calculating means for calculating the difference between a peak value on the upper limit side and a peak value on the lower limit side for every prescribed time period from each peak value obtained by said living body signal peak value detecting means and for setting the difference as the power value; a power value inclination calculating means for determining an inclination of said power values to the time base during the prescribed time period by slide calculating the prescribed times at a prescribed overlap rate for the prescribed time period; a fatigue degree calculating means for calculating an integral value by absolute value treatment of time base signal of power value inclination obtained from the slide calculation by said power value inclination calculating means to determine the obtained integral value as the degree of fatigue; a maximum Lyapunov index calculating means for calculating the maximum Lyapunov index by chaos analyzing said living body signal data; a maximum Lyapunov index peak value detecting means for detecting the peak value in each cycle of a time series change waveform of the calculated maximum Lyapunov index; a maximum Lyapunov index inclination calculating means for determining an inclination of each peak value of the maximum Lyapunov indexes obtained by the maximum Lyapunov index peak value detecting means to the time base during the prescribed time period by slide calculating the prescribed times at a prescribed overlap rate for the prescribed time period, in addition to said inclination of the power value; and a comparing and determining means for determining as the generating point of a fatigue signal when the inclination of the power value obtained by slide calculating using said power value inclination calculating means and the maximum Lyapunov index obtained by slide calculating using the maximum Lyapunov index inclination calculating means stably showing the phase difference of substantially 180° among time series signals, wherein said comparing and determining means includes a fatigue state determining means for determining the state of fatigue based on the inclinations of power value and the maximum Lyapunov index appearing in time series, and wherein said fatigue state determining means includes a means to perform frequency analysis of the change in the inclinations of power value and the maximum Lyapunov index appeared in time series, and determines a central fatigue predominant state when the power spectrum of the inclination of the maximum Lyapunov index is large, and a peripheral fatigue predominant state when the power spectrum of the inclination of the power value is large.