Visualized Pulse Signal Detecting Method For Mental Fatigue Recognition

Fatigue refers to an unhealthy state of human body under certain environment conditions which caused by too much prolonged or excessive physical or mental work and which can lead to decline of working efficiency. Mental fatigue is the origin of many diseases. Human brain under the excessive and overloaded tasks especially meatal tasks for a long period can cause the decline or damage of physical function.The state of chronic fatigue will lead to the decrease of immune system and endocrine disorders and so on. In that case, variety of diseases would be infected, such as influenza, cardiovascular disease, diabetes and other diseases. Therefore, avoiding the fatigue is the key to prevent the invasion of various diseases. Since fatigue is usually not accompanied with clear pathological features. Therefore, it's difficult to detect the fatigue state through clinical examination and evaluation.Pulse signal contains abundant human physiological information, which reflects the various physical and physiological changes in subsystems of hunman body. Through pulse feeling analysis can get the information which reflects the state of human health and can be applied on fatigue state judging and classifation the level of mental fatigue. The research on objectivizing of traditional Chinese pulse diagnosis have significant value on disease prevention, family health, accidents prevention and fatigue prevention and so on.This article summarized the present research situation both in domestic and abroad, then the research process and method on Chinese pulse checkings are systematically analyzed. Pulse image detecting device which was developed by our research team is applied to acquire the pulse image data of testees. In mental fatigue test, 30 volunters are organized to join the test designed as three arrays addition and subtraction operations for 3 hours in a quiet environment, in that case it was supposed that 30 volunters are all in mental fatigue situation. The pulse image data which acquired as vedio areprocessed with image correlation algorithm and the pulse signals of each volunter is obtained, pulse signals are processed by low pass filter for de-noising and non-drifting. According to the mechanism and characteristics of pulse signal, several features wich can reflect the physical and pathological relationship between human body and pulse signal, including the power spectrum peak value, peak frequency, center of gravity, gravity frequency of power spectrum, the value of SER, zero weight of cepstral, the ratio of cepetral first harmorous wave amplitude and zero weight of cepstral, energy value of four frequency bands form OHz to 20Hz which decomposed by wavelet-packet. Mental fatigue identification is also applied the morden signal processing method, through applying the maxim value of AR parameter spectrum, the accurate rate of the two patterns can reach 90%.After the classification test for 60 groups of samples which belong to 30 volunters by applying LDA examination, the average accurate rate reach to 81.7%.Though BP neural network classification for two patterns, the accurate rate reach to95%. Through these two kinds of classification methods, it is proved that our test and signal processing methods are efficient and objective. Finally the conclusion and the forecast are drawn for our subject.