Ultrasound Image Entropy Characteristics Of Muscle Fatigue Process Assessment Studies

Muscle fatigue is a phenomenon that the maximum voluntary contraction strength of the muscle would reduce with the muscular movement. When human body muscle fatigue far beyond the maximum power of muscle itself can afford, the muscle fibers will appear tiny separation or rupture which caused muscle strain, the phenomenon caused serious influence for people’s work, sports, and daily life. Effective assessment and monitoring of muscle fatigue, could reduce the damage caused by exercise or other contraction movement, and can improve people’s living standards, especially improve the level of sports training that has very vital significance.This paper in view of the muscle tissue ultrasonic image texture feature and with the corresponding structure changes because of muscle continuous movement, our study started from the simplified model of muscle tissue ultrasonic image, in view of the muscle tissue in the fatigue process of ultrasonic image entropy variation characteristics, we studied changing law for the ultrasonic image entropy, the conclusion shows that ultrasonic image entropy can be used as an evaluation method of muscle fatigue condition. Specific research work includes:(1) We based on the ultrasonic transmission characteristics in muscle tissue and the theory of ultrasonic imaging. Firstly, the paper studied the features of muscle fatigue. Secondly, we studied the muscle ultrasound images space characteristics that ultrasound image entropy characterized. Finally, we explored the skeletal muscle fatigue process with ultrasound image entropy variation by theoretical analysis.(2) We designed an ultrasonic image entropy detection system, and studied the correlation of muscle tissue structure change in the process of fatigue with the ultrasonic image entropy variation by experimental research.(3) We conducted data processing and analysis. We studied the correlation of each subject muscle fatigue process with ultrasound image entropy, and the SEMG under different load, the correlation of subjects under different load with image entropy variation, and the relationship between the exerted force torque and the time of the muscle ultrasonic entropy reaches the minimum value for the same subject.The conclusion of this paper includes:(1) The ultrasonic image entropy down slope has no significant differences for the same subject with different torque. So we could come to a conclusion that ultrasonic image entropy decreases with time during the muscle fatigue process which mainly depends on the muscle characteristics of the individual, and has no relevance with the exerted force torque.(2)the muscle image entropy downward slope of different subjects are different significantly over time during the muscle fatigue process, and the declining slope of the ultrasonic image entropy is different for different individual muscular development owing to the different person has the different muscle energy storage.(3) The time that the muscle ultrasonic image entropy in the muscle fatigue process decreased to the minimum value or that the muscle reached to a fatigue limit states would become short when the exerted maximal voluntary contraction torque (MVCT) become large for a same subject.The study provides a probable criterion to assess the level of muscle fatigue.