Method and device for acquiring biomechanical parameters based on ultrasonic elastomyogram

A device for acquiring a muscle biomechanical parameter based on an ultrasonic elastomyogram, the device comprising a processor and a non-transitory computer-readable storage medium storing program instructions executable by the processor, wherein the program instructions when executed by the processor cause the device to perform the following operations:

• synchronously collecting a dynamic myodynamics image sequence and a dynamic elasticity image sequence of a single skeletal muscle under continuous stretching;
• acquiring a myodynamics parameter corresponding to each myodynamics image in the dynamic myodynamics image sequence and an elasticity modulus value corresponding to each elasticity image in the dynamic elasticity image sequence respectively;
• and
• generating an ultrasonic elastomyogram curve with the myodynamics parameter as the abscissa and the synchronized elasticity modulus value as the ordinate, and estimate a muscle biomechanical parameter based on the ultrasonic elastomyogram curve;
• wherein after the generating an ultrasonic elastomyogram curve with the myodynamics parameter as the abscissa and the synchronized elasticity modulus value as the ordinate, and before the estimating a muscle biomechanical parameter based on the ultrasonic elastomyogram curve, the program instructions when executed by the processor further cause the device to perform the following operations:
• determining whether the ultrasonic elastomyogram curve matches with a preset mechanical model curve, and if the ultrasonic elastomyogram curve matches with the preset mechanical model curve, perform the operation of estimating a muscle biomechanical parameter based on the ultrasonic elastomyogram curve;
• wherein the myodynamics image comprises a displacement image, the myodynamics parameter comprises a muscle stretching length, and the estimating the muscle biomechanical parameter based on the ultrasonic elastomyogram curve comprises:
• acquiring a model formula corresponding to the ultrasonic elastomyogram curve and each of parameters in the model formula as follows:
• E=E0;l≤l0;
• E=k(eα(l−l0)−1)+E0:l>l0
• where E0 represents a relaxed elasticity modulus value of the single skeletal muscle, l0 represents a relaxed length of the single skeletal muscle, α represents a hardness index i.e. the muscle biomechanical parameter of the single skeletal muscle to be solved for, e represents the natural number, l represents the length of the single skeletal muscle when it is being stretched, and k is a proportionality coefficient;
• determining, according to the parameters, the length of the single skeletal muscle in the relaxed state, the elasticity modulus value corresponding to the length of the single skeletal muscle in the relaxed state, and an extension degree of the single skeletal muscle, wherein the extension degree is a difference between a maximum stretching length of the single skeletal muscle and the length of the single skeletal muscle in the relaxed state;
• and
• applying Gauss-Newton iterative method to the model formula to determine a hardness index of the single skeletal muscle, when the length of the skeletal muscle is greater than the length of the single skeletal muscle in the relaxed state.