The theory of ultrasound doppler response spectral analysis under isometric muscle contraction

Abstract

By means of the proposed ultrasound Spectral Tissue Doppler (STD) method, spectral characteristics of local isometric muscle contraction of skeletal muscle tissues were studied. The investigation of this method demonstrates its suitability for a more detailed spectral study of some features of biomechanical processes that have occurred under muscle contraction. The dynamic model of the muscle sarcomere movement that takes into account the viscous properties of muscle fibrils (ignoring their elastic properties) and the correlation between sarcomeres within the single myofibril. On the basis of the developed physical model, it is assumed that the mechanochemical characteristics of cross-bridges between actin and myosin filaments are the main factor having an influence upon the spectral peculiarities. Both the developed model of ultrasound Doppler response and the proposed dynamic model of the muscle sarcomere movement establish a link between the macroscopic measurements and the biomechanical processes and behavior of muscle sarcomeres at a microscopic level. The data obtained testify to the proposed ultrasound STD method as a reliable and valid diagnostic tool for diagnosing neuromuscular disorders.