Real-time detection of muscle thickness changes during isometric contraction from ultrasonography: A feasibility study

Ultrasonography is a convenient and widely-used technique to look into the muscle contraction as it is non-invasive and real-time. Muscle thickness has been investigated in many aspects and for various purposes. However, there are few studies on automatic estimation of changes of muscle thickness in cross-sectional plane during contraction. In this study we proposed a coarse-to-fine method based on compressive tracking algorithm for real-time estimation of muscle thickness during isometric contraction on ultrasound images. The real-time performance and precision are investigated with data from quadriceps muscle in five subjects. The detection results were compared with those obtained from both cross-correlation algorithm and manual measurement. It is shown that the proposed method agrees well with the manual measurement and outperforms the cross-correlation method in the sense of both accuracy and computation cost.