Ultrasonography has the characteristic of noninvasive

radiation-free

real-time and so on. It has unparalleled advantages in the study of muscle contraction and relaxation process. Ultrasonic images can be used to obtain tissue data in real-time

from which physiological anatomical information such as muscle fiber angle

muscle fiber length

muscle cross-sectional area and muscle thickness can be extracted. Based on this

a method for measuring the thickness of biceps brachii is proposed. The method includes three steps: extraction and tracking of the superior sarcolemma feature point; extraction and tracking of the feature line of the inferior sarcolemma; and calculation of muscle thickness. Effectiveness of this method is verified by manual measurement on the collected images. Experimental results show that this method can achieve auto measurement of muscle thickness in sequence of ultrasound images.