An ultrasonic technique for imaging of tissue motion due to muscle contraction

An ultrasonic technique to measure internal tissue motion accurately for real-time imaging of muscle contraction has been developed. An algorithm and procedure to calibrate motion artifact due to undesired body and/or probe movement has been proposed using an ultrasound echo reflected from bone. In order to verify the effectiveness of the proposed technique, a simulation experiment was conducted using a three-layer phantom mimicking a tissue structure of fat, muscle and bone. A mechanical stimulation system was used to produce periodical internal motion in the phantom. The motion artifact due to probe movement during ultrasound signal acquisition was successfully corrected by the proposed technique. Results of in vivo experiments of forced muscle contraction in the forearm using an electrical muscle stimulator showed accurate measurement of internal displacement with compensation of the motion artifact.