A non-contacted ultrasound system for inner muscle evaluation in rehabilitation support system

This paper describes an air-coupled ultrasound measurement system to evaluate activities of inner muscle. The system measures inner muscle with lower constrain than conventional method by using MR image, X-ray CT and contacted ultrasound. In generally, sound intensity of air-coupled ultrasound is too small to measure it. To measure the small signal, the system employs a pulsar-receiver with high sensitive pre-amplifier, and wave detection method based on fuzzy inference finds transmitted wave from noisy received wave. The fuzzy inference is derived from characteristics of transmitted wave such as amplitude, frequency, similarity and traveling time. In the experiment, we evaluate the accuracies of wave detection method for human body.