Abstract: Changes in the mechanical and/or physiological properties of blood vessel serve as important indicators for prediction of cardiovascular disease. One challenge of the ultrasonic blood vessel measurement is the compression of the vessel due to the weight of a conventional ultrasound probe employed, resulting in the error on the diameter estimation. The presented invention addresses this issue with low-cost wearable ultrasound film sensors, which is flexible and lightweight so that it does not deform the blood vessel of interest beneath the sensor or restrict its motion during the measurement. In the preferred embodiment, the sensor is attached on a body surface above a blood vessel of interest. Pulsed ultrasound is transmitted into the body and the echoes from the posterior and anterior boundaries of a blood vessel are acquired with an ultrasound M-mode measurement. Then, the depth of each boundary is obtained with an ultrasound time of light technique.

Abstract: The temperature distribution in water is measured by two thermocouples to obtain a temperature compensating parameter. Under measurement conditions where the temperature distribution in water varies, a measured V(z) curve is used to monitor a change in the wave number of a longitudinal wave in an ultrasonic wave propagation region in water to thereby detect variations in the water temperature and the longitudinal wave velocity with high accuracy.

Abstract: The temperature distribution in water is measured by two thermocouples to obtain a temperature compensating parameter. Under measurement conditions where the temperature distribution in water varies, a measured V(Z) curve is used to monitor a change in the wave number of a longitudinal wave in an ultrasonic wave propagation region in water to thereby detect variations in the water temperature and the longitudinal wave velocity with high accuracy.