Multiphysics analysis of a high-intensity ultrasound system applied to a three-layer animal tissue

Abstract

High-intensity ultrasound systems for medical therapy must be carefully designed, implemented, and applied to avoid tissue damage or injury considering stimulation and relaxation time, frequency, and intensity of ultrasound. Based on these concerns and considering a test three-layer animal tissue consisting of skin, muscle, and bone, we determined the frequency and intensity at which ultrasound effectively stimulates the test animal tissues. In addition, from these ultrasound frequencies and intensities, and taking care the critical temperature recommended to preserve the integrity of the human tissue and avoid any tissue injury, we determine the stimulation and relaxation times. For this purpose, we performed a multiphysics simulation that describes the spatial and temporal dynamics of the thermoacoustic effect of ultrasound applied to test animal tissues. To practically demonstrate this ultrasound behavior, we perform an experimental setup based on an electronic HITU device designed and implemented to freely adjust the ultrasound intensity and frequency, as well as the stimulation time of the test animal tissues. Finally, we conclude that, depending on the test tissue, an ultrasound therapy system should allow the selection of the intensity and frequency of applied ultrasound, as well as the stimulation time to avoid tissue injury, which can be considered by health ministries around the world.