Influence of biological tissues and material containment cultures on the behavior of the acoustic field of the therapeutic ultrasound.

Abstract

The uniform distribution of the acoustic field is an important parameter in the dosimetry of therapeutic ultrasound (TUS) since an acoustic beam can lead to non-uniform field production more concentrated or dispersed. Besides reflected in clinical practice, this may interfere with the results of experimental studies that radiate cell cultures or bacteria with UST in containers indices of reflection and refraction different from water and / or culture media. It is unclear how the sound field behaves when crossing biological tissues (skin, muscle and fat) or containers (plastic, glass and acrylic) used in the containment of samples. The objective of this study is to verify the transmission and behavior of the sound field of UST equipment after irradiation of biological tissues and materials containment experimental samples. Samples will be employed for this mouse skin, and skin, muscle and fat pork, all young adults. Will be delimited and withdrawn by incision with a scalpel one segment 6 x 6 cm for the mouse, and four segments for the pig, maintaining the tension of the skin and muscle segments. Biological tissues and materials for containment will be fixed on a specific device for this purpose and will receive the ultrasonic irradiation on acoustic tank and balance of radiation pressure. To verify the behavior of the acoustic field samples are irradiated by UST using an acoustic tank containing water and a hydrophone acoustic needle-shaped. To check the influence of the biological tissue or the containment material in power transmission, the power balance will be measured by acoustic radiation pressure. Based on the results of studies indicating attenuation of the ultrasonic wave to traverse different coupling means and the differences between tissue heating rates between different transducers, it is expected that there is a change in the distribution of the acoustic field to traverse the different tissues and biological materials containing sample, caused by the attenuation and scattering that promotes tissue.