|
ИСТИНА |
Войти в систему Регистрация |
Интеллектуальная Система Тематического Исследования НАукометрических данных |
||
Distortion of the focal region and saturation effects in strongly focused high intensity ultrasound beams with shocksстатья
- Авторы: Yuldashev P.V., Rosnitskiy P.B., Sapozhnikov O.A., Khokhlova V.A.
- Сборник: Proceedings of Forum Acusticum 2014
- Год издания: 2014
- Место издания: European Acoustics Association - EAA Poland, Krakow
- Аннотация: High intensity focused ultrasound (HIFU) beams containing high amplitude shocks are employed in several therapeutic applications. When shocks are present, saturation effects occur at the focus: the peak pressures increase very slowly with increasing the source power. This effect is explained mainly by efficient nonlinear absorption of ultrasound energy at the shock fronts and nonlinear refraction effects in the focal region of the beam. In this paper, a fine structure of acoustic field containing shocks in the focal region was studied. An axially symmetric focused beam generated by a piston transducer was modeled using the KZK equation in a wide range of the input parameters. It was shown that at very high initial pressures the focal region is strongly distorted in shape and the peak pressure maximum is shifted beyond the geometrical focus of the source. While the peak pressure saturates at the geometrical focus, the pressure at the spatial maximum continues growing. For the transducer of 1 MHz operational frequency, 10.7 cm diameter, and 10 cm radius of curvature, with linear focusing gain of 60, the shock amplitude at the geometrical focus saturated at 120 MPa, while reaching 160 MPa at the spatial maximum.
- Добавил в систему: Юлдашев Петр Викторович
Прикрепленные файлы
| № | Имя | Описание | Имя файла | Размер | Добавлен |
|---|---|---|---|---|---|
| 1. | Полный текст | R14_7.pdf | 353,4 КБ | 29 ноября 2014 [PetrYuldashev] |