Title :
Determination of focal field strength in ultrasound hyperthermia
Author :
Koymen, Hayrettin ; Ozyar, M. Serhat
Author_Institution :
Dept. of Electr. & Electron. Eng.., Middle East Tech. Univ., Ankara, Turkey
Abstract :
The lack of noninvasive thermometry systems capable of determining three-dimensional temperature distributions is a major problem in all types of hyperthermia treatment. A study of estimation of the temperature distribution around tumors for focused ultrasound hyperthermia systems was performed. The difference-frequency wavefield formed by focusing a 100% amplitude-modulated 925-kHz acoustic wave carrier with a 25-kHz modulating signal in a water medium was analyzed. Related phase and amplitude measurements of this field were performed. These measurements are used to determine the mean size of the focus and the intensity of acoustic energy at the focus, which yields an estimate for the temperature distribution in the focal volume.<>
Keywords :
biomedical ultrasonics; biothermics; focusing; radiation therapy; temperature distribution; 925 kHz; acoustic energy intensity; acoustic wave carrier; amplitude measurements; difference-frequency wavefield; focal field strength; focal volume; focused ultrasound hyperthermia systems; modulating signal; phase measurements; temperature distribution; tumors; ultrasound hyperthermia; water medium;
Conference_Titel :
Engineering in Medicine and Biology Society, 1988. Proceedings of the Annual International Conference of the IEEE
Conference_Location :
New Orleans, LA, USA
Print_ISBN :
0-7803-0785-2
DOI :
10.1109/IEMBS.1988.94779
