Heating Sequence Effect in Ultrasound Hyperthermia Treatment

• Main Authors: CHEN JUN YUAN, 陳俊源
• Other Authors: Y. Y. Chen
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/09037708116448804010

碩士 === 國立臺灣大學 === 電機工程學研究所 === 91 === To generate large thermal lesions in ultrasound thermal therapy, whose focused ultrasound applicators generate a single lesion that is usually very small. Hence, to generate large thermal lesions, the focus is scanned over the tumor region. The alternation of focus areas usually requires cooling intermissions to avoid excessive power accumulation in front of the target region. Due mainly to such cooling intervals, the time required to heat large thermal lesions is several hours. A possible strategy to shorten the total treatment time is to lessen, or even eliminate the cooling intervals. The first method minimizes the ultrasound energy focused on the target region to reduce the energy accumulation in the near-field. A second method uses the time, which treat the n point to be cooling the n-1 point.　A combination of these two strategies would allow treatment of a large target region, without cooling. Moreover, due to the fact that there is no cooling time during the heating sessions, the total treatment time is significantly reduced to only several minutes, compared to the existing several hours.