Design and Analysis of Ultrasound Transducers for Hyperthermia

• Main Authors: Chi-Chung Chang, 張志鈞
• Other Authors: 李振發
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/anm32x

碩士 === 崑山科技大學 === 機械工程研究所 === 96 === It has been shown that 60% of animal’s cells can be killed when their temperatures rise to 42℃ between 45℃ for 30 minutes due to the coagulation necrcosis. The survival rate was decreasing when temperature increased. Ultrasound has several characteristics, such as, small wavelength, deep pentration, which make it well suited for hymperthermia. The goodness of the combination of radiation therapy and hyperthermia is enhanced because the heat can decrease the cell’s radiation resistance about radiation. For tumors with different lecations and sizes , one can design appropriate ultrasound transducers with different shapes and sizes to provide ultrasound power distributions for hyperthermia treatments. This study is based on the theoretical studies of the wave theory and the bio-heat transfer equation to analyze the ultrasound intensity and temperature distribution a tissue-mimick material, jello. First, we calculate the transient temperature responses at several locations using the bio-heat transfer equation. Besides, we also fabricate ultrasound transducers and use them as heating sources to simulate the heating process of a hyperthermia treatment. We make a tissue mimck material using jello to simulate a tissue without blood flow. We use AIMS (Acoustic Intensity Measurement System) to measure the acoustic pressure fields of ultrasound transducers, and a data acquisition system (2701Ethernet Multimeter/Data Acquisition system) to measure the temperature responses at different locations during the heating process. Results can provide useful information about the design of ultrasound transducers for hyperthermia.