聚焦型超音波於熱治療之能量強度及溫度分佈探討

INTENSITY AND TEMPERATURE FIELD EXPLORATION OF FOCUSED ULTRASOUND THERMAL THERAPY

張揚(Yang Chang)

指導教授 ： 郭鴻森 ； 李基禎

大同大學/工程學院/機械工程學系所/碩士(2007年)

摘要

由超音波能量場分佈情形的複雜與未知，超音波熱治療所面臨的重要課題之ㄧ，即是透過瞭解各項參數變因對超音波聚焦點燒灼的影響，讓治療區域產生高溫時亦不破壞其他部分正常組織。
本研究以高頻率之超音波換能聚波器，搭配理論與電腦數值模擬，探討其產生的波場能量強度的分佈型態與特性；此外，也將對球狀等非平面狀之換能器的性能進行初步探討；最後，藉由生物熱傳方程式求得該超音波波場在組織中所形成的溫度分佈情形，並且透過實驗驗證之，以作為將來設計換能器與治療程序之參考。

關鍵字

生物熱傳、熱治療、高強度聚焦型超音波、超音波熱手術、熱劑量

並列摘要

The distribution of the intensity field of ultrasound is complicated and not fully explored. Focused ultrasound surgery demands the understanding how all the variables influence the heating region near the ultrasound focal point. The high temperature generated from the treated area should be prevented from damaging the normal tissue which is one of the most significant studies of this subject.

With the high-frequency ultrasound focusing transducer, this study combines the theories and the simulation to explore the intensity distribution and features due to the generated wave field. Furthermore, the functions of the spherical transducers are investigated. Through the bio-heat transfer equation, finally, the temperature distribution formed by the ultrasound wave field in the tissue is validated by the experiments. Then, this study can be used as the reference for the future design of the transducer and the therapy procedures.

並列關鍵字

focused ultrasound surgery ； Bio-heat transfer ； thermal therapy ； high intensified focused ultrasound ； thermal dose.

參考文獻

[1] N. Auersperg, “Differential heat sensitivity of cells in tissue culture”, Nature, vol.209, pp.415-416, 1966.

[2] J.G. Lynn, R.L. Zwemer, A.J. Chick, and A.E. Miller. “A new method for the generation and use of focused ultrasound in experimental biology.”, The Journal of General Physiology, vol.26, pp.179-193, 1942.

[3] W.J. Fry, “Action of ultrasound on nerve tissue-a review.”, The Journal of the Acoustical Society of America, vol.25, pp1-5, 1953.

[4] H.H. Penne, “Analysis of tissue and arterial blood temperatures in the resting human forearm..”, Journal of Applied Physiology, vol.1, pp.93-122, 1948.

[6] E.L. Carstensen, W.K. Law, N.D. Mckay, “Demonstration of nonlinear acoustical effects at biomedical frequencies and intensities.”, Ultrasound in Medicine and Biology, vol.6, pp.359-368, 1980.