國立臺灣大學電機工程學系暨研究所李百祺2006-07-252018-07-062006-07-252018-07-062004-09-30http://ntur.lib.ntu.edu.tw//handle/246246/7998以穴蝕效應為主之超音波治療法近年來在惡性腫瘤治療上受到越來越多的重視。利用 超音波聚焦的能力，可針對深度患部組織做非侵入式之治療。在超音波所有非加熱性的治 療方式中，利用穴蝕效應的治療方法，具有很高之潛力。穴蝕效應為液體中氣泡形成或脹 大的過程。為探討穴蝕效應治療法，本研究分為穴蝕之誘發及偵測兩方面來討論。首先就 誘發條件來說，由於產生穴蝕所需之穴蝕核在人體中濃度過低且分布不均，造成誘發穴蝕 效應的條件相當難以控制及預測。解決的方法之一為主動注射超音波微氣泡對比劑至人體 中，以提供大量之穴蝕核，且亦有助於影像偵測。本研究所採用之穴蝕核以Levovist®及自 製之微脂體為主。除加入微氣泡以作為穴蝕核之外，本計畫並設計特殊發射波形以有效誘 發穴蝕效應之產生。而在偵測穴蝕效應方面，本研究採用二種量化分析方法。第一種為使 用診斷用超音波儀器做影像擷取，進而利用影像亮度來定量分析治療前後之微氣泡數量， 計算穴蝕效應的程度。第二種則為利用慣性穴蝕劑量來偵測穴蝕效應。本計畫先期研究部 分主要成果包括成功建立一套實驗系統，探討誘發超音波穴蝕效應的條件，並能定量偵測 穴蝕效果。目前已完成與發射訊號長度及工作周期等相關實驗，及有關頻率、相位以及掃 瞄方式等各種不同誘發條件的討論。此外，亦以Rayleigh-Plesset 方程式及Runge-Kutta 法 為基礎，發展一模擬工具，以觀察氣泡在不可壓縮液體中受聲波驅動時其半徑變化，並進 一步將模擬結果與前述之穴蝕效應實驗做比較與討論。此一先期之成果，驗證了超音波穴 蝕效應有效誘發及偵測之可行性，並為後續計畫之良好基礎。Cavitation based ultrasonic therapy has received considerable research attention for noninvasive cancer treatment. The ultrasound’s low attenuation and focusing capabilities also provide opportunities for site-specific treatment of deep-seated tumors. Cavitation is the formation and activities of bubbles (or cavities) in a liquid. In order to make such a therapeutic technique feasible, efficient induction and detection of cavitation is necessary, and these are also the two main research goals of this project. Generally, acoustic cavitation is difficult to control due to the inhomogeneous concentration distribution of cavitation nuclei in blood. On the other hand, injection of microbubble based ultrasound contrast agent can provide a more uniform distribution of cavitation nuclei. The strong scattering associated with contrast microbubbles can also benefit detection of cavitation. In this project, we use Levovist® and liposome bubbles (produced in house) as our cavitation nuclei. Special transmit waveforms are also designed for effective induction of cavitation. For detection, the intensity change in B-mode and the inertial cavitation dose are used. We have successfully built an experimental system and studied the effects of pulse duration, duty cycle, frequency, phase and scanning sequence on cavitation induction. In addition, a simulator based on the Rayleigh-Plesset equation and the Runge-Kutta method has also been developed. The success of this preliminary project has built a solid foundation for on-going and future research in cavitation based ultrasonic cancer therapy.application/pdf85368 bytesapplication/pdfzh-TW國立臺灣大學電機工程學系暨研究所超音波微氣泡對比劑微脂體穴蝕化癌症治療ultrasoundcontrast microbubblesliposomecavitationcancer treatment[SDGs]SDG3reporthttp://ntur.lib.ntu.edu.tw/bitstream/246246/7998/1/922218E002044.pdf