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http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/44465
Title: | 活體小鼠組織之毫米波吸收常數量測 In-vivo Millimeter Wave Measurement of Mouse Tissue Absorption |
Authors: | Chiu-Chung Kuo 郭中秋 |
Advisor: | 孫啟光(Chi-Kuang Sun) |
Keyword: | 活體穿透式量測,衰減係數,乳癌,脂肪,毫米波,兆赫波, In-vivo transmission measurement,attenuation coefficients,breast cancer,fat,millimeter wave,THz, |
Publication Year : | 2009 |
Degree: | 碩士 |
Abstract: | 兆赫波是頻譜位於微波和遠紅外光之間的電磁波。由於許多物質在這個波段具有可辨識的吸收頻譜以及其他的優點,兆赫波在生醫檢測方面成為了一個有潛力的領域。而惡性腫瘤的檢測則是相關應用之中最重要的之一。然而,由於水對兆赫波強烈的吸收,到目前為止兆赫波都無法應用到活體生物上的穿透式偵測。我們注意到:在此頻段中,水對兆赫波的強烈吸收隨著頻率而降低。因此,為了實現活體組織的穿透式檢測,工作頻率選在兆赫波頻率最低的一端是較為適當的。此最低頻率已涵蓋到毫米波的部分。本論文的主題是透過量取活體組織在這工作頻率的穿透功率比,獲得該活體組織的衰減係數。首先,我們架設一了個操作在108-143 GHz簡單的穿透功率量測系統,此系統不需冷卻,最大訊雜比大約是60 dB。我們將被種植了脂肪或腫瘤的裸鼠做為實驗的動物模型,並且用前述的系統量測活體裸鼠身上的腫瘤、脂肪以及正常皮膚。研究結果發現:正常皮膚和腫瘤的衰減係數的差異在統計誤差之內,而此兩者的衰減係數都略小於水,但明顯的大於脂肪。我們推斷這是由於正常皮膚和腫瘤的衰減系數差異不大,因此兩者的差異被水強烈的吸收掩蓋。總結來說,在此頻率下兆赫波並無法直接分辨腫瘤和正常皮膚,而是分辨其水含量。 THz radiations, or simply THz, are electromagnetic waves lying on the spectrum between microwaves and infrared radiations. Due to distinguishable absorption spectra in this band and other advantages, THz is a potential field for biomedicine inspections. One of the most important THz applications is malignant tumor detection. Currently however, there is no in-vivo transmission detection due to critical liquid water absorption. Since liquid water absorption with decreased frequency is weaker, this work selects the lowest frequency in the THz band, the millimeter wave, for transmission measurement of in-vivo tissues. The current study sets up a simple room temperature transmission power measurement system with SNR (signal to noise ratio) of about 60 dB at 108 to 143 GHz. The nude mice implanted with breast cancer and fat are chosen as the animal models. Results of this study show that the attenuation coefficients of skin and tumors are indistinguishable, a little less than that of liquid water, and obviously larger than that of fat. To conclude, THz detection capability in low frequency is not to discriminate materials, but to measure water content. |
URI: | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/44465 |
Fulltext Rights: | 有償授權 |
Appears in Collections: | 光電工程學研究所 |
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ntu-98-1.pdf Restricted Access | 8.52 MB | Adobe PDF |
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