Near-infrared Absorption Property of Biological Soft Tissue Constituents

生物軟組織成分的近紅外光吸收係數

蔡正倫(Cheng-Lun Tsai) ； 陳志昌(Ji-Chung Chen) ； 王文竹(Wen-Jwu Wang)

《Journal of Medical and Biological Engineering》 21卷1期 (2001/03) Pp. 7-14

摘要

生物軟組織的近紅外吸收光譜隨其組成成分而改變，因而組織的組成成分比例亦可由分析近紅外光在不同成分中之穿透行徑長度來推測。此研究藉由量測單純的水、油脂、及膠原蛋白等生物組織主要成分的近紅外吸收光譜，來求得組織成分的近紅外光吸收係數以作為參考標準。實驗中的近紅外吸收光譜是使用Shimadzu 3101-PC的光譜儀來量測，為能重複量測到相同的吸收係數值，五種主要的脂肪酸依其在人體脂肪中的含量，以一特定的比例混和來作為標準的油脂樣本。而透明脫水的膠原蛋白與豬眼球的水晶體則分別測量其光譜，以做為生物組織內蛋白質成分近紅外吸收係數的參考標準。結果顯示溫度對水的吸收係數雖然有明顯的影響，對於油脂樣本的吸收係數則幾乎沒有改變，膠原蛋白與水晶體的近紅外吸收係數極為近似。不同生物組織成分之近紅外吸收光譜的差異，將可以用來評估不同種類的軟組織成分含量，或檢測血管壁中的油脂，以及檢測脂肪組織中高含水量的腫瘤等。

關鍵字

近紅外光譜 ； 光吸收 ； 水 ； 油脂 ； 水晶體

並列摘要

Near infrared (NIR) can penetrate relatively deep into biological soft tissues. The NIR absorption property of tissue varies with tissue constituents especially water, fat, collagen, and their combination ratio. Therefore, combination ratio of tissue constituents can be evaluated by decomposing the absorption spectrum to determine the light path length in each constituent. Standardized absorption spectra of tissue constituents are required in order to carry out decomposition. Since water, fat, and protein are the major contributors at NIR spectral region. This study is to measure their absorption spectra from standardized samples as reference for quantifying tissue constituents. Five kinds of major fatty acid found in human fat were mixed in proper ratio as a standard reference. Absorption spectrum of bovine skin gelatin and elastin in hog eye lens were used as references of protein. NIR absorption spectra were measured using a Shimadzu 3101-PC spectrophotometer. The results show that temperature has a strong effect on the absorption property of water but not on fatty acid mixture. Absorption spectrum of elastin is similar to that of dry bovine gelatin. NIR spectroscopy also can be used to characterize or identify different types of soft tissue based on their major chemical composition, such as detecting a fat plaque in a muscular tissue or a tumor in a high fat content tissue.

並列關鍵字

Near infrared spectroscopy ； Absorption ； Water ； Fat ； Eye lens