利用可改善透光效率之微探針陣列量測血氧濃度

Abstract

本論文之目的是觀測近紅外線光譜(NIRS)在生物組織內穿透和分布的情形，並以實驗所得結論和本實驗室先前研究EEG的成果開發一個可改善透光效率的微探針陣列，以此量測血氧濃度。由於NIR在生醫科技方面應用範圍廣泛，如何定位和定量NIR在組織中的透光量就成為一個十分有學術價值的課題。本論文主要是利用可調變的雷射光源系統和光功率計量測光在豬肉組織內之穿透深度和分布情形。再經由實驗結果來反覆進行軟體模擬和經驗公式驗證，提高實驗可信度。依照實驗結果，皮膚是阻擋光能最主要的因素。於是以本實驗室先前的研究結果為基礎，開發出半侵入式之透明微探針。將此元件刺入人體沒有感覺的皮膚淺層，以光照射，即可改善透光效率。最後再以透明微探針進行血氧濃度量測。計算出光的衰減比例後，經由公式推演、換算即可以求得血氧濃度值，證明即使只有微小光能亦可達致相同的血氧濃度量測結果。

The purpose of this dissertation is to study the depth penetration and distribution of NIR in biological tissue. Here, a transparent microprobe array that was developed previously in our laboratory for EEG biopotential signal is used to demonstrate the improvement of light transmission efficiency with oxygen saturation measurement capability. The broad applications of NIR for biomedical research have been studied extensively. However, to pinpoint the position of the NIR in tissue becomes an import research issue in biomedical field. Therefore, in this dissertation, an adjustable laser light source system and a power meter was used to measure the depth penetration and distribution of NIR in pork tissue. In order to verify the experimental results, software simulations were performed and corresponding mathematical model were established. As indicated from the experimental results, skin is the key factor that reflected the light source which reduced the power penetrating into the tissue. A transparent microprobe array that was developed in our laboratory is used to dramatically overcome the above-mentioned drawback that greatly improved the transmission efficiency. Finally, the transparent microprobe is used to measure the oxygen concentration. Experimental results indicated that with less incident light power, we are able to obtain same level of oxygen concentration as in the case without the transparent microprobe.