廣用型血氧濃度儀系統初探：以視網膜為例

A preliminary study on the widly-used oximeter system : Exemplified with the retina

張淵竣(Chang Yuan-Jun)

指導教授 ： 林康平 ； 董玉平

中原大學/工學院/電機工程研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400360

摘要

大腦是生命的中樞，而眼球視網膜血管具備有反應腦部狀況的窗口功能。經由視網膜血管來估測腦內血液流動及血氧濃度，可以以非侵入式之方式獲得腦部血液對腦組織的相互可能狀況，目前非侵入式血氧濃度計是以光學穿透受測組織之方式經由手指量測，對於無法以光學穿透的身體許多部位無法適用，視網膜血管所在部位即是如此。因此，本研究針對此一目的，研究設計一套可達到不受量測位置影響之廣用型血氧儀之初步架構，並以模擬視網膜血管的方法進行研究。
此系統主要是用雷射二極體將光源導入眼球，同樣也是以非侵入式的方式來對視網膜擷取光的反射及散射訊號。光源的初步選擇仍是以紅光及紅外光來偵測血氧濃度。由於血紅素和帶氧血紅素分別對這兩種波長有相當吸收程度，有別於現有傳統穿透式量測法之光脈式血氧濃度儀(Pulse Oximeter)是採用反射式量取反射光源，接續再做光源被吸收後反射程度的訊號處理。
為能增加此套儀器未來臨床上之應用可行性，本實驗建構出一眼球模型，並通入動物血液之不同含氧量測。藉以控制血液血氧濃度，得到的量測結果在系統穩定度方面，顯示光源輸出穩定且系統具重現性；在溫度與溶氧關係實驗中，也得到溫度越高越易達飽和；在吸收係數實驗中，紅光與紅外光吸收曲線呈相反之趨勢；以及在溶氧儀測定中，可由比對結果來進行更精確之校正；以提供未來人體實驗之評估及參考。

關鍵字

雷射二極體 ； 視網膜 ； 血氧濃度

並列摘要

The eyes are not just a window to the soul, they offer a looking-glass into the brain. After a heart attack, head injury or internal bleeding, doctors check the supply of oxygen to the brain by measuring the patient's pulse and blood pressure.

The objective of this dissertation is to develop a prototype device that directly measures the amount of oxygen reaching the brain. We use two laser diodes, which are red light and Infrared. Owing to the oxyhemoglobin and deoxyhemoglobin having the different absorption coefficient, we get the different reflecting and scattering signal. By analyzing this light, we can obtain oxygen saturation in blood.

In order to accomplish the instrument in clinical, we build a model eye to realize our study. By controlling the oxygen concentration in blood, we can get more and more accurate data. It is helpful for medical application in future.

並列關鍵字

retina ； oxygen saturation ； laser diode

參考文獻

[1] M. H. Smith, “Optimum wavelength selection for retinal vessel oximetry,” Appl. Opt. 38, 258–267 (1999).

[2] Delori F.C., “Noninvasive technique for oximetry of blood in retinal vessels,” Appl. Optics 27(6), 1113 (1988).

[3] M. H. Smith, K. R. Denninghoff, A. Lompado, L. W. Hillman, “Effect of multiple light paths on retinal vessel oximetry,”Applied Optics 39(7), 1183-1193 (2000).

[5] K. R. Denninghoff, M. H. Smith, “Optical model of the blood in large retinal vessels,” J. Biomed. Optics 5(4), 371-374 (2000).

[8] Rafat R. Ansari, Ph.D. “Non-Invasive Health Monitoring using Eye as a Window to the Body” 2003.