非接觸式雷射多普勒皮膚表層血流計

判斷皮膚燒傷程度或是植皮復原程度所使用的儀器以量測血液灌流程度的雷射多普勒血流計為主。非接觸式的雷射多普勒血流計因為大多使用紅光或近紅光雷射做為光源，其檢測深度將達到真皮層內的組織不適合用以判斷中度燒燙傷。本研究之目的是開發以綠光雷射為光源的非接觸式雷射多普勒血流計，以便能分辨與測量較淺層的微血管灌流程度、而更準確地判斷中度燒傷的深度。系統的組成包含雷射光源、控溫模組、光源模組、訊號放大與擷取電路以及訊號分析與操作介面的軟體系統。此系統將綠光雷射光束垂直投射在所要量測位置的皮膚上，並維持雷射溫度的穩定。光學透鏡模組使用大口徑的透鏡以收集到較多的逆向擴散反射的光能量，並聚集於光感測器轉換成電訊號，在經放大濾波後，由訊號擷取分析模組轉成數位訊號。將原始訊號經過傅利葉轉換後，進行訊號頻譜分析，由雷射多普勒的訊號功率頻譜分別求出血量與血流速度並將此訊號顯示於電腦螢幕上。此外搭配步進馬達移動進行掃瞄量測，攫取微循環系統上的平均血流頻率值，並經過程式處理後轉換為二維圖像顯示。此研究研製完成ㄧ套非接觸式的綠光雷射多普勒血流計，可同時偵測淺層皮膚的血流與血量變化訊號，以便量化受量測部位之微循環的血液灌流功能。此外此系統除了能單點量測該部位之微循環訊號外亦能使用於二維部位的微循環訊號影像。

關鍵字

微循環；血流；血液灌流；綠光雷射；雷射都卜勒

並列摘要

Laser Doppler flowmeter and blood perfusion meter are generally used for judging the burn depth. Since most non-contact laser Doppler flowmeters use red or near-infrared laser as the light source, the detecting depth could reach the dermis layer. This is too deep to determine the burn depth of second degree of burn wound. The purpose of this study is to design a non-contact laser Doppler flowmeter using green light laser. The green light measures blood perfusion mostly in the shadow layer which can more accurately evaluate the second degree of burn. The measurement system includes the laser light source, optical module, signal amplifier, data acquisition module and system control software. The system projects green laser vertically on the measuring site, the diffusive reflection light is collected by a large diameter lens set to gather more light energy. The reflection is focused on a photodiode to convert light signal into electric signal. After amplification and filtering, the signal is acquainted into computer and further processed. The blood flow and perfusion signals are calculated from the power spectrum of signal. By mounting the system on a three axis robot, a blood flow image can be constructed by scanning through skin surface. The changes in blood flow and perfusion rate with cold and hot stimuli were successfully measured using the non-contact green light Doppler system developed in this study.

並列關鍵字

microcirculation ； Blood Perfusion ； Green Laser ； Laser Doppler

參考文獻

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國際替代計量

非接觸式雷射多普勒皮膚表層血流計

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