雷射都卜勒血流計(Laser Doppler Flowmetry,~LDF)現今已廣泛應用，而一般量測血流變化方式主要有侵入式及非侵入式。由於以侵入式的方式量測，擷取生理量測訊號方法較為精準，但是可能會造成人體不適、傷害或感染，且需要專業醫療人員協助；而雷射都卜勒血流儀具有非侵入式、不接觸試驗流體、輕巧可攜、操作方便等特點，診斷組織微循環可有效對應人體生理相關資訊，使LDF技術在臨床微循環、生物醫學工程的研究上扮演重要的角色。

本論文研究提出的雷射都卜勒血流流速儀系統，旨在架設一套雷射都卜勒血流流速系統對人體微循環血流監視分析，由於監視人體微循環血流變化，因此系統能穩定量測血流量變化必然重要。本實驗中主要分為體外量測與體內量測，由於每個人在微循環結構上的差異，會因環境溫度、呼吸、情緒、脈搏等影響，先以奶粉為試驗溶液做為固定、可調物理量，以體外的方式量測，並且於本系統中，改變不同流速下，探討濃度與SNR關係及線性度、穩定度關係，再進一步量測試驗血的線性度、穩定度，本實驗中以馬血為試驗用血，綜合體外量測實驗，系統線性度在5%以下，穩定度 在1%，與一般商業用都卜勒血流儀器穩定度為5%來的穩定。

另外我們將本系統對受試者以非侵入式方式進行體內量測，藉由水銀式血壓計來改變壓脈帶束縛手臂的力道，以改變不同的血壓，經由電腦及LabVIEW軟體進行數據分析後可即時觀察到受試者的微循環流量頻率的變化，成功的擷取訊號，而這些生理資訊有助於判斷微循環障礙，血管阻塞等病徵。最後於本系統中，我們不但成功以非侵入式方式完成系統架設，藉由水銀式血壓計改變束縛在人體手臂上壓脈帶的力道來改變人體血流量，量測指尖微循環血流訊號，在不同束縛壓力下，可以和商業用血流儀一樣即時量測人體血流變化，且本系統的穩定度也較商業用好、價錢也來的便宜。

Laser Doppler Flowmetry, LDF has been widely utilized in bio-industry. In general, blood flow measuring are categorized into invasive and non-invasive methods. Invasive measurement enjoys the benefits of accuracy, however, it is criticized for causing discomfort, injury or infection and requires more professional medical assistance. On the other hand, LDF is non-invasive, lightweight, easy to operate and without any fluids contact. In addition, LDF can be used to diagnose diseases more effectively with information obtained from tissue microcirculation. It is obvious LDF technology has played a significant role in clinical microcirculation as well as biomedical engineering.

The aim of this study is to create a system utilized to monitor and analyze human microcirculation blood flow. Therefore, stability is a key feature of this design. Two major experiments were conducted in this research: in-vitro and in-vivo measurement. Human microcirculation varies due to different temperatures, breathing, emotions and pulses. At first, we use milk powder as trial liquids to identify SNR, linearity and stability in different flow rates and concentrations. In the next stage, horse blood is used for the same experiment. Compared with an average of 5% stability in commercial applications, our system is more stable cited at 1% or less and has better linearity of 5%.

Finally, we use the system to measure human microcirculation blood flow by observing the change of blood pressure. The device allows us to monitor the immediate change of blood flows and the data analyses with the aids of LabVIEW. To sum up, we have successfully set up a non-invasive system that can be used to monitor the change of microcirculation blood flows in more stable and effective way with less cost compared with commercial devices.

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