周邊血管病變是一種常見的糖尿病患周邊症狀，隨著台灣高齡化社會的來臨，老年人罹患糖尿病的比例更是逐年升高。其中，病患的足部血管病變，更是容易導致糖尿病足及其相關感染的產生。所以建構一套非侵入式的周邊血管監控系統，來監控周邊血管病變是相當重要的課題。本研究主要目的在利用光電技術，建立一套以光體積變化描述波形（PPG）與血氧濃度計（SaO2）為基礎的非侵入式微循環量測系統，並透過此系統來監控糖尿病患足部血管流量與血氧濃度的變化，來推論足部末梢血管微循環狀態，或是否有周邊動脈阻塞性疾病的症狀發生。本研究主要可分為兩個部份，第一個部分為雙通道微循環量測系統之硬體架設，欲藉由此系統同時量測左右兩側足部微循環流量與血氧的變化。第二部份是實際應用於人體足部末梢微循環量測，利用自行設計的近紅光系統，可以穩定擷取血量與血氧變化的訊號。在實際病患量測結果分析上發現，利用左右兩腳PPG波形與病患心電圖訊號（ECG），所產生左右兩側差異的時間參數△PTTp與△PTTf，可以明顯地判斷出足部末梢是否有血管病變的現象（P＜0.05）；但血氧濃度計（SaO2）參數上，並無統計差異。

Peripheral vasculopathy has been a very common symptom of many diseases, especially diabetes mellitus that is prevalent in the developed and developing countries worldwide. Because diabetic vasculopathy may cause diabetic foot and osteomyelitis, a noninvasive monitoring instrument for early detection and accurate diagnosis of peripheral vascular abnormalities like microcirculation or oxyhemoglobin saturation in diabetes is important. The aim of this study is to apply photo-electronic technology to develop a non-invasive measurement system for measuring microcirculation based on photoplethesmography (PPG) and arterial oxyhemoglobin saturation (SaO2). With this system, we could monitor the changes of blood volume and blood oxygenation in the lower limbs of diabetes. This research was mainly divided into two parts: First, a dual-channels measurement system was set up. We expected it could be applied to monitor the changes of blood volume and blood oxygenation both collected simultaneously from the right and left lower limbs. Secondly, we measured the microcirculation signals of human extremities. Till now, the self-designing non-invasive measurement system for microcirculation could detect the changes of blood volume and blood oxygenation in lower limbs. We also found there was a significant difference between the bilateral sites in terms of the physiological parameters (△PTTp and△PTTf) that were calculated by measuring the pulse timing difference between pulse peaks in the PPG and ECG signals. This result could be a potential tool for early determine whether the diabetic patients have diabetic vasculopathy.

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