周邊動脈阻塞性疾病(PAOD)是許多疾病的普遍症狀之一，且病變程度會隨著年齡增長而更趨嚴重，嚴重時可能造成跛行、缺血性疼痛與壞蛆等症狀，因此診斷與監測病患的周邊動脈阻塞性疾病是非常重要的。本研究的主要目的為利用光電技術建構一套以光體積變化描述波形(PPG)與血氧濃度(SaO2)為基礎的可攜式且非侵入式的雷射微循環量測系統，並利用此系統評估PAOD患者足部末梢的微循環狀態，作為快速診斷評估周邊血管異常與居家照護的工具。本研究主要可分為兩個部份，第一部份為非侵入式的微循環量測系統的硬體架設，並藉由此系統量測同時量測手指與雙腳的微循環參數與血氧濃度。第二部份為實際應用於人體量測實驗，並利用雙腳的微循環參數差異評估患者下肢的病變程度。研究結果顯示，兩側差異的時間參數(ΔPTTp 與ΔPTTf)可以明顯診斷出血管的病變現象，但血氧濃度(SaO2)的統計參數上並無太大的差異。最後結果也顯示本研究所開發的雷射微循環量測系統可作為周邊動脈阻塞性疾病患者的診斷評估與居家照護工具。

Peripheral artery occlusive disease (PAOD) has been a common symptom in many diseases and its risk increases sharply with age. Therefore detecting lower limb PAOD is important for patients to prevent disabling claudication, ischaemic rest pain and gangrene. The purpose of this research is to develop a portable and non-invasive microcirculation measurement system using the photo-electronic technique based on photoplethesmography (PPG) and arterial oxyhemoglobin saturation (SaO2) to evaluate the microcirculation state of PAOD patients. This device provides a help for diagnosis of peripheral artery abnormalities and a tool for health home-care. This device was mainly divided into two steps. First, the three channels PPG and one channel ECG was set up for measuring physiological parameters such as PTTf, PTTp, RT, and SaO2. Secondary, we evaluated the microcirculation by those parameters in different measuring point. The statistical results show that the significant differences between the bilateral sites (ΔPTTp andΔPTTf) are useful parameters for evaluating microcirculation in PAOD patients. Those results also indicated that the laser-based microcirculation measurement system in this study could be a tool for diagnosis or healthy home-care to determine the artery circulation state of PAOD patients.

[1]M. H. Criqu, R. D. Langer., A. Fronek, H. S. Feigelson, M. R. Klauber, T. J. McCann and D. Browner, “Mortality over a period of 10 years in patients with peripheral artery disease,” New England Journal of Medicine, vol. 326, pp. 381-6, 1992.
[2]M. H. Criqu, R. D. Langer., A. Fronek, H. S. Feigelson, M. R. Klauber, T. J. McCann and D. Browner, “The correlation between symptoms and non invasive test results in patients referred for peripheral arterial disease testing,” Vascular medicine, vol. 1, pp.65-71, 1996.
[3]http://www.kmuh.org.tw/www/kmcj/data/9006/4733.htm
[4]Y. Yoon, J. H. Cho and G. Yoon “Non-constrained Blood Pressure Monitoring Using ECG and PPG for Personal Healthcare,” Journal of Medical Systems, vol. 33, pp. 261-266 , 2009.
[5]E. D. Übeyli, D. Cvetkovic and I. Cosic, “AR Spectral Analysis Technique for Human PPG, ECG and EEG Signals,” Journal of Medical Systems, vol. 32, pp. 201-206, 2008.
[6]H. Deni, D. M. Muratore and R. A. Malkin, “Development of a Pulse Oximeter Analyzer for the Developing World,” Department of Biomedical Engineering, vol., pp. 1-2, 2005.
[7]P. A. Kyriacou, "Pulse oximetry in the oesophagus," physiological measurement, vol. 27, pp. 1-35 2006
[8]W. B. Murray and P. A. Foster, “The Peripheral Pulse Wave Information Overlooked,” Journal of Clinical Monitoring and Computing, val. 12, pp. 365-377 ,1996.
[9]M. Nitzan, B. Khonokh, and Y. Slovik, “The Difference in Pulse Transit Time to the Toe and Figure Measured by Photoplethysmography,” Physiological Measurement, vol. 23, pp.85-93, 2002.
[10]J. Allen and A. Murray, “Age-related Changes in Peripheral Pulse Timing Characteristics at the Ears, Thumbs, and Toes,” Physiological Measurement. Vol.24, pp. 297-307, 2002.
[11]J. Allen, “Photoplethysmography and its Application in Clinical Physiological Measurement,” Physiological Measurement, vol. 23, pp. 1-39, 2007.
[12]J. Allen, C. P. Oates, T. A. Lees, and A. Murray, “Photoplethysmography Detection of Lower Limb Peripheral Arterial Occlusive Disease a comparison of pulse timing, amplitude and shape characteristics”, Physiological Measurement, vol. 26, pp. 811-821, 2005.
[13]G.A. Millikan, “The oximeter an instrument for measuring continuously oxygen-saturation of arterial blood in man”, Review of Scientific Instruments, vol. 13, pp. 434-445, 1942.
[14]S. M. L. Silva, M. L. D. Castilla, J. P. S. Martin, ”Near-infrared Transmittance Pulse Oximetry with Laser Diodes,” Journal of Biomedical Optics, vol. 8, pp. 525-533 2003
[15]W. P. Joyce, K. Walsh, D. B. Gough, T. F. Gorey, and J. M. Fitzpatrick, “Pulse oximetry a new non-invasive assessment of peripheral arterial occlusive disease,” British Journal of Surgery, vol. 77, pp .1115-1117, 1990.
[16]G. I. Parameswaran, K. Brand, and J. Dolan, “Pulse oximetry as a potential screening tool for lower extremity arterial disease in asymptomatic patients with diabetes mellitus,” Archives of Internal Medicine, vol. 165, pp. 442-446, 2005
[17]laser diode datasheet, 華信光電, 台灣, http://www.aocepi.com.tw/html/
[18]laser diode driver datasheet, IC-HAUS, Germany, http://www.ichaus.com/index.php
[19]BPW96A silicon phototransistor datasheet, Vishay Telefunken, Germany, http://www.vishay.com/
[20]PIC32MX675F512L Data Sheet, Microchip, USA, http://www.microchip.com/
[21]FT245BL Data Sheet, Future Technology Devices International Ltd. USA, http://www.ftdichip.com/