非侵入式手腕脈搏光學檢測方法之研發-雷射都卜勒干涉儀及布拉格光纖光柵感測器之應用

近幾年來心血管之相關疾病，如: 缺血性心臟病與中風一直高居十大死因的前兩名，因此定期量測血壓已成為健康管理的趨勢，目前常見的市售電子血壓計是透過壓脈袖帶與示波振幅法的原理量測血壓，精準度高，但無法長時間連續測量，且動脈於量測過程中會受到劇烈壓迫，而使人感到不適，不適合作為長時間量測，因此血壓計將朝向無壓脈袖帶與可連續量測發展。本論文的研究目標為藉由光學方法量測橈動脈之表面脈搏振幅，探討其與血壓之相關性，發展具連續量測的穿戴式血壓計，將雷射都卜勒干涉儀應用於量測手腕皮膚表面的脈搏振幅，其優點為具有可達0.08 nm的高解析度，並可透過正交式光路架構，解決光學干涉的方向不可分辨性。為提升量測之穩定性，本研究採用腕帶將直角稜鏡固定於手腕處，使用壓阻式壓力感測器找出適合受試者穿戴的腕帶緊度(70~114 mmHg)，並與超音波動靜脈掃描系統量以及ECG生理訊號儀量測心跳週期進行比較及系統驗證。不同受試者之脈搏振幅的平均值皆不相同，而量測結果為25~56微米，經過分析後，脈搏振幅與血液流速之相關係數約為0.4~0.7，而心跳週期的平均值與心電圖量測結果有73.3%相近(相差小於0.05秒)，證明脈搏振幅與血液流速的相關性及心率量測的準確度。除了量測表面振幅，本團隊也發展布拉格光纖光柵感測器以量測脈搏造成的表面應變大小，因光纖光柵的布拉格波長偏移量與應變有極佳的線性關係，本論文在四點彎曲強度測試架構下之量測結果為每1με的應變量會產生0.1 pm的波長偏移，相關係數R=0.995，將光源改為窄頻光源，並調整此應變感測器的布拉格波長至適當區域，來量測脈搏的表面應變，從實驗結果中可以看到脈搏造成的0.4 V電壓變化，且可量測到與AVID量測結果相似之脈搏波形，並大幅增加量測的穩定度，由於此感測器體積極小，且無須光路校正，因此未來能與穿戴式裝置結合，達成長時間連續監測血壓的目標。

關鍵字

非侵入式；連續量測；血壓計；手腕脈搏；光學計量學；正交式干涉儀；布拉格光纖光柵

並列摘要

Cardiovascular diseases have been the leading cause of death in recent years. Therefore, regular monitoring of blood pressure has become current trend of personalized health management. The most common and commercialized blood pressure portable device is the electronic sphygmomanometer. It is based on the principle of Oscillometry with a pressurized cuff to measure the systolic and diastolic blood pressure. However, it cannot measure the complete profile of blood pressure, and it is not a comfortable process. To overcome these limitations, current studies have turned to the direction of cuffless and continuous Sphygmomanometer. In this study, we use laser Doppler interferometer to measure the pulse amplitude of the wrist skin. The advantage of this system is it has a resolution as high as 0.08 nm, and the directional ambiguity can be removed by the quadrature interferometer. To increase the stability, we use a wristband to fix a corner cube on wrist and identify the suitable pressure in the range between 70~114 mmHg testing by using a film pressure sensor. We compared our system with Arteriovenous Ultrasound Scanner system and ECG monitor to verify its. Different pulse amplitudes were obtained from different objects, the measurement result was in the range between 25 to 56 μm. The correlation coefficient between pulse amplitude and blood flow velocity was between 0.4 and 0.7. The mean value of heart beating cycle and the result of electrocardiogram have a 73.3% similarity with a less than 0.05 second difference. The correlations among pulse amplitude, blood flow velocity and the accuracy of heart rate measurement were evident. To develop personalized blood pressure sensor, we further develop the fiber Bragg grating to measure the surface strain induced by wrist pulse vibrations. The Bragg wavelength offset of the fiber grating has a nearly linear relationship with surface strain. Using the four point bending test, we found that 1 micro strain could induce 0.1 pm wavelength shift with the correlation coefficient of 0.995. By adjusting the Bragg wavelength, this strain sensor can be applied to measure the profile of wrist pulse. This sensor could potentially combine with wearable device to achieve long time continuous monitoring of blood pressure.

並列關鍵字

Non-invasive ； Continuous measurement ； Sphygmomanometer ； Wrist pulse ； Optical metrology ； Quadrature interferometer ； Fiber Bragg grating

參考文獻

[49] 陳昭宇, "高速電子斑點干涉儀之研製: 整合雷射都卜勒干涉術與時進相移法之創新設計," 臺灣大學應用力學研究所學位論文, pp. 1-181, 2005.

[6] M. A. Weber, E. L. Schiffrin, W. B. White, S. Mann, L. H. Lindholm, J. G. Kenerson, et al., "Clinical practice guidelines for the management of hypertension in the community," The journal of clinical hypertension, vol. 16, pp. 14-26, 2014.

[8] C. A. Figueroa and J. D. Humphrey, "Pressure Wave Propagation in Full-body Arterial Models: A Gateway to Exploring Aging and Hypertension," Procedia IUTAM, vol. 10, pp. 382-395, 2014/01/01/ 2014.

[9] J. Booth, "A short history of blood pressure measurement," ed: SAGE Publications, 1977.

[10] T. G. Pickering, J. E. Hall, L. J. Appel, B. E. Falkner, J. Graves, M. N. Hill, et al., "Recommendations for blood pressure measurement in humans and experimental animals," Circulation, vol. 111, pp. 697-716, 2005.

國際替代計量

非侵入式手腕脈搏光學檢測方法之研發-雷射都卜勒干涉儀及布拉格光纖光柵感測器之應用

全文下載

主題瀏覽