非接觸式血壓監測之研究-運用三維疊紋干涉術量測手腕表面脈搏振動

Measuring Three-dimensional Wrist Surface Pulsation by Moiré Interferometry for Non-contact Blood Pressure Monitoring

邱時雍(Shih-Yung Chiu)

指導教授 ： 李世光

共同指導教授 ： 吳文中 ； 許聿翔

國立臺灣大學/工學院/工程科學及海洋工程學研究所/碩士(2018年)

https://doi.org/10.6342/NTU201802805

摘要

目前主要的血壓量測方法是聽音診斷法及示波振幅法，它們是準確且成熟和的市售產品，但量測過程不舒服，並且不能提供連續量測結果。因此，研發方法如壓力描記法、恆定容積法及脈衝傳導時間法以解決前述的問題，但這些方法的精準度及限制不足以提供給醫療診斷使用。
對於老年人在一般健康照護使用的血壓計，需要非侵入式、連續量測且高精準度的需求，為了達到此目標，本論文使用疊紋干涉術為技術，量測手腕區域脈搏造成的皮膚表面振動。以陰影疊紋法量測面外變形；以面內疊紋法量測面內變形，使用週期400 μm的二進制條紋與紋身貼紙進行量測架構設計。另外，本研究團隊研發將陰影疊紋及面內疊紋進行複合量測的三維干涉術，以計算出三維變形。本研究證明，陰影疊紋量測系統的靈敏度足以量測手腕表面脈搏振動，系統量測結果足以作為可參考的生理訊號。
本研究使用商用系統紀錄心電圖、血氧訊號、脈壓式血壓輪廓及血流訊號來驗證了本研究開發的系統。根據量測結果研究，手腕表面脈搏振動在面外的峰對峰振幅為76.83±7.45 μm；在面內及三維因手腕晃動的訊號使結果無法找到明顯的波形，以面外振動量測的結果討論，波形特徵與血氧之相關係數大小落在0.09~0.57，心率比較的平均相對誤差為-0.16 %。本論文將振動量測結果計算成連續血壓梯度波形，在脈壓、收縮壓及舒張壓的相關係數大小分別為-0.14、0.33及0.77，心率比較的平均相對誤差為-2.82 %。研究結果證明疊紋干涉術對於連續監測血壓是一個適合的量測方法。

關鍵字

疊紋干涉術 ； 光學計量學 ； 無袖帶血壓計 ； 個人健康照護

並列摘要

Currently, Auscultatory and Oscillometry are primary and well-established blood pressure monitoring methods. However, their measuring processes are not confortable, and they cannot provide continuous information. As a consequence, methods such as tonometry, vascular unloading technique and pulse transit time are developed. Nevertheless, the accuracy and limitation of measurement restricted diagnostics application.
However, the current trend for self-monitoring blood pressure device for aging population is non-invasive, continuous measurement and high accuracy. To reach this goal, this study applies moiré interferometry around the wrist region for real-time monitoring artery-induced wrist skin vibration. Shadow moiré setup for out-of-plane displacement and in-plane moiré setup for in-plane displacement are designed by using a 400 μm pitched binary grating and a tattoo sticker. Moreover, this study develops a three-dimensional moiré by combing shadow moiré and in-plane moiré setup for three-dimensional displacement measurement. It is demonstrated that the sensitivity is sufficient for wrist skin vibration measurement. The result of out-of-plane integrated system provides the optimal sensitivity for recording artery-induced skin vibrations.
The developed system is validated with ECG signal, oximetry signal, blood pressure profile and blood flow signal collected by using commercial systems. According to ex-perimental studies, the peak-to-peak vibration amplitude of the out-of-plane measurement was 76.83±7.45 μm. The peak-to-peak vibration amplitude of in-plane measurement and three-dimensional measurement is not feasible due to body movement. According to the result of out-of-plane measurement. The correlation coefficient magnitude of waveform feature between wrist pulsation and oximetry signal is 0.09~0.57. The repeatability of wrist pulsation reaches an average relative error of -0.16 % with respect to heart rate. Finally, continuous blood pressure gradient profile is calculated. The correlation coefficient between blood pressure gradient profile and pulse pressure, systolic blood pressure and diastolic blood pressure are -0.14, 0.33 and 0.77, respectively. The repeatability of blood pressure gradient profile achieved with an average relative error of -2.82 %. This system demonstrates that moiré interferometry is a suitable technique for non-contact blood pressure monitoring.

並列關鍵字

moiré interferometry ； optical metrology ； cuffless blood pressure sensor ； personalized health care

參考文獻

[1] Who.int, 'The top 10 causes of death', 2017.

[2] Mohw.gov.tw, '105年國人死因統計結果', 2016.

[3] C. Vlachopoulos, M. O'Rourke, and W. W. Nichols, McDonald's blood flow in ar-teries: theoretical, experimental and clinical principles, ‎Boca Raton, Florida: CRC press, 2011.

[4] J. Liu, H.-m. Cheng, C.-H. Chen, S.-H. Sung, J.-O. Hahn, and R. Mukkamala, 'Model-based oscillometric blood pressure measurement: preliminary validation in humans', Engineering in Medicine and Biology Society (EMBC), 2014 36th Annual International Conference of the IEEE, pp. 1961-1964, 2014.

[5] T. G. Pickering, J. E. Hall, L. J. Appel, B. E. Falkner, J. Graves, M. N. Hill, D. W. Jones, T. Kurtz, S. G. Sheps, and E. J. Roccella, 'Recommendations for blood pres-sure measurement in humans and experimental animals: part 1: blood pressure meas-urement in humans: a statement for professionals from the Subcommittee of Profes-sional and Public Education of the American Heart Association Council on High Blood Pressure Research', Circulation, vol. 111, no. 5, pp. 697-716, 2005.