評估相位移法和傅立葉轉換法應用於結構光投影法進行橈動脈振動量測及連續血壓監測之初步研究

Preliminary Evaluations of Applying Phase Shifting and Fourier Transform Method in Structured Light Projection for Radial Artery Vibration Measurement and Continuous Blood Pressure Monitoring

丁炤元(Chao-Yuan Ting)

指導教授 ： 李世光

共同指導教授 ： 吳光鐘(Kuang-Chong Wu)

國立臺灣大學/工學院/應用力學研究所/碩士(2021年)

https://doi.org/10.6342/NTU202102639

摘要

在現今社會中，心血管疾病可畏是全世界共同面對的一大問題，伴隨著死亡率上升的趨勢，血壓的監測至關重要。就目前而言，血壓的主要量測方法為聽音診斷法和示波振幅法，需使用脈壓袖帶阻斷血流進而量測血壓，但是脈壓袖帶的使用使得量測者感到不舒適且無法進行連續血壓量測，因此脈衝傳導時間法最具發展潛力，屬於非接觸連續式血壓量測方法，但由於血壓的形成較複雜，僅考慮體積流率、心率和脈衝傳導時間等參數並不足以描述血壓。因此本研究致力於開發考慮血管管徑變化量之血壓迴歸模型，用以優化僅考慮體積流率、心率和脈衝傳導時間之連續血壓量測方法。
使用光學非接觸式結構光投影法中之條紋投影法的傅立葉轉換輪廓術和相位移輪廓數量測手腕橈動脈脈搏振動作為血管管徑變化量之參數，以利血壓迴歸模型的使用。在光學量測架構中，DLP投影機投射之條紋週期為0.1295 mm，搭配46 fps連續拍攝之相機，與物體之間呈現三角關係，使用條紋分析和相位與高度轉換求得連續橈動脈脈搏振動。
在結果方面，將橈動脈脈搏振動量測結果與商用儀器量測之心電圖和光體積描記法波形進行時序上心率和收縮峰值週期之間的均方根誤差評估，用以驗證光學量測架構在時序上展現足夠的精度描述橈動脈脈搏振動。在血壓迴歸模型分析方面，分成收縮壓和舒張壓各自進行迴歸分析，使用統計學之F檢定和t檢定檢驗血壓迴歸模型的預測能力和各項係數影響血壓之顯著性，共量測5位受試者，分為單一受試者分析和複數受試者分析。在單一受試者分析結果方面，對同一位受試者收縮壓參數和舒張壓參數共量測2次，透過F檢定和t檢定結果發現，考慮血管管徑變化量之模型整體優於未考慮血管管徑變化量之模型，而2次量測的模型解釋能力與參數影響的趨勢相同，因此可以驗證血壓迴歸模型的再現性。複數受試者分析結果方面，考慮血管管徑變化量之血壓迴歸模型整體能解釋血壓與生理參數之間的關係的比例較未考慮血管管徑變化量之血壓迴歸模型模型來的高，平均約能提升收縮壓0.47 mmHg的精準度，而舒張壓平均約能提升0.17 mmHg。因此本研究能改善血壓的量測準確度問題。

關鍵字

相位移輪廓術 ； 傅立葉轉換輪廓術 ； 脈衝傳導時間法 ； 橈動脈管徑變化 ； 血壓迴歸模型

並列摘要

Nowadays, cardiovascular disease is a major problem faced by the whole world. With the rising trend of mortality, blood pressure monitoring is very important. At present, the main measurement methods of blood pressure are auscultatory method and oscillometric method. It is necessary to use a cuff to block the blood flow to measure blood pressure, but the use of the cuff makes the human feel uncomfortable and unable to perform continuous blood pressure measurement. Therefore, the pulse transit time (PTT) method has the most potential for development which is a non-contact and continuous blood pressure measurement method. But the formation of blood pressure is more complicated, only considering parameters such as volume flow rate, heart rate and pulse transit time is not enough to describe blood pressure. Therefore, this research is dedicated to develop a blood pressure regression model that considers the change in vessel diameter to optimize the continuous blood pressure measurement method that only considers volume flow rate, heart rate, and pulse transit time.
Using structured light projection method, Fourier transform profilometry and phase shifting profilometry to measure the pulse vibration of radial artery which is used as a parameter of the blood pressure regression model. In the optical measurement system, based on a triangular configuration, the fringe period projected by the DLP projector is 0.1295 mm and a camera with frame rate of 46 fps. Use fringe analysis and phase to height to obtain radial artery pulse vibration.
In the results, several indicators such as heart rhythm (HR), root mean squared errors (RMSE) were adopted to compare the pulse vibration signal of radial artery with the ECG and PPG signals. It can be verified that the measurement of pulse vibration in this research can be adequate accurately described. In the regression analysis of the blood pressure regression model, the regression analysis is divided into systolic blood pressure analysis and diastolic blood pressure analysis. The F test and t test are used to observe the predictive ability of the blood pressure regression model and the significance of coefficients. The predictive ability of the blood pressure regression model with radial artery pulse vibration is much better. It can increase the accuracy of systolic blood pressure about 0.47 mmHg and diastolic blood pressure about 0.17 mmHg. Therefore, this study can improve the accuracy of blood pressure measurement.

並列關鍵字

phase shifting profilometry ； Fourier transform profilometry ； pulse transit time method ； radial artery diameter variation ； blood pressure regression model

參考文獻

[1] World Health Organization. "The top 10 causes of death." World Health Organization. https://www.who.int/news-room/fact-sheets/detail/the-top-10-causes-of-death (accessed May 9, 2021).

[2] World Health Organization. "About cardiovascular diseases." World Health Organization. https://www.who.int/cardiovascular_diseases/about_cvd/en/ (accessed May 9, 2021).

[3] 衛生福利部統計處. "108年國人死因統計結果." 衛生福利部. https://www.mohw.gov.tw/cp-16-54482-1.html (accessed May 9, 2021).

[4] T. De Venecia, M. Lu, and V. M. Figueredo, "Hypertension in young adults," Postgraduate medicine, vol. 128, no. 2, pp. 201-207, 2016.

[5] World Health Organization. "Obesity and overweight." World Health Organization. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight (accessed May 9, 2021).