非侵入式動脈硬化量測分析系統

A Non-invasive Arterial Stiffness Measurement and Analysis System

黃治堯(Zhi-Yao Huang)

指導教授 ： 蔡育秀

中原大學/工學院/醫學工程研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500760

摘要

動脈硬化為心血管疾病重要的指標之一，能夠早期發現動脈硬化現象，便能夠提早預防心血管病變的發生。傳統診斷動脈硬化以侵入式的方式為主，不但耗時費力，並對病人造成心理上的壓力。近年來非侵入式的方式逐漸發展，以脈波傳導速率（PWV）來預測動脈硬化，為目前發展較為成熟的技術之一；近年又有以共振法研究病患波形圖樣，並計算出動脈硬化參數（ASI），此兩種新技術，使得診斷動脈硬化可以在短時間內完成，且此兩種技術具有臨床上的意義。
本研究發展了一套非侵入式的動脈硬化量測及分析系統，以單點施行共振法量測血壓脈波訊號，加上心電訊號的輔助，可同時計算RPI與ASI指標，RPI是研究中制定的一個指標，原理相似於PWV，是計算血壓脈波的傳遞時間。系統分為軟體及硬體兩部份，硬體系統為訊號擷取裝置，也是可攜式的量測儀器，儀器由德儀（TI）的MSP430F149微處理機控制，可單獨使用計算動脈硬化指標，在短時間內即可完成動脈硬化的量測，適合作為居家看護的儀器。軟體系統以血壓、心率、ASI 及RPI四種指標輔助診斷動脈硬化，分析受測者之狀況，訊號可即時繪於圖表中，系統還提供分析工具與統計功能，醫療人員能夠利用這些工具對受測者的動脈硬化情形更加了解。
系統的血壓與心率指標與市售電子血壓計呈正相關（收縮壓: r=0.81, p<0.0001; 舒張壓: r=0.71, p<0.0001; 心率: r=0.90, p<0.0001），而ASI與RPI指標在此研究中無標準的數值可供比較分析。系統穩定性以人員間及個案間實驗來評估，個案間實驗以5位受測者接受施測5次，結果顯示收縮壓平均變異度為2.9%，舒張壓為5.43%，心率為4.92%，ASI為13.88%，RPI變異度為2.51%。人員間實驗由三位不同施測者對同一位受測者施測共9次，各指標變異度為收縮壓：3.80%、舒張壓：6.57%、心率：7.26%、ASI：13.83%、RPI：6.03%。
本研究所開發之系統中可同時提供ASI、RPI兩指標，加上血壓與心率的輔助，可提供非侵入式動脈硬化量測；另外醫護人員可透過系統的統計資料中進一步早期預測動脈硬化的發生；系統統計的數據結果，可作為研究動脈硬化相關人員的決策支援，進而對非侵入式診斷動脈硬化有新的突破，提升醫療品質。

關鍵字

動脈硬化 ； PWV ； ASI ； RPI

並列摘要

Arterial stiffness has been regarded as a predictor of cardiovascular disease. Traditional invasive measurement of arterial stiffness was not only time consuming, but also stressful to patients. The newly developed non-invasive methods, such as the Pulse Wave Velocity (PWV), and Arterial Stiffness Index (ASI) measurement, are derived from the blood pressure pulse and ECG waves. These novel techniques provide simple, time-saving ways with clinical significance in evaluation of arterial stiffness.

In this research, a non-invasive arterial stiffness measurement and analysis system has developed. The system integrated the oscillometric blood pressure measurement and ECG signal processing to yield the R-P Interval (RPI) and ASI. The RPI is similar to PWV, except the only the relative time difference between R wave and blood pressure pulse is derived. The system is consisting of a portable device and data analysis workstation. The portable device acquires ECG and wrist cuff blood pressure signal, and then calculates the HR, blood pressure, ASI, and RPI information. It can operate along and is ready to use as a homecare device. The analysis workstation real-timely received the signals for the portable device. It sequentially displays the signals, and processed the indexes simultaneously. The workstation not only verifies the accuracy of the portable device, it also provides post analysis functions. The longitudinal trend plots of each patient can be retrieved and displayed from an accompanied database. The workstation offers a comprehensive graphical user interface so that medical staffs can easily conceive patients condition through the statistics charts and signals plots..

The test results shown the blood pressure and HR measurement are highly correlated with the results with commercial available blood pressure monitor (Systolic: R=0.81, p< 0.0001; Diastolic: r=0.71, p<0.0001; HR: p<0.0001). The variance of repeated measurement (Systolic: 2.9%, Diastolic: 5.43%, HR: 4.92%, ASI: 13.88%, RPI: 2.51%) revealed the system is stable. The variance with three different operators on the same subject (SP: 3.80%, DP: 6.57%, HR: 7.26%, ASI: 13.83%, RPI: 6.03%) further proved the stability is operator independent.

This research offers a long-term and multi-dimensional methodology in evaluation of arterial stiffness. The integrated system can provide traces to take early intervention in prevention of cardiovascular diseases. Furthermore, physicians can use the system non-invasively assess the patients’ cardiovascular status and judge the effectiveness of treatment.
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Keywords: arterial stiffness, PWV, ASI, RPI

並列關鍵字

PWV ； RPI ； ASI ； Arterial Stiffness

參考文獻

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