發展以脈搏體積記錄法評估中心主動脈收縮壓之分析系統

Development of an Analysis System for the Estimation of Central Aortic Systolic Blood Pressure using Pulse Volume Recording

石圜達(Yuan-Ta Shih)

中原大學/工學院/生物醫學工程研究所/博士(2012年)

https://doi.org/10.6840/CYCU.2012.00606

摘要

中央升主動脈收縮壓(SBP-C)和脈搏壓(PP-C)是評估人類心血管疾病的總死亡率最重要的兩個判斷指標，因此、現今有許多已經商業化的測量裝置可用來非侵入式的取得中心動脈收縮壓及脈搏壓，這些裝置大部分必須使用昂貴的高傳導壓張計及經驗豐富的操作者用以獲得手腕壓力波形，經過不同的數學運算取得中央升主動脈收縮壓及脈搏壓，就像是SphygmoCor及HEM-9000AI。而總轉換函式(generalized transfer function, GTF)對於預測SBP-C則具有相當好的準確度，但是因為上述所提到的限制，以至於其普遍性不高。本研究提出一個方法可以使用一般電子血壓計即能簡單取得的脈搏體積記錄波形(pulse volume recording, PVR)，用其代替不易取得的血壓波形，以創造出一個具有方便性及低價位的電子血壓計，用以測量中央升主動脈收縮壓及脈搏壓的非侵入式裝置。而此測量結果則會與其它SBP-C預測函式作比較，如脈搏波形分析法(pulse wave analysis, PWA)及N點移動平均法(N-point moving average, NPMA)。
本篇論文提出以PVR波形用以取代侵入式肱動脈波形，而此PVR波形則是利用一般商業用的電子血壓計，將壓脈袋內壓力固定於特定壓力下而取得。此所得的PVR訊號經過GTF、PWA或NPMA分別之預測函數，則可以求得中央升主動脈收縮壓或脈搏壓。本篇論文將實驗分為兩個組別，一組為控制組，用以建立此三種預測函數各別所需之參數，且使用的電子血壓計為WatchBP Office, Microlife。參與此組別的研究人數為40人，平均年齡為64.1 ± 14.0歲。另一組別為測試組，不重複的100人加入此組別，平均年齡為61.9 ± 13.2歲，用以驗證所建立的三種中央升主動脈收縮壓之預測函數的能力及準確性，使用的電子血壓計為VP-2000, Colin。所有侵入式測量到的中央升主動脈壓力波形、肱動脈壓力波形及非侵入式測量的PVR波形皆為同步測量及記錄，實驗的地點為台北榮民總醫院導管室。
本論文證明了由兩種不同電子血壓計測量到的非侵入式PVR波形，且使用電子血壓計測量的收縮壓及舒張壓所校正，是適合且可用於GTF之SBP-C預測函數。在測試組裡，使用PVR波形與GTF預測函數預測中央升主動脈收縮壓的準確度為-2.1 ± 7.7 mmHg，此結果是與其它為比較標準的SBP-C之預測函數相似。PWA預測函數準確度為1.7 ± 7.9 mmHg及NPMA預測函數準確度為-0.6 ± 7.7 mmHg，此結果皆為與侵入式測量之中央升主動脈收縮壓作比較。
雖然以脈壓袋為基礎的PVR訊號比侵入式肱動脈壓力訊號缺少了較高頻的訊號，但PVR是足夠使用在GTF、PWA及NPMA上，且不論此三種預測函數是使用侵入式中央主動脈波形及肱動脈波形，或侵入式中央主動脈波形及非侵入式PVR所產生的結果，都可用以預測中央升主動脈收縮壓。本篇論文成功的應用由兩台不同電子血壓計所取得的PVR波形於三種不同的中央升主動脈收縮壓預測函數，且同時證明及比較與侵入式測量所得的中央升主動脈收縮壓的準確性。

關鍵字

總轉換函式 ； 脈搏波形分析法 ； 中央升主動脈收縮壓 ； 脈搏體積記錄波形 ； N點移動平均法

並列摘要

Central ascending aortic systolic (SBP-C) and pulse (PP-C) blood pressure are the most important indexes for cardiovascular mortality in humankind. Currently commercial devices for assessing SBP-C and PP-C non-invasively are almost dependent on an expensively high-fidelity tonometer and an experienced operator for obtaining a wrist pressure waveform, such as SphygmoCor and HEM-9000AI. Then, the wrist pressure waveform was calculated by several different mathematic model for yielding SBP-C and PP-C. The accuracy of gener-alized transfer function (GTF) for predicting SBP-C was quite good. However, according to limitations mentioned above, it was still not popular. This study brought a hypothesis that a pulse volume recording (PVR) waveform obtained easily from a common non-invasive blood pressure monitor could replaced the peripheral pressure waveform to estimate SBP-C non-invasively and with a convenient methodology and at lower cost. The result of this hy-pothesis was compared with other SBP-C prediction models, such as pulse wave analysis (PWA) and N-point moving average (NIBP).
The PVR waveform was presented as a surrogate for invasive brachial pressure waveform in this study. This waveform is easily obtained from a commercial noninvasive blood pressure monitor when the cuff pressure is fixed at a constant pressure. Then, the predicted SBP-C was yielded from the obtained PVR waveform using GTF, PWA and NPMA prediction model. Two study groups were used in the present study. The control group was used to create the parameters of these three prediction models by using WatchBP Office, Microlife. Forty subjects were joined in this group, and the average age was 64.1 ± 14.0 years. Another one hundred subjects were joined the other testing group, and the average age was 61.9 ± 13.2 years. This testing group was used to assess the accuracy of three prediction models to esti-mate SBP-C noninvasively that was using VP-2000, Colin. All the invasive aortic pressure waveform, invasive brachial pressure waveform and non-invasive PVR waveform were rec-orded simultaneously in the catheterization laboratory at Taipei Veterans General Hospital.
This study demonstrated that PVR waveform which calibrated to oscillometric base SBP and DBP from two different noninvasive blood pressure monitors was suited to predict SBP-C by using GTF prediction model. The accuracy of PVR waveform with GTF prediction model was -2.1 ± 7.7 mmHg, the result was similar to other benchmark of SBP-C prediction model. PWA prediction model was 1.7 ± 7.9 mmHg and with NPMA prediction model was -0.6 ± 7.7 mmHg in the testing group. These results were all compared with invasively measured SBP-C.
Although a brachial cuff-based PVR waveform was lack of sufficient high-frequency signals in comparison in a brachial waveform, it is good enough to estimate SBP-C using GTF. And it is accurate as well as PWA and NPMA with either an aortic-to-brachial or aor-tic-to-PVR transfer functions. This study successfully applied PVR waveform from two non-invasive blood pressure monitors in three kinds of SBP-C prediction models, and proved the accuracy compared with the standard invasively measured SBP-C.

並列關鍵字

pulse wave analysis ； N-point moving average ； generalized transfer function ； central aortic systolic blood pressure ； pulse volume recording

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