建構即時動脈順應性量測系統

Development of a real-time arterial compliance measurement system

陳盈潔(Yin-Chieh Chen)

指導教授 ： 徐良育

中原大學/工學院/生物醫學工程研究所/碩士(2012年)

https://doi.org/10.6840/cycu201200132

摘要

血壓波形可以代表心臟血管的生理變化，血壓波形提供很多的生理參數例如:動脈順應性、脈波傳送速率，這些生理參數，為心血管健康的指標。動脈順應性為評估動脈硬化的一種參數，但大部份的量測需要在醫院進行，若能建構一個即時的動脈順應性測量系統，可增加評估動脈硬化之便利性。
本研究沿用本實驗室自製的非侵入式連續血壓量測系統量測血壓波形，加入即時計算動脈順應性之功能。在LCD上即時顯示血壓波形即顯示結果。計算動脈順應性的方法採用兩元件風箱模型為基礎的時間衰減法。為了減少時間衰減法的繁瑣運算，本研究提出以泰勒展開式來代替ln的計算。為了減少雜訊干擾，本研究使用4點平均為一次動脈順應性的值，經由證實，4點平均可以取代ln的繁複計算。
以Valsalva Maneuver 閉氣方法改變血管的特性觀察泰勒展開式計算的時間常數，與一般常用的曲線擬合比較。T test統計結果顯示P>0.05，其誤差百分比平均為0.01。且結果可以合理的解釋生理的變化。因此泰勒展開式可當作計算動脈順應性之工具。

關鍵字

Valsalva Maneuver ； 動脈順應性 ； 動脈硬化

並列摘要

Blood pressure waveform represents physiological variation of cardiovascular system. It could provide several physiological parameter like arterial compliance, pulse wave velocity. These physiological parameters are indicator for the health of heart functions. Arterial compliance is an index for evaluating arteriosclerosis. It almost always is measured at the hospital. If we construct a real-time arterial compliance measuring system, it will improve the convenience of arteriosclerosis evaluation.
In this study, a real-time arterial compliance measurement capability is incorporated into the custom made non-invasive continuous blood pressure system. It shows the blood pressure waveform on the LCD touch panel. This study use the time decay method that is base on the two-element Windkessel model. To avoid complicate calculation for natural log(ln) , this study proposes to replace ln by its Taylor Series expension and average four points in order to reduce noise for one compliance evaluation. The results of experiment proves that average of four point could replace the complicate calculating of ln.
This study obtained time constant by Taylor Series during Valsalva Maneuver experiment to change blood vessel characteristic. Compared with linear regression method, the mean error percentage is 0.01 and P>0.05 using T test. Both of them have the same tendency. And it can to explain the changes in physiological characteristic reasonably. For this reason, Taylor Series can be used to calculate arterial compliance.

並列關鍵字

arteriosclerosis ； arterial compliance ； Valsalva Maneuver

參考文獻

[2] 饒憲堂，’’以非侵入式連續血壓量測系統即時評估血管特性之動

[3] 鐘文耀,”開發假體血壓校正系統以驗證即時低壓式血壓量測置”

[6] N. Stergipulos, J.-J. Meister, and N. Westerhof, ” Evaluation of methods for estimation of total arterial compliance”, the American Physiological Society, 1540-1548,1995

[7] Z. Liu, K. P. Brin, and F. C. P. Yin.” Estimation of total arterial compliance: an improved method and evaluation of current methods.”Am.J.PhysioZ., H588-H600,1986.

[8] N. Stergiopulos, , J.-J. Meister, and N. Westerhof, “Simple and accurate way for estimating total and segmental arterial compliance: the pulse pressure method” Ann Biomed Eng22 392-97,1994.