Arterial pressure transfer characteristics: effects of travel time.
نویسندگان
چکیده
We investigated the quantitative contribution of all local conduit arterial, blood, and distal load properties to the pressure transfer function from brachial artery to aorta. The model was based on anatomical data, Young's modulus, wall viscosity, blood viscosity, and blood density. A three-element windkessel represented the distal arterial tree. Sensitivity analysis was performed in terms of frequency and magnitude of the peak of the transfer function and in terms of systolic, diastolic, and pulse pressure in the aorta. The root mean square error (RMSE) described the accuracy in wave-shape prediction. The percent change of these variables for a 25% alteration of each of the model parameters was calculated. Vessel length and diameter are found to be the most important parameters determining pressure transfer. Systolic and diastolic pressure changed <3% and RMSE <1.8 mmHg for a 25% change in vessel length and diameter. To investigate how arterial tapering influences the pressure transfer, a single uniform lossless tube was modeled. This simplification introduced only small errors in systolic and diastolic pressures (1% and 0%, respectively), and wave shape was less well described (RMSE, approximately 2.1 mmHg). Local (arm) vasodilation affects the transfer function little, because it has limited effect on the reflection coefficient. Since vessel length and diameter translate into travel time, this parameter can describe the transfer accurately. We suggest that with a, preferably, noninvasively measured travel time, an accurate individualized description of pressure transfer can be obtained.
منابع مشابه
Enhanced external counterpulsation treatment improves arterial wall properties and wave reflection characteristics in patients with refractory angina.
OBJECTIVES To determine if arterial properties and wave reflection characteristics are favorably altered after enhanced external counterpulsation (EECP) treatment in patients with refractory angina. BACKGROUND Early return of reflected waves from the lower body, resulting from increased arterial stiffness, augments central aortic pressure and increases left ventricular (LV) afterload and myoc...
متن کاملمدلسازی شبه یکبعدی بالستیک داخلی راکت سوخت جامد با در نظر گرفتن مدل سوزش فرسایشی سادرهلم
In this study, different flow analysis models in solid rocket motor are introduced. Amongst these models, some are not capable of predicting the effects of significant phenomena such as erosive burning and longitudinal acceleration. In order to consider these effects on the internal ballistic, a quasi-one-dimensional model was developed which employs generalized flow equations. A non-viscous an...
متن کاملNumerical Investigation of Heat Transfer and Pressure Drop in a Corrugated Channel
The influence of variation in rib-height to channel-height ratio (e/H) on the heat transfer and pressure drop characteristics inside a channel with corrugated upper and lower plates was investigated numerically in the present study. The governing equations were solved by using finite volume approximations for a wide range of (0.06 < e/H < 0.26) and Reynolds numbers (5400 < Re < 23000), with a m...
متن کاملComaprison of Mass-Transfer Efficiencies of Scc and Structured Packing
In a previous paper, pressure drop, flooding and mass-transfer characteristics of a novel pilot-scale distillation column called spinning cone column (SCC) were presented. Here, we present the result of comparison of mass-transfer efficiencies of SCC and structured packing. Comparison of SCC and structured packing mass-transfer characteristics show that the gas and liquid-side height of transfe...
متن کاملEffect of hypobaric hypoxia on blood gases in patients with restrictive lung disease.
Several publications have reported effects of hypobaric conditions in patients with chronic obstructive pulmonary disease. To the current authors' knowledge, similar studies concerning patients with restrictive lung disease have not been published. The effect of simulated air travel in a hypobaric chamber on arterial blood gases, blood pressure, and cardiac frequency during rest and 20 W exerci...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- American journal of physiology. Heart and circulatory physiology
دوره 292 2 شماره
صفحات -
تاریخ انتشار 2007