Morphological analysis of pressure wave in the arterial tree with stenosis - a modeling approach
05 Nov 2015-Vol. 2015, pp 1894-1897
TL;DR: The morphological changes in peripheral signals due to arterial diseases with various severity conditions and site of stenosis are described using modeling approaches, and its effect in the morphological parameters of radial artery is described.
Abstract: This paper describes the morphological changes in peripheral signals due to arterial diseases with various severity conditions and site of stenosis using modeling approaches, and its effect in the morphological parameters of radial artery. As stenosis induces abrupt change in geometry and elastic properties of arterial tree (constitutes major reflection sites), hybrid model is well suited for studying the changes in shape of the pressure and flow wave transmitted through the stenosis. These morphological changes in wave shape of peripheral signal have significant diagnostic value in both modern and traditional medicine systems. It can be used for the quantitative assessment of the severity of the arterial diseases.
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18 Jun 2020
TL;DR: In this article, the estimation of blood flow rate is determined by applying the described technique, which can increase the redundance of electronical part that monitor the blood flow during the transfusion operation.
Abstract: The photoplethysmography technique take advantage of the pulsatile phenomena inside the cardiovascular system. In addition, the blood volume can be discriminated from the sourounding tissues because of its optical reflectance property under a certain wavelengh of light source. In medical systems that used blood for donation the setup of apparatus can made the optimum environment to apply the photopletysmography tecnique. Therefore, in the presented paper the estimation of blood flow rate is determined by applying the described technique. This measurement can increase the redundance of electronical part that monitor the blood flow during the transfusion operation. The actual method that calculate the previous parameter is based on the mass sensor however, in the event of the inoperability of the force sensor, the mass of the blood packet may be greater or less than a predetermined volume. The article discusses possible options for the passage of blood flow through the tube, as well as modeling the real process of donation. It is part of the work devoted to the modernization and development of new equipment for transfusion therapy based on LLC Lidkor production.
8 citations
Cites background from "Morphological analysis of pressure ..."
...In the human body the local volume of blood vessels changes due to the elastic properties [10, 11]....
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01 Jun 2020
TL;DR: The current paper will focus on the blood flow velocity where this feature has a major implication in the blood mixer device, which needs to constantly monitor the transfused blood volume with the most accurate level.
Abstract: Photoplethysmogram is an image of blood flow changes in the human body. It isn’t a simple shape signal rather it has at least six principle parameters form who derivate another useful. In the last decade, the PPG was exploited in order to extract more useful information about physiologic parameters. The current paper will focus on the blood flow velocity where this feature has a major implication in the blood mixer device. It needs to constantly monitor the transfused blood volume with the most accurate level. In transfusiological practice, special attention is paid to the accuracy of donation. The accuracy of donation means the correlation of a given volume and the resulting volume of the blood bag. Therefore, implementing the PPG principle to this device it can offer a good advantage at measuring the blood flow. This article is part of the work devoted to the modernization and development of new equipment for transfusion therapy based on LLC Lidkor production.
5 citations
Cites background from "Morphological analysis of pressure ..."
...In the human body the local volume of blood vessels changes due to the elastic properties [10, 11]....
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References
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TL;DR: Results show that blood flow through a particular artery can increase by a large factor, in the range of 4-5, under conditions of vasodilation with a corresponding large decrease in pressure distal to the stenosis, and suggest that a critical stenosis be defined in terms of its effect on maximal flow rather than resting flow.
Abstract: This study is concerned with the pressure drop that develops across an arterial stenosis, with particular emphasis on the effect of the stenosis at high blood flow rates induced by a locally administered vasodilator drug. Stenoses, ranging in severity from 55.7% to 91.0% reduction in lumen area were artificially induced in the femoral and carotid arteries of large mongrel dogs. Instantaneous flow rates and pressure drops were measured over a wide range of flow conditions. Mean velocities varied from 3.9 to 88.8 cm/sec. Experimental data support the applicability of a relatively simple equation for predicting the pressure drop over this wide range of velocities and stenosis geometries. Results show that blood flow through a particular artery can increase by a large factor, in the range of 4-5, under conditions of vasodilation with a corresponding large decrease in pressure distal to the stenosis. The pressure drop increases in a nonlinear manner with velocity and thereby accentuates the importance of the stenosis at elevated flow rates. We suggest that a critical stenosis be defined in terms of its effect on maximal flow rather than resting flow.
186 citations
"Morphological analysis of pressure ..." refers result in this paper
...These observations match with other simulations and experimental values ([8], [10])....
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TL;DR: The analysis of high-resolution flow profiles allows detection of early hemodynamic changes even at degrees of stenoses not associated with a reduction of mean flow, and Rmax(1/2) allows differentiation of the grade of hemodynamic compromise for a given morphologic stenosis independent ofmean flow in a single comprehensive MR examination.
Abstract: . In a noninvasive comprehensive magnetic resonance (MR) examination, the morphologic degree of renal artery stenosis was correlated to corresponding changes in renal artery flow dynamics. Different degrees of stenosis were created with the use of a chronically implanted inflatable arterial cuff in seven dogs. For each degree of stenosis, an ultrafast three-dimensional gadolinium MR angiography with high spatial resolution was performed, followed by cardiac-gated MR flow measurements with high temporal resolution for determination of pulsatile flow profiles and mean flow. Flow was also measured by a chronically implanted flow probe. In three of the dogs, trans-stenotic pressure gradients (ΔP) also were measured via implanted catheters. Five different degrees of stenosis could be differentiated in the MR angiograms (0%, 30%, 50%, 80%, >90%). The MR flow data agreed with the flow probe within ±20%. Stenoses between 30 and 80% gradually reduced the early systolic peak (Max 1 ) of the flow profile but only minimally affected the midsystolic peak (Max 2 ) or mean flow. Stenoses of more than 90% significantly depressed mean flow by more than 50%. The ratio between Max 1 and Max 2 (Rmax 1/2 ) gradually fell with the degree of stenosis. The onset of significant mean flow reduction and ΔP was indicated by a drop of Rmax 1/2 below 1 to 1.2. Thus, the analysis of high-resolution flow profiles allows detection of early hemodynamic changes even at degrees of stenoses not associated with a reduction of mean flow. Rmax 1/2 allows differentiation of the grade of hemodynamic compromise for a given morphologic stenosis independent of mean flow in a single comprehensive MR examination.
88 citations
"Morphological analysis of pressure ..." refers background in this paper
...Although aortic stenosis has been well described in the literature ([1],[2],[3]) the complete arterial tree model with patient specific data has not been addressed....
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TL;DR: A nonlinear mathematical model of arterial blood flow, which can account for tapering, branching, and the presence of stenosed segments, is presented and results indicate that these waveforms are significantly altered by moderate and severe stenoses.
Abstract: A nonlinear mathematical model of arterial blood flow, which can account for tapering, branching, and the presence of stenosed segments, is presented. With the finite-element method, the model equations are transformed into a system of algebraic equations that can be solved on a high-speed digital computer to yield values of pressure and volume rate of flow as functions of time and arterial position. A model of the human femoral artery is used to compare the effects of linear and nonlinear modeling. During periods of rapid alternations in pressure or flow, the nonlinear model shows significantly different results than the linear model. The effect of a stenosis on pressure and flow waveforms is also simulated, and the results indicate that these waveforms are significantly altered by moderate and severe stenoses.
68 citations
"Morphological analysis of pressure ..." refers background or result in this paper
...These observations match with other simulations and experimental values ([8], [10])....
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...The one dimensional flow equations are defined by (3), (4) and (5) based on [8]....
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TL;DR: The forward model was found closely to represent clinically observed haemodynamic characteristics of the human arterial system under the given test conditions, and demonstrated an error between 2 and 16% in comparison with mean clinical data for critical stenosis.
Abstract: A forward mathematical model of the human arterial system, based on an electrical transmission line analogy, has been developed, using a new method for the calculation of peripheral impedance. Simulations of the human arterial system under normal and stenotic arterial conditions were compared with other published simulations, as well as measured clinical data and known clinical quantitative and qualitative characteristics: the harmonic arterial input impedance spectrum demonstrated a mean error of 0.07–0.1 mmHg.s.cm−1, compared with equivalent simulation and physiological data, respectively; qualitative and quantitative variation of blood pressure and flow waveforms along the arterial tree followed clinical trends; arterial pulse wave velocities compared favourably with physiological data close to the aortic root (−50–20 cm s−1 difference), but there were larger differences in the periphery (149–1192 cm s−1 difference); qualitative as well as quantitative variation of blood flow waveforms with progressive stenotic arterial disease, as measured by the pulsatility index, demonstrated an error between 2 and 16% in comparison with mean clinical data for critical stenosis. Under the given test conditions, the forward model was found closely to represent clinically observed haemodynamic characteristics of the human arterial system.
49 citations
"Morphological analysis of pressure ..." refers methods in this paper
...Anatomical data which is published in [7] have been used for finding the parameters R, L, C and Rt The hybrid model detailed description is given in [4]....
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TL;DR: The results suggest that hemodynamically nonsevere stenoses may cause significant wave reflections, and that critical stenoses the reflection coefficient is frequency and pulsatility independent.
43 citations
"Morphological analysis of pressure ..." refers background or methods or result in this paper
...Predicted pressure waveforms for the control case: (a) Hybrid model (b) Nonlinear model from literature [3]...
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...model based on [3] to analyze the difference in predictions of both models due to the omission of nonlinear areapressure relationship in hybrid model....
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...Pressure and flow waveforms for the control case in hybrid model and nonlinear model from literature [3] are shown in Fig....
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...Under normal condition of arterial tree, the predicted waveforms are fairly insensitive to the shear stress relation [3]....
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...Morphological parameters of left posterior tibial artery pressure pulse are compared in hybrid model and nonlinear model based on [3] to analyze the difference in predictions of both models due to the omission of nonlinear areapressure relationship in hybrid model....
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