Search for: cardiovascular-parameters
0.007 seconds

    Analysis of non-stationary data for heart-rate fluctuations in terms of drift and diffusion coefficients

    , Article Journal of Biological Physics ; Volume 32, Issue 2 , 2006 , Pages 117-128 ; 00920606 (ISSN) Ghasemi, F ; Sahimi, M ; Peinke, J ; Rahimi Tabar, M. R ; Sharif University of Technology
    We describe a method for analyzing the stochasticity in non-stationary data for the beat-to-beat fluctuations in the heart rates of healthy subjects, as well as those with congestive heart failure. The method analyzes the return time series of the data as a Markov process, and computes the Markov time scale, i.e., the time scale over which the data are a Markov process. We also construct an effective stochastic continuum equation for the return series. We show that the drift and diffusion coefficients, as well as the amplitude of the return time series for healthy subjects are distinct from those with CHF. Thus, the method may potentially provide a diagnostic tool for distinguishing healthy... 

    Analysis of the effect of ageing on rising edge characteristics of the photoplethysmogram using a modified windkessel model

    , Article Cardiovascular Engineering ; Volume 7, Issue 4 , 2007 , Pages 172-181 ; 15678822 (ISSN) Zahedi, E ; Chellappan, K ; Mohd Ali, M. A ; Singh, H ; Sharif University of Technology
    Ageing is one of the main contributing factors towards increasing arterial stiffness, leading to changes in peripheral pulses propagation. Therefore the characteristics of the photoplethysmogram (PPG) pulse, especially the rising edge and peak position, are greatly affected. In this study, the PPG pulse rising edge and corresponding peak position have been investigated non-invasively in human subjects as a function of age. Fifteen healthy subjects were selected and grouped in five age intervals, from 20 to 59 years, based on their comparable systolic-diastolic blood pressure and PPG amplitude. As expected, the peripheral pulse shows a steep rise and early peak in younger subjects. With age,... 

    Atheroprone sites of coronary artery bifurcation: Effect of heart motion on hemodynamics-dependent monocytes deposition

    , Article Computers in Biology and Medicine ; Volume 133 , 2021 ; 00104825 (ISSN) Biglarian, M ; Firoozabadi, B ; Saidi, M. S ; Sharif University of Technology
    Elsevier Ltd  2021
    Atherosclerosis as a common cardiovascular disease is a result of both adverse hemodynamics conditions and monocyte deposition within coronary arteries. It is known that the adhesion of monocytes on the arterial wall and their interaction with the vascular surface are one of the main parameters in the initiation and progression of atherosclerosis. In this work, hemodynamic parameters and monocyte deposition have been investigated in a 3D computational model of the Left Anterior Descending coronary artery (LAD) and its first diagonal branch (D1) under the heart motion. A one-way Lagrangian approach is performed to trace the monocyte particles under different blood flow regimes and heart motion...