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artery-compliance
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Electrical analog model of arterial compliance during reactive hyperemia
, Article 2011 1st Middle East Conference on Biomedical Engineering, MECBME 2011, 21 February 2011 through 24 February 2011, Sharjah ; 2011 , Pages 49-53 ; 9781424470006 (ISBN) ; Zahedi, E ; Sharif University of Technology
2011
Abstract
Flow mediated dilation (FMD) measurement using ultrasound imaging (FMD-US) has been established as a standard method for assessing the endothelial function. Recently, a less skilled-operator demanding method has been proposed based on the photoplethysmogram (PPG) changes during reactive hyperemia. It was shown that the amplitude of the PPG pulse (FMD-PPG) changed in a quite similar manner to that of the artery diameter in the method of the FMD-US i.e. increases following releasing the cuff and then gradually returns to baseline. In this study PPG changes following reactive hyperaemia were modelled using time-varying passive electrical elements (R, L and C). The output of the electric analog...
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) ; Chellappan, K ; Mohd Ali, M. A ; Singh, H ; Sharif University of Technology
2007
Abstract
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,...
Experimental feasibility study of estimation of the normalized central blood pressure waveform from radial photoplethysmogram
, Article Journal of Healthcare Engineering ; Volume 6, Issue 1 , 2015 , Pages 121-144 ; 20402295 (ISSN) ; Sohani, V ; Mohd. Ali, M. A ; Chellappan, K ; Beng, G. K ; Sharif University of Technology
Multi-Science Publishing Co. Ltd
2015
Abstract
The feasibility of a novel system to reliably estimate the normalized central blood pressure (CBPN ) from the radial photoplethysmogram (PPG) is investigated. Right-wrist radial blood pressure and left-wrist PPG were simultaneously recorded in five different days. An industry-standard applanation tonometer was employed for recording radial blood pressure. The CBP waveform was amplitude-normalized to determine CBPN . A total of fifteen second-order autoregressive models with exogenous input were investigated using system identification techniques. Among these 15 models, the model producing the lowest coefficient of variation (CV) of the fitness during the five days was...