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vasodilation
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Discrimination of bilateral finger photoplethysmogram responses to reactive hyperemia in diabetic and healthy subjects using a differential vascular model framework
, Article Physiological Measurement ; Volume 34, Issue 5 , 2013 , Pages 513-525 ; 09673334 (ISSN) ; Aghajani, H ; Zahedi, E ; Sharif University of Technology
2013
Abstract
Endothelial dysfunction assessment has received considerable attention due to its potential in early screening of cardiovascular diseases. Since the seminal work by Celermajer in flow-mediated dilation (FMD) based on B-mode ultrasound measurement of the brachial artery dilation following limb ischemia, many attempts have been made toward applying this method to clinical, non-invasive endothelial dysfunction assessment. One major obstacle toward achieving this objective has been the relative high cost of the required setup and skilled manpower. Such limitations have prompted the investigation of other non-invasively accessible signals such as the photoplethysmogram (PPG) in relation to FMD....
Non-invasive techniques for assessing the endothelial dysfunction: ultrasound versus photoplethysmography
, Article IFMBE Proceedings, 3 December 2008 through 6 December 2008 ; Volume 23 , 2009 , Pages 65-68 ; 16800737 (ISSN) ; 9783540928409 (ISBN) ; Jaafar, R ; Zahedi, E ; Sharif University of Technology
Abstract
Endothelial dysfunction, which can be noninvasively assessed by flow mediated vasodilation (FMD), predicts an increased rate of adverse cardiovascular events. The endothelial dysfunction is considered as a leading cause of development and progression of the atherosclerotic process. The main aim of this study is to review different non-invasive methods to assess the endothelial dysfunction and to propose enhancements to a new method based on photoplethysmography (PPG). First, non-invasive techniques developed for the evaluation of peripheral endothelial function (including the Doppler ultrasound (US)) will be reviewed. Although noninvasive, US -based techniques present a few disadvantages. To...
Finger photoplethysmogram pulse amplitude changes induced by flow-mediated dilation
, Article Physiological Measurement ; Volume 29, Issue 5 , 2008 , Pages 625-637 ; 09673334 (ISSN) ; Jaafar, R ; Mohd Ali, M. A ; Mohamed, A. L ; Maskon, O ; Sharif University of Technology
2008
Abstract
This study was conducted to investigate the utility and efficacy of finger photoplethysmogram pulse amplitude (PPG-AC) in comparison with the standard Doppler ultrasound in assessing an endothelial function via flow-mediated dilation (FMD). High-resolution B-mode scanning of the right brachial artery (BA) of 31 healthy subjects aged 39.7 ± 11.3 (range 22-64) years and 52 risk subjects aged 47.7 ± 10.8 (range 30-65) years were performed before and after 4 min of upper arm occlusion. Concurrent with the ultrasound measurement (where color Doppler imaging was used to enhance arterial boundary detection), PPG signals were recorded from both index fingers for cross evaluation and comparison. Our...