Photoplethysmography (PPG) devices are widely used in clinical practice but the origin of PPG signal is still under debating. The classical theory assumes that waveform stems from variations blood volume pulsating arteries. In this research we analysed high-speed video recordings capillaries a fingernail bed. It was found speed erythrocytes has pronounced modulation time, which follows instantaneous pressure However, mean significantly differs even for neighbour whereas change occurs phase...

Assessment of the cardiovascular parameters using noncontact video-based or imaging photoplethysmography (IPPG) is usually considered as inaccurate because strong influence motion artefacts. To optimize this technique we performed a simultaneous recording electrocardiogram and video frames face for 36 healthy volunteers. We found that signal disturbances originate mainly from stochastically enhanced dichroic notch caused by endogenous mechanisms, with smaller contribution Our properly...

Imaging photoplethysmography (IPPG) is a recently developed technique for noncontact assessment of cardiovascular function. However, its wide use limited by low signal-to-noise ratio due to motion artifacts. The aim this work estimate the polarization-filtration impact on discriminating artifacts in IPPG measurements. Experiments were carried out in-vivo almost simultaneous illumination subject's palm with polarized and non-polarized light during video recording 41 subjects. It was found...

The automation of action recognition in laboratory animals is a crucial step simplifying behavioral tests the fields pathophysiology and rehabilitation research. most common method to analyze trajectories key skeletal points. However, existing methods are strongly tied specific animal species, selected points, set activities be recognized. Furthermore, there dearth mathematical formulations this problem research on algorithms for filtering obtained trajectories. task involves collection...

The velocity of the pulse wave (PWV) propagating through vascular tree is an essential parameter for diagnostic state cardiovascular system especially when it measured in pool carotid arteries. In this research, we showed first time that blood-pressure-wave propagation from heart to face a function body position. Significant asymmetry and asynchronicity blood pulsations facial area were found recumbent Parameters by advanced camera-based photoplethysmography 73 apparently healthy subjects....

Accurate and practical assessment of the brain circulation is needed to adequately estimate viability cerebral blood flow regulatory mechanisms in various physiological conditions. The objective our study was examine feasibility contactless green-light imaging photoplethysmography (PPG) for assessing autoregulation by revealing dynamic relationships between cortical microcirculation assessed PPG changes systemic pressure caused visceral somatic peripheral stimuli. In anesthetized male Wistar...

The non-invasive biomarkers of migraine can help to develop the personalized medication this disorder. In testing antimigraine drugs capsaicin-induced skin redness with activated TRPV1 receptors in sensory neurons associated release mediator CGRP has already been widely used.Fourteen patients (mean age 34.6 ± 10.2 years) and 14 healthy volunteers 29.9 9.7 participated experiment. A new arrangement imaging photoplethysmography recently developed by us was used here discover novel sensitive...

Assessment of skin blood flow is an important clinical task which required to study mechanisms microcirculation regulation including thermoregulation. Contactless assessment vasomotor reactivity in response thermal exposure currently not available. The aim this show the applicability imaging photoplethysmography (IPPG) method measure quantitatively local exposure. Seventeen healthy subjects aged 23 ± 7 years participated study. A warm transparent compress applied subject’s forehead served as...

Instrumental identification of proximal scleroderma, which is necessary for the early diagnosis systemic sclerosis (SSD), has not yet been developed. The aim this study was to assess potential diagnostic value imaging photoplethysmography (IPPG) method in patients with SSD.The enrolled 19 SSD and 21 healthy subjects matched by age sex patients. Spatial distribution capillary-blood-flow parameters their dynamics estimated facial area subjects. In IPPG system, a 40 s video subject's face...

Assessment of the cerebral blood-flow-reserve in patients with cerebrovascular diseases is extremely important terms making prognosis, determining treatment tactics, and controlling revascularization outcome case reconstructive interventions on brain vessels. However, there no easy-to-use, contactless method for either assessing functional reserve cortical vascular network or intraoperative monitoring surgical intervention. Our study aims to demonstrate feasibility green-light imaging...

Intraoperative assessment of cerebrovascular reactivity is a relevant problem neurosurgery. To assess the functional reserve cerebral blood flow, we suggest using imaging photoplethysmography for measuring changes in cortical perfusion caused by CO2 inhalation. Feasibility technique was demonstrated three groups anesthetized rats (n=21) with opened and closed cranial windows. Our study first time revealed that hemodynamic response to hypercapnia strongly depends on state. However, it shown...

Abstract Background Existent animal models of migraine are not without drawbacks and limitations. The aim our study was to evaluate imaging photoplethysmography (PPG) as a method assessing intracranial blood flow in rats its changes response electrical stimulation dural trigeminal afferents. Methods Experiments were carried out with 32 anesthetized adult male Wistar rats. Trigeminovascular system (TVS) activated by means afferents through closed cranial window (CCW). Parameters meningeal...

Abstract Among numerous approaches to the study of migraine, nitroglycerin (NTG) model occupies a prominent place, but there is relatively insufficient information about how NTG affects intracranial vessels. In this we aim assess effects on blood-flow parameters in meningeal vessels measured by imaging photoplethysmography (iPPG) animal experiments. An amplitude pulsatile component (APC) iPPG waveform was assessed before and within 2.5 h after administration saline (n = 13) or sumatriptan...

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Igor Gurov, Maxim Volynsky, Elena Vorobeva; Dynamic Wavefront Evaluation in Phase Shifting Interferometry Based on Recurrence Fringe Processing. AIP Conf. Proc. 15 April 2010; 1236 (1): 479–484. https://doi.org/10.1063/1.3426165 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley...

Parameters of blood microcirculation are revealed when obtaining in-vivo useful information by combined use the video-capillaroscopy, imaging photoplethysmography, and electrocardiography. Different time delays were found between signal pulsations evaluated various techniques allowing development new circulation diagnostic methods.

The possibility of using a new contactless method imaging photoplethysmography to assess thermoregulatory vasodilatation blood vessels was studied. Perfusion reaction in region the outer forearm response local heating up 41 ± 1 °C monitored six volunteers aged 39–52 years video recording study area, synchronized with an electrocardiogram, and subsequent correlation processing data obtained. It shown that change perfusion during has biphasic type is due nervous system mediated by axon reflex...

Recovery of an unwrapped wavefront in phase-shifting interferometry is considered when the phase increments are determined between previous and subsequent fringe patterns as well adjacent pixels current pattern. A parametric model a three-dimensional interferometric signal recurrence processing algorithm state space utilized, providing evaluation at each shift step dynamic mode. Estimates achievable accuracy experimental results recovery presented. Comparison with conventional seven-frame...

Endothelial dysfunction is one of the most important markers risk cardiovascular complications. This study aimed to demonstrate feasibility imaging photoplethysmography assess microcirculation response local heating in order develop a novel technology for assessing endothelial function. As measure vasodilation, we used relative dynamics pulsatile component photoplethysmographic waveform, which was assessed large area outer surface middle third subject’s forearm. The perfusion evaluated six...

Stochastic models of multilayer tissue and low-coherence interferometric signals are considered. The extended Kalman filtering method is investigated applied to dynamic evaluating layer borders tissues in Optical Coherence Tomography (OCT). Increased resolution provided by direct transforming input fringe signal samples series estimates amplitude local envelope maximum positions. Results experimental the resolving power case partially overlapped peaks presented discussed.

Recurrent stochastic data processing algorithms using representation of interferometric signal as output a dynamic system, which state is described by vector parameters, in some cases are more effective, compared with conventional algorithms. Interferometric signals depend on phase nonlinearly. Consequently it expedient to apply nonlinear filtering, such Kalman type filters. An application the second order extended filter and Markov that allows minimize estimation error described....

We describe highly reliable measurement method of the pulse wave transit time (PWTT) to human limbs by using simultaneous recordings imaging photoplethysmography and electrocardiography. High accuracy measurements was achieved access a larger number statistically independent data obtained simultaneously in different points. The is characterized higher diagnostic reliability because automatic selection regions less affected environmental noise. technique tested group 12 young healthy subjects...

The paper deals with the sequential Monte Carlo method applied to problem of interferometric signals parameters evaluation. A stochastic model signal formation is presented. Detailed description algorithm given. modification based on assumption Gaussian posterior probability density function proposed. peculiarities and its are considered discussed. results evaluation Data processing rate proposed methods estimated analyzed.

Video-based system allows measurements not only the heart rate and its variability but also time delay of blood pulsations in facial area. We found that is different right left cheeks for subjects recumbent position.