We present a new method of formation photoplethysmographic images with high spatial resolution from video recordings living body in the reflection geometry. The (patent pending) is based on lock-in amplification every pixel recorded frames. A reference function required for synchronous detection cardiovascular pulse waves formed same featured by ability to visualize dynamic changes wave during cardiac (or respiratory) cycle. demonstrate that system capable detect minimal irritations such as...

The non-invasive assessment of blood flow is invaluable for the diagnostic and monitoring treatment numerous vascular neurological diseases. We developed a non-contact method pulsation imaging capable visualizing two-dimensional distribution two key parameters peripheral flow: amplitude phase. based on photoplethysmographic in reflection mode. In contrast with previous systems we use new algorithm data processing which allows dimensional mapping pulsations large object's areas after every...

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....

Mono- and bimetallic systems of Ag, Fe, Ag–Fe exchanged in sodium mordenite zeolite were studied the reaction NO reduction. The transition metal cations Ag Fe introduced by ion exchange method both at room temperature 60 °C; modifying order component deposition systems. These materials characterized Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), ultraviolet-visible spectroscopy (UV-Vis), X-Ray photoelectron (XPS) High-resolution transmission electron microscopy (HR-TEM)....

A novel technique for distributed detection and localization of vibrational disturbances is presented. It based on a serial array identical low-finesse Fabry-Perot interferometers interrogated at fixed wavelength by DFB diode laser intensity modulated 10 KHz. Interferometers are formed directly in the single mode SMF-28 fiber pairs Bragg gratings with reflectivity < 0.05% each. simple signal processing Fourier transform detected signals evaluation phases different components enables...

Vasomotor reactivity, which is important to estimate neurogenic regulation of blood vessels in patients with different pathologies, still assessed by occlusion plethysmography using sensors contacting the limbs. Recently we proposed a contactless approach for measuring flow changes during venous imaging photoplethysmography [Kamshilin et al., Sci. Rep.7, 4642017]. In this work, response vascular system on was studied simultaneously contact air-plethysmography and remote optical under...

We report on the detection of a loss-inducing perturbation with variable localization accuracy along test fiber based analysis transmitted and reflected powers an unmodulated continuous-wave light source. The required is provided by suitable distribution differential reflectivity fiber. for strong disturbance has been estimated as /spl plusmn/ 1.0 m 3.939-km single-mode 5.0 mm designated 10-cm part both weak perturbations.

We analyze statistical properties of dynamic speckles formed when an optically rough surface is illuminated by a fast-deflecting laser beam. The modified space-time correlation function the light-intensity fluctuations has been introduced to estimate parameters speckle pattern. Dynamic are considered in their application range sensing using evaluation light-power-modulation frequency signal obtained from integrating photodetector after spatial filtering scattered light. Multichannel...

An optical fiber sensor system for localization of a vibrational disturbance along the is presented. The based on serial array identical Fabry-Perot interferometers, formed directly in single mode SMF-28e by pairs Bragg gratings with reflectivity 0.04% each. Interferometers were interrogated an intensity modulated distributed feedback diode laser. We present signal processing algorithm disturbed interferometer and experimental results 14 in-fiber interferometers. Simple configuration use...

We propose and experimentally demonstrate a simple approach to realize phase-sensitive correlation optical time-domain reflectometer (OTDR) suitable for detection localization of dynamic perturbations along single-mode fiber. It is based on the quantum phase fluctuations coherent light emitted by telecom DFB diode laser. Truly random probe signals are generated an interferometer with path difference exceeding coherence length laser light. Speckle-like OTDR traces were obtained calculating...

A novel interrogation method for fibre optic loss sensors based on the analysis of transmitted and reflected powers a continuous wave light source is presented. The position region determined from unique dependencies between normalised different locations disturbance along containing number Bragg gratings.

We present novel experimental method for estimation of the light penetration depth (LPD) in turbid media based on analysis speckle pattern structure. Under certain illumination conditions this structure is strongly dependent depth. Presented theoretical model Bragg diffraction from thick holograms allows LPD if only one parameter material, namely refractive index, material known. Feasibility was checked experimentally. Experimental results obtained variety materials are good agreement with...

New digital demodulation algorithm for recently announced twin-grating fiber-optic sensor is presented. The built with two short, identical, low reflectance, closely spaced Bragg gratings imprinted in a telecommunications fiber. Because of such design the reflection spectrum this sinusoidal wave within an envelope single grating. Similar to traditional based on gratings, change temperature or strain leads shift along wavelength axis. However has more complicated structure and instead...

Au cores partially covered with Pd (molar ratio Au20:Pd1) were homogeneously encapsulated into silica shells to form AuPd@SiO2 nanoreactors via usage of high polyvinylpyrrolidone (PVP) concentration and prolonged time nanoparticle treatment PVP before bimetallic encapsulation. The presence both metals in the core was confirmed by means STEM-EDS, UV-Vis XPS. showed enhanced catalytic activity CO oxidation compared that for reference Au@SiO2 nanoreactors. developed experimental procedure...

A new technique for distributed fiber-optic sensing is described. It a wavelength-scanning method that uses, as element, polarization-maintaining fiber illuminated with white-light source. The distribution of the mode-coupling coefficient determined by digital procedure fast-Fourier-transform algorithm. Experimental results demonstrate that, when birefringence dispersion taken into account, more than 300 elements can be resolved along fiber.