78 results about "Speckle contrast" patented technology

Optical patient monitoring systems are disclosed. The system may comprise an optical coupling system configured to transmit to and receive light signals from one or more locations on a subject; an optical processing system configured to generate optical data using the received light signals; and a computer programmed to receive the optical data; determine, using the optical data, at least one indicator of blood pressure; estimate an estimated blood pressure using the at least one indicator of blood pressure; and generate a report indicative of the estimated blood pressure. The at least one indicator of blood pressure comprises one or more of near-infrared spectroscopy (NIRS) data; photoplethysmography (PPG) data, diffuse correlation spectroscopy (DCS) data, speckle contrast optical spectroscopy (SCOS) data, speckleplethysmography (SPG) data, first derivative PPG data, second derivative PPG data, first derivative SPG data, second derivative SPG data, inflow (Fin) data, outflow (Fout) data, heart rate data, physiological data, and combinations thereof. Methods for estimating blood pressure are also disclosed.

The invention provides a large-field-of-view high-dynamic myocardial blood flow rate imaging method and device, and relates to the technical field of biomedical optical imagines.The method comprises the steps that imaging parameters of an imaging unit are optimized according to a preset optimization strategy, and the optimized imaging unit is used for collecting laser speckle images of an observation area; a plurality of laser speckle images are obtained; and determining a space speckle contrast matrix and a time speckle contrast matrix of the observation area based on the plurality of laser speckle images, and generating a blood flow index distribution image of the observation area based on the space speckle contrast matrix and the time speckle contrast matrix. According to the large-view-field high-dynamic myocardial blood flow rate imaging method and device, through multi-parameter optimization, the signal-to-noise ratio of myocardial blood flow imaging and the measurable range of the blood flow rate can be effectively increased, and the problem that the myocardial blood flow imaging area is limited is solved.

The invention discloses a three-dimensional blood flow imaging method based on blood flow velocity, a medium, equipment and a system, and belongs to the technical field of imaging. The method comprises the following steps: acquiring an OCT original spectral signal of a measured object; the OCT original spectral signals are converted into OCT intensity signals, time integral speckle intensity is obtained through grouping integration, and pixels of the same space area are obtained to form a pixel set; calculating a time integral speckle contrast of each spatial position in the pixel set, and obtaining statistics of all pixels in the pixel area; calculating the blood flow velocity according to the statistical magnitude; the blood flow velocity of each spatial position is obtained, and a three-dimensional blood flow image is generated. According to the method, the time integral speckle contrast of each spatial position in the pixel set is calculated, and the blood flow velocity of the pixel area is calculated according to the time integral speckle contrast, so that the fluid velocity detection upper limit is greatly expanded, and the problem of low blood flow velocity measurement accuracy in the three-dimensional blood flow imaging graph is solved.

A high-speed laser speckle contrast imaging system is for characterizing pressure wave or pulse wave propagation or vascular conducted response in at least one vessel of a biological target. The apparatus includes: a laser source generating a laser radiation; a high-speed camera configured for capturing at least 1000 frames per second (fps), preferably at least 5000 fps, more preferably 6000 fps of the target; an optical sub-system configured for 1) guiding the laser radiation from the laser source to the target 2) and for collecting and guiding a back-scattered light from the target to the camera; and a processing unit configured for receiving and processing raw image data from the camera for calculating at least one feature related to the pressure wave propagation or vascular conducted response.

Laser speckle contrast imaging techniques that apply a temporal sliding window to a sequence of speckle frames of an avian egg to determine overlapping sets of speckle frames used to reconstruct a sequence of extraembryonic blood vessel images (e.g., movie) showing blood flow dynamics, and where input to a machine learning model based on the overlapping sets of speckle frames can be used to predict the developmental stage of the avian egg, and where the overlapping sets of speckle frames can be used in drug screening.

The invention provides a speckle measurement method based on a spectrum, which is used for measuring the single-dispersion speckle contrast ratio of a measured picture, and comprises the following measurement steps: S1, starting a color speckle tester and measured measurement equipment, projecting a preset measured picture by the measured measurement equipment, and preheating the equipment; s2, acquiring spectral information of a measured picture projected by the measured measuring equipment by using the spectral measuring equipment; s3, selecting a monochromatic optical filter according to the characteristic wavelength in the spectral information obtained in the step S2 by means of a wavelength-optical filter transmittance change curve; s4, configuring the optical filter selected in the step S3 into an optical path of a color speckle tester; s5, readjusting the focal length of the lens of the color speckle tester to avoid the chromatic aberration defect of the lens; s6, adjusting the integral time of the color speckle tester to prevent the collected speckle image from having an overexposure or underexposure phenomenon; and S7, collecting a speckle image of the measured picture, and calculating the single-dispersion speckle contrast of the speckle image.

A system and method for visualizing blood flow are disclosed. The method generally includes obtaining a laser speckle contrast imaging (LSCI) image of blood flow; obtaining a white light image of a tissue, the white light image capturing an anatomical structure of a subject in a region associated with the LSCI image of the blood flow; spatially registering the LSCI image and the white light image with one another; overlaying the spatially registered LSCI and white light images; and generating display data which includes the spatially registered LSCI and white light images and that continuously depicts the blood flow overlaying the tissue.

The invention discloses a quantitative laser speckle blood flow imaging method based on a neuromorphic visual sensor, and relates to the technical field of biomedical engineering. The method solves the problem that static scattered light caused by physiological behaviors and electronic noise of imaging equipment have adverse effects on blood flow imaging quality in a traditional laser speckle contrast imaging method, and comprises the following steps: step 1, using a helium-neon laser as a light source, and irradiating a scattering medium with an expanded laser beam to form a speckle pattern; 2, a microfluidic injector is adopted, two parameters of the inner diameter and the flow of the injector are set, and the flow speed range is controlled; 3, asynchronously sensing the change of the light intensity of the speckle pattern by using an event camera, and shooting the speckle pattern by using a frame camera; and 4, acquiring event stream data by the event camera, and processing the data by using an algorithm. Real-time and high-resolution blood flow imaging and flow velocity calculation are achieved, and the inherent limitation of a traditional method is overcome.

The invention discloses a method and a device for automatically detecting the performance of an array light source metasurface projection device, and the method comprises the steps: receiving an initially collected array speckle image, calculating the axial offset, and transmitting a translation instruction to a three-axis wafer sample objective table according to the axial offset, so as to enable the array speckles to be accurately centered, and obtaining the adjusted array speckle centering image, performing mask segmentation to obtain image dot matrix information, extracting corresponding speckle feature information, performing contrast analysis on the array speckle centering image to obtain speckle contrast information, and combining the speckle feature information and the speckle contrast information to serve as a performance comprehensive detection result. According to the method, the axial offset is calculated, accurate centering of the speckles is achieved, the contrast of the speckles is rapidly and accurately calculated and the feature information of the speckles is rapidly extracted through contrast analysis and feature extraction of the speckles, and therefore the performance comprehensive detection result of comprehensive performance detection of the super-surface projection device is obtained.

The invention provides a radial artery compressor control method and related equipment, and can be applied to the technical field of image processing. The method comprises the following steps: acquiring a first laser blood image acquired by an image acquisition component for a hand region of a target object; determining a target speckle contrast according to the pixel intensity of the pixel points in the first laser blood image, and determining the current blood flow rate of the hand region according to the target speckle contrast; under the condition that the current blood flow rate indicates that the radial artery has the occlusion risk, the ulnar artery air bag is controlled to deflate, and target pressure is determined according to the maximum pressure pulse wave amplitude of the target object in the ulnar artery air bag deflation process; and the ulnar artery air bag is controlled to be inflated until the pressure applied to the ulnar artery by the ulnar artery air bag reaches the blocking pressure, and the radial artery air bag is controlled to be inflated or deflated until the pressure applied to the radial artery by the radial artery air bag reaches the target pressure. In the application, the blood flow of the radial artery is ensured to be smooth so as to avoid radial artery occlusion.

Augmented and / or virtual reality (AR / VR) near-eye display devices implementing adjustment of rendering quality based on saccade detection to preserve computational and power resources are disclosed. In examples, a wearable augmented reality / virtual reality (AR / VR) display device comprises a display to provide AR / VR content, an eye tracking system comprising a coherent light source and a camera, and a processor coupled to the display and the eye tracking system. The processor may capture a raw video of an eye, generate a speckle contrast video by applying speckle contrast computation on the raw video, construct a capillary map of the eye from the speckle contrast video, and authenticate a user based on the capillary map.

A speckle contrast optical spectroscopy techniques for measuring cerebral blood metrics such as cerebral blood flow and / or cerebral blood volume at multiple regions of the brain using one or more light sources and detectors of a plurality of channels disposed on a headset worn by a subject and detecting a brain injury or other brain malfunction by comparing cerebral blood metrics measurement at different regions.

This invention discloses a laser dimension measurement device and method for hollow plastic panels, belonging to the field of laser measurement technology. The method obtains the optical signal-to-noise coefficient based on laser echo intensity, surface reflection uniformity, and speckle contrast; it obtains the motion disturbance coefficient based on encoder slip rate, dynamic bow height of the panel, and edge burr fluctuation frequency; and it obtains the medium interference coefficient based on ambient stray light flicker frequency, transmission depth offset, and color saturation. Furthermore, based on the optical signal-to-noise coefficient and motion disturbance coefficient, combined with the resonant frequency of the internal cavity of the panel and the hollow layer collapse coefficient, a resonance-collapse measurability model is used to obtain resonance-collapse measurability. Finally, combining the medium interference coefficient and the current scanning axis acceleration, an optimized scanning axis acceleration is obtained through an acceleration optimization model. This invention can comprehensively evaluate multi-source interference during the measurement process, dynamically optimize scanning parameters, and improve measurement accuracy and stability.

The invention discloses an illumination system for three-color laser projection, which relates to the technical field of laser projection illumination and comprises an optical support, and the optical support is provided with a three-color laser light source module, a beam shaping module, a vibration speckle elimination device, a dodging module, a relay output module, a TIR total reflection prism and a DMD chip. According to the invention, through the cooperation of the vibration speckle-eliminating device and the light path of the three-color laser, the vibration speckle-eliminating device modulates laser polarization, on the premise of eliminating coherence and reducing speckle formation in principle, the three-color laser divergence is reduced, in the light-homogenizing module, the three-color laser is divided into a plurality of rectangular sub-light spots by the fly-eye lens, and after the rectangular sub-light spots are superposed by the relay output module, the sub-light spots are output. The light spot energy focused on the DMD chip is distributed more uniformly, the dual design of speckle contrast, polarization modulation and rectangular sub-light spot segmentation and superposition is further weakened, the problem of bright and dark spots of a picture of traditional laser projection can be remarkably solved, and the visual impression is improved.

A portable and cost-effective programmable scanning diffuse speckle contrast imaging (PS-DSCI) technique enables noncontact, fast and high-density imaging of deep tissue blood flow, blood oxygenation, and tissue optical properties. PS-DSCI incorporates a digital micromirror device (DMD) for programmable fast scanning of near-infrared lights (e.g., line shape scanning) at different wavelengths over a large region of interest (ROI). A high-resolution 2D camera captures intensity images at each scanning source position. Novel image processing algorithms are created to define the pixel / detection areas at varied distances from the illumination center for capturing diffused photons from the tissue at varied depths. Spatial laser speckle contrasts are calculated in the defined detector regions and then converted to blood flow images at different depths. Line-shape scanning enables high temporal resolution to detect low-frequency oscillations (<0.1 Hz) across different brain regions, thus allowing for the reconstruction of brain functional connectivity maps.

The imaging apparatus configured to assess and quantify motion associated with an object and, in a specific case of an eye—retinal vascular anatomy and hemodynamics and generate substantially contrast-free maps of retinal blood flow over a wide field-of-view at up to 590 fps and under short exposure durations (>50 μs), is applicable for diagnosis, study, and management of neurodegenerative conditions (i.e. mild cognitive impairment and Alzheimer's disease) and systemic cardiovascular diseases (i.e. athero- and arteriosclerosis, coronary artery occlusion, and hypertension). The apparatus employs a) a set of apertures substantially blocking light, delivered from a source of light to an illumination arm of the apparatus, from impinging onto an axial point of the front surface of the lens of the illumination arm, and b) polarization gating between the illumination and light-collecting arms of the apparatus. In one implementation, the apparatus is configured to allow for irradiation of the object with an optical field a degree of coherence and / or spectral content of which are varied delivered through the same optical train including the set of apertures.

Disclosed is system of reducing laser speckle contrast, the system has a laser light source arranged to emit laser light; an illumination target arranged to receive the emitted laser light; a speckle reducer on an optical path between the laser light source and the illumination target, the speckle reducer having one or more optical diffuser elements with a polymer free cholesteric liquid crystal medium; a voltage source connected to the one or more optical diffuser elements; and a controller operatively connected to the laser light source and the voltage source, wherein the controller is configured to apply and remove a driving voltage Vd to the one or more optical diffuser elements to toggle the one or more optical diffuser elements between a diffusing state and a non-diffusing state.

The invention relates to a stereo surgical microscope for observing an object, comprising an integrated illumination system for illuminating the object, an integrated camera system for recording the light emitted by the object, and a processing unit. The integrated illumination system is designed to illuminate the object in a first illumination mode with coherent light in a first wavelength range and in a second illumination mode with light in a second wavelength range, and the first and second wavelength ranges are disjoint, and / or the light of the first illumination mode and the light of the second illumination mode are emitted at different times, and / or coherent light is rendered incoherent before it strikes the object. The integrated camera system is designed to detect the light emitted by the object in a first observation mode and in a second observation mode.wherein the first observation mode is tuned to the light emitted by the object in the first illumination mode, and the second observation mode is tuned to the light emitted by the object in the second illumination mode, and the tuning of the first and / or second observation mode comprises at least one change in a property from the list of exposure time, wavelength range, polarization, acquisition time, intensity, and binning. The processing unit is configured to examine the light detected in the first observation mode for a speckle contrast, determine a perfusion value from the examined speckle contrast, generate a control signal taking the perfusion value into account, and control a component of the stereo surgical microscope or a component connected to the stereo surgical microscope using the control signal.

A system and method for visualizing blood flow is disclosed. The method generally includes obtaining a laser speckle contrast imaging (LSCI) image of blood flow, obtaining a white light image of tissue, where the white light image captures an anatomical structure of interest in a region associated with the LSCI image of blood flow, spatially registering the LSCI image and the white light image with respect to one another, overlaying the spatially registered LSCI image and the white light image, and generating display data including the spatially registered LSCI and white light images and continuously depicting the blood flow overlaying the tissue.

The application discloses a laser speckle blood flow imaging method and system, and the method comprises the following steps: acquiring a laser speckle image sequence to be processed; processing the laser speckle image sequence to be processed by using a non-overlapping window space contrast algorithm to obtain a low-resolution space contrast image in a logarithmic domain to be processed; inputting the low-resolution space contrast image in the logarithmic domain to be processed into a pre-trained image super-resolution model to obtain a predicted high-resolution speckle contrast image in the logarithmic domain; and calculating a laser speckle blood flow image according to the predicted high-resolution speckle contrast image in the logarithmic domain. The application adopts a lightweight image super-resolution network to improve the spatial resolution, is easy to process in real time, and is easy to realize laser speckle blood flow imaging.

A method of image enhancement of a reflectance confocal microscope is disclosed. The method comprises: receiving by a processor a first image captured by a detector of the confocal microscope, at a first position of a pinhole; receiving one or more second images captured by the detector, at at least one second position of the pinhole; and adding, by the processor, the one or more second images to the first image to reduce a speckle contrast in the combined image. In addition, the first position of the pinhole is a confocal position, and the at least one second position is a shifted position with respect to the confocal position.

An optical device, a projection system and an interaction method relate to the technical field of projection. The optical device comprises a light source, a dissipation mechanism located on the light-emitting side of the light source and a lens assembly located on the light-emitting side of the dissipation mechanism. The light source is used for emitting a light beam, the dissipation mechanism is used for inclining at a first position and a second position along a first axis, so that the light beam emits frame images through the lens assembly, and different frame images are projected at different positions of a projection picture for superposition display; pixels between adjacent frames of images are offset. The optical device can reduce the speckle contrast through the displacement and superposition of the pixel array, thereby improving the speckle elimination effect.

This application provides a method, device, system, and medium for monitoring blood perfusion. The method includes: acquiring a speckle image sequence of the tissue region to be monitored based on a laser emitted to it; acquiring ambient light information corresponding to the speckle image sequence and motion information between adjacent speckle images in the speckle image sequence; performing anti-interference processing on the speckle image sequence based on the ambient light information and the motion information between adjacent speckle images to obtain a corrected speckle image sequence; calculating the spatiotemporal joint speckle contrast of the corrected speckle image sequence to obtain a spatiotemporal joint speckle contrast; determining the blood perfusion parameters of the tissue region to be monitored based on the spatiotemporal joint speckle contrast using a pre-established mapping model between speckle contrast and blood perfusion parameters; and outputting a warning message when the blood perfusion parameters meet preset warning conditions. This method aims to improve the accuracy of blood perfusion monitoring.

This disclosure relates generally to speckle image analysis, and, more particularly, to a system and method for imaging of localized and heterogenous dynamics using laser speckle. Existing speckle analysis techniques do not offer the capability to achieve both the dynamic phenomenon which carries over a specific time duration and localizing the extent of the activity at a single, chosen instant of time simultaneously. The present disclosure records an image stack consisting of N speckle images sequentially over a period, divides the image stack into a spatial window and a temporal window, converts the speckle intensity data comprised in the spatial window into a column vector. Construct a diagonal matrix and extract a singular value from the diagonal matrix, then defines a speckle intensity correlation metric using the plurality of singular values, defines a speckle activity and generates a speckle contrast image by graphically plotting the speckle activity values.

This invention discloses a laser speckle contrast imaging system and method with shared transmission and reflection capabilities, relating to the field of optical imaging. In this system, coherent light is split into two beams by a beam splitter. Based on optical geometry principles, coherent transmitted and reflected light can coexist simultaneously, achieving shared transmission and reflection laser speckle contrast imaging. Furthermore, by utilizing the number of optical paths present in the first, second, and third light-shielding plates, either transmission-type or reflection-type laser speckle contrast imaging can be achieved. This invention can improve the imaging depth of blood vessels while maintaining the imaging quality of superficial blood vessels.

One aspect of the invention relates to an apparatus for assessment of parathyroid gland viability comprising a diffuser configured to diffuse a beam of light onto a tissue surface of a parathyroid gland of a patient to illuminate the tissue surface; and means for obtaining speckle contrast images for the assessment of parathyroid gland viability.

The invention discloses a coherent detection laser radar system and a multi-wavelength coherent ranging method. The coherent detection laser radar system at least comprises at least two fiber lasers with different central wavelengths, a first DWDM, a pulse modulation unit, an optical power amplification unit, an optical lens, a second DWDM, at least two photoelectric detectors and an FPGA. According to the embodiment of the invention, the speckle effect is effectively suppressed through the multi-wavelength diversity design, and the speckle contrast is remarkably reduced through the incoherent superposition of a plurality of independent wavelengths; meanwhile, a wavelength division amplification scheme is adopted, and the overall SBS threshold value of the system is improved through a multi-wavelength spectrum broadening effect on the premise that the power of each channel is kept to be lower than the SBS threshold value, so that the unification of high-power output and high coherence is realized; in addition, the method has remarkable advantages in the aspects of environmental adaptability, system expansibility and the like.

The present invention provides an optical measuring apparatus and optical measuring method that can improve the degree of freedom in imaging conditions of the surface to be measured for speckle contrast or sparkle contrast. [Solution] The optical measuring device 1 comprises an optical system 3 that images the light emitted from the surface to be measured 7 of a light-emitting electronic display or light-emitting surface to be measured for speckle contrast or sparkle contrast; a two-dimensional sensor array 4 having a two-dimensional sensor array surface 41 on which the emitted light is imaged and which images the emitted light; and a calculation unit 6 that calculates speckle contrast or sparkle contrast based on the emitted light imaged under imaging conditions in which the size of the light-emitting region on the surface to be measured that contributes to the imaging of the diffraction-limited spot of the emitted light on the two-dimensional sensor array surface is constant. The size of the light-emitting region is determined based on the size of the diffraction-limited spot and the magnification of the optical system, which is determined from the focal length of the optical system and the imaging distance from the surface to be measured to the optical system.

The invention discloses a projection system and a display control method thereof, by arranging a phase light modulator in the projection system, the effects of shaping and homogenizing light are achieved, the effects of a diffusion element, a lens group and the like in an illumination light path can be replaced, the light path design is simplified, and the size of an optical engine is optimized. After the phase light modulator is partitioned according to the distribution of incident light combination light spots, the phase needing to be loaded can be independently determined for each partition, pertinence is better achieved, for laser of the same wavelength, the phase light modulator is divided into a plurality of partitions to conduct phase modulation, and the phase modulation efficiency is improved. When the modulated laser enters the display element, the effect of overlapping a plurality of light spots is achieved, the uniformity of a light field is better improved, and the speckle problem is solved. The optical extensions of the three-color laser after partition modulation of the phase light modulator are roughly the same, the utilization rate of the three-color laser is improved, the speckle contrast ratio is reduced, the chromaticity uniformity of a projected image is improved, and the display effect is optimized.

A system include a light source configured to emit quasi-coherent light to tissue of a patient, the light source configured to emit the quasi-coherent light through at least one of a nasal passage or an ear canal of the patient. The system includes a detector configured to detect resulting light passing through at least a portion of the tissue and generate an interference pattern image. The interference pattern image is representative of the portion of the tissue interacting with the quasi-coherent light traveling through the nasal passage or the ear canal of the patient. The system includes processing circuitry configured to receive the interference pattern image from the detector, generate a speckle contrast signal based on the interference pattern image, determine, based on the speckle contrast signal or a metric derived therefrom, a physiological characteristic of the patient, and output a representation of the physiological characteristic of the patient.