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44 results about "Speckle contrast" patented technology

Speckle contrast is defined as the ratio of the standard deviation to the average intensity over the speckle pattern. When the contrast is unity, it is called fully developed speckle, which is the original form of speckle. Speckle standard diffuser is devised to generate stable and fully developed speckle.

System for and method of measuring blood pressure non-invasively with light

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.
Owner:THE GENERAL HOSPITAL CORP

Continuous blood flow visualization with laser speckle contrast imaging

PendingUS20250311936A1Image enhancementMedical imagingBlood flow visualizationAnatomical structures
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.
Owner:BOARD OF RGT THE UNIV OF TEXAS SYST

Portable multi-channel speckle contrast optical spectroscopy systems for cerebral blood flow and blood volume measurement in brain injury

PCT designated stageWO2026096812A1Medical imagingDiagnostics using spectroscopyInjury brainCerebral blood volume
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.
Owner:CALIFORNIA INST OF TECH +1

Hollow plastic plate laser size measuring device and method

PendingCN122281737AContrast levelEcho intensity
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.
Owner:SHANDONG LILE NEW MATERIAL CO LTD

Illuminating system for three-color laser projection

PendingCN121091586AProjectorsOptical elementsOptical mountLight spot
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.
Owner:YI PU GUANG DIAN (FU YANG) YOU XIAN GONG SI

Programmable scanning diffuse speckle contrast imaging (PS-DSCI) of deep tissue optical properties, hemodynamics, and function

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.
Owner:UNIVERSITY OF KENTUCKY RESEARCH FOUNDATION

Laser-speckle contrast imaging system and method

PendingUS20260053356A1OthalmoscopesContrast levelRetinal blood flow
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.
Owner:MEDICAL COLLEGE OF WISCONSIN INC +1

Laser speckle blood flow imaging method and system

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.
Owner:XI AN JIAOTONG UNIV

System and method for image enhancement of reflectance confocal microscopes

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.
Owner:TECHNION RES & DEV FOUND LTD

Blood perfusion monitoring methods, monitoring equipment, monitoring systems and media

PendingCN122312644AContrast levelSpeckle contrast
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.
Owner:SHENZHEN XINGHAN LASER TECH CO LTD

A laser speckle contrast blood flow imaging system and method with both transmissive and reflective capabilities

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.
Owner:TIANJIN POLYTECHNIC UNIV

Coherent detection laser radar system and multi-wavelength coherent ranging method

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.
Owner:11TH RES INST OF CHINA ELECTRONICS TECH GROUP CORP

Optical measuring apparatus and optical measuring method

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.
Owner:DAI NIPPON PRINTING CO LTD

Projection system and display control method thereof

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.
Owner:QINGDAO HISENSE LASER DISPLAY CO LTD

Method and system for intraoperative parathyroid gland identification and blood supply monitoring based on laser speckle contrast technology

The invention discloses an intraoperative parathyroid gland recognition and blood supply monitoring method and system based on a laser speckle contrast technology, relates to the technical field of intraoperative parathyroid gland recognition, and solves the problems that in the prior art, parathyroid gland recognition is difficult, the intraoperative mistaken cutting risk is high, and blood flow detection is insufficient. The method comprises the following steps: acquiring an autofluorescence image and a speckle contrast image, carrying out noise reduction and image enhancement processing on the autofluorescence image, and evaluating the blood vessel distribution and blood flow velocity of the identified parathyroid gland according to the speckle contrast of the speckle contrast image, according to the autofluorescence image and the speckle contrast image, the position and the form of the parathyroid gland are manually recognized, the autofluorescence image and the speckle contrast image are input into a pre-trained neural network model to obtain an AI recognition result, and by combining LSCI, NIRAF and AI technologies, real-time recognition and blood supply state monitoring of the parathyroid gland are achieved. And objective blood supply state evaluation and automatic parathyroid gland identification can be provided by using the neural network model.
Owner:ZHEJIANG SCI-TECH UNIV

Laser projection device and laser projection system

PendingCN122652878Areduce negative impactDecreased depolarization effectLight beamSpeckle contrast
The application relates to a laser projection device and a laser projection system. A depolarizer component is additionally arranged on a laser display light path between a light source and a light modulation component, so that birefringence and interference effects occur in the depolarizer component, and polarized light is converted into random polarized light. Birefringence caused by lens stress in the light modulation component usually has a fixed fast and slow axis direction, which can affect the polarization state of light passing through the lens. In the embodiments provided by the application, the depolarizer component can rotate around the light beam propagation direction in the working state. When the light beam passes through the lens each time, the polarization direction of the light changes relative to the axis of the stress birefringence. The phase delay caused by the stress has different effects in different directions, and the effects are offset after time averaging, so that the negative influence of the birefringence effect caused by the lens stress on the depolarization effect of the depolarizer component can be reduced, and the speckle contrast can be greatly reduced, and the speckle suppression effect is improved.
Owner:QINGDAO HISENSE LASER DISPLAY CO LTD

Roadbed transverse and longitudinal slope laser ruler real-time detection and three-dimensional curve presentation method

The invention discloses a roadbed transverse and longitudinal slope laser ruler real-time detection and three-dimensional curve presentation method, and relates to the technical field of roadbed optical measurement, and the method comprises the steps: carrying out the local contrast value statistics of a laser speckle image sequence, and generating a laser speckle contrast spectrum; performing phase calculation and point cloud construction on the laser interference ranging phase signal to obtain a laser interference ranging phase residual error; performing spatial correlation and weight statistics on the laser speckle contrast spectrum and the laser interference ranging phase residual, and outputting a roadbed quality state diagram; performing superposition fusion on the roadbed quality state diagram and the three-dimensional point cloud data, and outputting a roadbed enhanced three-dimensional data set; and performing elevation curved surface reconstruction on the roadbed enhanced three-dimensional data set, and performing transverse and longitudinal slope feature line extraction and graphical rendering to complete presentation of a roadbed transverse and longitudinal slope three-dimensional curve. According to the invention, through double-mechanism cooperation of the laser speckle contrast spectrum and the laser interference ranging phase residual, integrated evaluation of the surface and inner quality of the roadbed and accurate presentation of the three-dimensional morphology are realized.
Owner:BEIJING YILU TECH DEV CO LTD

A method, device and system for correcting laser speckle contrast images

Embodiments of the present application provide a kind of laser speckle contrast image correction method, device and system, it is related to image processing technical field.The method includes: obtaining multiple speckle images;According to each speckle image, determine light intensity distribution diagram;Determine the original speckle contrast image of target speckle image;According to light intensity distribution diagram, determine local light intensity variation coefficient diagram, wherein each pixel point in local light intensity variation coefficient diagram is used to indicate the variation coefficient of pixel intensity in the neighborhood of pixel point in light intensity distribution diagram;According to the value of each pixel point in local light intensity variation coefficient diagram, the value of pixel point in corresponding position in original speckle contrast image is corrected, to obtain corrected speckle contrast image and output.Selecting the present application, can reduce the influence of uneven illumination on laser speckle image, so that blood flow image luminance is uniform and contrast is accurate, to improve the accuracy of blood flow velocity estimation.
Owner:XIAN INST OF OPTICS & PRECISION MECHANICS CHINESE ACAD OF SCI +1

Testing method and testing device for laser display dynamic speckles

PendingCN121678123ATesting optical propertiesSpeckle contrastDynamic speckle
The invention provides a method for testing dynamic speckles displayed by laser. The method comprises the following steps of: a) acquiring multiple frames of laser speckle images of an area to be detected by using an imaging device; b) calculating the average space speckle contrast ratio and the average time speckle contrast ratio of the area to be detected according to the multiple frames of laser speckle images; c) collecting the average static space speckle contrast ratio of the test system, and calculating system coherence parameters according to the average static space speckle contrast ratio; step d), according to the formula, calculating to obtain a dynamic component proportionality coefficient of the to-be-measured area; and e) according to the mixed scattering model formula, calculating to obtain the dynamic speckle index of the to-be-measured area.
Owner:SHANGHAI WEISHIRUI OPTOELECTRONIC TECH CO LTD

Method and device for automatically detecting performance of array light source metasurface projection device

The application discloses a kind of array light source super surface projection device performance automatic detection method and device, method includes: receiving preliminary acquisition array speckle image and calculating axial offset, according to axis offset sending translation instruction to three-axis wafer sample stage to make array speckle accurate centering, obtain adjusted array speckle centering image and carry out mask plate segmentation to obtain image dot matrix information, after extracting corresponding speckle feature information, array speckle centering image is carried out contrast analysis, obtains speckle contrast information, speckle feature information and speckle contrast information are combined as performance comprehensive detection result.The above method, by calculating axial offset and realizing the accurate centering of speckle, by contrast analysis and speckle feature extraction, realize the quick and accurate calculation of speckle contrast and the quick extraction of speckle feature information, to obtain the performance comprehensive detection result of comprehensive performance detection to super surface projection device.
Owner:HANGZHOU NAJING TECHNOLOGY CO LTD

Laser speckle imaging with near infrared autofluorescence to minimize false positive with less perfused tissue

A tissue detection system includes a light source configured to illuminate tissue of interest. An imaging head including a detector is configured to acquire auto-fluorescence of the illuminated target tissue of interest responsive to the application of the light and generate one or more auto-fluorescence images of the target tissue of interest. A controller is configured to regulate operational control of the imaging head when acquiring, receiving, and processing images. If an intensity signal of the detected one or more auto-fluorescence images of the target tissue of interest leads to a determination of parathyroid tissue, the detector is configured to acquire laser speckle contrast images to determine the amount of perfusion of the target tissue of interest to distinguish well perfused parathyroid tissue having a low speckle contrast image from less perfused tissue having a high speckle contrast image. The less perfused tissue is identified a potential false positive.
Owner:AI BIOMED CORP

A method, device and system for correcting laser speckle contrast images

ActiveCN122089616AAccurate brightnesssmall variationImage enhancementSensorsImaging processingOphthalmology
This invention provides a method, apparatus, and system for correcting laser speckle contrast images, relating to the field of image processing technology. The method includes: acquiring multiple speckle images; determining a light intensity distribution map based on each speckle image; determining an original speckle contrast image of the target speckle image; determining a local light intensity variation coefficient map based on the light intensity distribution map, wherein each pixel in the local light intensity variation coefficient map represents the variation coefficient of pixel intensity in the neighborhood of the pixel in the light intensity distribution map; correcting the values ​​of corresponding pixels in the original speckle contrast image based on the values ​​of each pixel in the local light intensity variation coefficient map, obtaining and outputting a corrected speckle contrast image. Using this application can reduce the influence of uneven illumination on laser speckle images, resulting in more uniform brightness and accurate contrast in blood flow images, thereby improving the accuracy of blood flow velocity estimation.
Owner:XIAN INST OF OPTICS & PRECISION MECHANICS CHINESE ACAD OF SCI +1

Radial artery compressor control method and related devices

The application provides a radial artery compressor control method and related equipment, which can be used in the field of image processing technology; the method comprises the following steps: acquiring a first laser blood image of a hand region of a target object collected by an image acquisition component; determining a target speckle contrast according to the pixel intensity of a pixel point in the first laser blood image, and determining the current blood flow rate of the hand region according to the target speckle contrast; in the case that the current blood flow rate indicates that the radial artery has an occlusion risk, controlling the ulnar artery balloon to deflate, and determining a target pressure according to the highest pressure pulse wave amplitude of the target object in the deflation process of the ulnar artery balloon; controlling the ulnar artery balloon to inflate until the pressure applied by the ulnar artery balloon to the ulnar artery reaches a blockage pressure, and controlling the radial artery balloon to inflate or deflate until the pressure applied by the radial artery balloon to the radial artery reaches the target pressure. In the application, the blood flow of the radial artery is ensured to be unobstructed to avoid radial artery occlusion.
Owner:FUWAI HOSPITAL CHINESE ACAD OF MEDICAL SCI & PEKING UNION MEDICAL COLLEGE

A method and apparatus for evaluating laser thermal effects

ActiveCN119318478BImage enhancementImage analysisBlood flowSpeckle contrast
The application discloses a laser heat effect evaluation method and device, and belongs to the technical field of biology. The method comprises the following steps: acquiring an original laser speckle blood flow image sequence, analyzing the original laser speckle image by using a time contrast analysis algorithm to acquire a laser speckle contrast image; converting the laser speckle contrast image to acquire a laser speckle blood flow image. The half-height width of the blood vessel in the laser speckle blood flow image is calculated as the width of the blood vessel; the blood flow image after laser irradiation is subtracted from the blood flow image before laser irradiation to acquire a difference image; the blood vessel with blood flow change caused by laser irradiation is acquired according to the difference image, then a region of interest is selected, and the mean value of the blood flow of the blood vessel before and after laser irradiation is acquired, so that the final laser treatment effect is evaluated. The mouse dorsal window 108 is irradiated from the complete skin side of the mouse dorsal window 108, and the blood flow change is monitored in real time by using the laser speckle blood flow imaging technology on the exposed blood vessel side of the opposite side. The influence of the upper skin tissue is considered, the blood flow change is monitored in real time, and the precise evaluation of the laser heat effect on the blood vessel is realized.
Owner:XI AN JIAOTONG UNIV

Tongue picture texture analysis and phlegm-dampness constitution recognition method and device based on multispectral imaging and storable medium

The invention discloses a tongue picture texture analysis and phlegm-dampness constitution recognition method and device based on multispectral imaging and a storable medium, and belongs to the technical field of traditional Chinese medicine tongue diagnosis objectification and artificial intelligence application. In order to solve the problem of lack of objective and standardized quantitative analysis of tongue picture analysis at present, the device defines a tongue coating viscoelasticity index and a sublingual microcirculation response index by collecting a lingual surface multispectral image, tongue coating deformation recovery sequence data and sublingual speckle contrast sequence data; thick and greasy tongue coating, sticky and unsmooth tongue coating, phlegm-dampness blocking, qi and blood blocking and the like in traditional Chinese medicine are converted into quantitative indexes, classification and recognition are carried out on the phlegm-dampness constitution according to an AI recognition model, and results are output. According to the device, by fusing multispectral biological imaging and artificial intelligence analysis technologies, the conventional tongue diagnosis process depending on experience is objectively quantified, the physiological mechanism behind phlegm-dampness discrimination is disclosed, and the consistency and credibility of diagnosis results are improved.
Owner:BEIJING CHINESE MEDICINE HOSPITAL AFFILIATED CAPITAL MEDICAL UNIV

A method of imaging by displaying changes in speckle contrast

The invention relates to a method of imaging by displaying variations in speckle contrast, which makes it possible to reveal more reliably the movements of parts of a scattering object (100) to be analyzed. The method comprises the use of a reference object (101) to verify that the illuminating laser source used does not undergo operational fluctuations during the execution of the method. The use of a reference object also makes it possible to know the maximum speckle contrast that the illuminating laser source is capable of producing. The method can also continue by constructing speckle contrast variation images by subtracting each contrast value calculated for the object to be analyzed from the average speckle contrast value calculated for the reference object. Thus, speckle contrast variation images constructed during repetitions of the method separated in time, using different laser sources, in particular with different spectral bandwidths, different imaging optics and different image sensors, can be effectively compared with one another. To this end, each speckle contrast image of the object to be analyzed is corrected by the specific contribution of the illuminating laser source and optionally also by another contribution caused by the image detection noise.
Owner:国家航空航天研究所

A method to improve the accuracy of laser speckle contrast blood flow imaging based on 3D-CNN

The present invention provides a method for improving the accuracy of laser speckle contrast blood flow imaging based on 3D-CNN. The method is characterized by comprising behavioral feature analysis of a speckle motion image, designing a blood flow velocity model based on spatiotemporal feature analysis, and testing the predictive ability of the model based on experimental data from a rotating scattering plate. The method uses a 3D-CNN model with excellent performance to extract the spatiotemporal features of three-dimensional speckle image pixels representing different blood flow velocities using a 3D convolution kernel. By fully exploiting the spatiotemporal pixel information of the speckle motion image under single exposure, the pixel features of the speckle motion image under different flow velocities are extracted. A characteristic function is established between the speckle motion image obtained using a single exposure technique and the flow velocity measured using a multiple exposure method. This method accurately predicts the flow velocity represented by the speckle image, thereby improving the measurement accuracy of LSCI and enabling linear measurement. The method becomes a low-cost, high-resolution, real-time linear imaging technology with better clinical application.
Owner:BEIJING UNIV OF TECH

Time autocorrelation imaging method and system based on adaptive orientation space window

The invention is suitable for the technical field of computer vision, and provides a time self-correlation imaging method and system based on an adaptive orientation space window. The speckle contrast imaging and self-correlation imaging method comprises the following steps: acquiring continuous multi-frame speckle images; the method comprises the following steps: presetting a basic space window by taking a target pixel as a center, and giving a plurality of orientations; selecting a certain frame of speckle image, respectively extracting speckle light intensity sequences of corresponding orientations in the basic space window, and calculating the spatial domain variance of the light intensity sequence of each orientation; selecting the orientation with the maximum light intensity variance, and determining the orientation as an effective calculation window of the target pixel; and performing time autocorrelation function calculation based on the effective calculation window so as to solve a blood flow velocity parameter of the target pixel. According to the method, the noise of the blood flow area can be reduced, and the real-time monitoring requirement is met while the high spatial resolution is guaranteed.
Owner:SHENZHEN INSTITUTE OF INFORMATION TECHNOLOGY

Device, method and systems for providing imaging of one or more aspects of blood perfusion

The present invention relates to a device (100), systems (500, 500′, 500″) and a method for providing imaging of one or more aspects of blood perfusion induced by cardiac induced blood motion in a skin region (12) of a subject. Current perfusion imaging systems use either photoplethysmography (PPG) or speckle contrast (SC), but a problem of both techniques is that considerable ambiguity exists because the source of the signal (volume pulsatility in PPG or blood flow in SC) is unknown. The present invention is based on the idea of combining two different types of measurement, namely widefield imaging and radial imaging, in order to estimate the source depth (20) of the signal to provide more accurate PPG imaging and SC imaging.
Owner:KONINKLIJKE PHILIPS NV

Laser speckle contrast imaging device for foot microcirculation perfusion evaluation

PendingCN120983015ADiagnostics using lightSensorsMicrocirculatory perfusionLaser imaging
The invention relates to the technical field of diabetic feet, in particular to a laser speckle contrast imaging device for foot microcirculation perfusion assessment, which comprises a laser imager, a controller and a placement frame, a top plate is hinged to the top of the placement frame, a driving part is fixedly connected to the bottom of the top plate, and a rotating shaft is fixedly connected to an output shaft of the driving part; the bottom of the inclined table is rotatably matched with an eccentric rod, the bottom of the eccentric rod is fixedly connected with a mounting plate, the bottom of the mounting plate is fixedly connected with a first electric control cylinder, and an output shaft of the first electric control cylinder is fixedly connected with the laser imager; a limiting frame is fixedly connected to the end, away from the eccentric rod, of the rotating rod, a limiting plate is further fixedly connected to the bottom of the top plate, and the limiting plate is located in the middle of the limiting frame and is in vertical sliding fit with the limiting frame; through the design of the eccentric rod, the angle of the laser imager can be automatically adjusted, it is guaranteed that the laser imager can shoot stable pictures, and the evaluation efficiency is improved.
Owner:CHONGQING TRADITIONAL CHINESE MEDICINE HOSPITAL