111 results about "Speckle contrast" patented technology

The invention 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, and analyzing an original laser speckle image by adopting a time contrast analysis algorithm to obtain a laser speckle contrast image; and converting the laser speckle contrast image to obtain a laser speckle blood flow image. Calculating the full width at half maximum of the blood vessel in the laser speckle blood flow image as the width of the blood vessel; subtraction is conducted on the blood flow image obtained after laser irradiation and the blood flow image obtained before laser irradiation, and a difference image is obtained; blood vessels with blood flow changes due to laser irradiation are obtained according to the difference image, then a region of interest is selected, the blood flow mean value of the blood vessels before and after laser irradiation is obtained, and therefore the final laser treatment effect is evaluated. The mouse spine window 108 is irradiated from the complete skin side of the mouse spine window 108, and the blood flow change is monitored in real time on the opposite exposed blood vessel side by adopting technologies such as laser speckle blood flow imaging and the like. The influence of the upper skin tissue is considered, the blood flow change is monitored in real time, and accurate evaluation of the blood vessel laser heat effect is achieved.

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.

Methods and systems for motion-corrected and motion-compensated laser speckle contrast imaging are disclosed. The method comprises: exposing a target region to coherent first light of a first wavelength, the target region comprising living tissue; and capturing at least one sequence of images. The at least one image sequence includes a first speckle image that is captured during exposure with the first light. The method further includes determining one or more registration parameters of an image registration algorithm for registering the first speckle images to each other. The method may further include determining a registered first speckle image by registering the first speckle image based on one or more registration parameters and an image registration algorithm, and determining a combined speckle contrast image based on the registered first speckle image; or determining a first speckle contrast image based on the first speckle image, determining a registered speckle contrast image by registering the first speckle contrast image based on one or more registration parameters and an image registration algorithm, and determining a combined speckle contrast image based on the registered first speckle contrast image.

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.

A SyntheticMulti-Exposure Speckle Imaging (syMESI) methodology necessarily utilizing an optical interferometer apparatus as part of the speckle imaging system to overcome the optical detector noise that conventionally limits the reliable and accurate determination of a speckle contrast characteristic at low exposure times. The use of such methodology enabled a quantitative determination of absolute value(s) of changes of motion at the target object (such as blood flow changes in tissue) at low photon budget of less than 40 counts of average detection intensity and / or quantitative imaging of the blood flow at the object in interoperative setting with a low-cost camera sensor.

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.

One aspect of the invention relates to a method for intraoperative detection of parathyroid gland viability in a surgery, comprising obtaining speckle contrast images of a parathyroid gland of a patent; and displaying the speckle contrast images of the parathyroid gland in real-time.

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 provides a method and device for observing a high blood flow rate. The method for observing the high blood flow rate comprises the steps that multiple frames of laser speckle images of an area to be observed are obtained; determining a space speckle contrast matrix and a time speckle contrast matrix of the to-be-observed area according to the laser speckle image of the to-be-observed area; obtaining system coherence parameters, and determining a dynamic scattering component proportionality coefficient of the to-be-observed area according to the system coherence parameters, the space speckle contrast matrix and the time speckle contrast matrix; determining a blood flow index matrix of the to-be-observed area according to the system coherence parameters, the space speckle contrast matrix, the time speckle contrast matrix and the dynamic scattering component proportionality coefficient; and displaying a blood flow index distribution image of the to-be-observed area according to the blood flow index matrix. According to the method and device for observing the high blood flow rate, the problem that the measurable range of the coronary artery blood flow rate is limited can be effectively solved.

The invention discloses a method for simultaneously measuring tissue optical parameters and blood flow information, which comprises the following steps of: obtaining an effective attenuation coefficient of a tissue based on speckle images at different light source-detector distances; and based on the effective attenuation coefficient and diffusion speckle contrast degrees at different exposure times and different light source-detector distances, establishing a target function for simultaneously solving multiple parameters. And a global minimum value of the target function is obtained based on an optimization solution algorithm, so that tissue optical parameters and blood flow information are obtained at the same time. The invention provides a new technical approach for comprehensively describing haemodynamics and metabolism characteristics of tissues.

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 laser speckle contrast imaging system includes a laser light source, configured to emit a laser beam on a subject; a plurality of visible light sources, configured to respectively emit a visible light beam on the subject; an image capturing module, configured to obtain a first image corresponding to the laser beam emitting toward the subject and a plurality of second images corresponding to the plurality of visible light beams emitting toward the subject; and an image processor, coupled to the image capturing module, configured to process the first image with a laser speckle stacking algorithm to determine a variation of a cortical spreading depression (CSD) waveform according to at least a speckle pattern determined in the first image.

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.