University of Tsukuba

Topcon Corporation

Kabushiki Kaisha Topcon

Shofu Inc.

Nidek Co., Ltd.

Yoshiaki Yasuno

Shuichi Makita

Toyohiko Yatagai

Masahide Itoh

Tatsuo Yamaguchi

Masahide Ito

Lian Duan

Yasufumi Fukuma

Hiroyuki Aoki

Hisashi Tsukada

Tsutomu Kikawa

Takashi Fujimura

Masami Tamura

Toshihiro Mino

Shinnosuke Azuma

Youngjoo Hong

Deepa Kamath Kasaragod

Myeong Jin Ju

Kensuke Oikawa

Daisuke Oida

Thitiya Seesan

An image generation device includes a tomographic image acquisition unit configured to acquire an OCTA tomographic image that captures a distribution of a blood flow of an object, a light attenuation acquisition unit configured to acquire a light attenuation of measurement light emitted to the object in a direction in which the tomographic image is layered, and an image generation unit configured to generate a light attenuation-blood flow distribution chart indicating a distribution of the light attenuation based on the acquired OCTA tomographic image and the light attenuation.

Image generation device, program, and image generation method

A method of processing ophthalmic data of some embodiment examples includes preparing a data set acquired by applying optical scanning of a two-dimensional pattern to a subject's eye. The two-dimensional pattern of the optical scanning includes a series of cycles that intersects each other. The method further includes generating position history data based on the data set. The position history data represents a temporal change in a position of the subject's eye.

Method of processing ophthalmic data, ophthalmic data processing apparatus, and ophthalmic examination apparatus

A model learning unit determines a model parameter for calculating an estimated value for each of a plurality of training sets, each including a measurement signal and at least one type of predetermined characteristic value indicating characteristics of the measurement signal as a target value, to minimize a difference between the estimated value calculated for the measurement signal using a predetermined mathematical model and the target value is minimized, determines characteristic value sets, each being a set of a plurality of types of characteristic values indicating characteristics of the measurement signal including the target value, with which, for each target value, the target value is common to a plurality of characteristic value sets, and generates, for each of the characteristic value sets, each of the plurality of training sets including the target value and a measurement signal having characteristics indicated by the plurality of types of characteristic values.

Measurement signal processing device, measurement signal processing method, and program

A phase gradient calculation unit calculates a phase gradient on a plane intersecting an irradiation direction of light corresponding to an optical coherence tomography signal indicating a state of a sample for each of sample points arranged on the plane. A bulk phase error calculation unit integrates, for each of plurality of paths from an origin that is a sample point where a bulk phase error is determined to a destination that is a sample point where the bulk phase error is not determined, the phase gradient for each of the sample points along each of the plurality of corresponding paths to calculate a path specific phase error at the destination, and combines the path specific phase errors among the plurality of corresponding paths to determine the bulk phase error at the destination.

Optical coherence tomography device, optical coherence tomography method, and non-transitory computer readable medium storingin structions therefore

In a scanning imaging apparatus of some aspect examples, a scanner applies an optical scan to a sample to acquire data. A scan controller controls the scanner to sequentially apply, to the sample, pattern scans according to a two-dimensional pattern including cycles. A movement unit relatively moves a scan area corresponding to the two-dimensional pattern and the sample. A movement controller controls the movement unit such that cycles in first and second scans of the pattern scans cross each other. An image constructing unit constructs an image based on data acquired under controls performed by the scan controller and the movement controller. The scan controller and the movement controller perform controls of the scanner and the movement unit respectively such that first and second cycles in a pattern scan cross each other at least at one point.

Scanning imaging apparatus, method of controlling the same, scanning imaging method, and recording medium

A Jones matrix OCT offers improved image stability, image quality, and depth range of image, wherein light from a wavelength-scanning light source is split into two optical paths, and a reference arm is provided along one optical path, while a probe arm that irradiates and reflects light onto the measuring target to generate object light is provided along the other optical path. The probe arm has a polarization delay unit that linearly polarizes the light and then splits it into S-wave component and P-wave component, where the S-wave component and P-wave component are superimposed through optical paths of different optical path lengths, respectively, after which optical detectors are used to detect different spectral interference beams in the depth direction of the measuring target corresponding to the vertically polarized component and horizontally polarized component, which respectively correspond to the S-wave component and P-wave component, to obtain four spectral interference signals.

Jones matrix OCT system and program for carrying out image processing on measured data obtained by said OCT

From OCT-measured data, only the image data of the choroidal vascular network present in the layer of the choroidal layer is selectively extracted, thereby accurately obtaining the thickness of the choroidal vessels and thickness of the choroidal vascular network from the image data, to allow for quantitative evaluation of the choroidal vascular network. The optical coherence tomography apparatus has an optical coherence tomography device, and a computer that processes the three-dimensional OCT tomographic images obtained based on the OCT-measured data acquired by the optical coherence tomography device. The computer functions as a means for selectively separating out only the images of the choroidal vessels from the three-dimensional OCT tomographic images to acquire image data of the choroidal vessels, and also as a means for obtaining the data to be used in the quantitative evaluation of the shape of the choroidal vessels based on the image data of the choroidal vessels.

Optical coherence tomography apparatus for selectively visualizing and analyzing vascular network of choroidal layer, and image-processing program and image-processing method for the same

In polarization-sensitive optical image measurement, noise-containing OCT signals obtained by polarization OCT are processed using a birefringence calculation algorithm, to obtain measured birefringence, after which noise is statistically adjusted to simulate a measured birefringence distribution and determine the noise characteristics of the measured birefringence values, and then Monte Carlo calculations are repeated by assuming different values for the noise level and the true birefringence value, respectively, to form three-dimensional histogram of combinations of true birefringence values, SN ratios, and measured birefringence values, after which specified measured birefringence values and SN ratios are assumed from the three-dimensional histogram information to obtain a true birefringence probability density distribution, and true birefringence values are estimated from the true birefringence probability density distribution.

Polarization-sensitive optical image measuring system and program installed in said system

Data measured by PS-OCT is corrected in a non-linear manner to enhance the quantitative analysis capability of PS-OCT and permit accurate quantitative diagnosis, including diagnosis of disease stage of lesions, as a useful means for computer diagnosis. Even when retardation per PS-OCTcontains error and becomes noise and its distribution is not normal or symmetrical around the true value, measured data is converted using a distribution conversion function obtained by analyzing the characteristics of noise via Monte Carlo simulation to remove the systematic error and estimate the true value otherwise buried in noise and thereby correct the PS-OCTimage more clearly.

Program for correcting data measured by PS-OCT and PS-OCT system equipped with the program

In an embodiment, a computer, which generates tomographic images based on spectral interference signals detected by a light detectorfrom overlaid reference light emitted by a swept-source type light sourceof a SS-OCT, split, and then reflected by a fixed reference mirroron one hand and object light reflected by an object to be measuredon the other, is caused to function to apply rough correction using a first correction means and then apply detailed correction using a second correction means, to stabilize the phases of the SS-OCT. The phases can be stabilized by eliminating, without adding any expensive, complex hardware, the jitter between the wavelength scanning of a light source of SS-OCT and the timing of collecting the scan data with the light detector as spectral interference signals.

Swept source optical coherence tomography and method for stabilizing phase thereof

The scanning speed of a sample in Doppler OCT, etc., is increased to enable quick measurement of blood flow rate, blood flow volume, etc. Wideband light from a light sourceis linearly polarized by a polarization controllerand this linearly polarized beam is split into vertically polarized light and horizontally polarized light using a Wollaston prismat a sample arm, which are then irradiated simultaneously onto two different locations of the sample in the scanning direction using a galvanometer mirror, and reference light from a reference armand object light from a sample armare merged and caused to interfere with each other, with the resulting interference signal light passed through a diffraction gratingfor spectroscopy, while the horizontal component and vertical component are separated by a polarized beam splitter, to simultaneously measure the components with two polarization-sensitive optical detectorsand thereby obtain two tomography images of the same location at different times by one mechanical scan, thus allowing the amount of temporal change in phase to be measured using the two tomography images.

Two beams formed by Wollaston prism in sample arm in an optical coherence tomography apparatus

A dental optical coherence tomography apparatus for measuring tissue in a stomatognathic region of a living body or an artificial composition in the stomatognathic region as a measured object includes: a variable wavelength light source (); a light splitting portion () that splits light-source light emitted from the variable wavelength light source () into reference light () and measuring light (); an interference portion () that causes the measuring light () and the reference light () to interfere with each other, thereby generating interference light; a photodetection portion () that measures the interference light; and an arithmetic portion () that generates an image of a measured object () by Fourier transforming or inverse Fourier transforming the intensity of the interference light, whose wavelength changes with time, that has been detected by the photodetection portion for each of the wavelengths. Accordingly, an optical coherence tomography apparatus applicable to dental measurement can be provided.

Dental optical coherence tomograph

An optical image measuring device which can form a highly reliable image even if an object moves during scanning of a signal light is provided. An optical image forming devicecomprises: an interferometer that splits a low coherence light Linto a signal light LS and a reference light LR and generates an interference light LC by overlaying the signal light LS reflected by a fundus oculi with the reference light LR reflected by a reference mirror; a CCDwhich receives the interference light LC and outputs a detection signal; Galvanometer mirrorsandto scan the signal light LS in a main scanning direction and a sub-scanning direction; and a computerforming tomographic images Gto Gm along the main scanning direction at different positions of the sub-scanning direction. The Galvanometer mirrorsandscan the signal light LS in a given direction crossing the main scanning direction, and the computerforms a tomographic image for correction GR along the given direction to correct displacement of each topographic image Gi based on the tomographic image for correction GR.

Optical image measuring device, optical image measuring program, fundus observation device, and fundus observation program

The present invention achieves multiplexing spectrum interference optical coherence tomography capable of full-range OCT measurement that causes no delays in measurement time due to high-order scans and is also free from complex conjugated images. This multiplexing spectrum interference optical coherence tomography comprises: a first beam splitterpositioned in an optical pathfrom a light sourceand used to separate an object lightand a reference light; a galvano mirrorpositioned in the optical path of the object lightand used to scan the object light onto a measured object; a second beam splitterpositioned in the optical path of the reference light; a first reference mirrorpositioned in the optical path of a first reference lightseparated by the second beam splitter; a second reference mirrorpositioned in the optical path of a second reference lightseparated by the second beam splitter; and a chopperthat passes the first reference lightand second reference lightalternately.

Growing community of inventors

Tsukuba, Japan

Yoshiaki Yasuno