Patent classifications
G01B9/02077
METHOD FOR COMPENSATING THE ARTIFACTS GENERATED BY MOVING MEASUREMENT OBJECTS IN MEASUREMENT SIGNALS OF SWEPT-SOURCE OCT SYSTEMS
A method for compensating the artifacts generated by moving measurement objects in measurement signals of swept-source OCT systems by moving measurement objects. Signal reconstruction is implemented without the aid of additional reference signals in respect of the movement of the measurement object and only by way of especially adapted algorithms. Example methods relate firstly to the especially adapted, Fourier transform-based algorithms for processing the captured measurement signals and secondly to the measurement signals to be captured, in particular to the optical coherence interferometry-based measurement systems used for the production thereof. Although the proposed method is provided for applications in ophthalmology in particular, it can be used, in principle, wherever signals reflected by curved surfaces or backscattered from structures are analyzed.
Scanning imaging apparatus, method of controlling the same, scanning imaging method, and recording medium
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.
METHODS AND SYSTEMS FOR IN VIVO FULL-FIELD INTERFERENCE MICROSCOPY IMAGING
According to one aspect, the invention relates to a system (101) for in vivo, full-field interference microscopy imaging of a scattering three-dimensional sample. It comprises a full-field OCT imaging system (130) for providing en face images of the sample, wherein said full-field OCT system comprises an interference device (145) with an object arm (147) intended to receive the sample and a reference arm (146) comprising an optical lens (134) and a first reflection surface (133), and an acquisition device (138) configured to acquire a temporal succession of two-dimensional interferometric signals (I.sub.1, I.sub.2) resulting from interferences produced at each point of an imaging field; an OCT imaging system (110) for providing at the same times of acquisition of said two-dimensional interferometric signals, cross-sectional images of both the sample and a first reflection surface (133) of said full-field OCT imaging system (130); a processing unit (160) configured to determine a plurality of en face images (X-Y) of a plurality of slices of the sample, each en face image being determined from at least two two-dimensional interferometric signals (I.sub.1, I.sub.2) having a given phase shift; determine from the cross-sectional images provided by the OCT imaging system (110) at the times of acquisition of each of said two two-dimensional interferometric signals (I.sub.1, I.sub.2) a depth (z) for each en face image (X-Y) of said plurality of slices; determine a 3D image of the sample from said plurality of en face images of said plurality of slices of the sample and depths.
OPTICAL INTERFERENCE RANGE SENSOR
An optical interference range sensor includes: a light source configured to project a light beam while continuously varying a wavelength thereof using a predetermined sweep frequency pattern; a processing unit configured to measure the distance to a measurement target based on an electrical signal converted by a light-receiving unit; and a storage unit configured to store distance information indicating the measured distance. The predetermined sweep frequency pattern includes a first sweep frequency pattern and a second sweep frequency pattern. The processing unit includes an average distance value calculation unit configured to calculate an average distance value based on the measured distance, first distance information indicating a distance based on a light beam projected using the first sweep frequency pattern, and second distance information indicating a distance based on a light beam projected using the second sweep frequency pattern, of past distance information regarding multiple measurements stored in the storage unit.
Non-confocal Point-scan Fourier-domain Optical Coherence Tomography Imaging System
A non-confocal point-scan Fourier-domain optical coherence tomography, OCT, imaging system, comprising: a scanning system arranged to perform a two-dimensional point scan of a light beam across an imaging target, and collect light scattered by the imaging target; a light detector arranged to generate a detection signal based on an interference between a reference light and the light collected by the scanning system. The OCT imaging system further comprises hardware arranged to: generate complex volumetric OCT data of the imaging target based on the detection signal, the OCT data including a component which, when the OCT data is processed to generate an enface projection of the OCT data, provides a defocusing and/or distortion in the enface projection; and generate corrected OCT data by executing a correction algorithm which uses phase information in the OCT data to remove at least some of the component from the OCT data.
DATA AGE REDUCTION
Disclosed are method and electronic components for: i) electronically extracting a sequence of values from a measurement signal corresponding to a position of a moving object, wherein the sequence of values indicates the position of the moving object at corresponding time increments; ii) electronically determining at least one of an estimate for a velocity of the moving object and an estimate for an acceleration of the moving the object based on a plurality of the values in the sequence of values; and iii) electronically correcting a value in the sequence of values to substantially reduce the effect of processing and signal delays based on one or both of the velocity and acceleration estimates.
In vivo optical flow imaging
Described herein is an optical coherence tomograph (OCT) angiography technique based on the comparison of OCT signal amplitude to provide flow information. The full OCT spectrum can be split into several narrower spectral bands, resulting in the OCT resolution cell in each band being isotropic and less susceptible to axial motion nose. Inter-B-scan flow values can be determined using the individual spectral bands separately and then averaged. Recombining the flow images from the spectral bands yields angiograms that use the full information in the entire OCT spectral range. Such images provide significant improvement of signal-to-noise ratio (SNR) for both flow detection and connectivity of microvascular networks compared to other techniques. Further, creation of isotropic resolution cells can be useful for quantifying flow having equal sensitivity to axial and transverse flow.
OPTICAL COHERENCE TOMOGRAPHY DEVICE
An optical coherence tomography device is provided with a split beam generating means which splits a beam emitted from a single light source into at least four split beams and outputs these, a measurement beam irradiating means which irradiates measurement beams onto different positions of a measurement target through a mechanism that can change the position of said measurement beams on the measurement target, a reference beam irradiating means which irradiates at least two of the at least four split beams that are not the measurement beams onto a reference beam mirror as reference beams, and an optical spectrum data generating means which acquires depth-direction structural data about the measurement target from interference light obtained by causing one of the reference beams reflected by the reference beam mirror to interfere with each of the measurement beams reflected or scattered by the measurement target.
System and method for authentication of collectable objects
Provided is a system and method for authentication of collectable objects. A hi-resolution digital camera in communication with a nonvolatile data storage device having a data partition capable of being made immutable is provided. The nonvolatile data storage device is compatible with a computerized device, and the hi-resolution digital camera is operated to record at least one hi-resolution digital image of at least one unique appearance characteristic of a collectable object at an image resolution of at least 300 pixel dots per inch at 1:1 image scale. The at least one hi-resolution digital image is stored in the data partition of the nonvolatile data storage device, together with additional image data. A tamper-resistant marking associated with the collectable object is placed on the nonvolatile data storage device.
OPHTHALMIC IMAGING APPARATUS, CONTROLLING METHOD OF THE SAME, AND RECORDING MEDIUM
In an ophthalmic imaging apparatus of some aspect examples, a data acquiring unit acquires data by applying an OCT scan to an eye. An image constructing unit constructs an image from the data acquired. A focal position changing unit is provided to the measurement arm. A scan controller controls the data acquiring unit according to a scan pattern including first and second partial patterns that are continuous patterns for central and peripheral regions of an OCT scan application area, respectively. A focus controller controls the focal position changing unit such that a first focal position is applied in parallel with an OCT scan of at least part of the first partial pattern and a second focal position is applied in parallel with an OCT scan to at least part of the second partial pattern.