Imaging system including scanner and modulator, and improved accuracy response method

Abstract

It provides accurate lateral mapping of images acquired via a scanning mechanism. [Solution] The system includes a modulator synchronized with the imaging engine clock to generate image markers. These markers are then used to remove distortion and generate spatially accurate mapping. Image distortion is corrected by identifying modulations and removing distortion according to the modulation intervals. The system includes an OCT configuration that images the entire eyeball while simultaneously scanning the cornea and retina, and an on-axial imaging system that evaluates the quality of the eyeball surface, and can be applied to ocular biomechanics and topography.

Description

Technical Field

[0001] The present disclosure is directed to methods that enable accurate mapping within an optical coherence tomography imaging system and other scanner-based imaging systems.

[0002] The present disclosure is directed to adjusting on an OCT image obtained using an OCT system so as to match results calculated based on images obtained using another system having different performance characteristics.

[0003] The present disclosure is directed to preferred scanning geometries for optical biometrics.

Background Art

[0004] Optical coherence tomography (OCT) is an imaging technique widely used in medicine, metrology, and industrial applications. The OCT technique enables non-contact, high-resolution imaging in turbid media. This interference-based technique provides excellent sensitivity to the weak intensity of light backscattered or backreflected from a sample. The technique provides a unique means of visualizing topography as well as subsurface features and structures at the micron level. The interference signal provides accurate spatial mapping in the depth (axial) dimension of the sample. The lateral dimension of an OCT scan depends on the scanning mechanism of the light beam or the sample itself. Scanning can be horizontal and vertical, or circumferential or helical. Commercial OCT systems utilize a mechanical scanner to scan the beam, resulting in low spatial precision along the lateral direction. Mechanical scanners typically have a dynamic nature and change over time.

[0005] This causes distortion. Due to this limitation, OCT can machine the surface with nanometer-level precision. It lacks the possibility of ripping. Lateral scanning accuracy is increasing with the speed of OCT systems. This is expected to become more difficult as the demand for mechanical scanners increases.

[0006] Achieving an accurate OCT-based mapping system would allow for the combination of OCT and other commonly used technologies. Complementary mapping systems, such as ocular placidotopography, become unnecessary. Reflection-based topographs, such as sid ring topographs, are useful for examining the quality of optical surfaces. However, a large space is necessary to accurately measure topographic information.

[0007] There is a need to provide accurate, distortion-free OCT images in all dimensions. The procedure involves measuring the optical surface and improving the ocular surface for cataract surgery and refractive surgery. Useful for accurate mapping and many other applications. It shows the health of an object on its optical surface. A complementary, compact imaging system is needed to help with understanding the subject.

[0008] In many cases, OCT images are used to provide quantitative data using image analysis tools. It is possible. In many diseases, tracking this data allows us to monitor the progression of a patient's disease over several years. It can be monitored. The importance of consistently monitoring the progress is evident in the OCT system's picture. It is necessary that the quality remains unchanged. Therefore, measurements are taken from improved images of the same patient. Because the values ​​may change, implementing a significant improvement in image quality in the new system is not feasible. There are limits.

[0009] Improvements that enable quantitative analysis similar to the legacy system without changing the image analysis method. We need to provide a way to convert the type system to OCT images.

[0010] Photobiometric systems typically focus light into the anterior segment of the eye, and therefore, in most cases, the fovea A blurred spot appears. Axial length is the most important factor for IOL (intraocular lens) calculators. This is a biological measurement, and therefore accurate measurement of the distance within the fovea is essential.

[0011] To acquire photobiometric data, the patient must fixate on a target adjusted by the measurement system. It is assumed that this is the case. Several techniques are used to provide fixation based on the anterior part of the eyeball. Several methods have been proposed and some have been implemented, but they do not accurately represent actual foveal fixation. Other methods confirm foveal fixation, but capture the foveal position after the actual measurement. This method is susceptible to errors caused by eye movements. [Overview of the project] [Problems that the invention aims to solve]

[0012] We propose a more accurate optical biosensing system that incorporates precise and simultaneous fixation confirmation and correction. It is required to be provided. [Means for solving the problem]

[0013] Overview: Spatiotemporal Modulation and Demodulation System This disclosure relates to an OCT imaging system, a single-pixel imaging system, or a system for generating multidimensional images. To provide accurate lateral mapping for other systems that utilize scanners. This applies to laws and systems. This method involves spatiotemporal modulation and demodulation (Spatio-T). (emporal Modulation-Demodulation), or abbreviated as S It is called TMD.

[0014] In some embodiments, the system includes an imaging engine and an object scanner. The object scanner is composed of an optical setup having a scanning mechanism. The setup is adjusted to scan an object, collect light, and return it to the imaging engine. In the setup, an active modulator is inserted after the scanner and generates an image marker in synchronization with the clock of the imaging engine. In this embodiment, the modulator is placed after the scanner. The modulator is synchronized with the clock of the imaging engine to generate an image marker, and the modulator starts at a speed at which the image marker is generated.

[0015] In some embodiments, the active modulator starts at a speed that causes a measurable marker to occur on the image. For example, the modulator is clocked to generate at least one marker for at least one image element, and further, the modulator is clocked at a speed that results in a modulation that is an integer division of the imaging engine clock.

[0016] In some embodiments, the modulation causes at least one marker to occur for at least one image element, such as a pixel or an A-line.

[0017] In some embodiments, the modulation speed is clocked by an integer divider of the system's master clock.

[0018] In some embodiments, the imaging engine can be an OCT A-line scanner composed of a light source, a beam splitter, and a configuration of a collimator, a reference arrangement, at least one detector, a processor, and a display.

[0019] In some embodiments, the imaging engine may be a single-pixel camera or detector. It is possible.

[0020] In some embodiments, the imaging system can be a line scanning camera. .

[0021] In some embodiments, the imaging system is LiDAR (Light Detector). It can be expressed as (tion and Ranging).

[0022] In some embodiments, the active modulator is located in a substantially optical plane in which the scanning mechanism is imaged. It will be installed.

[0023] In some embodiments, the active modulator is located near the scanning mechanism.

[0024] In some embodiments, the active modulator is located distal to the optical element of the scanning light probe. It will be done.

[0025] In some embodiments, the active modulator is placed anywhere in the optical path.

[0026] In some embodiments, the active modulator controls the mechanical drift and optical section of the scanner. To eliminate the need to calibrate the optical distortion of the product, after all optical components of the system are... It will be installed.

[0027] In some embodiments, the active modulator is an acoustic-optic modulator, a liquid crystal modulator, or an electro-optic modulator. Modulator, piezoelectric element, galvanometer scanner, voice coil, or other type of modulator It is possible.

[0028] In some embodiments, the active modulator has a phase delay on at least one image element. It can be done.

[0029] In some embodiments, the active modulator modulates the amplitude of at least one image element. It can be done.

[0030] In some embodiments, the active modulator causes a color change in at least one image element. It is possible.

[0031] In some embodiments, the active modulator corresponds to at least one image element. The clarity of the signal can be altered or stripe patterns removed.

[0032] In some embodiments, the active modulator speckles at least one image element. It can be made uncorrelated.

[0033] In some embodiments, the active modulator applies a blur to at least one image element. It is possible to make changes in image characteristics like these.

[0034] In some embodiments, the active modulator can be replaced with a passive modulator.

[0035] In some embodiments, the passive modulator modulates the phase, intensity, and of one or more imaging events. This can incorporate spatial characteristics that cause a different shift.

[0036] In some embodiments, the system is used for the development of precise IOL computers or cataract computers. To assist in the development of 3D eyeball models for planning surgeries and refractive surgery, the positive surface of the eyeball It is used to provide accurate mapping.

[0037] In some embodiments, the system precisely maps optical or precision surfaces. It is used to provide [something].

[0038] In some embodiments, the image scale is used to calibrate the image to precise spatial dimensions. To generate a fiducial that can be used, at least one characteristic is objective It will be added to the scanner.

[0039] In some embodiments, at least one optical object is a fiber optic, cylindrical The material is selected from the group consisting of objects, specular reflectors, and scatterers.

[0040] In some embodiments, the optical object is integrated with the modulator. In terms of form, the optical object is located at the end of the modulator.

[0041] In some embodiments, the reference optical path length is the optical path length of the reference arm of the imaging engine. They match.

[0042] In some embodiments, the reference does not interfere with the reference arm of the imaging system. It is generated by optical interactions within the optical object.

[0043] In some embodiments, the reference is inserted outside the image region.

[0044] Overview: Image Processing Image markers generated using the STMD method are processed using image processing to remove distortion from the image. Final measurements can be taken based on the image.

[0045] In some embodiments, a method for correcting image distortion involves causing modulation of elements within the image. The modulator creates image markers that are distributed along the surface of the object, and the surface Placing the object within at least one image, identifying modulation, imaging beam A horizontal direction perpendicular to the z-direction, and according to the modulation interval in the horizontal dimension, individual This includes removing image distortion.

[0046] In some embodiments, z modulation is achieved by applying a shift along the z direction. It is removed from the A-line of the OCT.

[0047] In some embodiments, removing the phase delay applied to an image element is possible for the image This is achieved by applying a phase shift on the conjugate data that is equal to the phase shift on the element. ru.

[0048] In some embodiments, the modulated elements are removed from the image.

[0049] In some embodiments, a second unmodulated image of an object without an image marker pattern The system receives the signal, applies the distortion data calculated from the modulated image to the unmodulated image, and constructs a corrected image. do.

[0050] In some embodiments, the method involves shifting an image from a pattern on a first set. A second set modulated with a marker pattern, which receives a second modulated image of the object. This involves identifying shifted image markers and, according to the modulation interval, within the image of the second image. To remove distortion in the first set and the second image, and to use the unmodulated portion to supplement it. This includes forming a positive image.

[0051] In some embodiments, the method extracts topographic information from multiple corrected images. Calculating, based on prior knowledge scaling within a portion of an image that has spatial data Perform spatial scaling and / or generate image references using known pairs This may include one or more of the following: performing spatial scaling of an image based on measurements of an object. ru.

[0052] In some embodiments, the image reference is at least one optical element with known width and height A child, or at least two elements with known spacing, used as an objective for capturing an image. It is generated by inserting it into a scanner.

[0053] In some embodiments, the method for correcting image distortion produces modulation of elements within the image. Image markers created by a modulator, comprising multiple OCs of an object including a surface Placing image markers on T images, generating topographic maps from images, Identifying modulations along the topographic projection, and a topographic map according to the modulation interval. This includes removing the distortion.

[0054] In some embodiments, the topography map is used instead of modulated image elements. The data is interpolated to fill in the gaps.

[0055] In some embodiments, z modulation is performed before calculating the topographic map using OCT. It is removed by shifting line A in the z direction.

[0056] In some embodiments, performing spatial scaling of an image generates an image reference. Based on measurements of known objects.

[0057] In some embodiments, the image reference is at least one optical element with known width and height A child, or at least two elements with known spacing, is used as an objective skid to capture an image. It is generated by inserting it into Yana.

[0058] In some embodiments, the method involves a plurality of objects that do not have an image marker pattern. Receiving a second set of unmodulated images and from the modulated topography map The distortion data is applied to the unmodulated topography map to create a corrected topography map. It includes the act of accomplishing something.

[0059] In some embodiments, baseline curvature is removed from OCT images. This can be done. To identify the index of the image marker, numerical differentiation of the image is performed. It is possible.

[0060] In some embodiments, the phase delay applied to the A line is used to select the A line data. It can be removed by using a futon, or to obtain more accurate results, space Apply an index shift on spectral data equal to the phase shift to A-line data. By doing so, a phase shift is applied.

[0061] In some embodiments, line A having an image marker is used to correct distortion. It can be present, but the A-line itself can be removed from the image.

[0062] In some embodiments, the same object having a shifted image marker pattern Another image is obtained. At least one image is processed to identify image markers. At the same time, the index data of the marked area of ​​the image is then used for other images. It will be replaced with data from areas that are not marked.

[0063] In some embodiments, accurate spatial scaling of images is based on reliable spatial data. This can be achieved based on scaling prior knowledge within a portion of an image that contains a 'ta'.

[0064] In some embodiments, accurate spatial scaling of the image is performed before or after scanning. This can be achieved based on measurements of known objects.

[0065] In some embodiments, precise spatial scaling of the image is performed by installing an objective scanner. This is achieved based on at least two image criteria that are based on at least one object. It is possible.

[0066] In some embodiments, the image reference is an optical reference with a known width relative to the objective scanner. This can be achieved by inserting one element, or two elements with a known spacing between them. ru.

[0067] In some embodiments, the optical element can be automatically removed from the optical path.

[0068] In some embodiments, at least one object having an image marker and a reference To record one image and an unmarked image of the object, the image sequencer A score is obtained. Image analysis of image markers and references is performed on unmarked images. It can be applied to provide distortion correction information that is applicable to this purpose.

[0069] In some embodiments, the image data is uniform and accurate in terms of A-lines or image elements. To achieve a suitable interval, interpolation can be performed based on the image marker index.

[0070] In some embodiments, the final analysis data, for example, the topographic data, is positive. To obtain accurate topographic information, interpolation is performed based on the image marker index. It is possible.

[0071] Overview: Quality evaluation of optical surfaces This disclosure describes how to examine the quality of an optical surface in detail by using an OCT imaging system in a small pattern This invention relates to a base reflection system that complements the existing system.

[0072] The reflection of the light pattern captured by the camera provides corneal topography and This is an effective method for evaluating the breakdown of the tear film. To measure corneal topography... This technique requires a relatively large angle between the incident and reflected light rays on the cornea. As the tear film breaks down across the surface, the quality of reflected light deteriorates, along with the quality of the tear film and the uptake image. A correlation can be established between image quality and other factors.

[0073] STMD provides accurate mapping of the eyeball surface, thus providing topographic information. Therefore, there is no need to use a reflection pattern. As a result, the difference between the angle of incidence and the angle of reflection is significantly reduced. or can be eliminated, and the lighting pattern and camera placement allow for a compact system. This method can adequately provide analysis of the tear film.

[0074] In some embodiments, the imaging system includes an imaging engine and a scanner. A scanner system and a modulator placed after the scanner for generating image markers. A modulator that starts up in sync with the imaging engine clock at a rate that generates image markers, The lighting pattern and the imaging camera are configured with nearly identical optical cone angles, resulting in dichroism. Includes a pattern-based reflection system coupled to a scanner system via a viner. .

[0075] In some embodiments, the imaging engine is an OCT system, and dichroism combine The N is placed in the OCT imaging path.

[0076] In some embodiments, the pattern-based reflection system further includes the OCT imaging path. It includes a light source that generates a pattern, which is then combined with it.

[0077] In some embodiments, the system processes the pattern after it has been reflected from the corneal surface. Includes a camera to capture images of the turn.

[0078] In some embodiments, the reflection pattern is recorded to cancel out eye movements. .

[0079] In some embodiments, the system analyzes the reflection patterns of the eye surface. Includes a processor programmed to perform differential analysis.

[0080] In some embodiments, the camera uses an imaging system to align with the eyeball. It is also used for guidance.

[0081] In some embodiments, the light source uses a dichroic beam combiner to access the objective scanner. The light is masked to merge into the optical path and generate a pattern. The light is projected onto the surface of the cornea. The reflected light is collected through the same dichroic beam combiner and imaged through a camera. .

[0082] In some embodiments, the light source is one or more light sources, preferably light-emitting diodes. It can be configured as follows.

[0083] In some embodiments, the light source illuminates different areas sequentially at different times. This allows us to generate patterns like that.

[0084] In some embodiments, a reflection image from the corneal surface is recorded, and after motion correction, To establish an analysis of the health status of the eyeball surface, differential analysis can be applied.

[0085] In some embodiments, the same camera is used to guide an ophthalmic system to position the eyeball. They can be placed side by side.

[0086] Overview: Robust biomeasurement using fixation evaluation This disclosure provides accurate measurement of axial length at the fovea for all ocular powers of the eye. A scanning configuration for optical biomedical measurement that provides accurate fixation confirmation simultaneously with biomedical measurement scanning. This applies to the following.

[0087] Ophthalmic biometers generally utilize a beam of light focused within the anterior chamber of the eyeball. Because the numerical aperture is generally small, the spot size on the retina is not greatly enlarged. Due to variables such as different eyeball lengths and visual acuity, the spot size on the retina varies from patient to patient. They are quite different. Axial length measurement is best for examining the center of the fovea, while spot size is better. Increasing the size means measuring the average over a larger area, and therefore the signal strength and completeness The accuracy decreases. Both result in a reduction in the precision of the most important parameter in ocular biometric measurements. This is the result.

[0088] The aforementioned beam is typically not scanned by an A-line biometer, or it does not reach the anterior segment surface. They are scanned almost coaxially to cover more. Both of these configurations are fixation confirmation. It is not suitable for real-time visualization of the fovea for correction. Eyes with diopter correction of 0. In contrast, when scanning in the paraxial direction, the scanning beam will always be concentrated in the fovea.

[0089] In eyes with diopter correction, the beam is concentrated posteriorly or anteriorly on the foveal surface. Therefore, the examination spot will scan the fovea for different A-lines, resulting in The data will be averaged over a uniform area. Similar results occur with other semi-axis scans. During analysis, the A line is averaged, which can lead to errors due to blurring, or one line Because only line A is used for analysis, this system measurement is prone to errors due to noise.

[0090] The optical biosensing beam scans within the pupil, or with a rotation center approximately in front of or behind the pupil. It is preferable to do so. To perform ocular biomedical measurements, it is preferable to focus the beam onto the retina. This configuration provides a clear cross-sectional image of the retina.

[0091] In some embodiments, the ocular biomedical measurement system generates an OCT (Optical Coherence Tomography) beam. The engine, the scanner that directs the imaging beam towards the eyeball, and the system that focuses the imaging beam almost onto the retina The focus assembly and the plane containing the pupil of the eyeball or immediately before or after the pupil In a parallel plane, the first laser in the path of the imaging beam scans with a center of rotation located in the anterior chamber of the eyeball. The lens set rotates around a central point to image the entire eyeball, while simultaneously capturing images of the retina of the eye. It includes an imaging beam that scans lines on the cornea.

[0092] In some embodiments, the imaging beam is directed simultaneously across the corneal and crystalline lens structures. An optical assembly that swivels the imaging beam at a point anterior or posterior to the cornea for scanning. It can be inserted into the path of the imaging beam.

[0093] In some embodiments, the optical assembly comprises an assembly lens and a delay element. Includes. In some embodiments, the delay element is located in the path of the imaging beam when the optical assembly is in the path of the imaging beam. When the assembly is outside the path of the imaging beam, the optical path length difference is reduced or eliminated. It is selected to be selected.

[0094] In some embodiments, the first set of lenses is used for the first telescope and the second telescope. The telescope includes a second lens, and each telescope includes two lenses, with the optical assembly being the lens of the second telescope. It is inserted between them.

[0095] In some embodiments, the system is located within the path of the imaging beam after the beam scanner. It further includes a modulator.

[0096] In some embodiments, the ocular biomedical measurement system generates an OCT (Optical Coherence Tomography) beam. The engine, the scanner that directs the imaging beam towards the eyeball, and the path of the imaging beam, within the anterior chamber A first lens focuses and scans the imaging beam so that the structure can be imaged, and the imaging beam Imaging beams are placed at an anterior or posterior point on the cornea to simultaneously scan the structure of the cornea and lens. A second lens that can be inserted into the path of the imaging beam, which rotates the lens, and the second lens When the imaging beam is in the path of the imaging beam, the beam is nearly focused on the retina, and the second lens When the object is in the path of the imaging beam, the beam rotates around the center of rotation, and on the retina and cornea of ​​the eyeball. This includes imaging the entire eyeball while simultaneously scanning lines.

[0097] In some embodiments, the modulator is placed within the path of the imaging beam.

[0098] In some embodiments, the fovea is visualized and combined with a camera image of the anterior surface of the eyeball. Combined, cross-sectional scanning of the entire eyeball visualizes the pits, identifying the optical and visual axes of the eyeball. It can be used for this purpose, as well as for calculating angular kappa and angular lambda. Furthermore, even in the absence of precise fixation, reliable fixation confirmation and accurate biometric measurements can be obtained. It can be used to calculate [something].

[0099] In one embodiment, multiple cross-sectional scans at different locations are used for volumetric biometric measurements and eyeball measurements. It can be used to generate information about direction.

[0100] In some embodiments, the optical system within the objective scanner ensures that the beam is directed onto the retina. To achieve true focusing, adjustments are made to compensate for eye power and eye length.

[0101] In one embodiment, the above adjustments are prior to the ocular power, visual acuity, or ocular length. Based on knowledge.

[0102] In some embodiments, focus adjustment is performed according to astigmatism or higher-order aberrations, and the cross-sectional area is altered. Change it during the investigation.

[0103] In one embodiment, the lens or anterior chamber is combined with a scanning area on the retina. The rotational position is used to calculate the effective position of the lens.

[0104] In one embodiment, a delay line in the objective scanner or reference arm complements the eyeball length. It will be used to make amends.

[0105] In some embodiments, speckle analysis is used to precisely position the scanning rotation center. Applies to the image.

[0106] In one embodiment, the preferred scanning geometry is the same as another scanning geometry dedicated to the anterior segment of the eye. They can be combined at times or sequentially. [Brief explanation of the drawing]

[0107] The accompanying drawings illustrate exemplary embodiments of the systems and methods disclosed herein. And, together with the text, it is used to explain the principles of this disclosure.

[0108] [Figure 1] Figure 1 shows an example of a system embodiment for performing optical coherence tomography for the purpose of accurately mapping the surface of an object by incorporating a spatiotemporal modulation / demodulation (STMD) method.

[0109] [Figure 2] Figure 2 is a sketch representing an anterior segment OCT image showing STMD modulation as z-modulation.

[0110] [Figure 3] Figure 3 is a timing diagram for achieving this type of modulation using swept-source OCT (SSOCT).

[0111] [Figure 4] Figure 4 shows an example of an optical setup for achieving z-modulation using a high-speed optical delay line assembly.

[0112] [Figure 5]Figure 5 shows an STMD-based OCT system with two candidate modulator placements: one conjugate to the scanner and the other near the scanner.

[0113] [Figure 6] Figure 6 is a sketch representing an anterior segment OCT image showing STMD modulation as i-modulation.

[0114] [Figure 7a] Figure 7a shows the system from Figure 1, but with the object being imaged being an eyeball. The optical system scans the beam over the eyeball almost paraxially. The modulator is positioned almost conjugate-plane to the scanner.

[0115] [Figure 7b] Figure 7b shows the system of Figure 1, but with the object being imaged being the eyeball. The optical system scans the beam over the eyeball almost paraxially in the anterior segment. The modulator is located near the scanner.

[0116] [Figure 7c] Figure 7c shows the system of Figure 1, where the object to be imaged is the eyeball. The optical system scans the beam over the eyeball almost paraxially over the anterior segment. The large-area modulator is installed in free space within the telescope assembly.

[0117] [Figure 8a] Figure 8a shows a system similar to Figure 7b, but modified so that the beam scans to concentrate on the anterior segment and then almost swirls around the pupillary plane to scan the posterior segment. The modulator is located near the scanner.

[0118] [Figure 8b] Figure 8b shows a system that can, in some cases, scan the eyeball using a nearly parallel beam in the anterior segment, and can switch to a beam that nearly swirls within the pupil to scan the posterior segment. The difference in optical delay between the anterior and posterior segments in each of the two modes is minimized. The modulator is mounted on the conjugate plane of the scanner.

[0119] [Figure 8c] Figure 8c shows a system that can, in some cases, scan the eyeball using a nearly parallel beam in the anterior segment and switch to a nearly swirling beam within the pupil to scan the posterior segment. The difference in optical delay between the anterior and posterior segments in each of the two modes is minimized. The modulator is placed after the last target in the paraxial scanning mode and removed from the optical path in the pupillary swirling scanning mode.

[0120] [Figure 9] Figure 9 shows a simplified scanning optical setup that can be used for single-pixel imaging of an object.

[0121] [Figure 10] Figure 10 shows an example workflow for an algorithm that reconstructs spatially corrected information from an image with z-modulation.

[0122] [Figure 11] Figure 11 shows an example workflow for an algorithm that reconstructs spatially corrected information from an image with i-modulation.

[0123] [Figure 12] Figure 12 illustrates the main steps of an algorithm for reconstructing spatially corrected information from an image with z-modulation, as shown in Figure 10.

[0124] [Figure 13] Figure 13 shows an STMD-based OCT system with a reflection-based imaging system that projects images onto the corneal surface to examine the health of the eyeball surface.

[0125] [Figure 14] Figure 14 shows a setup using portable devices to examine the health of the eye surface.

[0126] [Figure 15]Figure 15 shows a scanning pattern that is preferred for optical biosensors, in which the beam is almost focused on the retina and scans mainly the pupillary plane while the OCT is imaging along the entire eyeball.

[0127] [Figure 16] Figure 16 shows preferred scanning patterns for optic biosensors, one example where the beam is nearly focused on the retina and scans around the pupillary plane while the OCT images along the entire eyeball, and another example where the beam is nearly focused on the anterior segment and scans along the anterior segment while the OCT images along a portion or the entire eye.

[0128] [Figure 17a] Figures 17a and 17b show, in one example, an arrangement that scans the eyeball paraxially, and in another example, an arrangement that scans within the pupillary plane with a swirling beam. Switching is achieved by removing the optical system from the optical path, taking into account a specific difference in optical path length between the two states. [Figure 17b] Figures 17a and 17b show, in one example, an arrangement that scans the eyeball paraxially, and in another example, an arrangement that scans within the pupillary plane with a swirling beam. Switching is achieved by removing the optical system from the optical path, taking into account a specific difference in optical path length between the two states.

[0129] [Figure 17c] Figures 17c and 17d show, in one example, an arrangement that scans the eyeball paraxially, and in the other example, an arrangement that scans within the pupillary plane with a swirling beam. Switching is achieved by removing the optical system from the optical path, which has the ability to move the optical setup to adjust to a specific optical path length difference between the two states. [Figure 17d] Figures 17c and 17d show, in one example, an arrangement that scans the eyeball paraxially, and in the other example, an arrangement that scans within the pupillary plane with a swirling beam. Switching is achieved by removing the optical system from the optical path, which has the ability to move the optical setup to adjust to a specific optical path length difference between the two states.

[0130] [Figure 18a] Figure 18a shows an example of an OCT image of the anterior segment of the eyeball with a reference mark placed outside the region of interest.

[0131] [Figure 18b] Figure 18b shows the ring mechanism, which is part of the element.

[0132] [Figure 18c] Figure 18c shows a ring mechanism, which is the part of the optical element that is bonded, mounted, or installed near the modulator.

[0133] [Figure 18d] Figure 18d shows the four-point mechanism, which is the optical element.

[0134] [Figure 18e] Figure 18e shows an optical fiber attached to an optical element adjacent to the modulator. [Modes for carrying out the invention]

[0135] For the purpose of facilitating understanding of the principles of this disclosure, embodiments shown in the drawings are described herein. It will be explained using a specific language. Nevertheless, this does not limit the scope of this disclosure. It will be understood that there are no such restrictions on the systems, apparatus, devices, or methods described. Any changes and further modifications, as well as any further application of the principles of this disclosure, shall be in accordance with the relevant laws and regulations of this disclosure. It is given full consideration to the way that a person skilled in the art would normally conceive. In particular, one embodiment The features, components, and / or steps described herein may be found in other embodiments of this disclosure. It can be combined with the features, components, and / or steps described in relation to it. For the sake of consistency, in some examples, the same reference number may be the same or similar throughout the drawing. It is used to indicate parts.

[0136] Figure 1 shows two-dimensional or three-dimensional OCT images for the purpose of accurately correcting static and dynamic distortions. An example of a system that encodes modulation in the image is shown. A-line scanner 100 is used with objective scanner 1 Light is directed towards the object or tissue to be examined through the optical system of 01. OCT imaging is optical This can be performed on surfaces or aggregate surfaces of precision parts such as faces. For example, examining the retina. To perform posterior segment imaging and / or to examine, for example, the lens and / or cornea. Anterior segment imaging of the eye can also be performed.

[0137] Figure 1 shows how to perform accurate 3D mapping of OCT data using STMD. The system is shown. The A-line scanner 100 includes a light source 102, an interferometer 104, and a reference arm. Includes 103, detector 105, processor 106, and display 107. Interferometer or The sample light is directed towards the objective scanner 101, and a set of optical components is positioned horizontally on the object 110. The light beam is scanned in the vertical dimension. The light passes through waveguide 120 and optical component 121. The object enters the objective scanner 101 and generally forms a beam with a parallel beam 126. , the maximum angular range indicated by the peripheral rays 127 by the scanner (or scanning mechanism) 122 It is scanned by a swept saw. The telescope, consisting of lenses 123 and 124, is a swept saw. In the case of OCT, via the connection part 129, the signal runs on the modulator 128 which is synchronized with the light source 102. The surface of the part to be inspected is imaged. The light beam is ultimately directed through the objective lens 125 to the object 110. It is scanned above. The distance between lens 123 and lens 124 is the distance of the beam over object 110. It can be changed to adjust focus or divergence.

[0138] In one example, to achieve the modulation required for STMD, a scanner (or scanning mechanism) A high-speed modulator 128 is incorporated after 122. The modulator 128 has an A-line trigger and a Match the timing and mark one or more A lines out of every N A lines. If the controller 128 can apply a large phase shift in the z direction, as shown in Figure 2, The modulation is observed as a z-shifted A line. This shift 201 is called z-modulation. While the image is not moving at a constant speed, the modulation is performed at regular time intervals, so the image The spacing between image markers is used to correct the distortion caused by the nonlinearity of lateral scanning, and the distortion Images and measurements without the z-shift can be obtained. In one example, the z-shift is used in image processing. At least one pixel so that the position of the modulated A line can be detected. It is equal to. Image modulation can be removed to produce a clean image. z modulation This can be reversed by inverting the shift amount in the digital domain.

[0139] Figure 2 shows the anterior cornea 202, posterior cornea 203, anterior lens 204, posterior lens 205, and The image shows a cross-sectional OCT image of the anterior part of the eyeball, including the iris 206. In the example in Figure 2, z modulation The A line is shown which has been phase-shifted. Marker 201 indicates the nonlinearity of the scanning mechanism. It can be used to correct for inaccuracies.

[0140] Figure 3 shows one example of a timing scheme for applying modulation to a single A-line. To achieve this modulation, the modulator 128 is driven by the step function 303. A delay is applied to a specific A line. In this case, the response time of modulator 128 is the same as that of the subsequent A line. This is enough time to perform the transition between the two. Most Swept Source (SS)OC The T laser operates with a duty cycle of approximately 70%, and switching is 30% off. It can happen during the day. 301 indicates the ID number of line A. 302 is, The laser sweep profile versus time is shown. 303 is the modulation command with a solid line, and the points are... The line shows the time response of the modulator.

[0141] The modulation interval is the total number of A lines per period (modulated A lines + unmodulated A lines). This represents (n). The duty cycle of the modulation represents the ratio of the modulated A line to the interval. In this example, two conditions are met to detect positional distortion in the image. The condition is that the interval between scans is A-lines in order to provide sufficient sampling of scanning dynamics. The second condition is to avoid averaging during modulation. The duty cycle must be significantly larger than 1 / 2. In the experiment, the OCT image When the modulation on the image is represented by a single A-line that is modulated at once, the best result is obtained. It has been found that the result can be obtained. Modulated A line represented by a single A line The interval between the dots does not provide recoverable information regarding the lateral speed of the scan, therefore 1 / 2 de The utility cycle does not transmit distortion information.

[0142] Experiments have shown that the direct phase modulation method using lithium niobate crystals is stable and reproducible. It was found to be possible. In this example, the implementation with lithium niobate crystals was possible with small apertures. This is limited to IZ, and the polarization dependence of the shift is not considered.

[0143] In another example, phase modulation using an acousto-optic (AO) crystal is an execution to produce z-modulation. This is a possible method. In this case, the first-order diffraction beam separates the first-order diffraction from the zero-order diffraction. A sufficient modulation frequency f0 is selected from the AO phase shifter. The OCT depth information is assigned to the frequency. Because it is modulated based on this, when this constant frequency shift is applied, the zero delay position is f=0 Instead, it will match f0. f0 is f N This is the analog-to-digital conversion process. The killst frequency is f N If it is equal to / 2, the zero-delay position will be in the center of the imaging range. To achieve frequency shift, the modulation frequency of the first-order diffraction is the period during which the A line is shifted. This can be changed to f0+δf. Baseline frequency modulation can be maintained if necessary. It can be maintained. If not necessary, demodulate during A-line reconstruction processing, or another A Install the O modulator on either the sample arm or the reference arm to remove f0 modulation and δf It can be restricted to that.

[0144] Figure 4 shows the piezoelectric device (mechanism 407) in the optical path to achieve the desired modulation parameters. This example shows how an alternative modulation scheme can be realized by placing a mirror. The A-line scanner 100 (also called the OCT engine) is transmitted via the collimator 401. Illuminate the optical setup. The beam is directed towards the scanner mechanism 405 and lenses 402, 40 3 and 404 are scanned over the object 408. Mechanism 407 modulates the A line. A folding reflector set up mounted on a piezoelectric actuator that operates to perform this function. It is composed of a p. Modulation is performed via an A-line sweep through an A-line trigger 406. It will be synchronized with that.

[0145] Furthermore, it is also possible to perform intensity modulation (i-modulation) instead of phase modulation. The advantage is that intensity modulation is easier to implement. Intensity modulators operate at high speed, and modulation is It can be applied to a single A-line without affecting preceding or succeeding A-lines. It is possible. An example of an intensity modulator is a solid-state modulator such as an AO that operates in intensity modulation mode. In the example, the modulated A line is empty, so refer to Figure 6 for example, when scanning... It can help identify and correct positional errors. The modulated A-line information is It is not possible to reconstruct it from the same image. This effect is due to one of the following two methods It is possible to address this. The first method involves repeating the same scanning pattern, which will then lead to the following two The purpose is to record the scans. One scan is subjected to i-modulation, and the other scan is subjected to modulation. No. Apply the distortion information calculated based on the modulated scan to the second scan. Then, an image or map without distortion can be created. The second method is to use a multidimensional surface. Applicable to topography applications that conform to segmented OCT surfaces, with blank A-lines. The sparse absence of corresponding data points may not be deemed to affect the results. .

[0146] In another example, intensity modulation can be performed by incorporating an intensity modulator into the optical path. Figure 5 shows the OCT engine or A-line scanner 100 via the collimator 501. This shows the setup that illuminates the optical setup. The beam is, if scanner mechanism 502 The lenses 503, 504, and 505 are then scanned over the object 509. Only one of the two modulators 506 or 507 shown in the figure is required. Modulator 5 The modulation performed by 06 and 507 is transmitted via the A-line trigger 508 to the A-line switch. It is synchronized with the loop. In one example, modulator 507 synchronizes with scanner 502 and lens 503. It is placed in between. In this example, modulator 507 is connected via A-line trigger 508 to OCT It is coupled to the 100. In another example, the modulator 506 is coupled to the lens 504 and lens 505 It is placed between them. In this example, modulator 506 is connected via A-line trigger 508 to OC It is coupled to the T engine 100.

[0147] In one exemplary embodiment, intensity modulation occurs at either position 506 or 507. The means of inserting an AO modulator into the optical path, or simply as explained in the dynamic optical delay in Figure 4. Activate the mirror between the A lines to blur the contents of the mirror (in the case of SSOCT) Alternatively, the mirror can be made blank by washing the spectral fringes (spectral domain OCT) This can be done by the case. The step response request for dynamic optical delay in this case is This is significantly lower than what is required for z-modulation. For example, a modulation amplitude of π-2π is sufficient. , and the rise and fall times become faster. In this example, this technique is low It operates in two modes: z-modulation at OCT speed and i-modulation at high speed.

[0148] Figure 6 shows an example where the i-modulation marker 601 is created by intensity modulation rather than phase modulation. As shown, marker 601 can be placed on each imaging surface.

[0149] Figure 7a shows that the scanned object is the eyeball 701 or any part of the eyeball 701 or the eyeball This shows the same setup as in Figure 1, which is a fragment of 701.

[0150] Figure 7b shows the same configuration as Figures 1 and 7a, but with a different arrangement of modulator 701 adjacent to the scanning component. This indicates that it is installed. In this example, modulator 701 is a scanner (or scanning mechanism) It is placed in close proximity to 122. This placement of modulator 701 increases the degree of freedom in the downstream optical design. It is possible to do so. For example, lenses 125, 124, and 123 can be removed. In this example, modulator 701 is wider than modulator 128 in the setup of Figure 7a. It has a wide receptive angle and a large opening.

[0151] Figure 7c shows the same configuration as in Figures 7a and 7b, but with a modulator between lenses 123 and 124. This shows that 702 is installed in a different configuration. In this example, modulator 702 is a wide-area modulator. This configuration of modulator 702 can increase the flexibility of downstream optical designs. For example, Lenses 125 and 124 can be removed. The configuration in this example is the receiving angle of the modulator. This reduces the demands on large-area modulators such as liquid crystal modulators, which generally have slow response times. However, it is sufficient for the purposes here.

[0152] Figure 8a shows an example configuration that enables OCT imaging of the posterior part of the eyeball 701. The example in Figure 8a is: This is similar to the example in Figure 7b. In this example, the OCT engine or A-line scanner 100 , the scanning mechanism (or scanner) 122 is illuminated via the collimator 121. Modulator 702 It is placed near the scanning mechanism (or scanner) 122. Lens 123 and lens 1 The telescope, composed of 24 elements, is approximately the pupillary plane of the eyeball (the plane located in the anterior chamber of the eyeball that contains the pupil). The beam is rotated around. The distance between lens 123 and lens 124 is such that the focal point is on the retinal tissue. It can be modified to match. An example in Figure 8a shows the posterior part of the eye, such as the retina and retinal layers. It is suitable for imaging not only structures but also objects or structures within the posterior part of the eyeball.

[0153] Figure 8b shows the OCT engine or A-line scanner 100, collimator 121, scanning It consists of a mechanism (or scanner) 122, and lenses 123 and 124. An example configuration is shown in which modulator 128 is illuminated through a telescope. The modulated light beam is then... The posterior part of the eyeball 701 is connected via lens 125 and lens 801, or by adding lens 802. This scans the anterior part of the eyeball. In this example, lens 802 is an optical setup. The lens 802 is either in the anterior part of the eyeball (when the lens 802 is out of the optical path) or in the posterior part of the eyeball (when the lens 802 is out of the optical path). It is a movable objective lens that can scan either (when it is in the optical path). In another example... Lens 802 is in the optical path when imaging the anterior segment, and when imaging the anterior segment Sometimes it deviates from the optical path. This configuration is for switching between anterior segment scanning and posterior segment scanning. This reduces the aperture requirements of the modulator 128, providing flexibility and enabling higher speeds.

[0154] Figure 8c shows the OCT engine or A-line scanner 100, collimator 121, scanning The mechanism 122, and the lenses 123, 124, 125, 801, and 802, are modified. An example configuration for illuminating the controller 804 is shown. In this example, the modulated light beam is directed in front of the eyeball 701. It scans directly. Modulator 804 is installed as the last optical element of the system, so this The configuration provides the ability to compensate for distortions in all static and dynamic systems within the system. To scan the posterior eye, both the lens 802 and the modulator 804 are removed from the optical path. In this case, the STMD is not applied to the scan of the posterior part of the eye. In this example, the modulator 8 04 is incorporated into the assembly including the lens 802.

[0155] FIG. 9 shows an example of a scanning mechanism and an imaging engine 900. In this example, the imaging engine 9 00 may be an OCT or another technique, such as a single pixel camera. For a single pixel camera based imaging system, a portion of the object 901 is imaged by the lens 902 on the scanning mechanism 905 via the modulator 904. The beam then propagates to the camera 900. To image another portion of the object, the scanning mechanism is moved to collect light from that portion As the scanning mechanism 905 continues to move, multiple image points are collected and an image is generated The angular range of the scanned beam is shown as 903. The modulator 904 is synchronized with the imaging engine 900 via line 907 and starts to generate i-modulation on the image. The modulation is used to correct the distortion of the image.

[0156] FIG. 10 shows an example of a method for a modulated image or topography. The input to this method is an STMD image in which the z-modulation holds distortion information, and the output is an image with the distortion removed The modulated image 1001 is processed at 1002 to remove the baseline curvature if necessary, for example, to flatten the front surface of the cornea The differentiation applied at 1003 is taken along the horizontal direction of one or more surfaces. The result of the differentiation is used at 1004 and 1006 to identify the start index 1005 and the end index 1007 of the modulation event ​​

[0157] The z modulation is removed at 1008, and the indexes calculated at 1005 and 1007 define the first and last A lines that are shifted within a predetermined interval. The shift is applied by applying a sub - pixel phase shift to the z - modulated A lines. The shift can be realized by oversampling or by offsetting the wavelength index to process the spectral A lines. This results in an exact phase shift of the A lines. The offset amount can be calculated in advance based on prior knowledge of the system or based on minimizing the difference between pixels. The z modulation is removed at 1008, and the indexes calculated at 1005 and 1007 define the first and last A lines that are shifted within a predetermined interval. The shift is applied by applying a sub - pixel phase shift to the z - modulated A lines. The shift can be realized by oversampling or by offsetting the wavelength index to process the spectral A lines. This results in an exact phase shift of the A lines. The offset amount can be calculated in advance based on prior knowledge of the system or based on minimizing the difference between pixels. The z modulation is removed at 1008, and the indexes calculated at 1005 and 1007 define the first and last A lines that are shifted within a predetermined interval. The shift is applied by applying a sub - pixel phase shift to the z - modulated A lines. The shift can be realized by oversampling or by offsetting the wavelength index to process the spectral A lines. This results in an exact phase shift of the A lines. The offset amount can be calculated in advance based on prior knowledge of the system or based on minimizing the difference between pixels. The z modulation is removed at 1008, and the indexes calculated at 1005 and 1007 define the first and last A lines that are shifted within a predetermined interval. The shift is applied by applying a sub - pixel phase shift to the z - modulated A lines. The shift can be realized by oversampling or by offsetting the wavelength index to process the spectral A lines. This results in an exact phase shift of the A lines. The offset amount can be calculated in advance based on prior knowledge of the system or based on minimizing the difference between pixels. The z modulation is removed at 1008, and the indexes calculated at 1005 and 1007 define the first and last A lines that are shifted within a predetermined interval. The shift is applied by applying a sub - pixel phase shift to the z - modulated A lines. The shift can be realized by oversampling or by offsetting the wavelength index to process the spectral A lines. This results in an exact phase shift of the A lines. The offset amount can be calculated in advance based on prior knowledge of the system or based on minimizing the difference between pixels. The z modulation is removed at 1008, and the indexes calculated at 1005 and 1007 define the first and last A lines that are shifted within a predetermined interval. The shift is applied by applying a sub - pixel phase shift to the z - modulated A lines. The shift can be realized by oversampling or by offsetting the wavelength index to process the spectral A lines. This results in an exact phase shift of the A lines. The offset amount can be calculated in advance based on prior knowledge of the system or based on minimizing the difference between pixels. The z modulation is removed at 1008, and the indexes calculated at 1005 and 1007 define the first and last A lines that are shifted within a predetermined interval. The shift is applied by applying a sub - pixel phase shift to the z - modulated A lines. The shift can be realized by oversampling or by offsetting the wavelength index to process the spectral A lines. This results in an exact phase shift of the A lines. The offset amount can be calculated in advance based on prior knowledge of the system or based on minimizing the difference between pixels.

[0158] If the goal is to remove the distortion caused by the scanning mechanism from individual images, for example, from a B - scan, interpolation steps are applied to the image 1009 at 1010, and the horizontal dimension is rescaled according to the indexes of 1005 and 1007. The output is the corrected image 1011 without scanning distortion. If the goal is to remove the distortion caused by the scanning mechanism from individual images, for example, from a B - scan, interpolation steps are applied to the image 1009 at 1010, and the horizontal dimension is rescaled according to the indexes of 1005 and 1007. The output is the corrected image 1011 without scanning distortion. If the goal is to remove the distortion caused by the scanning mechanism from individual images, for example, from a B - scan, interpolation steps are applied to the image 1009 at 1010, and the horizontal dimension is rescaled according to the indexes of 1005 and 1007. The output is the corrected image 1011 without scanning distortion.

[0159] If the goal is to remove the distortion caused by the scanning mechanism from a large amount of data such as a topographic map, the topography is calculated from multiple images 1009. Next, at 1013, the 3 - D information is interpolated according to the indexes of 1005 and 1007, thereby correcting the topography. The output is the corrected topography 1014 without scanning distortion. If the goal is to remove the distortion caused by the scanning mechanism from a large amount of data such as a topographic map, the topography is calculated from multiple images 1009. Next, at 1013, the 3 - D information is interpolated according to the indexes of 1005 and 1007, thereby correcting the topography. The output is the corrected topography 1014 without scanning distortion. If the goal is to remove the distortion caused by the scanning mechanism from a large amount of data such as a topographic map, the topography is calculated from multiple images 1009. Next, at 1013, the 3 - D information is interpolated according to the indexes of 1005 and 1007, thereby correcting the topography. The output is the corrected topography 1014 without scanning distortion.

[0160] If the goal is to remove the distortion caused by the scanning mechanism from a large amount of data such as a topographic map, the topography is calculated from multiple images 1009. Next, at 1013, the 3 - D information is interpolated according to the indexes of 1005 and 1007, thereby correcting the topography. The output is the corrected topography 1014 without scanning distortion. Figure 11 shows an example of a method for processing a modulated image or topography. The input to the algorithm is an STMD image in which the i - modulation holds distortion information, and the output is an image with the distortion removed. This is an image. The modulated image 1101 is processed in 1102, for example, to make the anterior surface of the cornea nearly flat. To achieve this, remove the baseline curvature if necessary. Differential applied in 1103 This is taken along the horizontal direction of one or more surfaces. The result of differentiation is 1104 and 110 In 6, the start index 1105 and end index 1107 of the modulation event are specified. It is used to determine.

[0161] The i-modulation is removed at 1108, and the indices calculated at 1105 and 1107 are, A line from the unmodulated image 1109 acquired following image 1101 indicates a predetermined interval. Defines the first and last A-lines that are replaced within the structure.

[0162] If the objective is to remove distortion caused by the scanning mechanism from individual images, for example, B-scan images, Apply an interpolation step to image 1109 at 1110, and index 1105 and 1107 The horizontal dimensions are rescaled according to the scaling. The output is a corrected image 111 without scanning distortion. It is 1.

[0163] For example, removing distortion caused by the scanning mechanism from large amounts of data such as topographic maps. If the objective is to calculate the topography from multiple images 1109, then 1 In 113, 3D information is interpolated according to indices 1105 and 1107. This corrects the topography. The output is a corrected topography without scanning distortion. It is 1114.

[0164] Figure 12 shows the steps taken to remove modulation and distortion from an anterior segment OCT image. An example is shown. Most of the curvature of the anterior corneal surface in z-modulated image 1201 is removed in step 1202. This can be done by removing the average corneal curvature, or by detecting the curvature on the anterior eye surface of this specific image after smoothing the surface and then shifting the A-line according to the curvature information. Image 1203 is the image after removing the curvature of 1201 and is the same as 1201. Envelope line 1204 indicates that the anterior corneal surface is exactly separated from the remaining image. In step 1205, a horizontal differential is applied to the envelope line portion of image 1204. The result of the differential is shown in 1206, where the negative spikes and positive spikes correspond to the start and end of each modulation event respectively. In step 1207, in order to select only the positive spikes as shown in 1208, the negative spikes are removed by excluding all values below the horizontal line. In step 1209, the spike index is identified, and in step 1210, the index vector is stored. In step 1211, the z modulation is removed, the image is interpolated to remove distortion, and the index is applied to generate the corrected image 1212. This can also be achieved by detecting the curvature on the anterior eye surface of this specific image after smoothing the surface and then shifting the A-line according to the curvature information. Image 1203 is the image after removing the curvature of 1201 and is the same as 1201. Envelope line 1204 indicates that the anterior corneal surface is exactly separated from the remaining image. In step 1205, a horizontal differential is applied to the envelope line portion of image 1204. The result of the differential is shown in 1206, where the negative spikes and positive spikes correspond to the start and end of each modulation event respectively. In step 1207, in order to select only the positive spikes as shown in 1208, the negative spikes are removed by excluding all values below the horizontal line. In step 1209, the spike index is identified, and in step 1210, the index vector is stored. In step 1211, the z modulation is removed, the image is interpolated to remove distortion, and the index is applied to generate the corrected image 1212. The image of 1212 is distortion-corrected for all the previous lateral distortion parts caused before the modulator used to modulate the image. This includes static distortion from the optical system as well as static and dynamic distortion from the scanning mechanism. The static distortion of the optical system downstream of the modulator and the fan distortion can be excluded from the calibration. In this example, the surface used for distortion correction, that is, the anterior corneal surface in the example of Figure 12, is used as the reference when other distortion corrections are applied.

[0165] The image of 1212 is distortion-corrected for all the previous lateral distortion parts caused before the modulator used to modulate the image. This includes static distortion from the optical system as well as static and dynamic distortion from the scanning mechanism. The static distortion of the optical system downstream of the modulator and the fan distortion can be excluded from the calibration. In this example, the surface used for distortion correction, that is, the anterior corneal surface in the example of Figure 12, is used as the reference when other distortion corrections are applied. In this example, the surface used for distortion correction, that is, the anterior corneal surface in the example of Figure 12, is used as the reference when other distortion corrections are applied. In this example, the surface used for distortion correction, that is, the anterior corneal surface in the example of Figure 12, is used as the reference when other distortion corrections are applied.

[0166] Proper lateral scaling of STMD-corrected images is performed using known targets. This can be achieved by calibrating the image. Scanning mechanisms are typically nonlinear with respect to speed. Because they exhibit different reactions, different scanning patterns may require different scaling. To ensure accurate scaling regardless of the scanning pattern, a spatial basis The semi-mark can be incorporated into the image. As mentioned above, the image distortion has been removed. Therefore, two points are sufficient to accurately scale the image. This is because it has precise dimensions. This is done by adding markers that represent additional image criteria based on physical characteristics. This marker is used to provide a reference point for accurate scaling. It is possible.

[0167] In the case of an OCT system, the reference is two optical objects within the sample arm, and those optical objects This can be generated by interfering with the object's signal on a reference arm and then imaging it. To achieve this, the reference arm must be shortened, or the optical path extended toward a reference within the sample path. Either of the above means that the reference optical path length must be matched with the reference arm.

[0168] To ensure that the reference point does not interfere with the image, insert the reference point outside the image's field of view, Furthermore, the scanner's scanning range is widened before, after, or during the imaging process. It is necessary. Instead, the reference is activated to insert into or remove from the optical path. You can also set standards for the setup that allows you to do this.

[0169] The reference marker can be a specular reflector or a scatterer. With a scatterer, adjustment is less important. Because it is not required, it is particularly desirable for operational criteria.

[0170] The reference marker is instead a switch, laser marking, or simply the edge of the modulator. By capturing images, it is also possible to incorporate them into the modulator.

[0171] Thin, cylindrical objects such as optical fibers can be used as reference markers. Because the fiber is thin, it is easy to generate autocorrelation signals within the optical fiber. This can be easily confirmed on the OCT image. The autocorrelation of the sample pathway is obtained from the reference arm. Since this method does not require interference with light, the optical path length between the sample arm and the reference arm is less important. This eliminates the need for adjustment. These mechanisms are relative to the optical path between correlated mechanisms within the sample arm. Through the given depth, it becomes possible to visualize near zero delay.

[0172] Figure 18a shows the eyeball 1801 with a reference mark 1800 placed outside the region of interest 1802. An example of an OCT image of the anterior segment of the eye is shown.

[0173] In the case of swept-source OCT, autocorrelation is usually suppressed by equilibrium detection. However, However, this suppression is limited to about 30 dB. In this case, the autocorrelation strength exceeds the suppression of equilibrium detection. It cannot be seen unless you look closely.

[0174] The function for generating autocorrelation criteria is located within the modulator itself or within an optical element that can be joined to the modulator. It is also possible to generate it by creating a function. For example, connected to a modulator By changing the refractive index of the optical medium, phosphorus consisting of two surfaces separated by approximately 0.25 mm can be created. It is possible to create a ring. Alternatively, a ring consisting of cloud-like scatterers can be used. The ring mechanism, when stationary in the optical path, is drawn outside the imaging field of view. If the mechanism is removable from the optical path, it can be within the field of view.

[0175] Figure 18b shows an example where the ring mechanism 1804 is part of element 1803, and this element is variable The control device itself may be capable of this, or a separate optical element may be capable of it.

[0176] Figure 18c shows that the ring mechanism 1804 is joined, mounted, or adjacent to the modulator 1806. An example of the optical element 1805 to be installed is shown.

[0177] In another example, a four-point mechanism mark can be used instead of a ring. The mark indicates the mechanism. If the mechanism is stationary in the optical path, it should be written outside the imaging field of view. If removable, it can be placed within the field of view.

[0178] Figure 18d shows the four-point mechanism 1807 being joined, attached, or installed near the modulator 1806. An example of the part of the optical element 1805 that is placed there is shown.

[0179] Figure 18e shows the mechanism composed of optical fibers 1808 near modulator 1806 An example is shown of it being attached to an optical element 1805 which is joined, mounted, or installed. The Ibar is mounted to the optical element 1805 via a mount 1809 that does not obstruct the B scanning field of view. At least four points on the fiber are exposed for optical inspection. Biomedical measurements and topography for quality evaluation of optical surfaces

[0180] Figure 13 shows a precise measurement of the eye surface, similar to the systems shown in Figures 1, 7a, and 8a. The OCT-based STMD system used for topping is applied to the corneal surface and tear film of the eyeball. An example of combining this with a small reflective base placement to assess the health status is shown. At Toup, STMD allows OCT to accurately topographically analyze the corneal and lens surfaces. It can provide a topography map. Topography maps can provide sphericity, toricity, and higher-order properties. This represents the shape of a specific surface containing aberrations, such as the anterior surface of the cornea. The arrangement of the reflection bases in Figure 13 is O Because light reflection from the anterior cornea is more sensitive to tear film disturbances than CT scans, the health of the tear film is important. It provides information about the state. Because topographic information is not extracted in reflection-based placement. Unlike Placido topographs, which require a large angle between the illumination light on the cornea and the imaging light... Furthermore, the system can be built with a small setup.

[0181] The arrangement in Figure 13 generates pattern 1302, which has dark and bright regions. It consists of the following: The illumination beam 1304 from the pattern is connected to the beam splitter 1306. After passing through, it is injected into the OCT pathway via the dichroism combiner 1301. Next, the pattern The image is projected onto the anterior surface of the cornea, and the image of the pattern on the cornea is transmitted via 1301 to the outside of the OCT pathway. The collected beam is returned to the camera 1303 via 1306. It is directed to capture 5. Lighting pattern 1302 is a function of time as well as space. It can be composed of certain characteristics, or combinations of time and space.

[0182] The reflective base patterns that can be used with this configuration are concentric rings and spot arrangements. It can be composed of a grid of columns or lines. Other patterns or shapes can also be used. It is possible. To avoid aliasing of discrete spots on the cornea, temporal changes You can use the key signature.

[0183] Figure 14 shows time-modulated data to evaluate corneal topography and tear film degradation characteristics. This shows a setup using a mobile device with a defined lighting spot for facial recognition and LiDAR. The mobile phone hardware is imaged using a camera system adjacent to the lighting array. Includes an array of lighting spots. Distortions in the lighting pattern are converted into a 3D map. The illumination area and field of view of the optical system unique to the mobile phone (or iPhone®) are It's quite wide, with a resolution on the order of 1 millimeter, which isn't sufficient for monitoring the corneal surface. As shown in Figure 14, in order to increase the spot density of the eyeball 1404, the portable device 1401 and An optical imaging system 1402 is inserted between the eyeball 1404 and the eyeball 1404. The system 1402 is The divergent rays of lighting pattern 1403 are projected onto the eyeball, and a high-resolution topographic map is reconstructed. To achieve this, the eyeball is re-imaged with a camera. Due to the sensitivity of infrared reflection to the quality of the tear film. Furthermore, since video data is recorded by the camera, differences can be made for the analysis of tear film breakdown. Minute-time analysis can be applied. Robust biometric measurement

[0184] Today's optical biosensing devices continue to have limitations in measuring refractive errors such as amblyopia, presbyopia, and emmetropia. Furthermore, there is no robust indicator of fixation accuracy during measurement, so the accuracy of the results depends on the patient's fixation. It depends heavily on the IOL Master 700 (Carl Zeiss Me ditec has a fixation confirmation function that does not occur simultaneously with data acquisition. The axial length (AL) of the eye is measured by shining a fixed, nearly parallel beam of light onto the cornea. A scanning biometer uses a biometer to perform the measurement of axial length at the fovea. This method depends on the patient's eye position relative to the fixed position used. In this technique, the light beam is focused on the foveal surface. It functions effectively only in properly fixed, emmetropic eyes. It covers a wide area of ​​the fovea. In cases of refractive errors such as amblyopia and presbyopia, the axial retinal signal is blurred, and refractive errors spread the light beam. Accurate reading of refractive errors, amblyopia, and presbyopia becomes difficult. The B-scanning biometer is used for the cornea. The same concept is used, but the difference is that it's a scanned beam rather than a fixed beam. Scanning biometers face the same challenges as A-scanning biometers do with refractive errors, amblyopia, and presbyopia. Furthermore, the beam, scanned paraxially over the anterior segment, is not focused. Therefore, all beams will swirl around the fovea of ​​an emmetropic eye and a fixed eyeball. In cases of refractive errors, amblyopia, and presbyopia, the center of rotation shifts either anteriorly or posteriorly to the foveal surface. And when AL is calculated using information from all beams, it causes further blurring. That will happen.

[0185] To overcome issues of focus, blurring, and fixation confirmation, Figure 15 shows accurate biometric information. A set of scanning patterns applied to the entire eyeball to simultaneously generate reports and fixation confirmations. This shows a close-up. The beam 1503 is almost swirled around the pupillary plane of the anterior segment 1501. The pupillary plane is the plane in the anterior chamber of the eyeball that contains the pupil. The pupillary center is (for example, a camera It can be determined (by imaging) and used as the center of rotation. Peripheral rays 15 04 traverses the region on the retina 1502 while acquiring biometric measurement information. The fovea 1505 can be clearly resolved in the image. The beam is directed towards the R of the retina. It has a wavefront that is preset to generate a focal point approximately on the PE (retinal pigment epithelium) plane. It enters the cornea.

[0186] To make this possible, the optical setup in the sample arm of the OCT system is: Illuminate the eye with a focused scanning beam, and position the center of rotation around or behind the pupillary surface. To allow for adjustment. In this example, the collection of the sample arm of the OCT system. The beam could be located at the center of the pupil, within the pupillary plane, or slightly anterior or posterior to the pupillary plane. It is concentrated around a certain center of rotation.

[0187] This setup allows for beams to reach the retina of any eye, regardless of refractive error, amblyopia, presbyopia, or normal vision. It further includes a focusing optical system that is adjusted to ensure reliable focusing.

[0188] This setup allows for the simultaneous visualization of all eye surface areas necessary for biometric measurements. This can be done. Lateral resolution defects in the anterior segment are related to axial length (AL), anterior chamber depth (ACD), and This does not affect the accuracy of the basic measurement of lens thickness (T). The beam is focused on the retina, and the retinal surface Because it crosses the foveal, consistency and accuracy in determining the axial length of the eye are improved. The same image also provides information about eye fixation, allowing for simultaneous confirmation of fixation. Furthermore, even with eyes that are not fixed, important biometric values ​​(AL, ACD, T) can be obtained. It is possible to do so.

[0189] The configuration shown in Figure 15 provides the ability to focus the beam onto the fovea and scan along the fovea. This provides clear visualization for accurate foveal distance measurement and fixation evaluation. This configuration offers the advantage of [missing information]. However, this configuration impairs the detailed field of view of the anterior segment. Figure 16 is a comparison of Figure 1. The same system as in 5 is supplemented with a different scanning configuration 1601, which is approximately paraxial with the approximate focal plane in the anterior chamber. The completed system is shown. In the example in Figure 16, the center of rotation is the cornea, lens, iris, and anterior chamber. To achieve scanning, the sensor is moved away from the pupil. By adding paraxial scanning, swirling scanning is possible. Using a pattern, high-resolution images of the anterior segment can be obtained that can be registered in the recorded images. By registering two images or volumes, the accuracy of biometric measurements obtained using rotational scanning can be improved. To obtain a high-resolution, complete image of the ocular surface in both the anterior and posterior segments without loss of quality. .

[0190] Figure 17 shows the arrangement that realizes the scanning patterns described in Figures 15 and 16. 'a' indicates a configuration for performing paraxial scanning of the eyeball. OCT engine or A-line scanner 100 The beam 1703 is parallel to the collimator 1701 via waveguide 1700. The beam 1704 is scanned using the scanning mechanism 1702. Images are captured using 5 and 1706. A phase modulator or amplitude modulator 1707 is used for scanning. It is installed on the image plane. The modulator is connected to 100 masters via trigger line 1708. - Synchronized with the trigger. The scanned beam is further connected to lens 1709, delay element 1712 , propagating through the optical system consisting of lenses 1710 and 1711, to the eyeball 17 14 is illuminated by a paraxially scanned beam. It consists of a lens 1710 and a delay element 1712. The assembly 1713 is mounted on the movable mechanism.

[0191] Figure 17b shows assembly 1713 being moved outside the usable optical aperture, as shown in Figure 17a. This shows the same arrangement. This is to realize the biomedical measurement scanning shown in Figures 15 and 16. It is used to provide a rotational scan on the eyeball.

[0192] The optical delay element 1712 eliminates the difference in optical path length between the arrangements in Figure 17a and Figure 17b. or reduce. The delay element 1712 can simply be a glass cube. Alternatively, the delay element 1712 is configured as an element with an adjustable delay to take into account different eyeball lengths. This is achieved by utilizing the tilt of the optical cube to adjust the delay, or by using a bee This is achieved by using a movable wedge to adjust for the light delay encountered by the system. This is possible. This preferred configuration allows switching between two imaging modes with the same optical path delay. It will become replaceable.

[0193] As the beam propagates through the eyeball, it may encounter optical focusing or blurring. As mentioned above, this is a telescope consisting of lenses 1705 and 1706. A telescope consisting of lenses 1706 and 1709, or lenses 1709 and 17 This can be corrected by changing the magnification of the telescope, which is composed of 11 elements. In all of these adjustments, it is necessary to adjust the drive signal of the scanning mechanism in order to maintain the lateral imaging range. This is the result.

[0194] Figures 17c and 17d are used to achieve rotational scanning and paraxial scanning of the eyeball. Figure 17c shows two different configurations that can be used. The OCT engine or A-Live The scanner 100 transmits parallel beams through the collimator 1701 and waveguide 1700. This shows how the scanning mechanism 1702 is illuminated by the beam. The scanned beam 1704 is 17 A modulator synchronized with the trigger of the OCT engine or A-line scanner 100 via 08. Modulated by 1707. The telescope, consisting of lenses 1705 and 1706, is an eye The beam is translated so as to cross the rear of sphere 1714. The telescope also projects the desired image onto the retina. It is used to achieve focus. Lens 1706 can be removed or inserted into the optical path. It is mounted on a mechanism. Assembly 1715 is movable in the axial direction.

[0195] Figure 17d shows that to achieve paraxial scanning on the eyeball, lens 1706 is removed from the optical path. The arrangement shown in Figure 17c is as follows. Assembly 1715 adjusts the optical path length of the sample arm. It is moved in order to work with lens 1706. Delay element 1 in Figures 17a and 17b Additional optical delays, such as those in the 712, can also be employed in this configuration.

Claims

1. A system for providing accurate lateral mapping of images acquired via a scanning mechanism. And, Imaging engine and A scanner system equipped with a scanner, A modulator placed after the scanner, which generates an image marker using an imaging engine The modulator, which is synchronized with the clock and starts at a speed that generates the image marker, comprises A system.

2. The modulator generates at least one marker for at least one image element. It is clocked to, and furthermore, the modulator is a variable which is an integer division of the imaging engine clock. The system according to claim 1, which is clocked at a speed that brings about adjustment.

3. The aforementioned imaging engine, Light source and Beam splitter and combiner configuration, Reference placement and, Sample scanning arrangement, Detector and Processor and The system according to claim 1 comprises a display and an A-line scanner of an OCT. Hmm.

4. The modulator causes a phase delay or amplitude change in at least one image element. The system described in Item 1.

5. A method for correcting image distortion, A picture created by a modulator that generates modulation of elements in the aforementioned image and distributed along the surface The steps include: placing an image marker in at least one image of an object including the surface; 、 The step of identifying the modulation, The horizontal direction perpendicular to the z-direction of the imaging beam, and the interval of the modulation in the horizontal dimension. A method comprising the steps of removing distortion from each of the aforementioned images accordingly.

6. By applying the shift along the z-direction, z-modulation is removed from the A-line of the OCT. The method according to claim 5.

7. By applying a phase shift on the conjugate data that is equal to the phase shift on the image element, The claim 6 further includes the step of removing the phase delay applied to the image element. method.

8. The steps include receiving a second unmodulated image of the object which does not have an image marker pattern, and 、 A corrected image is constructed by applying the distortion data calculated from the modulated image to the unmodulated image. The method according to claim 5, further comprising the step of:

9. The step of receiving a second modulated image of the object, wherein the second set is the first Modulation is performed by an image marker pattern shifted from the aforementioned pattern on the set, and a step, The steps include identifying the shifted image markers, Steps to remove the distortion within the image of the second image according to the interval of the modulation P and, A corrected image is constructed using the unmodulated portion from the first set and the second image. Top and, The method according to claim 5, further comprising:

10. To generate an image reference, spatial scaling of the image is performed based on measurements of known objects. The method according to claim 5, further comprising the step of performing a g.

11. At least one optical element with known width and height, or at least two elements with known spacing The child is inserted into the objective scanner used to take the aforementioned image, thereby creating an image reference. The method according to claim 10, further comprising the step of generating.

12. A method for correcting image distortion, An image marker created by a modulator that generates modulation of elements in the aforementioned image, The steps include: placing the image marker on multiple OCT images of an object including a surface; The steps include generating a topographic map from the aforementioned image, A step of identifying the modulation along the topographic map, A step of removing the distortion of the topography map according to the interval of the modulation, A method that includes this.

13. To generate an image reference, spatial scaling of the image is performed based on measurements of known objects. The method according to claim 12, further comprising performing a g.

14. A second set of multiple unmodulated images of the object that does not have an image marker pattern is received. The steps to take, The distortion data from the modulated topography map is converted to the unmodulated topography map. The method of claim 12, further comprising the step of constructing an applied and corrected map. 。

15. Imaging engine and A scanner system equipped with a scanner, A modulator placed after the scanner, which generates an image marker using an imaging engine A modulator that starts in sync with the clock and at a speed that generates the image marker, The illumination pattern and imaging camera are configured with nearly identical optical cone angles, and the dichroic combiner An imaging system comprising a pattern-based reflection system coupled to the scanner system via system.

16. The imaging engine is an OCT system, and the dichroism combiner is located in the OCT imaging path. The imaging system according to claim 15, which is provided for placement.

17. The pattern-based reflection system is a light source and is combined with the OCT imaging path. The imaging system according to claim 15, comprising a light source for generating a pattern.

18. The OCT engine generates the imaging beam, A scanner that directs the imaging beam towards the eyeball, A focus assembly that focuses the beam onto the retina, The plane containing the pupil of the eyeball, or a parallel plane immediately before or after the pupil, and the eyeball A first lens set in the path of the imaging beam scanning at a rotation center placed in the anterior chamber, Prepare, The imaging beam rotates around the rotation center to image the entire eyeball, and simultaneously An eye biomedical measurement system that scans lines on the retina and cornea of ​​the eyeball.

19. The optical assembly simultaneously projects the imaging beam across the structure of the cornea and the lens. To scan, the imaging beam is rotated at a point in front of or behind the cornea. The system according to claim 18, which is insertable into the path of the imaging beam.

20. A further comprising a modulator in the path of the imaging beam after the beam scanner. The system described in item 19.

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