WO2017157828A1 - Systèmes et procédés de mesure des distorsions tissulaires autour de poches de liquide - Google Patents

Systèmes et procédés de mesure des distorsions tissulaires autour de poches de liquide Download PDF

Info

Publication number
WO2017157828A1
WO2017157828A1 PCT/EP2017/055792 EP2017055792W WO2017157828A1 WO 2017157828 A1 WO2017157828 A1 WO 2017157828A1 EP 2017055792 W EP2017055792 W EP 2017055792W WO 2017157828 A1 WO2017157828 A1 WO 2017157828A1
Authority
WO
WIPO (PCT)
Prior art keywords
phase
oct
recited
fluid
pocket
Prior art date
Application number
PCT/EP2017/055792
Other languages
English (en)
Inventor
Nathan SHEMONSKI
Matthew J. Everett
Original Assignee
Carl Zeiss Meditec, Inc.
Carl Zeiss Meditec Ag
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Carl Zeiss Meditec, Inc., Carl Zeiss Meditec Ag filed Critical Carl Zeiss Meditec, Inc.
Publication of WO2017157828A1 publication Critical patent/WO2017157828A1/fr

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
    • A61B3/10—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions
    • A61B3/102—Objective types, i.e. instruments for examining the eyes independent of the patients' perceptions or reactions for optical coherence tomography [OCT]

Definitions

  • OCT optical coherence tomography
  • FD-OCT frequency domain OCT
  • SD- OCT spectral-domain OCT
  • SS-OCT swept laser source
  • Functional OCT can provide important clinical information that is not available in the typical intensity based structural OCT images.
  • functional contrast enhancement methods including OCT Angiography, Doppler OCT, Phase-sensitive OCT, Polarization-Sensitive OCT, and Spectroscopic OCT. Integration of functional extensions can greatly enhance the capabilities of OCT for a range of applications in medicine.
  • the human retina is a flexible piece of tissue which can deform under normal biological forces.
  • the ability to measure these elastic properties of the retina may provide insight into the underlying cellular structure and therefore the state or progression of disease or the efficacy of treatments.
  • Such measurements have been investigated for in vivo anterior segment imaging using an air puff as an external force (Twa, Michael D., et al. (2014) "Spatial characterization of corneal biomcchanical properties with optical coherence eiastography after UV cross-linking.” Biomedical optics express 5(5): 1419-1427), ex vivo retinal imaging using a laser pulse (M Ciller, I leike EL, et al. (2012) "Imaging thermal expansion and retinal tissue changes during photocoagulation by high speed
  • the present application describes a method and algorithm for measuring and quantifying retinal distortions.
  • a key aspect of the method is to analyze the intrinsic distortion of tissue above and below a pocket of fluid.
  • the distortion of the tissue is measured as a relative thickness change of the pocket of fluid along the optical axis and utilizes the phase of the OCT signal.
  • FIG. 1 is a generalized optical coherence tomography (OCT) system for imaging an eye.
  • FIG. 2 is a flow chart of a generalized method for measuring and quantifying tissue distortions according to one aspect of the present application.
  • OCT optical coherence tomography
  • FIG. 3a and FIG. 3b show two different selections of tissue above and below a pocket of fluid in a B-scan.
  • FIG. 3a shows a slab above the fluid as derived from a
  • FIG. 3b shows an arbitrary region above and below the fluid having fixed lateral extent.
  • FIGS. 4a-c shows different visualizations of the motion distortion analysis of the present invention.
  • FIG. 4a shows a depth-projected phase from one region of an OCT scan.
  • FIG. 4b shows the corresponding 'phase-stabilized' frame.
  • FIG. 4c shows an en face view generated by averaging the phase change for motion analysis.
  • FIG. 5 is a block diagram of a general computer system that may perform the functions discussed in this disclosure according to one aspect of the present invention.
  • An FD-OCT system 100 includes a light source, 101, typical sources including but not limited to, broadband light sources with short temporal coherence lengths for SD-OCT systems or swept laser sources for SS-OCT systems.
  • Abeam of light from source 101 is routed, typically by optical fiber 105, to illuminate the sample 110, the sample in this case being tissues in the retina of the human eye.
  • the light is scanned, typically with a scanner 107 between the output of the fiber and the sample, so that the beam of light (dashed line 108) is scanned laterally (in x and y) over the region of the sample to be imaged.
  • Light scattered from the sample is collected, typically into the same fiber 105 used to route the light for illumination.
  • Reference light derived from the same source 101 travels a separate path, in this case involving fiber 103 and retro-reflector 104 with an adjustable optical delay.
  • a transmissive reference path can also be used and that the adjustable delay could be placed in the sample or reference arm of the interferometer.
  • Collected sample light is combined with reference light, typically in a fiber coupler 102, to form light interference in a detector 120, said detector generating signals in response thereto.
  • a single fiber port is shown going to the detector, those skilled in the art recognize that various designs of interferometers can be used for balanced or unbalanced detection of the interference signal.
  • the output signal from the detector 120 is supplied to a processor 121 that converts the observed interference into depth information of the sample.
  • the results can be stored in the processor 121 or other storage medium or displayed on display 122.
  • the processing and storing functions may be localized within the OCT instrument or functions may be performed on an external processing unit to which the collected data is transferred. This unit could be dedicated to data processing or perform other tasks which are quite general and not dedicated to the OCT device.
  • the processor 121 may contain for example a field-programmable gate array (FPGA), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a graphics processing unit (GPU), a system on chip (SoC) or a combination thereof, that performs some, or the entire data processing steps, prior to passing on to the host processor or in a parallelized fashion.
  • FPGA field-programmable gate array
  • DSP digital signal processor
  • ASIC application specific integrated circuit
  • GPU graphics processing unit
  • SoC system on chip
  • each measurement is the real- valued spectral interferogram (S(k, x, y)).
  • the real-valued spectral data typically goes through several postprocessing steps including background subtraction, dispersion correction, etc.
  • reveals the profile of scattering intensities at different path lengths, and therefore scattering as a function of depth (z-direction) in the sample.
  • phase, ⁇ ( ⁇ , x, y) can also be extracted from the complex valued OCT signal.
  • the profile of scattering as a function of depth is called an axial scan (A-scan).
  • a set of A-scans measured at neighboring locations in the sample produces a cross-sectional image (tomogram or B-scan) of the sample.
  • B-scan cross-sectional image
  • a collection of B-scans collected at different transverse locations on the sample makes up a data volume or cube.
  • fast axis refers to the scan direction along a single B-scan whereas slow axis refers to the axis along which multiple B-scans are collected.
  • cluster scan herein to refer to a single unit or block of data generated by repeated acquisitions at the same location for the purposes of analyzing motion of interest within the sample.
  • a cluster scan can consist of multiple A- scans or B-scans collected over time at approximately the same location(s) on the sample.
  • the cluster scan would be collected using a system capable of tracking the sample during acquisition and reducing the incidence of undesirable motion artifacts to insure that the B-scans within a cluster scan are collected at the same set of transverse locations (see for example US Patent No. 8,857,988 the contents of which are hereby incorporated by reference).
  • B-scans A variety of ways to create B-scans are known to those skilled in the art including but not limited to along the horizontal or x-direction, along the vertical or y-direction, along the diagonal of x and y, or in a circular or spiral pattern. The majority of the examples discussed herein refer to B-scans in the x-z dimensions but the invention would apply equally to any cross sectional image.
  • the sample and reference arms in the interferometer could consist of bulk-optics, fiber-optics or hybrid bulk-optic systems and could have different architectures such as Michelson, Mach- Zehnder or common-path based designs as would be known by those skilled in the art.
  • Light beam as used herein should be interpreted as any carefully directed light path.
  • the reference arm needs to have a tunable optical delay to generate interference.
  • Balanced detection systems are typically used in TD-OCT and SS-OCT systems, while spectrometers are used at the detection port for SD-OCT systems.
  • the invention described herein could be applied to any type of OCT system.
  • the timing between repeat scans should be considered to allow for intrinsic motion of the tissue. Depending on the frequency and amplitude of motion, timing differences on the order of 1 - 100 ms are preferable. If acquired too closely in time, no motion will be seen, and if acquired too far apart in time, phase wrapping may occur or information regarding the dynamics may be missed.
  • n is the repetition number of the scan and, for simplicity, only the z (depth) and x (transverse) dimensions are denoted, but A is understood to be three-dimensional. Furthermore, the transverse variables z and x are understood to be discrete representing each location that data is acquired.
  • a section of tissue above and below a pocket of fluid is isolated (step 204).
  • the exact boundaries of the fluid pocket need not be identified, rather only a slab/region laying above and a slab/region laying below as is shown in FIGS. 3a and 3b. This can be accomplished, for instance, using traditional segmentation approaches as are well known in the prior art.
  • FIG. 3a an OCT scan of retinal tissue (300) contains a pocket of fluid (302).
  • a slab is shown (304) as derived from the segmentation of the inner limiting membrane (ILM).
  • a slab is defined (306) as derived from a segmentation of the retinal pigment epithelium (RPE).
  • RPE retinal pigment epithelium
  • the phase of the OCT data at different lateral locations in the tissue portions above and below the pocket of fluid is calculated (step 206). This can be done by projecting each slab along the z dimension to generate two phase values for each lateral location and scan repetition number, (p n above (x) and (p n below (x). It is noted that many techniques can be used for this projection. The simplest is a complex average along depth, but other methods involving first thresholding the data or normalizing each point by the amplitude, etc. can be imagined by one skilled in the art.
  • ⁇ ⁇ ( ⁇ ) (poul below (x) - (p n above (x)
  • step 208) we recognize that it is preferable to add and subtract phase values in the complex domain rather than just add or subtract the actual phase values to avoid phase wrapping errors (O'Hara, Keith E., et al. (2013) "Measuring pulse-induced natural relative motions within human ocular tissue in vivo using phase-sensitive optical coherence tomography.” Journal of biomedical optics 18(12): 121506).
  • phase differences are performed (such as ⁇ - ⁇ 2 )
  • phase differences it is not meant be restricted to only subtracting phase values, but also recognizing that the phases can be subtracted in complex form using exp(i(pi)*exp( ⁇ i(p 2 ) or
  • the phase change can be stored or displayed or analyzed further (step 212).
  • the phase change is directly proportional to the change in thickness between scan Ai(x) and Aj(x).
  • Phase changes can be calculated between multiple pairs of scans in the set with the same time separations (e.g. between scan 1 & scan 2, scan 2 & scan 3, etc.) and then be combined such as averaging or curve fitting to improve the measurement.
  • phase changes can be calculated and compared for scan pairs with different time separations (e.g. scan 1 and scan 2 vs. scan 1 & scan 4) to look at different time dynamics of the motion.
  • the number of scans taken at the same location, N can be varied depending on the desired analysis of the dynamic motion. If only the amplitude of the motion is desired, N between 1 and 10 is likely sufficient. On the other hand, if advanced frequency analysis is desired, imaging each location for a longer period of time (N greater than 10 and even up to 500) may be necessary.
  • a cumulative sum (or other discrete integrals) can be computed to estimate the absolute change in thickness of the tissue over time.
  • the change in thickness over time (or the incremental change in thickness) can be used for further analysis.
  • One such example is the possibility of not observing dynamic changes in thickness before treatment then observing motion after treatment. This could provide insight into the effectiveness of the treatment or the health of the tissue.
  • an increase or decrease in measured motion could also be a useful metric.
  • Many other metrics such as frequency of oscillations, power within a frequency band, standard deviation of motion over time or of differential motion over time could also equally be used by one skilled in the art.
  • FIGS. 4a-c it may also be beneficial to use the depth-projected phase from one region (e.g. A(pij below (x)) to 'phase-stabilize' the frame of data.
  • A(pi,i+i(z, x) is shown for a select i. Similar tissue and fluid pocket features as in FIGS. 3a and 3b can be seen.
  • FIG. 4b a 'phase-stabilized' frame is shown. The frame is calculated using: A(pi,i+i(z, x)-A(pi,i+i below (x) where A(pi,i+i below (x) is calculated using the segmentation 306 defined in FIG.3a.
  • the RPE and choroid depths in the retina (404) show zero radians, meaning no motion.
  • the retina shows some measured motion (as is seen by the whiter shade of grey). This means that, relative to the RPE, the retina on the left side moved up approximately 2.5 radians. This can be converted to physical units by multiplying the phase by ⁇ /(4 ⁇ ⁇ ).
  • the tissue to the right of 406 shows, motion in the downward direction is measured (as is seen by the darker shade of grey).
  • a volume of data is acquired (e.g., a number clusters of B- scans at different spatial locations along a slow axis) using an OCT angiography technique
  • FIG. 4c This en face view is generated by averaging the phase change, A(pi,i+i(z, x)-A(pi,i+i below (x), along the z axis between the segmentation lines (304) shown in FIG. 3a. Other types of projections along the z axis are also possible.
  • the outline of the cyst is shown (410), and an increase in motion within the cyst boundary can be seen (412).
  • the distortion of the retina due to a pocket of fluid is influenced by two main factors.
  • the first factor is the pulsatile flow of blood.
  • the retina Naturally expands and contracts, especially near large blood vessels (Spahr, Hendrik, et al. (2015) "Imaging pulse wave propagation in human retinal vessels using full-field swept-source optical coherence tomography.” Optics letters 40(20): 4771-4774).
  • This motion though, is relatively sparse in time.
  • a second type of motion which can lead to distortions of the retina in the presence of fluid pockets is ocular tremors. These tremors occur continuously, at high frequency, and at low amplitudes.
  • the processing unit 121 that has been discussed herein in reference to FIG. 1 can be implemented with a computer system configured to perform the functions that have been described herein for this unit.
  • the processing unit 121 can be implemented with the computer system 500, as shown in FIG. 5.
  • the computer system 500 may include one or more processors 502, one or more memories 504, a communication unit 508, an optional display 510, one or more input devices 512, and a data store 514.
  • the display 510 is shown with dotted lines to indicate it is an optional component, which, in some instances, may not be a part of the computer system 500.
  • the display 510 discussed herein is the display 122 that has been discussed herein in reference to FIG. 1.
  • the components 502, 504, 508, 510, 512, and 514 are communicatively coupled via a communication or system bus 516.
  • the bus 516 can include a conventional communication bus for transferring data between components of a computing device or between computing devices.
  • the computing system 500 described herein is not limited to these components and may include various operating systems, sensors, video processing components, input/output ports, user interface devices (e.g., keyboards, pointing devices, displays, microphones, sound reproduction systems, and/or touch screens), additional processors, and other physical configurations.
  • the processor(s) 502 may execute various hardware and/or software logic, such as software instructions, by performing various input/output, logical, and/or mathematical operations.
  • the processor(s) 502 may have various computing architectures to process data signals including, for example, a complex instruction set computer (CISC) architecture, a reduced instruction set computer (RISC) architecture, and/or architecture implementing a combination of instruction sets.
  • the processor(s) 502 may be physical and/or virtual, and may include a single core or plurality of processing units and/or cores.
  • the processor(s) 502 may be capable of generating and providing electronic display signals to a display device, such as the display 510, supporting the display of images, capturing and transmitting images, performing complex tasks including various types of feature extraction and sampling, etc.
  • the processor(s) 502 may be coupled to the memory(ies) 504 via a data/communication bus to access data and instructions therefrom and store data therein.
  • the bus 516 may couple the processor(s) 502 to the other components of the computer system 500, for example, the memory(ies) 504, the communication unit 508, or the data store 514.
  • the memory(ies) 504 may store instructions and/or data that may be executed by the processor(s) 502.
  • the memory(ies) 504 stores a retinal distortion detection module 505 which may include software, code, logic, or routines for performing any and/or all of the techniques described herein.
  • the retinal distortion detection module 505 may perform all or some of the operations depicted in FIG. 2.
  • the memory(ies) 504 may also be capable of storing other instructions and data including, for example, an operating system, hardware drivers, other software applications, databases, etc.
  • the memory(ies) 504 are coupled to the bus 516 for communication with the processor(s) 502 and other components of the computer system 500.
  • the memory(ies) 504 may include a non-transitory computer-usable (e.g., readable, writeable, etc.) medium, which can be any apparatus or device that can contain, store, communicate, propagate or transport instructions, data, computer programs, software, code, routines, etc. for processing by or in connection with the processor(s) 502.
  • Anon-transitory computer-usable storage medium may include any and/or all computer-usable storage media.
  • the non-transitory computer-usable (e.g., readable, writeable, etc.) medium can be any apparatus or device that can contain, store, communicate, propagate or transport instructions, data, computer programs, software, code, routines, etc. for processing by or in connection with the processor(s) 502.
  • Anon-transitory computer-usable storage medium may include any and/or all computer-usable storage media.
  • the instructions e.g., readable, writeable, etc.
  • memory(ies) 504 may include volatile memory, non- volatile memory, or both.
  • the memory(ies) 504 may include a dynamic random access memory (DRAM) device, a static random access memory (SRAM) device, flash memory, a hard disk drive, a floppy disk drive, a CD ROM device, a DVD ROM device, a DVD RAM device, a DVD RW device, a flash memory device, or any other mass storage device known for storing instructions on a more permanent basis.
  • DRAM dynamic random access memory
  • SRAM static random access memory
  • the computer system for the processing unit 121 may include one or more computers or processing units at the same or different locations. When at different locations, the computers may be configured to communicate with one another through a wired and/or wireless network communication system, such as the communication unit 508.
  • the communication unit 508 may include network interface devices (I/F) for wired and wireless connectivity.
  • the communication unit 508 may include a CAT-type interface, USB interface, or SD interface, transceivers for sending and receiving signals using Wi-FiTM; Bluetooth® , or cellular communications for wireless communication, etc.
  • the communication unit 508 can link the processor(s) 502 to a computer network that may in turn be coupled to other processing systems.
  • the display 510 represents any device equipped to display electronic images and data as described herein.
  • the display 510 may be any of a conventional display device, monitor or screen, such as an organic light-emitting diode (OLED) display, a liquid crystal display (LCD).
  • OLED organic light-emitting diode
  • LCD liquid crystal display
  • the display 510 is a touch-screen display capable of receiving input from one or more fingers of a user.
  • the device 510 may be a capacitive touch-screen display capable of detecting and interpreting multiple points of contact with the display surface.
  • the input device(s) 512 are any devices for inputting data on the computer system 500.
  • an input device is a touch-screen display capable of receiving input from one or more fingers of the user.
  • the functionality of the input device(s) 512 and the display 510 may be integrated, and a user of the computer system 500 may interact with the system by contacting a surface of the display 510 using one or more fingers.
  • an input device is a separate peripheral device or combination of devices.
  • the input device(s) 512 may include a keyboard (e.g., a QWERTY keyboard) and a pointing device (e.g., a mouse or touchpad).
  • the input device(s) 512 may also include a microphone, a web camera, or other similar audio or video capture devices.
  • the data store 514 can be an information source capable of storing and providing access to data.
  • the data store 514 is coupled for communication with the components 502, 504, 508, 510, and 512 of the computer system 500 via the bus 516, and coupled, via the processor(s) 502, for communication with the data correction module 505 and the artifacts removal module 506.
  • the data correction module 505 and the artifacts removal module 506 are configured to manipulate, i.e., store, query, update, and/or delete, data stored in the data store 514 using programmatic operations.
  • a computer-usable or computer-readable medium can be any apparatus that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device.

Landscapes

  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Biomedical Technology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Radiology & Medical Imaging (AREA)
  • Biophysics (AREA)
  • Ophthalmology & Optometry (AREA)
  • Engineering & Computer Science (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Physics & Mathematics (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • General Health & Medical Sciences (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Investigating Or Analysing Materials By Optical Means (AREA)

Abstract

La présente invention décrit un procédé d'analyse des données de tomographie de cohérence optique (OCT) d'un œil contenant au moins une poche de liquide comprenant le recueil de deux balayages OCT à approximativement les mêmes emplacements transversaux sur l'œil. Les emplacements comprennent une poche de liquide à une profondeur dans l'œil. Des parties de tissu situées au-dessus et en-dessous de la poche de liquide sont identifiées dans les deux balayages OCT. La phase des données OCT est calculée dans les parties de tissu situées au-dessus et au-dessous de la poche de liquide dans chacun des balayages OCT. La différence de phase des données OCT dans les parties de tissu situées au-dessus et au-dessous de la poche de liquide pour chaque balayage OCT est calculée. Le changement de phase des différences de phase est calculé entre les deux balayages OCT. Le changement de phase calculé est affiché ou stocké ou une analyse supplémentaire de ce dernier est effectuée.
PCT/EP2017/055792 2016-03-14 2017-03-13 Systèmes et procédés de mesure des distorsions tissulaires autour de poches de liquide WO2017157828A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US201662307720P 2016-03-14 2016-03-14
US62/307,720 2016-03-14

Publications (1)

Publication Number Publication Date
WO2017157828A1 true WO2017157828A1 (fr) 2017-09-21

Family

ID=58266658

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2017/055792 WO2017157828A1 (fr) 2016-03-14 2017-03-13 Systèmes et procédés de mesure des distorsions tissulaires autour de poches de liquide

Country Status (1)

Country Link
WO (1) WO2017157828A1 (fr)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070216909A1 (en) * 2006-03-16 2007-09-20 Everett Matthew J Methods for mapping tissue with optical coherence tomography data
US20150148654A1 (en) * 2012-06-29 2015-05-28 The General Hospital Corporation System, method and computer-accessible medium for providing and/or utilizing optical coherence tomographic vibrography

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070216909A1 (en) * 2006-03-16 2007-09-20 Everett Matthew J Methods for mapping tissue with optical coherence tomography data
US20150148654A1 (en) * 2012-06-29 2015-05-28 The General Hospital Corporation System, method and computer-accessible medium for providing and/or utilizing optical coherence tomographic vibrography

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
HENDRIK SPAHR ET AL: "Imaging pulse wave propagation in human retinal vessels using full-field swept-source optical coherence tomography", OPTICS LETTERS, vol. 40, no. 20, 14 October 2015 (2015-10-14), pages 4771, XP055376997, ISSN: 0146-9592, DOI: 10.1364/OL.40.004771 *

Similar Documents

Publication Publication Date Title
EP3102090B1 (fr) Système de tomographie par cohérence optique (oct) avec enregistrement de balayage en mode b sensible à la phase
US9759544B2 (en) Methods of reducing motion artifacts for optical coherence tomography angiography
US10238284B2 (en) Acquisition and analysis techniques for improved outcomes in optical coherence tomography angiography
US10264963B2 (en) Methods for high sensitivity flow visualization
EP2852317B1 (fr) Analyse et visualisation de données d'angiographie par oct
JP6320937B2 (ja) フルレンジ・フーリエ領域光干渉断層撮影用セグメント化および高性能可視化技術
US9107609B2 (en) Inter-frame complex OCT data analysis techniques
EP3102091B1 (fr) Système de tomographie en cohérence optique (oct) ayant un contraste de mouvement amélioré
US10856735B2 (en) Optical coherence tomography (OCT) system with improved image quality
US20160317026A1 (en) Optical coherence tomography system for health characterization of an eye
US20150230708A1 (en) Methods and systems for determining volumetric properties of a tissue
US20160317020A1 (en) Phase gradient optical coherence tomography angiography
US10441164B1 (en) Correction of decorrelation tail artifacts in a whole OCT-A volume
WO2017157828A1 (fr) Systèmes et procédés de mesure des distorsions tissulaires autour de poches de liquide
JP7466727B2 (ja) 眼科装置
Pratinya et al. OCT in Glaucoma
Zhang et al. Principles of optical coherence tomography

Legal Events

Date Code Title Description
NENP Non-entry into the national phase

Ref country code: DE

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17710263

Country of ref document: EP

Kind code of ref document: A1

122 Ep: pct application non-entry in european phase

Ref document number: 17710263

Country of ref document: EP

Kind code of ref document: A1