Binocular Optical Coherence Tomography Imaging System

Abstract

A binocular OCT imaging system for simultaneously imaging areas of a first eye (110) and a second eye (120) using an interferometer having a reference arm (170), a first sampling arm (150), and a second sampling arm (160) by: obtaining an electrical signal (S) having a first frequency component and a second frequency component, the first frequency component spanning a first frequency band and caused by interference between reference light in the reference arm and light in the first sampling arm reflected from the first eye, and the second frequency component spanning a second frequency band and caused by interference between the reference light and light in the second sampling arm reflected from the second eye; and generating an OCT image of the area of the first eye using the first frequency component in a portion of the first frequency band that does not overlap with the second frequency band; and generating an OCT image of the area of the second eye using the second frequency component in a portion of the second frequency band that does not overlap with the first frequency band.

Description

Technical Field

[0001] Example aspects herein relate generally to the field of ophthalmic optical coherence tomography (OCT) imaging systems, and more particularly, to binocular OCT imaging systems for imaging both eyes of a subject. background

[0002] Optical coherence tomography (OCT) provides a powerful tool for examining and assessing eye health. In a swept-source OCT (SS-OCT) imaging system, a tunable light source with a narrow linewidth rapidly sweeps the optical frequency of its light across a wide spectral bandwidth, and the interference signal is detected by the SS-OCT imaging system's photodetector based on frequency.

[0003] Figure 1 Figure 1 is a schematic diagram of a conventional ophthalmic SS-OCT imaging system with an interferometer, which includes a swept light source 10, a beam splitter 20, a reference mirror 30, a scanning element 40, and a photodetector 50. The light beam generated by the swept light source 10 is split into two beams by the beam splitter 20, with the first beam directed along the interferometer's reference arm to the reference mirror 30, and the second beam directed along the interferometer's sampling arm toward the subject's eye 70. The scanning element 40 is controlled to direct the light beam 80 in the sampling arm to a target scanning area 90 of the eye 70 and to direct backscattered light from the eye 70 back to the interferometer. The backreflected light traveling along the reference arm and the backscattered light traveling along the sampling arm are then combined at the photodetector 50 to generate an interference light signal. Specifically, interference is observed only when the optical path lengths differ by less than the coherence length of the light source, a quantity inversely proportional to its optical bandwidth. For each scanning position in the target scanning area 90, the wavelength of light generated by the swept light source 10 (which is usually provided in the form of a tunable laser or other light source with a narrow line width) is quickly swept within the wavelength range, and the generated interference light signal is detected by the photodetector 50 during the sweep. As the detector 50, a balanced photodiode can be used to increase the signal-to-noise ratio of the detection. Figure 2A As schematically shown, the output of the photodetector 50 (i.e., the interference pattern) is sampled by a sample acquisition module (not shown), and then the inverse Fourier transform of the sampled electrical signal is calculated to obtain A-scan data, which provides information about the structure of the target scanning area 90 of the retina of the eye in the depth direction of the area 90. Therefore, for each scanning position in the target scanning area 90, a single wavelength sweep can be used to acquire an A-scan.

[0004] Figure 2A Shown by Figure 1Interference pattern generated by the photodetector 50 of the ophthalmic SS-OCT imaging system. The horizontal axis of the interference pattern represents time (and also represents the wave number of the light from the light source 10), while the vertical axis represents the power of the interference light signal detected by the photodetector 50. For an interference pattern with a single frequency signal (corresponding to interference caused by, for example, a single retinal layer), the frequency of the interference pattern is proportional to the product of the wavelength sweep rate of the swept light source 10 and the optical path difference between the reference arm and the sampling arm. Figure 2B The intensity of the detected interference light is schematically shown as a function of the depth along the target scanning area 90. Figure 2A The interferogram samples are obtained by performing an inverse Fourier transform.

[0005] Figure 2A An example interference pattern in Figure 2B The exemplary depth profile in FIG is obtained from reflections from a single layer within the target scanning area 90 of the eye 70. More generally, light scattered from multiple layers at different corresponding depths within the eye 70 will interfere with the light in the reference arm, and the resulting interference pattern will therefore include multiple frequency components, each corresponding to scattered light from a corresponding layer. In this case, the corresponding depth profile obtained from the interference pattern can contain multiple peaks, one for each layer that contributes backscattered light to the interference light signal.

[0006] Overview

[0007] Most current OCT imaging systems capture OCT images of one eye at a time. After imaging that eye, patients must typically align their other eye with the OCT system for imaging, slowing the overall imaging acquisition process. Furthermore, existing binocular OCT imaging systems capable of simultaneously capturing OCT images of both eyes require duplicate imaging hardware for each eye, resulting in high imaging system costs.

[0008] In view of the above problems, the present inventors have recognized that the long coherence length of a swept-source light source used in a swept-source OCT imaging system can be used to design a binocular OCT imaging system that is capable of imaging both eyes in a single OCT capture using fewer components than conventional binocular OCT imaging systems of the type described above and, in particular, using a single photodetector and a single reference arm.

[0009] More specifically, according to a first exemplary aspect of the present disclosure, the inventors have designed a binocular optical coherence tomography (OCT) imaging system for simultaneously imaging a region of a first eye and a region of a second eye of a subject. The binocular OCT imaging system includes a swept light source configured to generate light of a wavelength that varies over time. The binocular OCT imaging system also includes an interferometer having a reference arm and a first sampling arm including a first scanning module, the first scanning module configured to scan a first light beam across the region of the first eye and receive first reflected light reflected from the region of the first eye as a result of the first light beam being scanned across the region of the first eye by the first scanning module. The interferometer also includes a second sampling arm including a second scanning module configured to scan a second light beam across the region of the second eye simultaneously with the first scanning module scanning the first light beam across the region of the first eye. The second scanning module is further configured to receive second reflected light reflected from the region of the second eye as a result of the second light beam being scanned across the region of the second eye by the second scanning module. The binocular OCT imaging system further includes a photodetector configured to receive the first reflected light, the second reflected light, and reference light (the reference light being light from a swept-frequency light source propagating along a reference arm) and generate an electrical signal having frequency components, the frequency components including a first frequency component caused by interference between the first reflected light and the reference light and a second frequency component caused by interference between the second reflected light and the reference light, the first frequency component spanning a first frequency band and the second frequency component spanning a second frequency band. A difference between an optical path length of the first sampling arm and an optical path length of the second sampling arm is such that at least a portion of the first frequency band does not overlap with the second frequency band, and at least a portion of the second frequency band does not overlap with the first frequency band. The binocular OCT imaging system further includes: a filter module configured to filter the electrical signal by passing at least some first frequency components in a portion of the first frequency band that does not overlap with the second frequency band, and passing at least some second frequency components in a portion of the second frequency band that does not overlap with the first frequency band; and an OCT image data generation module configured to generate first OCT image data representing an image of an area of the first eye based on at least some of the first frequency components that pass through the filter module, and to generate second OCT image data representing an image of an area of the second eye based on at least some of the second frequency components that pass through the filter module. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Example embodiments will now be explained in detail, by way of non-limiting example only, with reference to the accompanying drawings described below. Like reference numerals appearing in different figures of the drawings may indicate identical or functionally similar elements, unless otherwise indicated.

[0011] Figure 1 Schematic diagram of a traditional swept-source OCT imaging system.

[0012] Figure 2A is Figure 1 Schematic illustration of the interferogram generated by the photodetectors of an ophthalmic swept-source OCT imaging system.

[0013] Figure 2B is based on Figure 2A Schematic diagram of the depth distribution of the eye determined by the interferogram.

[0014] Figure 3 is a schematic diagram of a binocular OCT imaging system according to a first exemplary embodiment of this document.

[0015] Figure 4 Shown by Figure 3 The photodetectors of the binocular OCT imaging system generate a first frequency component and a second frequency component of an electrical signal.

[0016] Figure 5 Shown Figure 3 Example hardware implementation of the OCT image data generation module of the binocular OCT imaging system.

[0017] Figure 6 is a schematic diagram of a binocular OCT imaging system according to a second exemplary embodiment of this disclosure.

[0018] Figure 7 is a schematic diagram of a binocular OCT imaging system according to a third exemplary embodiment of this disclosure.

[0019] Figure 8 FIG. 4 is a schematic diagram showing a binocular OCT imaging system according to a fourth exemplary embodiment of the present invention.

[0020] Figure 9 It shows the use of Figure 3 、 Figure 6 、 Figure 7 and Figure 8 Flowchart of a process for a binocular OCT imaging system of any one of the example embodiments shown in FIG. 1 to acquire an image of a first region of a first eye and an image of a second region of a second eye.

[0021] Figure 10 A mapping of A-scan data to an A-scan of a region of a first eye and an A-scan of a region of a second eye is shown according to an example embodiment.

[0022] Detailed Description of Example Embodiments

[0023] Figure 31 is a schematic diagram of a binocular OCT imaging system 100 for simultaneously imaging a region 115 of a first eye 110 and a region 125 of a second eye 120 of a subject, according to a first exemplary embodiment herein. As in this exemplary embodiment, the region 115 of the first eye 110 may be in the posterior segment 111 of the first eye 110, but may alternatively be in the anterior segment 112 of the first eye 110. Furthermore, in this exemplary embodiment, the region 125 of the second eye 120 is in the posterior segment 121 of the second eye 120, but may alternatively be in the anterior segment 122 of the second eye 120.

[0024] exist Figure 3 In the example embodiment, the binocular OCT imaging system 100 includes a swept light source 130 configured to generate light having a wavelength that varies over time. As in the present example embodiment, the swept light source 130 can be configured to output substantially monochromatic light, where the wavelength of the monochromatic light is swept over a range of wavelength values. The swept light source 130 can thus be configured to output light whose wavelength / wavenumber varies over time. For example, denoting the wavenumber of light output by the swept light source 130 at time t as k(t), the wavenumber k(t) can be linearly swept and can be written as k(t) = k0 + δk×t, where k0 is the starting wavenumber at the start of the sweep, and δk = Δk / Δt is the rate at which the wavenumber of the output light is swept, where Δk is the range of the wavenumber variation during the sweep, and Δt is the duration of the sweep. The linewidth of the swept light source 130 (i.e., the width of the spectrum of light generated by the swept light source 130, such as the full width at half-maximum (FWHM)) determines the coherence length of the light and, therefore, the imaging depth of the swept source OCT imaging system 100, while the wavelength / wavenumber sweep range determines the axial resolution.

[0025] Figure 3 The binocular OCT imaging system 100 in FIG. 1 further includes an interferometer 140 having a first sampling arm 150, a second sampling arm 160, and a reference arm 170 having a reference mirror 172. As in the present example embodiment, the interferometer 140 may be a fiber optic interferometer in which a span of optical fiber guides light along the reference arm 170, the first sampling arm 150, and the second sampling arm 160 of the interferometer 140. However, the interferometer 140 may alternatively be provided in the form of a free-space interferometer in which light propagates through air between optical elements.

[0026] exist Figure 3, the first sampling arm 150 includes a first scanning module 152 configured to scan a first light beam 210 across the region 115 of the first eye 110 and receive first reflected light 215 that is reflected from the region 115 of the first eye 110 as a result of the first light beam 210 being scanned across the region 115 of the first eye 110 by the first scanning module 152. Furthermore, the second arm 160 includes a second scanning module 162 configured to scan a second light beam 220 across the region 125 of the second eye 120 simultaneously with the first scanning module 152 scanning the first light beam 210 across the region 115 of the first eye 110. The second scanning module 162 is further configured to receive second reflected light 225 that is reflected from the region 125 of the second eye 120 as a result of the second light beam 220 being scanned across the region 125 of the second eye 120 by the second scanning module 162.

[0027] like Figure 3 As shown in FIG, during imaging of region 115 of first eye 110 using binocular OCT imaging system 100, region 115 of first eye 110 may, as in this example, extend along the propagation direction of first light beam 210 incident on first eye 110. Furthermore, during imaging of region 125 of second eye 120 using binocular OCT imaging system 100, region 125 of second eye 120 may, as in this example embodiment, extend along the propagation direction of second light beam 220 incident on second eye 120. Furthermore, as in this example embodiment, region 115 of first eye 110 and region 125 of second eye 120 may, for example, substantially correspond to the same portion of each respective eye (such as the retina). Furthermore, as in this example embodiment, region 115 of first eye 110 may have substantially the same thickness from the retinal surface of first eye 110 as region 125 of second eye 120 may have substantially the same thickness from the retinal surface of second eye 120. However, it should be noted that region 115 and region 125 need not correspond to the same region of the eye and need not have the same thickness.

[0028] As in the present exemplary embodiment, each of the first scanning module 152 and the second scanning module 162 may include a dual-mirror scanner device and a focusing element (not shown). The dual-mirror scanner device includes an H-type galvanometer mirror and a V-type galvanometer mirror, which are arranged in an optical device for scanning a light beam into the eye 110 or 120 in the horizontal and vertical directions via the focusing element. However, it should be noted that one or both of the first scanning module 152 and the second scanning module 162 may take different forms known to those skilled in the art and may, for example, employ a scanning mechanism such as one or more microelectromechanical systems (MEMS) scanners. The focusing element is configured to focus light received from the H-type galvanometer mirror and the V-type galvanometer mirror to a target scanning location in the eye. However, it should be noted that the first scanning module 152 and the second scanning module 162 are not limited to this, as each of these modules may alternatively include a single scanning mirror rotatable about two (e.g., orthogonal) axes. In addition, as in the present example embodiment, the binocular OCT imaging system 100 may further include a focus adjustment module (not shown) configured to adjust the respective focuses of the respective focusing elements of the first scanning module 152 and the second scanning module 162 .

[0029] In this exemplary embodiment, the two galvanometer mirrors in each of the first scanning module 152 and the second scanning module 162 can be rotated by corresponding actuation mechanisms such as motors to change the optical paths of the first light beam 210 and the second light beam 220, and thus change the scanning positions within the first eye 110 and the second eye 120 during imaging. Furthermore, as in this exemplary embodiment, the scanning angles of the light beams scanned into each eye can depend on the tilt angles (θ, φ) of the H-type galvanometer mirror and the V-type galvanometer mirror, where the angle θ is the tilt angle of the H-type galvanometer mirror and the angle φ is the tilt angle of the V-type galvanometer mirror. The tilt angles θ and φ represent the degrees of rotation of the H-type galvanometer mirror and the V-type galvanometer mirror, respectively, about their respective rotation axes.

[0030] exist Figure 3In the example, binocular OCT imaging system 100 further includes a photodetector 180 configured to receive first reflected light 215, second reflected light 225, and reference light 235. Reference light 235 is light from swept light source 130 that propagates along reference arm 170 (after being reflected by reference mirror 172 in this exemplary configuration). Photodetector 180 is further configured to generate an electrical signal S comprising frequency components, including a first frequency component caused by interference between first reflected light 215 and reference light 235, and a second frequency component caused by interference between second reflected light 225 and reference light 235. The first frequency component spans a first frequency band, while the second frequency component spans a second frequency band. Furthermore, the difference between the optical path length of first sampling arm 150 and the optical path length of second sampling arm 160 is such that at least a portion of the first frequency band does not overlap with the second frequency band, and at least a portion of the second frequency band does not overlap with the first frequency band.

[0031] As in the present example embodiment, the photodetector 180 may take the form of a balanced avalanche photodiode detector, but may alternatively take the form of any standard point detector. As in the present example embodiment, the photodetector 180 may generate an electrical signal S based on the intensity of the interfering light signal 270 detected by the photodetector 180. For example, if the region 115 of the first eye 110 has N retinal layers and the region 125 of the second eye 120 has M retinal layers, then for wave number k, the photodetector current I of the photodetector 180 is D (k) can be expressed by the following formula:

[0032]

[0033] Wherein, S(k) is the optical power spectral density of the swept light source (130), which is defined as a function of the wave number k of the light output by the swept light source, R n is the reflectivity of the nth retinal layer of the first eye, R m is the reflectivity of the mth retinal layer of the second eye 120, R R is the reflectivity of the reference arm 170, z n is a value representing the optical path length difference between the reference arm 170 and the nth retinal layer of the first eye 110, and z m is a value representing the difference in optical path length between the reference arm 170 and the m-th retinal layer of the second eye 120. Equation (1) therefore represents the detected intensity caused by the interference between the reflected light from the first eye 110, the reflected light from the second eye 120, and the reflected light 235 in the reference arm 170. Due to the typically low reflectivity of the eye, the interference between the reflected light from the two eyes may be small in magnitude compared to the interference caused by the reference light in the reference arm 170.

[0034] exist Figure 3 In the example embodiment, the binocular OCT imaging system 100 further includes a filter module 190 configured to filter the electrical signal S by passing at least some first frequency components in a portion of the first frequency band that does not overlap with the second frequency band, and passing at least some second frequency components in a portion of the second frequency band that does not overlap with the first frequency band. As in the present example embodiment, the filter module 190 may include a bandpass filter 190-1. Furthermore, as in the present example embodiment, the filter module 190 may further include a sample acquisition module 190-2 configured to acquire a set of samples i(m) of the filtered electrical signal, and more specifically, acquire a set of samples of at least some first frequency components and at least some second frequency components. By appropriately setting the optical path difference between the first sampling arm 150 and the second sampling arm 160, the frequency components of the electrical signal S caused by light reflected from the retinal layer at the same depth within each respective eye are spaced apart along the frequency axis. Accordingly, providing a sufficient optical path difference between the first sampling arm 150 and the second sampling arm 160 may allow for simultaneous extraction of reflectance information of layers at the same depth within each eye.

[0035] exist Figure 3 In the example embodiment, the binocular OCT imaging system 100 further includes an OCT image data generation module 195 configured to generate first OCT image data representing an image of a region 115 of the first eye 110 based on at least some of the first frequency components that passed through the filter module 190. The OCT image data generation module 195 is further configured to generate second OCT image data representing an image of a region 125 of the second eye 120 based on at least some of the second frequency components that passed through the filter module 190. As in the present example embodiment, the first OCT image data may include a first A-scan of the region 115 of the first eye 110, and the second OCT image data may include a second A-scan of the region 125 of the second eye 120. Furthermore, as in the present example embodiment, the OCT data generation module 195 may be configured to generate the first A-scan and the second A-scan by performing an inverse Fourier transform on samples of the filtered electrical signal.

[0036] As in the present example embodiment, the binocular OCT imaging system 100 may further include a visual display unit 197 configured to display an image of a region 115 of the first eye 110 represented by the first OCT image data, and / or an image of a region of the second eye 120 represented by the second OCT image data.

[0037] refer to Figure 4, a schematic diagram 310 shows how the electrical signal S generated by the photodetector 180 based on the interference light 270 during the wavelength sweep performed by the swept light source 130 varies with the wavelength of the swept light source 130 . Figure 4 Graph 320 in FIG. 3 shows the frequency components of the electrical signal S and is obtained by performing an inverse Fourier transform on samples of the filtered electrical signal. As shown in graph 320 , a first frequency component 322 of the electrical signal S (caused by interference of light reflected from region 115 of the first eye 110) spans a first frequency band 324, while a second frequency component 326 of the electrical signal S (caused by interference of light reflected from region 125 of the second eye 120) spans a second frequency band 328. Figure 4 Also shown are a first scanning element 152 shown in association with the first eye 110 and a second scanning element 162 shown in association with the second eye 120 .

[0038] exist Figure 4 In the example of FIG, the difference between the optical path length of the first sampling arm 150 and the optical path length of the second sampling arm 160 is such that the first frequency band 324 does not overlap with the second frequency band 328. By ensuring that the first frequency band 324 and the second frequency band 328 do not overlap, it is possible to extract the first frequency component 322 and the second frequency component 326, thereby allowing the entire reflectivity depth profile of each of the two regions 115 and 125 to be obtained.

[0039] Reference again Figure 3 In this example embodiment, the first sampling arm 150 has a larger optical path length than the second sampling arm 160. Figure 3 In the binocular OCT imaging system 100 , the first frequency band 324 and the second frequency band 328 do not overlap. As in the present example embodiment, a difference between the optical path length of the first sampling arm 150 and the optical path length of the second sampling arm 160 may be equal to or greater than a length of the region 125 of the second eye 120 , wherein the length of the region 125 of the second eye 120 is along a propagation direction of the second light beam 220 incident on the second eye 120 during imaging of the region 125 of the second eye 120 using the binocular OCT imaging system 100 .

[0040] Furthermore, to ensure that the region 115 of the first eye 110 and the region 125 of the second eye 120 can be imaged in their entirety by the binocular OCT imaging system 100, as in the present exemplary embodiment, the coherence length of the swept light source 130 can be greater than the sum of the lengths of the region 115 of the first eye 110 and the lengths of the region 125 of the second eye 120. During imaging of the region 115 of the first eye 110 using the binocular OCT imaging system 100, the length of the region 115 is along the propagation direction of the first light beam 210 incident on the first eye 110. Furthermore, during imaging of the region 125 of the second eye 120 using the binocular OCT imaging system 100, the length of the region 125 of the second eye 120 is along the propagation direction of the second light beam 220 incident on the second eye 120. Furthermore, as in the present exemplary embodiment, the coherence length of the swept light source 130 can be greater than the difference between the optical path lengths of the first sampling arm 150 and the optical path lengths of the second sampling arm 160.

[0041] Despite Figure 3 In the example of FIG, the optical path length difference between the first sampling arm 150 and the second sampling arm 160 is set so that the first frequency band 324 and the second frequency band 328 do not overlap, but it should be noted that in alternative example embodiments, the optical path length difference between the first sampling arm 150 and the second sampling arm 160 may be such that there is a certain degree of overlap between the first frequency band 324 and the second frequency band 328. However, as long as at least a portion of the first frequency band 324 does not overlap with the second frequency band 328, and as long as at least a portion of the second frequency band 328 does not overlap with the first frequency band 324, reflectivity information of at least a portion of the region 115 of the first eye 110 and at least a portion of the region 125 of the second eye 120 can be obtained.

[0042] Figure 5 An example implementation of the signal processing apparatus 500 of the example embodiment of the present invention is shown in the form of programmable signal processing hardware. In one example embodiment of the present invention, the signal processing apparatus 500 may be formed Figure 3 (and / or Figure 6-8) of the OCT image data generation module 195 of the device. The signal processing device 500 includes an interface module 510 for receiving samples of the filtered electrical signal provided by the filter module 190 and for providing first OCT image data and second OCT image data to the visual display unit 197. The signal processing device 500 also includes a processor (CPU) 520, a working memory 530 (e.g., a random access memory), and an instruction storage device 540 storing a computer program 545 including computer-readable instructions that, when executed by the processor 520, cause the processor 520 to perform the processing operations of the device OCT image data generation module 195. The instruction storage device 540 may include a ROM (e.g., in the form of an electrically erasable programmable read-only memory (EEPROM) or flash memory) preloaded with computer-readable instructions. Alternatively, the instruction storage device 540 may include a RAM or similar type of memory, and the computer-readable instructions may be input to the instruction storage device 540 from a computer program product (e.g., a computer-readable storage medium 550 (e.g., a CD-ROM, etc.) or a computer-readable signal 560 carrying computer-readable instructions). In this example embodiment, the system including the processor 520, the working memory 530, and the instruction storage device 540 Figure 5 The combination of hardware components 570 shown in FIG. 5 is configured to perform the functions of the OCT image data generation module 195 .

[0043] Return to Figure 3 In the binocular OCT imaging system 100, as in this example embodiment, the reference arm 170 may further include a first optical coupler 174 configured to split the light generated by the swept light source 130 into a first light 230 and a second light 240, and to direct the first light 230 to the reference mirror 172. The first sampling arm 150 also includes a second optical coupler 176 configured to split the second light 240 into a third light 250 and a fourth light 260. The first scanning module 152 is configured to scan the beam of the third light 250 across the region 115 of the first eye 110 and to direct the first reflected light 215 to the second optical coupler 176. Furthermore, the second sampling arm 160 also includes a second optical coupler 176, and the second scanning module 162 is configured to scan the beam of the fourth light 260 across the region 125 of the second eye 120 and to direct the second reflected light 225 to the second optical coupler 176. In addition, the second optical coupler 176 is configured to combine the first reflected light 215 and the second reflected light 225 to generate a combined reflected light 265. The electrical signal S generated by the photodetector 180 represents the interference between the combined reflected light 265 and the reference light (third reflected light) 235.

[0044] As in the present exemplary embodiment, the first optical coupler 174 can use an uneven split ratio to split the light generated by the swept light source 130, such that the second light 240 (which is split into the third light 250 and the fourth light 260) has a higher optical power than the first light 230 directed to the reference mirror 172. For example, the first optical coupler 174 can use a 75:25 split ratio, where 75% of the power of the light generated by the swept light source 130 is output as the first light 230, and 25% of the power of the light generated by the swept light source 130 is directed to the reference mirror 172. However, the first optical coupler 174 can be configured to use another split ratio to split the generated light. In the present exemplary embodiment, the second optical coupler 176 is a 1×2 optical coupler and has a 50:50 split ratio to deliver equal power to the first eye 110 and the second eye 120. However, the second optical coupler 176 is not limited in this respect and can use different split ratios.

[0045] Figure 3 The reference arm 170 of the binocular OCT imaging system 100 includes a single reference mirror 172. In this example embodiment, the first optical coupler 174 is further configured to receive third reflected light 235 caused by reflection of the first light 230 by the reference mirror 172, and to generate interference light 270 by combining the third reflected light 235 with the combined reflected light 265. The photodetector 180 is also configured to receive the interference light 270.

[0046] As in this example embodiment, Figure 3 The binocular OCT imaging system 100 may further include a first shutter 154 disposed in the first sampling arm 150 and operable to open and close, and a second shutter 164 disposed in the second sampling arm and operable to open and close. The first shutter 154 is configured to allow the first reflected light 215 to propagate to the photodetector 180 when the first shutter 154 is open, and to prevent the first reflected light 215 from propagating to the photodetector 180 when the first shutter 154 is closed. The photodetector 180 is configured to receive the first reflected light 215 when the first shutter 154 is open and generate an electrical signal S including a first frequency component 322. The second shutter 164 is configured to allow the second reflected light 225 to propagate to the photodetector 180 when the second shutter 164 is open, and to prevent the second reflected light 225 from propagating to the photodetector 180 when the second shutter 164 is closed. The photodetector 180 is configured to receive the second reflected light 225 when the second shutter 164 is open and generate an electrical signal S including a second frequency component 326. Using shutters in one or both sampling arms in the manner described above allows each eye to be imaged individually without unnecessarily exposing the other eye to the imaging beam. This is advantageous when only one eye needs to be imaged.

[0047] like Figure 3 As shown, the binocular OCT imaging system 100 may also optionally include a scan controller 199 configured to control the first scanning module 152 and the second scanning module 162 to perform scans synchronously using a common scanning pattern. By using a common scanning pattern, a common ocular region can be imaged simultaneously in both eyes, thereby allowing for faster image acquisition. However, in other example embodiments, the scan controller 199 may be configured to independently control the first scanning module 152 and the second scanning module 162 to perform respective scans of different respective regions of the first eye 110 and the second eye 120 (using potentially different scanning patterns).

[0048] although Figure 3 The reference arm 170 in the embodiment of includes a single reference mirror 172, but the reference arm 170 is not limited in this respect. As an example, Figure 6 A binocular OCT imaging system 600 according to a second example embodiment is shown. Figure 3 The same as the first example embodiment, but with an alternative implementation of the reference arm. Figure 6 In, instead of Figure 3 The single reference mirror 172 is shown, and the reference arm 470 of the binocular OCT imaging system 600 includes a first reference mirror 472 and a second reference mirror 474. The first reference mirror 472 is configured to reflect the first light 230 from the first optical coupler 174 to the second reference mirror 474. In addition, the binocular OCT imaging system 600 of the second exemplary embodiment further includes a third optical coupler 177, which is configured to generate interference light 270 by combining the combined reflected light 265 with the third reflected light 235 caused by the reflection of the first light by the second reference mirror 474. The photodetector 180 is also configured to receive the interference light 270.

[0049] Figure 7 A binocular OCT imaging system 700 according to a third example embodiment is shown, which includes an interferometer 740. Figure 3 The first example embodiment of the interferometer 140 is a free space implementation. Figure 7 The interferometer 740, as shown above Figure 3 The various lights described propagate in free space rather than through optical fibers. Additionally, the first optical coupler 174 and the second optical coupler 176 are replaced by a first free space beam splitter 774 and a second free space beam splitter 776, respectively. Figure 7 The first free space beam splitter 774 and the second free space beam splitter 776 are configured to perform the same as for Figure 3The first optical coupler 174 and the second optical coupler 176 in the fiber optic interferometer 140 have the same functions as described above. Figure 7 In the interferometer 740 , the first sampling arm 150 further includes a mirror 151 , which is configured to guide the fourth light 250 to the second scanning module 162 , and further guide the second reflected light 225 from the second scanning module 162 to the second free-space beam splitter 776 .

[0050] Figure 8 A binocular OCT imaging system 800 according to a fourth example embodiment is shown. Figure 6 The binocular OCT imaging system 800 is the same as the binocular OCT imaging system 600 of the second exemplary embodiment, except that the binocular OCT imaging system 800 includes an interferometer 840. Figure 6 Free space implementation of fiber interferometer 640. Figure 8 In the interferometer 840, Figure 6 The optical couplers 176, 174, 177 of the interferometer 640 are replaced by corresponding beam splitters 776, 774, 777, which are arranged to perform Figure 6 In addition, the same as the corresponding function of the optocoupler in Figure 7 The free space implementation is the same as Figure 8 The first sampling arm 150 further comprises a mirror 151, which is configured to perform Figure 7 The mirror 151 has the same function as described above.

[0051] Figure 9 Shows the use Figure 3 The binocular OCT imaging system 100 is used to generate first OCT image data representing an image of a region 115 of a first eye 110 and second OCT image data representing an image of a region 125 of a second eye 120. Figure 3 The system 100 is described for illustrative purposes in the context of Figure 9 process, but it should be noted that Figure 9 The process is also applicable to (and is performed in the same manner for) any other example embodiments described herein (e.g. Figure 6-8 those example embodiments).

[0052] exist Figure 9In step S10, the photodetector 180 detects the interference light 270 and generates an electrical signal S, which includes a first frequency component 322 caused by interference between the light in the first sampling arm 150 and the light in the reference arm 170, and a second frequency component 326 caused by interference between the light in the second sampling arm 160 and the light in the reference arm 170. The difference between the optical path length of the first sampling arm 150 and the optical path length of the second sampling arm 160 is such that at least a portion of the first frequency band 324 does not overlap with the second frequency band 328, and at least a portion of the second frequency band 328 does not overlap with the first frequency band 324. When the wavelength of the swept light source 130 is swept across its usable optical frequency range, the electrical signal relates the detected intensity of the interference signal 270 to the wavelength.

[0053] exist Figure 9 In step S20, the filter module 190 filters the electrical signal S by passing at least some of the first frequency components 322 in the portion of the first frequency band 324 that does not overlap with the second frequency band 328, and passing at least some of the second frequency components 326 in the portion of the second frequency band 328 that does not overlap with the first frequency band 324. In this example embodiment, the filter module 190 includes a bandpass filter 190-1 and a sample acquisition module 190-2. As in this example embodiment, the bandpass filter 190-1 may be a tunable bandpass filter whose passband is set by a controller (not shown) of the binocular OCT imaging system 100, for example, based on the position of the region 115 of the first eye 110 and the position of the region 125 of the second eye 120.

[0054] Bandpass filter 190-1 can have any suitable implementation (such as, for example, a planar filter, a cavity filter, a surface acoustic wave filter, a passive LC filter, or an active filter). By using a tunable bandpass filter, the passband of bandpass filter 190-1 can be adjusted so that only frequency components caused by the respective regions of interest in first eye 110 and second eye 120 are obtained. Therefore, adjustment of the passband of bandpass filter 190-1 can be combined with adjustment of the focus of the respective focusing elements of first scanning module 152 and second scanning module 162 to change the respective positions of the imaged regions in the respective eyes. However, it should be noted that bandpass filter 190-1 does not need to be a tunable bandpass filter, but can be a non-tunable bandpass filter with a fixed passband. In implementations using non-tunable bandpass filters, the positions of the respective regions in first eye 110 and second eye 120 imaged by binocular OCT imaging system 100 can be adjusted by changing the optical path length in reference arm 170. Changing the optical path length of the reference arm in this manner effectively shifts the frequency components arising from the region of interest (in the axial / depth direction of the eye) along the frequency axis into the passband of the bandpass filter 190-1.

[0055] It should be noted that although the present exemplary embodiment employs a single bandpass filter 190-1 to extract at least some of the first frequency components and at least some of the second frequency components, in other exemplary embodiments, more than one bandpass filter may be employed to perform the extraction. For example, multiple bandpass filters may be employed in a filter bank arrangement, with each individual filter extracting a portion of at least some of the first frequency components and at least some of the second frequency components. Filtering a signal by dividing the target frequency band into sub-bands in this manner is advantageous because, when bandpass sampling is employed, a lower sampling rate may be employed for each sub-band.

[0056] exist Figure 9 In step S30, the filtered electrical signal output by the bandpass filter 190-1 is sampled by the sample acquisition module 190-2 to obtain a set of samples of at least some of the first frequency components 322 that passed through the filter module 190 and at least some of the second frequency components 326 that passed through the filter module 190. As in this example embodiment, the sample acquisition module 190-2 can obtain samples of the filtered electrical signal by bandpass sampling the filtered electrical signal. For example, the frequency band of interest in the electrical signal S may include the first frequency band 324 and the second frequency band 328. Therefore, the sampling rate of the sample acquisition module 190-2 can be selected based on the frequency band of interest using the bandpass sampling theorem.

[0057] More specifically, for a c and bandwidth B for the frequency band of interest, bandpass sampling refers to selecting the sampling rate f according to the following criteria s :

[0058]

[0059] Where n is the value that ensures that for the selected sampling rate f s Satisfy f s > any positive integer of the Shannon-Nyquist criterion of 2B. It should be noted that although equation (2) is expressed using specific variables, it should be noted that the bandpass sampling theorem can also be expressed differently using different variables (such as the upper and lower limits of the frequency band spanned by the bandpass signal) and still express the same theorem.

[0060] Although the present example embodiment employs bandpass sampling to acquire samples of the filtered electrical signal, it should be noted that alternative sampling techniques may be used. For example, in some example embodiments, the filtered electrical signal may be heterodyned to an intermediate frequency before acquiring samples. Heterodyning the high-frequency signal to an intermediate frequency before sampling allows the sampling rate requirement of the sample acquisition module 190-2 to be significantly reduced. Furthermore, in other example embodiments, the sample acquisition module 190-2 may directly acquire samples of the filtered electrical signal according to the Nyquist criterion, i.e., by selecting a sampling rate that is at least twice the maximum frequency in the frequency band of interest.

[0061] The filtered electrical signal over time is expressed as w(t), and the sampling rate of the sample acquisition module 190-2 is expressed as f s =1 / T s , where T s is the sampling interval, the sampling signal I s (t) is given by:

[0062]

[0063] exist Figure 9 In step S40, the OCT image data generation module 195 generates first OCT image data representing an image of the region 115 of the first eye 110 based on at least some of the first frequency components 322 that passed through the filter module 190. The OCT image data generation module 195 also generates second OCT image data representing an image of the region 125 of the second eye 120 based on at least some of the second frequency components 326 that passed through the filter module 195.

[0064] As in the present example embodiment, the first OCT image data may be a first A-scan of the region 115 of the first eye 110. Furthermore, as in the present example embodiment, the second OCT image data may be a second A-scan of the region 125 of the second eye 120. More specifically, as in the present example embodiment, the OCT image data generation module 195 may generate the filtered electrical signal S by first calculating the filtered electrical signal S F Sampling I s (t) is inverse Fourier transform to generate the first A-scan and the second A-scan to generate A-scan data. In particular, for the SS-OCT imaging system, the reflection distribution along the depth direction (axial direction) can be determined by inverse Fourier transform of the detected electrical signal in terms of wave number.

[0065] For example, by representing the samples of the filtered electrical signal as i(m), m = 0, 1, 2 ... M-1, the inverse discrete Fourier transform (IDFT) of the time domain sample sequence gives A-scan data consisting of multiple frequency domain data points, which can be written as:

[0066]

[0067] Where A(l) represents the intensity value of the lth frequency index. In this example, since the output of the IDFT operation is complex-valued, only the amplitude of each A(l) value is used to represent reflectivity information. For computational efficiency, as in this example embodiment, the OCT image data generation module 195 can use a fast Fourier transform algorithm to calculate the IDFT of sample i(m).

[0068] As part of step S40, after obtaining A-scan data, as in the present example embodiment, the OCT image data generation module 195 can generate a first A-scan representing region 115 of the first eye 110 by mapping a first set of data points of the A-scan data to corresponding A-scan elements of the first A-scan, where each A-scan element of the A-scan represents a pixel of the A-scan. The amplitude of each data point mapped to an A-scan element can be understood as representing the intensity of the pixel represented by that A-scan element. Furthermore, the OCT data generation module 195 can generate a second A-scan representing region 125 of the second eye 120 by mapping a second set of data points of the A-scan data to corresponding A-scan elements of the second A-scan. In the present example, the optical path length of the first sampling arm 150 is longer than the optical path length of the second sampling arm 160, and therefore, the higher frequency indices of the A-scan data correspond to region 115 in the first eye 110 and are therefore mapped to A-scan elements of the first A-scan. Similarly, the lower frequency indices of the A-scan data correspond to the area 125 in the second eye 120 and are therefore mapped to A-scan data elements of the second A-scan. More generally, a predetermined mapping between frequency indices and A-scan elements can be used to map data points of the A-scan data to A-scan elements of either the first A-scan (corresponding to the first eye 110) or the second A-scan (corresponding to the second eye 120).

[0069] Figure 10The mapping of a first set of data points 1010 of A-scan data 1000 to A-scan elements of a first A-scan 1050 and a mapping of a second set of data points 1020 of A-scan data 1000 to A-scan elements of a second A-scan 1060 are shown. First A-scan 1050 represents region 115 of first eye 110, while second A-scan 1060 represents region 125 of second eye 120. However, it should be noted that not every frequency index of A-scan data 1000 needs to be mapped to either the first A-scan or the second A-scan. For example, in an example embodiment where there is a frequency gap between a first frequency band and a second frequency band, the frequency index corresponding to the frequency gap represents neither region 115 of first eye 110 nor region 125 of second eye 120. Therefore, the A-scan data points for these frequency indexes are not mapped to either A-scan.

[0070] In this exemplary embodiment, the first scanning module 152 is configured to scan the image by changing its scanning angle. to scan the first light beam 210 across multiple areas of the first eye 110, and the second scanning module 162 is configured to scan the first light beam 210 across multiple areas of the first eye 110 by changing its scanning angle The second light beam is scanned across multiple regions of the second eye 120. In addition, the scan controller 199 of the binocular OCT imaging system 100 is configured to control the first scanning module 152 and the second scanning module 162 to synchronously perform scanning using a common scanning pattern. For example, as in the present example embodiment, the binocular OCT imaging system 100 can synchronously change the respective scanning angles of the first scanning module 152 and the second scanning module 162 during simultaneous imaging of the first eye 110 and the second eye 120.

[0071] As in this example, the OCT image data generation module 195 can also generate a plurality of first A-scans corresponding to a plurality of regions of the first eye 110, and generate a plurality of second A-scans corresponding to a plurality of regions of the second eye 120. More specifically, when the first scanning module 152 and the second scanning module 162 use the scanning angle When the first eye 110 and the second eye 120 are scanned respectively by the values of the OCT image data generation module 195, the OCT image data generation module 195 can generate the image data corresponding to the scanning angle pair based on the obtained value of the electrical signal S generated by the photodetector 180. In addition, for the A-scan data with the scanning angle The OCT image data generation module 195 may also perform a mapping of the first set of data points of the A-scan data to corresponding A-scan elements of the A-scan of the first eye 110. For each A-scan data associated with each value of , the OCT image data generation module 195 may perform a mapping of a second set of data points of the A-scan data to corresponding A-scan elements of the A-scan of the second eye 120 .

[0072] When generating a plurality of first A-scans corresponding to a plurality of scanning positions in the scanning area 115 of the first eye 110 and a plurality of second A-scans corresponding to a plurality of scanning positions in the scanning area 125 of the second eye 120, the OCT data generation module 195 may further arrange the plurality of first A-scans to form a first array of A-scans representing an image of the area 115 of the first eye 110. Furthermore, the OCT data generation module 195 may arrange the plurality of second A-scans to form a second array of A-scans representing an image of the area 125 of the second eye 120. As in the present exemplary embodiment, the first array and the second array may be two-dimensional arrays constituting B-scans, although a three-dimensional array constituting C-scans may similarly be formed.

[0073] While the above example describes the binocular OCT imaging system 100 acquiring multiple A-scans for each eye by scanning the first scanning module 152 and the second scanning module 162 using a common scanning pattern, it should be understood that the scanning controller 199 can alternatively independently control the first scanning module 152 and the second scanning module 162 to perform respective scans (using potentially different scanning patterns) on different respective regions of the first eye 110 and the second eye 120. In an alternative exemplary embodiment, because the two scanning modules use different scanning angles when acquiring the electrical signal (measured for intensity across the entire wavelength range swept by the swept light source 130), the OCT image data generation module 195 can map data points of the respective A-scan data (derived from the electrical signal S) to respective A-scans of the first eye 110 and the second eye 120 based on the respective scanning angles used to acquire the electrical signal S. In other words, after the A-scan data is acquired by performing an inverse Fourier transform on the filtered electrical signal, a first set of data points is mapped to the A-scan of the first eye based on the scanning angle of the first scanning module 152 used to acquire the electrical signal. Furthermore, based on the scanning angle of the second scanning module 162 used to obtain the electrical signal, a second set of data points of the A-scan is mapped to the A-scan of the second eye.

[0074] The example aspects described herein avoid limitations, at least some of which are particularly rooted in computer technology, associated with conventional OCT imaging systems that capture OCT images of one eye at a time and can have a slow overall image acquisition process, as well as conventional OCT imaging systems that can capture OCT images of both eyes simultaneously but require duplicate imaging hardware and high imaging system costs. By utilizing the example aspects described herein, for example, the long coherence length of a swept-source light source used in a swept-source OCT imaging system can be utilized to design a binocular OCT imaging system that can image both eyes in a single OCT capture using fewer components (particularly, using a single photodetector and a single reference arm) than conventional binocular OCT imaging systems of the types described above. By utilizing the capabilities of the example aspects described herein, at least some of which are rooted in computer technology, the example aspects described herein improve computer processing and, in addition to OCT imaging systems, the fields of medical imaging and medical devices.

[0075] In the foregoing description, example aspects have been described with reference to several example embodiments. Therefore, the description should be regarded as illustrative rather than restrictive. Similarly, the figures shown in the accompanying drawings, which highlight the features and advantages of the example embodiments, are presented for illustrative purposes only. The architecture of the example embodiments is sufficiently flexible and configurable that it can be utilized in ways other than those shown in the accompanying drawings.

[0076] In one example embodiment, the example software embodiments presented herein may be provided as a computer program or software (e.g., one or more programs having instructions or sequences of instructions) that is included or stored in a product (such as a machine-accessible or machine-readable medium, instruction storage device, or computer-readable storage device, each of which may be non-transitory). The program or instructions on the non-transitory machine-accessible medium, machine-readable medium, instruction storage device, or computer-readable storage device may be used to program a computer system or other electronic device. Machine- or computer-readable media, instruction storage devices, and storage devices may include, but are not limited to, floppy disks, optical disks, and magneto-optical disks, or other types of media / machine-readable media / instruction storage devices / storage devices suitable for storing or transmitting electronic instructions. The techniques described herein are not limited to any particular software configuration. They may be applicable to any computing or processing environment. As used herein, the terms "computer-readable," "machine-accessible medium," "machine-readable medium," "instruction storage device," and "computer-readable storage device" shall include any medium that is capable of storing, encoding, or transmitting instructions or sequences of instructions for execution by a machine, computer, or computer processor and causing the machine / computer / computer processor to perform any of the methods described herein. Furthermore, it is common in the art to refer to software in one form or another (e.g., program, procedure, process, application, module, unit, logic, etc.) as taking an action or causing a result. Such expressions are merely a shorthand way of stating that execution of the software by a processing system causes the processor to perform an action to produce a result.

[0077] Some embodiments may also be implemented by the preparation of application specific integrated circuits, field programmable gate arrays or by interconnecting an appropriate network of conventional component circuits.

[0078] Some embodiments include computer program products. A computer program product may be one or more storage media, instruction storage devices, or storage devices having stored thereon or therein instructions that may be used to control or cause a computer or computer processor to perform any of the procedures of the example embodiments described herein. Storage media / instruction storage devices / storage devices may include, for example, but not limited to, optical disks, ROM, RAM, EPROM, EEPROM, DRAM, VRAM, flash memory, flash memory cards, magnetic cards, optical cards, nanosystems, molecular memory integrated circuits, RAID, remote data storage / archiving / warehousing, and / or any other type of device suitable for storing instructions and / or data.

[0079] Some implementations include software stored on any of one or more computer-readable media, instruction storage devices, or storage devices that controls the system's hardware and enables the system or microprocessor to interact with a human user or other entity using the results of the example embodiments described herein. Such software may include, but is not limited to, device drivers, operating systems, and user applications. Finally, as described above, such computer-readable media or storage devices also include software for performing example aspects of the present invention.

[0080] Included in the system's programming and / or software are software modules for implementing the procedures described herein. In some example embodiments herein, the modules include software, while in other example embodiments herein, the modules include hardware or a combination of hardware and software.

[0081] Although various exemplary embodiments of the present invention have been described above, it should be understood that they are presented by way of example and not limitation. It will be apparent to those skilled in the relevant art that various changes in form and detail may be made thereto. Therefore, the present invention should not be limited by any of the exemplary embodiments described above, but should be defined only in accordance with the appended claims and their equivalents.

[0082] Furthermore, the purpose of the abstract is generally to enable patent offices and the public, and especially scientists, engineers, and practitioners in the field who are not familiar with patent or legal terminology or wording, to quickly ascertain the nature and essence of the technical disclosure of the application based on a cursory inspection. The abstract is not intended to limit the scope of the example embodiments presented herein in any way. It should also be understood that any process recited in the claims need not be performed in the order presented.

[0083] Although this specification contains many specific embodiment details, these should not be interpreted as limitations on the scope of any invention or what may be claimed, but rather as descriptions of features specific to the particular embodiments described herein. Certain features described in this specification in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable subcombination. In addition, although features may be described above as functioning in a particular combination and even initially claimed as such, one or more features from the claimed combination may be deleted from the combination in some cases, and the claimed combination may be directed to subcombinations or variations of subcombinations.

[0084] In some cases, multitasking and parallel processing may be advantageous. Moreover, the separation of various components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0085] Now that some illustrative embodiments and implementations have been described, it will be apparent that the foregoing embodiments are illustrative rather than restrictive and have been presented by way of example. In particular, although many of the examples presented herein involve specific combinations of devices or software elements, these elements can be combined in other ways to achieve the same goals. Actions, elements, and features discussed in conjunction with only one embodiment are not intended to be excluded from similar roles in other embodiments or implementations.

[0086] The apparatus described herein may be embodied in other specific forms without departing from its characteristics. The foregoing embodiments are illustrative rather than restrictive of the systems and methods described. The scope of the apparatus described herein is therefore indicated by the appended claims rather than the foregoing description, and changes that come within the meaning and range of equivalents of the claims are intended to be embraced therein.

[0087] Aspects of the present disclosure may be implemented in one or more of the following embodiments.

[0088] 1) A binocular optical coherence tomography imaging system 100, 600, 700, 800 for simultaneously imaging an area 115 of a subject's first eye 110 and an area 125 of a subject's second eye 120, the binocular optical coherence tomography imaging system 100 comprising:

[0089] a swept light source 130 configured to generate light having a wavelength that varies with time;

[0090] Interferometer 140, 640, 740, 840, comprising:

[0091] Reference arm 170;

[0092] a first sampling arm 150 comprising a first scanning module 152 configured to scan a first light beam 210 across the region 115 of the first eye 110 and to receive first reflected light 215 reflected from the region 115 of the first eye 110 as a result of the first scanning module 152 scanning the first light beam 210 across the region 115 of the first eye 110;

[0093] a second sampling arm 160 comprising a second scanning module 162 configured to scan a second light beam 220 across the region 125 of the second eye while the first scanning module 152 scans the first light beam 210 across the region 115 of the first eye 110, the second scanning module 162 further configured to receive second reflected light 225 reflected from the region 125 of the second eye 120 as a result of the second scanning module 162 scanning the second light beam 220 across the region 125 of the second eye 120;

[0094] a photodetector 180 configured to receive the first reflected light 215, the second reflected light 225, and a reference light 235 and generate an electrical signal S having frequency components, wherein the reference light 235 is light from the swept light source 130 and propagates along the reference arm 170, the frequency components including a first frequency component 322 caused by interference between the first reflected light 215 and the reference light 235 and a second frequency component 326 caused by interference between the second reflected light 225 and the reference light 235, the first frequency component 322 spanning a first frequency band 324, and the second frequency component 326 spanning a second frequency band 328, wherein a difference between an optical path length of the first sampling arm 150 and an optical path length of the second sampling arm 160 is such that at least a portion of the first frequency band 324 does not overlap with the second frequency band 328, and at least a portion of the second frequency band 328 does not overlap with the first frequency band 324;

[0095] a filter module 190 configured to filter the electrical signal S by passing at least some of the first frequency components 322 in a portion of the first frequency band 324 that does not overlap with the second frequency band 328, and passing at least some of the second frequency components 326 in a portion of the second frequency band 328 that does not overlap with the first frequency band 324;

[0096] An optical coherence tomography image data generation module 195 is configured to generate first optical coherence tomography image data representing an image of the region 115 of the first eye 110 based on the at least some first frequency components 322 passing through the filter module 190, and to generate second optical coherence tomography image data representing an image of the region 125 of the second eye 120 based on the at least some second frequency components 326 passing through the filter module 190.

[0097] 2) The binocular optical coherence tomography imaging system 100 according to 1), wherein:

[0098] The reference arm 170 includes at least one reference mirror 172 and a first beam splitter 774, wherein the first beam splitter 774 is configured to split the light generated by the swept light source 130 into a first light 230 and a second light 240, and guide the first light 230 to the at least one reference mirror 172.

[0099] The first sampling arm 150 further includes a second beam splitter 776, which is configured to split the second light 240 into a third light 250 and a fourth light 260. The first scanning module 152 is configured to scan the beam of the third light 250 across the region of the first eye 110 and guide the first reflected light 215 to the second beam splitter 776.

[0100] The second sampling arm further includes a second beam splitter 776 , and the second scanning module 162 is configured to scan the beam of the fourth light 260 across the region 125 of the second eye 120 and guide the second reflected light 225 to the second beam splitter 776 .

[0101] The second beam splitter 776 is further configured to combine the first reflected light 215 and the second reflected light 225 to generate a combined reflected light 265, and

[0102] The electrical signal S generated by the photodetector 180 represents the interference between the combined reflected light 265 and the reference light 235 .

[0103] 3) The binocular optical coherence tomography imaging system 100, 700 according to 2), wherein the reference arm 170 includes a single reference mirror 172, the first beam splitter 774 is further configured to receive a third reflected light caused by reflection of the first light 230 by the single reference mirror 172, and to generate interference light by combining the third reflected light with the combined reflected light 265, and the photodetector 180 is configured to receive the interference light 270.

[0104] 4) The binocular optical coherence tomography imaging system 600, 800 according to 2), wherein:

[0105] The reference arm includes a first reference mirror 472 and a second reference mirror 474, wherein the first reference mirror 472 is configured to reflect the first light 230 from the first beam splitter 774 to the second reference mirror 474.

[0106] The binocular optical coherence tomography imaging system 600, 800 further includes a third beam splitter 777 configured to generate interference light 270 by combining the combined reflected light 265 with a third reflected light caused by reflection of the first light 230 by the second reference mirror 474, and

[0107] The photodetector 180 is configured to receive the interference light 270 .

[0108] 5) The binocular optical coherence tomography imaging system 100, 600 according to any one of 1) to 4), wherein the interferometer 140, 640 is a fiber optic interferometer, wherein the span of the optical fiber guides light to propagate along the reference arm 170, the first sampling arm 150 and the second sampling arm 160 of the interferometer 140, 640.

[0109] 6) The binocular optical coherence tomography imaging system 100, 600, 700, 800 according to any one of 1) to 5), wherein the area 115 of the first eye 110 is located in one of the front segment 112 or the back segment 111 of the first eye 110, and the area 125 of the second eye 120 is located in one of the front segment 122 or the back segment 121 of the second eye 120.

[0110] 7) The binocular optical coherence tomography imaging system 100, 600, 700, 800 according to any one of 1) to 6), wherein the photodetector 180 comprises a balanced avalanche photodiode detector.

[0111] 8) The binocular optical coherence tomography imaging system 100, 600, 700, 800 according to any one of 1) to 7) further includes a visual display unit 197, which is configured to display at least one of an image of an area 115 of the first eye 110 represented by the first optical coherence tomography image data or an image of an area 125 of the second eye 120 represented by the second optical coherence tomography image data.

[0112] 9) The binocular optical coherence tomography imaging system 100, 600, 700, 800 according to any one of 1) to 8), further comprising at least one of the following:

[0113] a first shutter 154 disposed in the first sampling arm 150 and operable to open and close, the first shutter 154 being configured to allow the first reflected light 215 to propagate to the photodetector 180 when the first shutter 154 is open, and to prevent the first reflected light 215 from propagating to the photodetector 180 when the first shutter 154 is closed, the photodetector 180 being configured to receive the first reflected light 215 when the first shutter 154 is open and generate the electrical signal S including the first frequency component 322; or

[0114] A second shutter 164 is provided in the second sampling arm 160 and is operable to open and close, the second shutter 164 being configured to allow the second reflected light 225 to propagate to the photodetector 180 when the second shutter 164 is open, and to prevent the second reflected light 225 from propagating to the photodetector 180 when the second shutter 164 is closed, the photodetector 180 being configured to receive the second reflected light 225 when the second shutter 164 is open and to generate the electrical signal S including the second frequency component 326.

[0115] 10) The binocular optical coherence tomography imaging system 100, 600, 700, 800 according to any one of 1) to 9) further includes a scanning controller 199, which is configured to control the first scanning module 152 and the second scanning module 162 to perform scanning synchronously using a common scanning mode.

[0116] 11) The binocular optical coherence tomography imaging system 100, 600, 700, 800 according to any one of 1) to 9) further includes a scanning controller 199, which is configured to independently control the first scanning module 152 and the second scanning module 162 to perform corresponding scans on different corresponding areas of the first eye 110 and the second eye 120.

Claims

1. A binocular optical coherence tomography imaging system (100, 600, 700, 800) for simultaneously imaging an area (115) of a first eye (110) and an area (125) of a second eye (120) of a subject, the binocular optical coherence tomography imaging system (100) comprising: a swept light source (130) configured to generate light having a wavelength that varies with time; An interferometer (140, 640, 740, 840) comprising: Reference arm (170); a first sampling arm (150) comprising a first scanning module (152) configured to scan a first light beam (210) across an area (115) of the first eye (110) and receive first reflected light (215) reflected from the area (115) of the first eye (110) as a result of the first scanning module (152) scanning the first light beam (210) across the area (115) of the first eye (110); a second sampling arm (160) comprising a second scanning module (162), the second scanning module (162) being configured to scan a second light beam (220) across an area (125) of the second eye simultaneously with the first scanning module (152) scanning the first light beam (210) across an area (115) of the first eye (110), the second scanning module (162) being further configured to receive second reflected light (225) reflected from the area (125) of the second eye (120) as a result of the second scanning module (162) scanning the second light beam (220) across the area (125) of the second eye (120); a photodetector (180) configured to receive the first reflected light (215), the second reflected light (225), and a reference light (235), and generate an electrical signal (S) having frequency components, wherein the reference light (235) is light from the swept light source (130) and propagates along the reference arm (170), the frequency components including a first frequency component (322) caused by interference between the first reflected light (215) and the reference light (235), and a second frequency component (323) caused by interference between the second reflected light (225) and the reference light (235). a second frequency component (326) caused by interference between the first sampling arm (150) and the second sampling arm (160), the first frequency component (322) spanning a first frequency band (324) and the second frequency component (326) spanning a second frequency band (328), wherein a difference between an optical path length of the first sampling arm (150) and an optical path length of the second sampling arm (160) is such that at least a portion of the first frequency band (324) does not overlap with the second frequency band (328), and at least a portion of the second frequency band (328) does not overlap with the first frequency band (324); a filter module (190) configured to filter the electrical signal (S) by passing at least some of the first frequency components (322) in a portion of the first frequency band (324) that does not overlap with the second frequency band (328), and passing at least some of the second frequency components (326) in a portion of the second frequency band (328) that does not overlap with the first frequency band (324); An optical coherence tomography image data generation module (195) is configured to generate first optical coherence tomography image data representing an image of an area (115) of the first eye (110) based on the at least some first frequency components (322) passing through the filter module (190), and to generate second optical coherence tomography image data representing an image of an area (125) of the second eye (120) based on the at least some second frequency components (326) passing through the filter module (190).

2. The binocular optical coherence tomography imaging system (100) according to claim 1, wherein: The reference arm (170) includes at least one reference mirror (172) and a first beam splitter (774), wherein the first beam splitter (774) is configured to split the light generated by the swept light source (130) into a first light (230) and a second light (240), and to guide the first light (230) to the at least one reference mirror (172). The first sampling arm (150) further includes a second beam splitter (776), the second beam splitter (776) being configured to split the second light (240) into a third light (250) and a fourth light (260), the first scanning module (152) being configured to scan the beam of the third light (250) across the region of the first eye (110) and to direct the first reflected light (215) to the second beam splitter (776), The second sampling arm further includes the second beam splitter (776), the second scanning module (162) being configured to scan the beam of the fourth light (260) across the region (125) of the second eye (120) and direct the second reflected light (225) to the second beam splitter (776), The second beam splitter (776) is further configured to combine the first reflected light (215) and the second reflected light (225) to generate a combined reflected light (265), and The electrical signal (S) generated by the photodetector (180) represents interference between the combined reflected light (265) and the reference light (235).

3. The binocular optical coherence tomography imaging system (100, 700) according to claim 2, wherein: The reference arm (170) includes a single reference mirror (172), the first beam splitter (774) is further configured to receive third reflected light caused by reflection of the first light (230) by the single reference mirror (172), and generate interference light by combining the third reflected light with the combined reflected light (265), and the photodetector (180) is configured to receive the interference light (270).

4. The binocular optical coherence tomography imaging system (600, 800) according to claim 2, wherein: The reference arm includes a first reference mirror (472) and a second reference mirror (474), the first reference mirror (472) being configured to reflect the first light (230) from the first beam splitter (774) to the second reference mirror (474), The binocular optical coherence tomography imaging system (600, 800) further includes a third beam splitter (777) configured to generate interference light (270) by combining the combined reflected light (265) with a third reflected light caused by reflection of the first light (230) by the second reference mirror (474), and The photodetector (180) is configured to receive the interference light (270).

5. The binocular optical coherence tomography imaging system (100, 600) according to claim 1, wherein: The interferometer (140, 640) is a fiber optic interferometer, wherein a span of optical fiber guides light along the reference arm (170), the first sampling arm (150), and the second sampling arm (160) of the interferometer (140, 640).

6. The binocular optical coherence tomography imaging system (100, 600) according to claim 2, wherein: The interferometer (140, 640) is a fiber optic interferometer, wherein a span of optical fiber guides light along the reference arm (170), the first sampling arm (150), and the second sampling arm (160) of the interferometer (140, 640).

7. The binocular optical coherence tomography imaging system (100, 600) according to claim 3, wherein: The interferometer (140, 640) is a fiber optic interferometer, wherein a span of optical fiber guides light along the reference arm (170), the first sampling arm (150), and the second sampling arm (160) of the interferometer (140, 640).

8. The binocular optical coherence tomography imaging system (100, 600) according to claim 4, wherein: The interferometer (140, 640) is a fiber optic interferometer, wherein a span of optical fiber guides light along the reference arm (170), the first sampling arm (150), and the second sampling arm (160) of the interferometer (140, 640).

9. The binocular optical coherence tomography imaging system (100, 600, 700, 800) according to any one of claims 1 to 8, wherein: The area (115) of the first eye (110) is located in one of the front segment (112) or the back segment (111) of the first eye (110), and the area (125) of the second eye (120) is located in one of the front segment (122) or the back segment (121) of the second eye (120).

10. The binocular optical coherence tomography imaging system (100, 600, 700, 800) according to any one of claims 1 to 8, wherein: The photodetector (180) comprises a balanced avalanche photodiode detector.

11. The binocular optical coherence tomography imaging system (100, 600, 700, 800) according to any one of claims 1 to 8, further comprising a visual display unit (197), wherein the visual display unit (197) is configured to display at least one of an image of an area (115) of the first eye (110) represented by the first optical coherence tomography image data or an image of an area (125) of the second eye (120) represented by the second optical coherence tomography image data.

12. The binocular optical coherence tomography imaging system (100, 600, 700, 800) according to any one of claims 1 to 8, further comprising at least one of the following: a first shutter (154) disposed in the first sampling arm (150) and operable to open and close, the first shutter (154) being configured to allow the first reflected light (215) to propagate to the photodetector (180) when the first shutter (154) is open, and to prevent the first reflected light (215) from propagating to the photodetector (180) when the first shutter (154) is closed, the photodetector (180) being configured to receive the first reflected light (215) and generate the electrical signal (S) including the first frequency component (322) when the first shutter (154) is open; or a second shutter (164) disposed in the second sampling arm (160) and operable to open and close, the second shutter (164) being configured to allow the second reflected light (225) to propagate to the photodetector (180) when the second shutter (164) is open, and to prevent the second reflected light (225) from propagating to the photodetector (180) when the second shutter (164) is closed, the photodetector (180) being configured to receive the second reflected light (225) when the second shutter (164) is open and to generate the electrical signal (S) including the second frequency component (326).

13. The binocular optical coherence tomography imaging system (100, 600, 700, 800) according to any one of claims 1 to 8, further comprising a scan controller (199), wherein the scan controller (199) is configured to control the first scanning module (152) and the second scanning module (162) to synchronously perform scanning using a common scanning mode.

14. The binocular optical coherence tomography imaging system (100, 600, 700, 800) according to any one of claims 1 to 8, further comprising a scan controller (199), wherein the scan controller (199) is configured to independently control the first scanning module (152) and the second scanning module (162) to perform corresponding scans on different corresponding areas of the first eye (110) and the second eye (120).

15. A computer-readable storage medium carrying instructions, which, when executed by a processor, cause the processor to perform the processing operations of the binocular optical coherence tomography imaging system according to any one of claims 1 to 14.

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