Ultra-wide field of view imaging system for the rear section

Abstract

An apparatus for illuminating the posterior segment of an eye, which may include a plurality of channels. Each channel may include a plurality of illumination paths, such as a first region illumination path and a second region illumination path. The first region illumination path and the second region illumination path may be illuminated at different times so that the first region and the second region can be imaged without interference from unilluminated illumination paths.

Description

Technical Field

[0001] The present disclosure generally relates to systems for ultra-wide field imaging of the posterior segment of the eye. Background Art

[0002] Eye imaging is typically used for screening diseases and documenting findings discovered during a clinical examination of the eye. Specifically, the recording and analysis of the posterior segment of the eye (e.g., retinal imaging) may be relevant to a comprehensive eye examination and a comprehensive assessment of the current status, treatment, and / or early prevention of various eye conditions and diseases.

[0003] To obtain an image with a wider field of view, some methods utilize a laser scanning image illumination method. However, such images have an unrealistic color and require a very large device. Another method includes a conventional fundus camera (a low-magnification microscope with an additional camera for retinal imaging) that repeatedly relocates to capture consecutive images and uses numerical algorithms to form a composite image from each individually relocated image.

[0004] The subject matter claimed herein is not limited to embodiments that solve any disadvantages or operate only in environments such as those described above. Rather, this background art is provided only to illustrate an example technical field in which some embodiments described herein may be practiced. Summary of the Invention

[0005] One embodiment of the present disclosure may include a device for illuminating the posterior segment of the eye, the device including a plurality of channels. Each channel may include two or more illumination regions, such as a first region illumination path and a second region illumination path. The first region illumination path and the second region illumination path may be illuminated at different times such that the first region and the second region may be imaged without being disturbed by unilluminated illumination paths.

[0006] One or more objects and / or advantages of the embodiments will be achieved or obtained at least by the elements, features, and combinations particularly pointed out in the claims.

[0007] It should be understood that the foregoing general description and the following detailed description are both exemplary and explanatory and are not restrictive of the claimed present disclosure. Brief Description of the Drawings

[0008] Example embodiments will be described and illustrated with additional features and details by using the drawings, in which:

[0009] Figure 1A and Figure 1B shows a circle with grid lines, which represents the posterior segment of the eye;

[0010] Figure 2A andFigure 2B An example of a single imaging channel is shown;

[0011] Figure 3 Another example of a single imaging channel is shown;

[0012] Figures 4A to 4D An example of a multi-channel imaging system is shown;

[0013] Figures 5A to 5D Aspects of an example illumination system are shown;

[0014] Figures 6A to 6C An example illumination pattern for a given region of the posterior segment of the eye for imaging is shown;

[0015] Figure 7 An example of an illumination system for illuminating the radially inner portion of the posterior segment of the eye is shown;

[0016] Figures 8A to 8D An apparatus for generating imaging light for illuminating the radially inner portion of the posterior segment of the eye is shown;

[0017] Figure 9 An example of an apparatus for illuminating the radially inner portion and the radially outer portion of the posterior segment of the eye is shown;

[0018] Figures 10A to 10D An example of an apparatus for generating imaging light for illuminating the radially outer portion of the posterior segment of the eye is shown;

[0019] Figures 11A to 11D An example apparatus for generating imaging light for illuminating the intermediate portion of the posterior segment of the eye is shown;

[0020] Figures 12A to 12D An example apparatus for generating imaging light for illuminating the radially outer portion, the radially inner portion, and the intermediate portion of the posterior segment of the eye is shown;

[0021] Figures 13A to 13D An example apparatus and components associated with guiding the placement of the example apparatus relative to the eye are shown;

[0022] Figure 14 An example arrangement of a condenser in the apparatus is shown;

[0023] Figure 15 An example group of imaging channels is shown;

[0024] Figure 16 An example apparatus having a fixation system that generates fixation illumination light on which the eye will focus during operation of the example apparatus is shown;

[0025] All in accordance with at least one embodiment described in the present disclosure. Detailed Description

[0026] In some embodiments of the present disclosure, different image channels can be used to image the wide field of view of the posterior segment of the eye using a single device. In particular, three different channels are oriented around a common axis such that multiple regions of the posterior segment can be imaged without repositioning the imaging device. To facilitate the wide field of view, different portions of the posterior segment can be illuminated at different times to avoid interference of the illumination beam with the imaging channels.

[0027] Figure 1A and Figure 1B A circle with grid lines is shown, which represents the posterior segment of the eye 100a. Overlaid on the posterior segment 100a is a first region 110 representing the portion of the posterior segment 100a imaged and / or illuminated by the first imaging channel.

[0028] As Figure 1B shown, the posterior segment 100b can be covered by multiple channels. For example, a first region 110 covered by the first imaging channel is shown, a second region 120 covered by the second imaging channel is shown, and a third region 130 covered by the third imaging channel is shown. The three regions 110, 120, and 130 include overlapping regions such that almost the entire posterior segment is covered by the three regions 110, 120, and 130. For example, the overlapping regions 140, 142, and 144 (as indicated by the jumbled markings) show the regions covered by two imaging channels, and the overlapping region 144 shows the region covered by all three imaging channels. By using this overlapping pattern, the central region of the posterior segment is covered by all three imaging channels. Additionally, as described below, the use and orientation of the three imaging channels allow the imaging device to image all three channels via a handheld device without reorienting the imaging device relative to the eye.

[0029] In some embodiments, each imaging channel includes a separate imaging system having an imaging sensor, a filter, etc. The size of the imaging system can be smaller compared to a typical fundus camera. For example, the three imaging channels together can be housed in a single handheld device. In these and other embodiments, the three imaging channels can be offset from each other around the center of the imaging device and can be angled to cover the corresponding regions 110, 120, or 130. For example, the imaging systems can be offset from each other by one hundred and twenty degrees around the center point of the imaging device. In another embodiment, the imaging systems can be offset by different or variable angles from the central axis of the imaging device, with or without asymmetric regions of the retina imaged by each imaging system. In yet another embodiment, the imaging systems offset from the central axis can be combined with imaging channels coaxial with the optical axis of the device and / or the eye.

[0030] Figure 2A and Figure 2B and Figure 3 A single imaging channel is shown.Figure 2A and Figure 2B Systems 200a and 200b that show the optical trace 210 of the imaging path of a single imaging channel. Figure 3 Shows the various parts of the imaging system 300 of a single imaging channel, such as lenses, windows, sensors, etc.

[0031] As Figure 2A and Figure 2B Shown, the optical trace 210 shows the imaging light path when it passes through the anterior segment of the eye to image the region 230 of the posterior segment of the eye.

[0032] As Figure 3 Shown, the imaging system 300 shows the optical trace 310 of the imaging of the posterior segment. As Figure 3 Shown, the imaging system 300 may include a single imaging channel 350. The single imaging channel 350 may include a glass window 352, one or more glass lenses 354, one or more polarizers 356, one or more relay lenses 358, one or more camera sensors 364, and a camera aperture 362. To facilitate understanding of the positions and interactions of the various components of the single imaging channel 350, the optical trace 310 shows the path from the retina of the eye to the camera sensor 359.

[0033] As Figure 3 Shown, tracing from the posterior wall of the eye at the retina, the optical trace 310 passes through the posterior lens and exits at the anterior lens of the eye. The place where the optical trace 310 exits the anterior lens and enters the cornea is the entry / exit point of the imaging path of the imaging system 300 into / out of the interior of the eye. As the optical trace 310 passes through the cornea, then they pass through the glass window 352 of the single imaging channel 350 at the end of the single imaging channel 350 near the eye. The glass window 352 may be the physical interface between the imaging device and the eye and may be shaped to have a curvature shaped to dock with the eye (e.g., having a curvature that matches the average eye curvature). In some embodiments, the glass window 352 may be oriented and aligned with the center of the eye, and the glass window 352 may have a size through which each imaging channel of the plurality of imaging channels may pass, rather than including a glass window for each channel. Additionally or alternatively, each imaging channel of the plurality of imaging channels may include its own glass window. In some embodiments, the glass window 352 may be positioned to be in direct contact with the cornea with or without a coupling gel or fluid, while in other embodiments, the glass window 352 may be positioned at a distance from the cornea.

[0034] After passing through the window glass 352, the optical path 310 may pass through one or more glass lenses 354, such as glass lens 1 354a and glass lens 2 354b. The initial glass lens 354 may cause the optical path 310 from a single imaging channel 350 to form an intermediate image, which may be located at approximately one-third of the length of the imaging path of the single imaging channel 350. In some embodiments, the single imaging channel 350 may be oriented approximately twenty-five degrees off the central axis of the eye and / or the centerline of the multi-channel imaging device, but any position may be contemplated, such as five to forty-five degrees off the central axis. In these and other embodiments, the angle may be changed based on the entrance pupil position and / or the mechanical mounting of the single channel 350 within the multi-channel imaging device.

[0035] The optical path 310 may continue through the single imaging channel 350 to pass through the cleaning polarizer 356. The cleaning polarizer 356 may be configured to act as a polarization filter such that any light from an orthogonally polarized illumination source that is reflected back from the surfaces within the single imaging channel 350 to the camera sensor 364 may be filtered out, while allowing the unpolarized light scattered from the retina to pass through the cleaning polarizer 356 for imaging. In some embodiments, a filter or other feature may be used to orient the polarized illumination source. In some embodiments, the illumination source and / or the cleaning polarizer 356 may be adjustable.

[0036] The optical path 310 may continue through the single imaging channel 350 to pass through one or more relay lenses 358, and the relay lenses 358 may include individual relay lenses or any system of relay lenses. Although shown as a single relay lens 358, any number of reflective or refractive optical elements may be included. As Figure 3 shown, each objective has a relay system (e.g., relay lens 358) and a camera (camera sensor 364 and / or camera aperture 362), and the relay system may be aligned with the objective. The present disclosure may be multiple cameras with relays, each camera oriented towards the intermediate image in a patterned or random arrangement.

[0037] As the relay lens 358 begins to focus the light beam of the single imaging channel 350, the optical path 310 may pass through the camera aperture 362 and reach the camera sensor 364 to capture an image of the posterior segment of the eye. In some embodiments, the intermediate image plane may be aligned with the plane of the camera sensor 364. The camera aperture 362 may be aligned with the plane of the camera sensor 364 and may be conjugate with the system entrance pupil (e.g., Figure 3 the entrance pupil position shown).

[0038] As Figure 3As shown, a single imaging channel 350 is offset from the center of the eye such that multiple such single channels can be provided within the same single imaging device.

[0039] Figures 4A to 4D A multi-channel imaging system 400 is shown. Figure 4A A side view of the multi-channel imaging system 400 is shown, Figure 4B A top view of the multi-channel imaging system 400 is shown, Figure 4C A front view of the multi-channel imaging system 400 (e.g., looking out from the eye towards the multi-channel imaging system) is shown, Figure 4D A rear view of the multi-channel imaging system 400 is shown.

[0040] As Figures 4A to 4D shown, a first imaging channel 410a may include an optical path 412a to illustrate imaging of a first region 414a, a second imaging channel 410b may include an optical path 412b to illustrate imaging of a second region 414b, and a third imaging channel 410c may include an optical path 412c to illustrate imaging of a third region 414c. Although shown as three equally spaced channels, any number of channels and any spacing of these channels may be included. For example, two, four, five, six, or any number of channels may be used. As another example, the channels are not equally distributed, but may be arranged in a varying or weighted arrangement rather than an equally distributed arrangement.

[0041] In some embodiments, due to the three imaging channels shown converging at a single point, there is overlap at the vertex of the three imaging channels. To address the overlap, the imaging channels may be symmetrically truncated and mounted against a symmetric three-part wall 420. In these and other embodiments, different portions of the three-part wall 420 may be used as axial baffles to block light from passing between different channels. In some embodiments, the imaging channels may be truncated in an asymmetric manner and mounted against an asymmetric wall 420. In some embodiments, the wall 420 may include within it optical illumination and / or imaging channels separate from those described herein. In some embodiments, if more than three channels are used, the wall 420 may be a multi-part wall having the same number of parts as the number of channels.

[0042] In some embodiments, the glass lenses of the individual channels may be cut separately and mounted to be separated by the three-part wall 420. Additionally or alternatively, the glass lenses may be mounted without the three-part wall 420. In these and other embodiments, the glass lenses spanning different channels may be molded together into a single component and / or mounted as separate components.

[0043] In some embodiments, a single glass window can be used across all three channels. Additionally or alternatively, the present disclosure contemplates multiple windows for multiple channels, and / or no windows. For example, if the imaging device does not contact the eye, a glass window may not be used. In these and other embodiments, the objective lens can contact the cornea, or a contact lens or other barrier can be mounted or otherwise disposed between the cornea and the objective lens. In some embodiments, materials other than glass can be used, including transparent and / or translucent materials; for example, a plastic lens can be used in place of any glass lens of the present disclosure; as another example, a plastic window can be used in place of any glass window of the present disclosure.

[0044] Figures 5A to 5D Aspects of an illumination system associated with a multi-channel imaging system 500 are shown. Each channel uses the illumination system to facilitate illumination of the posterior segment of the eye for imaging. Figure 5A A top view of the multi-channel imaging system 500 is shown, Figure 5B A side view of the multi-channel imaging system 500 is shown, Figure 5C A front view of the multi-channel imaging system 500 (e.g., looking out from the eye towards the multi-channel imaging system 500) is shown, and Figure 5A A rear view of the multi-channel imaging system 500 (e.g., looking from the back of the multi-channel imaging system 500 towards the eye) is shown. As Figures 5A to 5D shown, each respective channel includes an illumination portion 510 (e.g., illumination portions 510a, 510b, and 510c). The illumination portion 510 includes an LED 512 or any other light-emitting element. Additionally, the illumination portion can include one or more lenses or filters 514 to align, shape, and / or direct the light emitted from the LED 512. In some embodiments, the filter 514 can include a polarization filter such that the illumination light directed towards the eye can be polarized in the same direction to allow filtering of certain undesired polarizations of the light, such as specular reflections from the objective lens (e.g., glass lens 524). In other words, by polarizing the illumination light, any reflections from the lens or other elements of the imaging device will maintain their polarization and can thus be filtered by a polarization filter in the imaging channel (e.g., Figure 3 the cleanup polarizer 356 in ), while allowing the scattered illumination on the retina that returns along the imaging channel and is thus used to image the posterior segment of the eye to pass through the polarization filter. In some embodiments, polarization can be excluded from the design of the imaging device and scattered light can be managed in other ways (e.g., in the optical design of the imaging device or in the software post-processing of the acquired images).

[0045] In some embodiments, the camera sensor and / or the aperture can be directly oriented in line with the centerline of the illumination portion 510. In these and other embodiments, the camera sensor can be located within a cylindrical chamber, and the LED 512 can be located outside the cylindrical chamber. In these and other embodiments, the walls of the cylindrical chamber can serve to prevent illumination from the LED 512 from leaking into the image capture of the camera device. In other words, when the camera sensor is in line with the centerline of the illumination portion 510, the LED 512 can be located at a position offset from the centerline.

[0046] Figures 5A to 5D Shown is a three-part wall 522 (which can be similar or equivalent to Figure 4D the three-part wall 420) and a glass lens 524 (which can be similar or equivalent to Figure 3 the lens and / or window 352 and / or 354) within the nose cone portion 520 of the imaging device.

[0047] Using the imaging device 510, various parts of the posterior segment of the eye can be illuminated along different paths at different times to avoid illumination light interfering with the imaging path. For example, an overlap between the illumination path to the posterior segment and the imaging path returning from the posterior segment may result in diffuse scattering from the eye surface, which may appear as blurring in the captured image.

[0048] Figures 6A to 6C Shown is an illumination pattern for a given region of the posterior segment of the eye for imaging. The grid lines represent the same grid lines as used in Figures 1A to 1B . The dark blue regions represent Figures 1A to 1B the respective regions covered by the field of view as shown in Figures 6A to 6C Shown is how the respective parts of a given region can be illuminated by different illumination elements to avoid contamination of the imaging path by the illumination path. By illuminating different regions at different times, each part can be illuminated individually, and the images can be combined to cover the entire region, thereby covering the entire wide field of view. Figures 6A to 6C The grid lines in

[0049] show the posterior segment protruding outward from the fovea. The radially inner portion 610 can illuminate approximately 30 to 60 degrees from the fovea, the radially outer portion 620 can illuminate approximately 50 to 90 degrees from the fovea, and the intermediate portion 630 can illuminate approximately -15 to +40 degrees from the fovea and the overlapping regions between the channels (e.g., regions 140, 142, 144, and 150 in FIG. 1). Figures 6A to 6CIlluminated and oriented in the manner shown, which avoids interference with the posterior and anterior surfaces of the eye's lens and cornea with respect to the imaging channels that have always interfered with the illuminated and imaged portions in the past. In some embodiments, the respective portions 610, 620, and 630 can be illuminated one portion at a time for all three channels simultaneously (e.g., the radially inner portion 610 of all three channels when capturing an image, the radially outer portion 620 of all three channels when capturing an image, and the intermediate portion 630 of all three channels when capturing an image), the respective portions 610, 620, and 630 can be illuminated individually (e.g., the radially inner portion 610 of one channel can be illuminated when capturing an image of the illuminated posterior segment portion through one channel), or any combination or variation thereof.

[0050] Figure 7 An example of an illumination system 700 for illuminating the radially inner portion of the posterior segment of the eye is shown. The illumination system 700 can include a base component 710 and a nasal cone component 720.

[0051] As Figure 7 shown, the base component 710 can include an LED 712 (or other light-emitting device) and an associated aperture. The base component 710 can also include an illumination condenser system 714 and a baffle and pre-polarizer 716. The base component 710 can additionally include a camera component 730 having a camera sensor 732 and a housing 734. The camera sensor 732 can be disposed within the housing 734, and the housing 734 can serve to prevent light from the LED 712 from affecting the image capture of the camera sensor 732.

[0052] In some embodiments, the illumination condenser system 714 can include two elements (e.g., four surfaces) symmetrically patterned with respect to the plane bisecting the imaging channel and the retina. In these and other embodiments, the illumination condenser system 714 can include one or more passive refractive or reflective optical elements, or active elements (e.g., a reflective MEMS micromirror array or a transmissive spatial light modulator) to effect beam control and steering.

[0053] As Figure 7 shown, the plane in which the LED 712 is located and the illumination condenser system 714 can be positioned orthogonal to the channel axis (e.g., the axis along which the optical trajectory of the imaging channel is directed to the camera sensor 732), such that the plane in which the LED 712 is located and the illumination condenser system 714 can be mounted around the housing 734. It should be understood that the LED 712 and the illumination condenser system 714 can be placed anywhere in space such that the illumination path of the radially inner segment does not interfere with the imaging path of that segment on any eye surface.

[0054] In some embodiments, the illumination condenser system 714 can be aligned and configured to image the cornea onto the aperture plane. In these and other embodiments, such an imaging location can also be based on the characteristics of the objective lens system 740 (which can be similar or equivalent to the glass lens 524 of FIG. 5). For example, as Figure 7 shown, the illumination light rays can pass through the illumination condenser system to be directed by the objective lens system 740 such that the illumination is approximately at its narrowest point in the cornea, thereby reducing and / or minimizing interference with the light rays in the imaging channel returning through the cornea. Although the imaging of the illumination light rays at the cornea, LED 712, and associated aperture has been described, the illumination condenser system 714 and / or the objective lens system 740 can be configured such that the illumination light rays can be configured to image at any location along an axis that does not overlap the imaging path of the illuminated radial segment between the cornea and the posterior lens of the eye. In these and other embodiments, the size and / or position of the aperture associated with the LED 712 can be selected to limit the path of the illumination light rays through the exit pupil such that the illumination light rays do not interfere with the path of the imaging light rays when imaging a portion and / or portions of the posterior segment being imaged.

[0055] In some embodiments, baffles associated with the illumination channel can be placed and / or configured to intercept stray light at the back side (e.g., on the other side of the illumination condenser system 714 different from the LED 712) and the front side (e.g., on the same side as the LED 712) of the illumination condenser system 714. Additionally or alternatively, the baffles can be placed and / or configured to intercept stray light between elements within the illumination condenser system 714. In some embodiments, the baffles can be movable within the device 700. For example, the baffles can be mechanized and / or motorized such that their position can be adjusted to vary the illumination optics for different eyes and / or different applications. In some embodiments, the housing 734 can be used as a baffle to intercept such stray light. Additionally or alternatively, the three-part wall of the imaging device can be used as a baffle to block certain stray light (e.g., Figures 4A to 4D the three-part wall 420).

[0056] In some embodiments, the prepolarizer 716 can be configured to polarize the incident illumination light to facilitate filtering. For example, by polarizing the illumination light, any specular reflections (e.g., from the objective lens system 740) maintain their polarization state. This arrangement allows the clean-up polarizer in the imaging path to reject the specularly reflected light because such light remains polarized upon reflection (e.g., can be filtered by the clean-up polarizer 356). Additionally, such an arrangement can allow non-polarized light (e.g., illumination light scattered by the retinal tissue and propagating along the imaging channel) to pass through the clean-up polarizer for imaging.

[0057] Figures 8A to 8DAn imaging system 800 is shown that generates imaging light for illuminating the radially inner portion of the posterior segment. Figure 8A A side view of the imaging system 800 is shown, Figure 8B A top view of the imaging system 800 is shown, Figure 8C A front view of the imaging system 800 (e.g., looking out from the eye towards the multi-channel imaging system) is shown, and Figure 8D A rear view of the multi-channel imaging system 800 is shown.

[0058] As Figures 8A to 8D shown, in some embodiments, all three channels can be illuminated simultaneously such that the radially inner portions of all three imaging channels can be illuminated simultaneously. For example, all three imaging channels can be illuminated and imaged simultaneously at the radially inner portion of the posterior segment. Additionally or alternatively, the radially inner portion of each imaging channel can be illuminated and imaged independently or sequentially, e.g., three different images of each radially inner portion of each imaging channel can be captured at different times.

[0059] Figure 9 An example of an illumination system 900 for illuminating the radially inner and outer portions of the posterior segment of the eye is shown. The illumination system 900 can include a base component 910 and a nasal cone component 920. The illumination system 900 can be similar or equivalent to Figure 7 the illumination system 700 shown. The illumination system 900 can include different LEDs 912 and associated apertures that can be different or distinct from Figure 7 the LED 712 of Figure 7 where the LED 912 can be configured to illuminate the radially outer portion while the LED 712 can be configured to illuminate the radially inner portion of the posterior segment. In these and other embodiments, the illumination system 900 can include Figure 9 all of the components shown in Figure 7 and the components shown in

[0060] Figure 9 such that the illumination system 900 can illuminate the radially inner segment and the radially outer segment. Similarly numbered components can operate or function in the same or similar manner as the components described above with respect to Figure 7 The elements of Figure 7is similar or comparable to the base component 710 (e.g., may include an LED 912 and an associated aperture that are similar or comparable to the LED 712 (or other light-emitting device)). The base component 910 may also include an illumination condensing system 914 that may be similar or comparable to the illumination condensing system 714. The base component 910 may also include a baffle and / or a pre-polarizer 916 that may be similar or comparable to the baffle and / or the pre-polarizer 716. The base component 910 may additionally include a camera component 930 that may be similar or comparable to the camera component 730, including a camera sensor 932 that is comparable or similar to the camera sensor 732 and a housing 934 that is similar or comparable to the housing 734.

[0061] As Figure 9 shown, the illumination beam 960 of the illumination radially outer segment and the illumination beam 970 of the illumination radially inner segment are shown to act simultaneously. As Figure 9 seen, the combination of the illumination beams 960 and 970 consumes more space within the anterior segment of the eye, increasing the likelihood that the illumination interferes with the imaging of the posterior segment of the eye. In these and other embodiments, if the illumination beams 960 and 970 are oriented and / or aligned (e.g., via the aperture, the illumination condensing system 914, and / or the objective system 940) such that both segments can be imaged without interference in the imaging channel, then both can be illuminated and imaged simultaneously. Additionally or alternatively, the radially inner segment and the radially outer segment can be illuminated sequentially such that the two segments can be imaged independently, where a smaller portion of the space within the anterior segment of the eye is consumed by the illumination beams.

[0062] Figures 10A to 10D An imaging system 1000 is shown that generates imaging rays for illuminating the radially outer portion of the posterior segment. Figure 10A A side view of the imaging system 1000 is shown, Figure 10B A top view of the imaging system 1000 is shown, Figure 10C A front view of the imaging system 1000 (e.g., looking out from the eye towards the multi-channel imaging system) is shown, and Figure 10D A rear view of the multi-channel imaging system 1000 is shown.

[0063] As Figures 10A to 10D shown, in some embodiments, all three channels can be illuminated simultaneously such that the radially outer portions of all three imaging channels can be illuminated simultaneously. For example, all three imaging channels can be illuminated and imaged simultaneously at the radially outer portion of the posterior segment. Additionally or alternatively, the radially outer portion of each imaging channel can be illuminated and imaged independently or sequentially, e.g., three different images of each radially outer portion of each imaging channel can be captured at different times.

[0064] Figures 11A to 11DIllustrates an imaging system 1100 that generates imaging light for illuminating an intermediate portion of a posterior segment. Figure 11A Shows a side view of the imaging system 1100, Figure 11B Shows a top view of the imaging system 1100, Figure 11C Shows a front view of the imaging system 1100 (e.g., looking out from the eye towards a multi-channel imaging system), and Figure 11D Shows a rear view of the multi-channel imaging system 1100.

[0065] As Figures 11A to 11D shown, in some embodiments, all three channels can be illuminated simultaneously such that the intermediate portions of all three imaging channels can be illuminated simultaneously. For example, all three imaging channels can simultaneously illuminate and image at the intermediate portion of the posterior segment. Additionally or alternatively, the intermediate portions of each imaging channel can be illuminated and imaged independently or sequentially, e.g., three different images of each intermediate portion of each imaging channel can be captured at different times.

[0066] In these and other embodiments, the imaging system 1100 of the intermediate segment can include and / or utilize a similar or equivalent illumination condensing system, such as Figure 7 and Figure 9 the illumination condensing system shown in. Additionally or alternatively, the imaging system 1100 of the intermediate segment can include and / or utilize Figure 7 and Figure 9 the baffles and / or pre-polarizers of.

[0067] In some embodiments, a given intermediate portion can be illuminated by two adjacent channels rather than an actual imaging channel. For example, for a three-channel imaging system, during initial channel imaging, since the intermediate portion is imaged by the initial channel, the other two channels can illuminate the intermediate portion. In these and other embodiments, a series of images can be captured while one channel is imaging and the other two channels illuminate in a rotating or sequential manner. For example, for a first channel, a second channel, and a third channel, the first channel can image while the second and third channels illuminate, then the second channel can image while the first and third channels illuminate, and then the third channel can image while the first and second channels illuminate.

[0068] Figures 12A to 12D Illustrates an imaging system 1200 that generates imaging light for illuminating the radially outer portion, the radially inner portion, and the intermediate portion of a posterior segment. Figure 12A Shows a side view of the imaging system 1200, Figure 12B Shows a top view of the imaging system 1200, Figure 12C Shows a front view of the imaging system 1200 (e.g., looking out from the eye towards a multi-channel imaging system), andFigure 12D The rear view of the multi-channel imaging system 1200 is shown.

[0069] As Figures 12A to 12D shown, the light rays for illuminating all three sections and the light rays for imaging the posterior segment are shown. For example, the light rays for illuminating the outer radial portion (red), the inner radial portion (green), and the intermediate portion (magenta) are shown together with the light rays for imaging the posterior segment (blue).

[0070] Figures 13A to 13D The imaging system 1300 for guiding the placement of the associated imaging device relative to the eye is shown. For example, the imaging system 1300 may include one or more LEDs 1312 that may be configured to provide reflection and / or scattering from the eye surface (such as the cornea, lens, and / or retina) so that the operator of the imaging device can correctly orient the imaging device onto the eye. As another example, the imaging system 1300 may include an illumination condenser system 1314 that can direct or shape the guiding illumination. In these and other embodiments, the illumination condenser system 1314 may be bisected by a plane that bisects the imaging channel and the retina. Additionally, the imaging system 1300 may utilize a nasal cone portion 1320 that includes an objective lens system 1340 to direct the guiding light rays 1350 from equidistant positions around the center of the eye to the center of the eye. For example, as Figures 13A to 13D shown, each guiding light ray 1350 from each of the three channels may be combined near the center of the eye such that the operator of the imaging system 1300 can direct the reflection of each of the multiple guiding light rays 1350 around the center of the eye.

[0071] In these and other embodiments, the guiding light rays 1350 may consume a large portion of the space that the imaging light rays can pass through in the anterior segment of the eye in order to allow the imaging device to be guided relative to the eye to an appropriate position for imaging. In these and other embodiments, the imaging and / or illumination of the retina may occur after the guiding has been completed such that the consumption of a large portion of the space does not affect the imaging that occurs after the imaging device has been guided.

[0072] Figure 13A The side view of the imaging system 1300 is shown, Figure 13B The top view of the imaging system 1300 is shown, Figure 13C The front view of the imaging system 1300 (e.g., looking out from the eye towards the multi-channel imaging system) is shown, and Figure 13D The rear view of the multi-channel imaging system 1300 is shown.

[0073] Figure 14An example arrangement 1400 of the condenser is shown. For example, the arrangement 1400 includes a radially inner segment condenser 1410, a radially outer segment condenser 1420, an intermediate segment condenser 1430, and a guiding condenser 1440.

[0074] As Figure 14 shown, each of the condensers 1410, 1420, 1430, and 1440 can be oriented around a central region into which light rays of the imaging channel can be directed. For each of the condensers 1410, 1420, 1430, and 1440, it can be symmetrically aligned about a plane that bisects the imaging channel and the retina (as shown by the green arrows).

[0075] In some embodiments, the radially inner segment condenser 1410 and / or the radially outer segment condenser 1420 can be oriented along the outer edge of the imaging device (e.g., in three imaging channels, the radially inner segment condenser 1410 and / or the radially outer segment condenser 1410 can be located on a side away from the other imaging channels). In some embodiments, the intermediate segment condenser 1430 and / or the guiding condenser 1440 can be oriented along the inner edge of the imaging device (e.g., in three imaging channels, the intermediate segment condenser 1430 and / or the guiding condenser 1440 can be located on a side closer to the other imaging channels). Using such an arrangement, the radially inner segment and outer segment illumination can project further outward toward the outer part of the radial segment of the eye. In these and other embodiments, the intermediate segment condenser 1430 and the guiding condenser 1440 can be configured to direct the illumination toward the intermediate part of the eye.

[0076] Figure 15 An example group 1500 of imaging channels is shown, including a first imaging channel 1510a, a second imaging channel 1510b, and a third imaging channel 1510c. As described above, each of the individual channels can be imaged and / or illuminated separately, including illuminating a specific portion guided by one or more condensers shown in the present disclosure.

[0077] Figure 16 An example imaging device 1600 including a fixation system is shown, the fixation system generating fixation rays 1660 of illumination on which the eye will focus during operation of the imaging device 1600. As Figure 16 shown, the fixation system can be positioned and oriented near or along the central axis of the imaging device 1600, with the imaging and illumination channels positioned around the fixation system. For example, the fixation system can be on the same axis on which the eye focuses, and the imaging channels are oriented around the central channel. In some embodiments, the fixation system can be located within one or more optical imaging systems rather than outside the optical imaging systems.

[0078] The fixation system may include an LED 1610, an aperture 1620, and a lens 1630 to direct fixation light 1660 to the retina of the eye. The LED 1610 may be any device configured to emit a light beam. The LED 1610 may be selected to limit the amount of scattering into other lenses or portions of the imaging device 1600.

[0079] In some embodiments, the LED 1610, the aperture 1620, and the lens 1630 may be selected to provide a focused light beam (represented by the fixation light 1660) to the eye. In these and other embodiments, the fixation light 1660 may be converged through the aperture 1620 into a light beam projected through the focusing chamber 1670. In some embodiments, the (one or more) apertures may produce a focused pattern of fixation light, thereby producing a discrete fixation pattern for the eye to view.

[0080] The focusing chamber 1670 may be a chamber having an absorptive region and absorptive material within the chamber. The chamber may include an opening near the region where the light beams combine, proximate the lens 1630 and the LED 1610, and may include a pinhole opening 1680 on the opposite side of the focusing chamber 1670. In some embodiments, the opening near the LED 1610 may also be a pinhole opening. In these and other embodiments, by using the focusing chamber 1670, any light beam from the LED 1610 that is not narrowly directed towards the retina may be absorbed within the focusing chamber 1670. In this way, a highly focused fixation beam may be produced, on which the eye may focus during use. Since the fixation light 1660 is focused into a narrow beam, the size of the fixation system is minimized such that most of the volume of the imaging device 1600 may be available for the imaging channel. According to such an arrangement, there may be a clear line of sight between the LED 1610 and the retina of the eye.

[0081] In some embodiments, one or more imaging channels may share a central axis with the fixation system. For example, an intermediate illumination and imaging channel for illuminating and imaging an intermediate portion of the posterior segment may share the central axis of the imaging device 1600. In these and other embodiments, a beam splitter may be positioned between the central axis imaging camera and the eye such that the fixation system may share the same central axis.

[0082] In some embodiments, a set of optical components (e.g., aperture 1620, lens 1630, and / or other components) can be selected, designed, and / or positioned to image aperture 1620 onto the retina of the eye through a clear line of sight achieved by a pinhole opening exiting the focusing chamber 1670 such that the eye can see and focus on a resolvable point that can be used as a fixation target for the eye during image capture, such that when the eye is focused on the resolvable point, the eye surface (e.g., lens) of the eye is in a fixed position, thereby reducing variations in the position and imaging characteristics of the eye during image capture.

[0083] In some embodiments, the imaging device can include a computing device or be communicatively coupled to a computing device. For example, the computing device can include a memory and at least one processor configured to perform operations described in the present disclosure among other things. In some embodiments, the computing device can include computer-readable instructions configured to be executed by the imaging device to perform operations described in the present disclosure. In some embodiments, the computing device can instruct the imaging device to illuminate one or more illumination channels, such as radial inner segment illumination, radial outer segment illumination, etc. Additionally or alternatively, the computing device can capture and / or store images captured by the camera sensor.

[0084] Generally, a processor can include any suitable dedicated or general-purpose computer, computing entity, or processing device including various computer hardware or software modules, and can be configured to execute instructions stored on any applicable computer-readable storage medium. For example, a processor can include a microprocessor, a microcontroller, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or any other digital or analog circuit configured to interpret and / or execute program instructions and / or process data.

[0085] It should be understood that a processor can include any number of processors distributed across any number of networks or physical locations, configured to perform any number of operations described herein either individually or jointly. In some embodiments, the processor can interpret and / or execute program instructions stored in the memory and / or process data. By interpreting and / or executing program instructions stored in the memory and / or processing data, the device can perform operations such as those performed by the retinal imaging device described in the present disclosure.

[0086] A memory may include a computer-readable storage medium or one or more computer-readable storage media for bearing or storing computer-executable instructions or data structures thereon. Such computer-readable storage media can be any available media that can be accessed by a general or special-purpose computer such as a processor. By way of example and not limitation, such computer-readable storage media may include non-transitory computer-readable storage media including random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, magnetic disk storage or other magnetic storage devices, flash memory devices (e.g., solid state memory devices) or any other storage media that can be used to bear or store the desired program code in the form of computer-executable instructions or data structures and that can be accessed by a general or special-purpose computer. Combinations of the foregoing may also be included within the scope of computer-readable storage media. In these and other embodiments, the term “non-transitory” as used herein should be construed to exclude only those types of transitory media found to fall outside the scope of patentable subject matter in the Federal Circuit decision In re Nuijten, 500 F.3d 1346 (Fed. Cir. 2007). In some embodiments, computer-executable instructions may include, for example, instructions and data configured to cause a processor to perform specific operations or a set of operations described in this disclosure.

[0087] By convention, the various features shown in the drawings may not be drawn to scale. The illustrations presented in this disclosure are not meant to be actual views of any particular device (e.g., apparatus, system, etc.) or method, but rather are idealized representations used to describe various embodiments of this disclosure. Accordingly, for clarity, the dimensions of the individual features may be arbitrarily enlarged or reduced. Additionally, for clarity, some of the drawings may be simplified. Thus, the drawings may not depict all components of a given device (e.g., apparatus) or all operations of a particular method.

[0088] The terms used herein and especially in the appended claims (e.g., the body of the appended claims) are generally intended to be “open” terms (e.g., the term “comprising” should be interpreted as “comprising but not limited to,” the term “having” should be interpreted as “having at least,” the term “including” should be interpreted as “including but not limited to,” etc.).

[0089] Additionally, if an intention is to introduce a specific number of claim recitations, that intention should be explicitly recited in the claims, and in the absence of such a recitation, there is no such intention. For example, for the help of understanding, the appended claims may include the use of introductory phrases "at least one" and "one or more" for introducing claim recitations. However, even when the same claim includes an introductory phrase "one or more" or "at least one" and an indefinite article such as "a" or "an", the use of such a phrase should not be construed as implying that the introduction of a claim recitation by the indefinite article "a" or "an" will limit any particular claim including such introduced claim recitation to an embodiment containing only one such recitation (e.g., "a" and / or "an" should be construed to mean "at least one" or "one or more"); the same is true for the use of a definite article for introducing a claim recitation.

[0090] Moreover, even if a specific number of introduced claim recitations are explicitly recited, those skilled in the art will recognize that such a recitation should be construed to mean at least the recited number (e.g., the sole recitation of "two recitations" without any other modifiers means at least two recitations, or two or more recitations). Additionally, in those cases where a convention similar to "at least one of A, B, and C, etc." or "one or more of A, B, and C, etc." is used, generally such a construction is intended to include A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B, and C together, etc. For example, the use of the term "and / or" is intended to be construed in this manner. Additionally, the term "about" or "approximately" should be construed to mean a value within 10% of the actual value.

[0091] Furthermore, regardless of whether in the specification, claims, or drawings, any disjunctive word or phrase presenting two or more alternative terms should be understood to contemplate the possibility of including one term or any one of the two terms or both terms. For example, the phrase "A or B" should be understood to include the possibility of "A" or "B" or "A and B".

[0092] However, even when the same claim includes an introductory phrase "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be construed to mean "at least one" or "one or more"), the use of such a phrase should not be construed as implying that the introduction of a claim recitation by the indefinite article "a" or "an" will limit any particular claim including such introduced claim recitation to an embodiment containing only one such recitation; the same is true for the use of a definite article for introducing a claim recitation.

[0093] Additionally, the use of terms such as "first," "second," "third," etc. in this document does not necessarily imply a particular order or number of components. Generally, terms such as "first," "second," "third," etc. are used as general identifiers to distinguish different components. Without indicating that the terms "first," "second," "third," etc. imply a particular order, these terms should not be construed as implying a particular order. Additionally, without indicating that the terms "first," "second," "third," etc. represent a particular number of components, these terms should not be construed as implying a particular number of components. For example, a first small machine may be described as having a first side, while a second small machine may be described as having a second side. The use of the term "second side" with respect to the second small machine may be to distinguish that side of the second small machine from the "first side" of the first small machine, rather than implying that the second small machine has two sides.

[0094] All of the examples and conditional language recited herein are intended for pedagogical purposes to assist the reader in understanding the present invention and the concepts that the inventors have made for further development of the field, and should be construed as not being limited to such specifically recited examples and conditions. Although the embodiments of the present disclosure have been described in detail, it should be understood that various changes, substitutions, and alterations can be made without departing from the spirit and scope of the present disclosure.

[0095] The following paragraphs list sample embodiments. Any embodiments can be combined in any order or combination. For example, the embodiments in the subsequent paragraphs can be combined with any combination of the preceding and / or subsequent paragraphs.

[0096] One embodiment of the present disclosure may include a device for illuminating the posterior segment of the eye, and the device may include a plurality of channels. Each channel may include a first regional illumination path and a second regional illumination path. The first regional illumination path and the second regional illumination path may be illuminated at different times such that the first region and the second region can be imaged without being disturbed by the unilluminated illumination paths.

[0097] In combination with and / or consistent with any of the embodiments described herein, the device may include a window at the end of the plurality of channels close to the eye, where the window may be shared by at least two of the plurality of channels.

[0098] In combination with and / or consistent with any of the embodiments described herein, the window may be an interface between at least two of the plurality of imaging channels and the eye.

[0099] The device according to claim 1, wherein the plurality of channels includes three channels that are oriented between approximately five degrees and forty-five degrees off the central axis of the eye and are spaced apart approximately equally around the center of the eye.

[0100] In combination with and / or consistent with any of the embodiments described herein, multiple channels can converge at a single point near the eye, and the device can include a multi-part wall disposed at that single point.

[0101] In combination with and / or consistent with any of the embodiments described herein, each part of the multi-part wall can be shaped and positioned to act as a baffle to prevent light from crossing between the multiple channels within the device.

[0102] In combination with and / or consistent with any of the embodiments described herein, a first channel of the multiple channels can include a camera sensor that is substantially in line with the centerline of the first channel.

[0103] In combination with and / or consistent with any of the embodiments described herein, the device can further include a first illumination source for a first illumination path of the first channel and a second illumination source for a second illumination path of the first channel, wherein both the first illumination source and the second illumination source can be disposed at positions offset from the centerline of the first channel.

[0104] In combination with and / or consistent with any of the embodiments described herein, the first channel of the multiple channels can further include a third illumination path.

[0105] In combination with and / or consistent with any of the embodiments described herein, the first illumination path can illuminate the radially outer portion of the posterior segment of the eye, the second illumination path can illuminate the radially inner portion of the posterior segment of the eye, and the third illumination path can illuminate the intermediate portion of the posterior segment of the eye.

[0106] In combination with and / or consistent with any of the embodiments described herein, the radially outer portion can include from approximately 50 to 90 degrees from the fovea, the radially inner portion can include from approximately 30 to 60 degrees from the fovea, and the intermediate portion can include from approximately -15 to +40 degrees from the fovea.

[0107] In combination with and / or consistent with any of the embodiments described herein, the first illumination paths of each of the multiple channels can be illuminated simultaneously.

[0108] In combination with and / or consistent with any of the embodiments described herein, the first illumination paths of each of the multiple channels can be illuminated independently.

[0109] In combination with and / or consistent with any of the embodiments described herein, the first channel of the plurality of channels may further include a base component, where the base component may include: a camera within a housing, the camera being aligned with the central axis of the first channel. The base component may further include a first light source associated with a first illumination path and located outside the housing, an aperture associated with the first light source, and an illumination condenser system that provides beam control and steering of light from the first light source, where the illumination condenser system may be located outside the housing and orthogonal to the central axis of the first channel. The base component may further include a baffle that blocks stray illumination from the first light source, where the baffle may be substantially flush with the top of the housing in which the camera is disposed.

[0110] In combination with and / or consistent with any of the embodiments described herein, the base component may further include a pre-polarizer to polarize the light from the first light source:

[0111] In combination with and / or consistent with any of the embodiments described herein, the device may further include a cleaning polarizer that is positioned along the imaging path returning to the camera such that light having the same polarization as the light leaving the pre-polarizer is filtered out and prevented from reaching the camera.

[0112] In combination with and / or consistent with any of the embodiments described herein, the illumination condenser system may include at least one of a reflective microelectromechanical systems (MEMS) micromirror array or a transmissive spatial light modulator.

[0113] In combination with and / or consistent with any of the embodiments described herein, the first channel may further include an objective lens system at an end of the first channel opposite the base component, the objective lens system being configured to introduce light from the first light source into the eye.

[0114] In combination with and / or consistent with any of the embodiments described herein, the objective lens system may be configured to cause the light from the first light source to be at its narrowest point in the cornea of the eye or between the cornea and the posterior lens of the eye.

[0115] In combination with and / or consistent with any of the embodiments described herein, the base component may further include a second light source corresponding to a second illumination path and a third light source corresponding to a third illumination path.

[0116] In combination with and / or consistent with any of the embodiments described herein, the first illumination path may illuminate a radially inner segment of the posterior segment of the eye, and the first light source may be located outside the housing and towards the outer edge of the device, the second illumination path may illuminate a radially outer segment of the posterior segment of the eye, and the second light source may be located outside the housing and towards the outer edge of the device, and the third illumination path may illuminate an intermediate segment of the posterior segment of the eye, and the third light source may be located outside the housing and towards the inner region of the device.

[0117] In combination with and / or consistent with any of the embodiments described herein, each of a plurality of channels may include a guiding illumination source for aligning the device with the eye, wherein the guiding illumination source of the first channel may be located outside the housing and directed towards the interior region of the device, and each guiding illumination source for each of the plurality of channels may be configured to illuminate such that when the device is close to the eye, light from the guiding illumination source is reflected from the eye.

[0118] In combination with and / or consistent with any of the embodiments described herein, the device may further include a fixation system, wherein the fixation system may include: a fixation light source that is located within the central region of the device and aligned with the centerline of the device; and a focusing chamber through which light from the fixation light source passes, wherein the focusing chamber may include a pinhole located at an end of the focusing chamber opposite the fixation light source.

Claims

1. An apparatus for illuminating the posterior segment of an eye, the apparatus comprising: a plurality of channels, each of the plurality of channels comprising: a first region illumination path; and a second region illumination path; and wherein the first region illumination path and the second region illumination path are illuminated at different times such that the first region and the second region can be imaged without interference from the non-illuminated illumination path; and wherein the plurality of channels converge at a single point close to the eye, and the apparatus further comprises a multi-part wall disposed at the single point.

2. The apparatus according to claim 1, the apparatus further comprising a window at the eye-proximal end of the plurality of channels, the window being shared by at least two of the plurality of channels.

3. The apparatus according to claim 2, wherein, The window is an interface between the at least two of the plurality of channels and the eye.

4. The device according to claim 1, wherein The plurality of channels includes three channels oriented between five degrees and forty-five degrees off the central axis of the apparatus and spaced substantially equally around the central axis of the apparatus, the central axis of the apparatus being substantially aligned with the central axis of the eye.

5. The apparatus according to claim 1, wherein Each part of the multi-part wall is shaped and positioned to act as an axial baffle to prevent light from crossing between the plurality of channels within the apparatus.

6. The device according to claim 1, wherein The first channel of the plurality of channels includes a camera sensor substantially in line with the central axis of the first channel.

7. The apparatus according to claim 6, the apparatus further comprising a first illumination source for the first region illumination path of the first channel and a second illumination source for the second region illumination path of the first channel, both the first illumination source and the second illumination source being disposed at a position off the central axis of the first channel.

8. The apparatus according to claim 1, wherein The first channel of the plurality of channels further includes a third region illumination path.

9. The device according to claim 8, wherein, The first region illumination path illuminates the radially outer portion of the posterior segment of the eye, the second region illumination path illuminates the radially inner portion of the posterior segment of the eye, and the third region illumination path illuminates the middle portion of the posterior segment of the eye.

10. The device according to claim 9, wherein, The radially outer portion includes a portion from 50 degrees to 90 degrees from the fovea of the eye, the radially inner portion includes a portion from 30 degrees to 60 degrees from the fovea, and the middle portion includes a portion from -15 degrees to +40 degrees from the fovea.

11. The apparatus according to claim 9, wherein, The first region illumination paths of each of the plurality of channels are illuminated simultaneously.

12. The apparatus according to claim 9, wherein, The first region illumination paths of each of the plurality of channels are illuminated independently.

13. The device according to claim 1, wherein, The first channel of the plurality of channels further includes a base member, the base member comprising: a camera within a housing, the camera being aligned with the central axis of the first channel; a first illumination source associated with the first region illumination path and located outside the housing; an aperture associated with the first illumination source; an illumination condenser system that provides beam control and steering of light from the first illumination source, the illumination condenser system being located outside the housing and orthogonal to the central axis of the first channel; and a baffle that blocks stray illumination from the first illumination source, the baffle being substantially flush with the top of the housing.

14. The apparatus according to claim 13, wherein, The base component further includes a pre-polarizer to polarize the light from the first illumination source.

15. The apparatus according to claim 14, the apparatus further includes a cleaning polarizer positioned along the imaging path returning to the camera such that light having the same polarization as the light leaving the pre-polarizer is filtered out and cannot reach the camera.

16. The apparatus according to claim 13, wherein, The illumination condensing system includes at least one of a reflective microelectromechanical system (MEMS) micromirror array or a transmissive spatial light modulator.

17. The apparatus according to claim 13, wherein, The first channel further includes an objective lens system at an end of the first channel opposite to the base component, the objective lens system being configured to introduce light from the first illumination source into the eye.

18. The device according to claim 17, wherein, The objective lens system is configured to narrow the light from the first illumination source in the cornea of the eye or between the cornea and the posterior lens of the eye.

19. The apparatus according to claim 13, wherein The base component further includes a second illumination source corresponding to the second region illumination path and a third illumination source corresponding to the third region illumination path.

20. The apparatus according to claim 19, wherein: The first region illumination path illuminates a radially inner segment of the posterior segment of the eye, and the first illumination source is located outside the housing and faces the outer edge of the apparatus; The second region illumination path illuminates a radially outer segment of the posterior segment of the eye, and the second illumination source is located outside the housing and faces the outer edge of the apparatus; and The third region illumination path illuminates a middle segment of the posterior segment of the eye, and the third illumination source is located outside the housing and faces the inner region of the apparatus.

21. The apparatus according to claim 20, wherein: Each of the plurality of channels includes a guiding illumination source for aligning the apparatus with the eye; The guiding illumination source of the first channel is located outside the housing and faces the inner region of the apparatus; and wherein each guiding illumination source for each of the plurality of channels is configured to illuminate such that when the apparatus is close to the eye, light from the guiding illumination source is reflected from the eye.

22. The apparatus according to claim 1, the apparatus further includes a fixation system, the fixation system including: A fixation light source located within the central region of the apparatus and aligned with the central axis of the apparatus; and A focusing chamber through which light from the fixation light source passes, the focusing chamber including a pinhole at an end of the focusing chamber opposite to the fixation light source.

Images