Patent Description:
Ocular imaging is commonly used both to screen for diseases and to document findings discovered during clinical examination of the eye. Specifically, documentation and analysis of the posterior segment of the eye (e.g., retinal imaging) may be relevant to comprehensive eye examinations and full evaluations of current conditions, treatment, and/or early prevention of various eye conditions and diseases.

To achieve wider field of view images, some approaches utilize a laser-scanning image illumination approach. However, such images are not true to color, and require a very large device. Another approach includes a traditional fundus camera (a low-powered microscope with an attached camera for retinal imaging) that is repeatedly repositioned to capture successive images, and numerical algorithms are used to form a composite image from each of the individual repositioned images.

Further background is provided in the following documents.

<CIT> discloses a device for use in the screening, documentation, and diagnosis of various diseases of the eye. Several images are taken substantially simultaneously, preferably in a non-coplanar orientation relative to each other. The images represent multiple different zones of the retina taken using different optical imaging pathways. Image distortion is minimized, because the individual optical imaging pathways need to account for significantly less differential curvature of the object plane than a wide-field optical pathway that attempts to capture both the central and peripheral retina in a single image. A single composite wide field image can be generated, by merging the overlapping fields of multiple, concurrently captured images taken at different angles.

<CIT> discloses a device and methods for concurrently taking multiple partially overlapping still or video images of the iridocorneal angle of an eye. The device typically comprises a single chassis with an outer surface that approximately matches the curvature of the ocular surface. Multiple discrete optical imaging systems are aimed through the cornea and the anterior chamber, producing non-coplanar optical paths directed towards corresponding partially overlapping zones of the iridocorneal angle. Each system may comprise one or more optical lenses, with either fixed or variable position, and a corresponding digital sensor or portion of a larger common shared digital sensor.

<CIT> discloses a method and system for wavelength-dependent imaging and detection using a hybrid filter. An object to be imaged or detected is illuminated by a single broadband light source or multiple light sources emitting light at different wavelengths. The light is detected by a detector, which includes a light-detecting sensor covered by a hybrid filter.

<CIT> discloses methods and apparatus for pupil detection. First light is emitted from a first light source at a first illumination angle relative to the axis of a detector. Second light is emitted from a second light source at a second illumination angle relative to the axis. The first light and the second light can have substantially equal intensities. The second illumination angle is greater than the first illumination angle. Reflected first light and reflected second light are received at the detector. The difference between the reflected first light and the reflected second light can be determined. The difference can be used to detect the pupils of a subject's eyes.

<CIT> discloses an imaging device which includes first and second optical channels, where each of the first and second optical channels include a discrete optical imaging pathway. The first and second optical channels may be aimed at different angles relative to each other, and each may be directed towards corresponding partially overlapping zones of an object for imaging. Each of the optical channels may include an illuminating source configured to be turned on or off, where illumination from the illuminating sources follow respective illumination paths to the object. Each of the optical channels may additionally include lenses shared by both the respective optical imaging pathways and the respective illumination paths, and each may include an image sensor. The imaging device may also include a computing device configured to turn on the illuminating source of the first optical channel while capturing an image using the image sensor of the second optical channel.

The present invention provides a device for illuminating a posterior segment of an eye as set out in claim <NUM>.

It is to be understood that both the foregoing general description and the following detailed description are given as examples and explanatory and are not restrictive of the present disclosure, as claimed.

According to the invention, distinct image channels are used to image a wide field of view of the posterior segment of the eye using a single device. In particular, the three distinct channels are oriented about a common axis such that multiple regions of the posterior segment may be imaged without readjusting the location of the imaging device. To facilitate the wide field of view, different portions of the posterior segment are illuminated at different times to avoid interference by the illumination beams with the imaging channel.

<FIG> illustrate a circular shape with grid-lines, representing the posterior segment 100a of the eye. Overlaid on the posterior segment 100a is a first region <NUM> representing a portion of the posterior segment 100a that is imaged and/or illuminated by a first imaging channel.

As illustrated in <FIG>, the posterior segment 100b is covered by multiple channels. For example, the first region <NUM> covered by the first imaging channel is illustrated, a second region <NUM> covered by a second imaging channel is illustrated, and a third region <NUM> covered by a third imaging channel. The three regions <NUM>, <NUM>, and <NUM> include overlapping regions such that nearly the entire posterior segment is covered by the three regions <NUM>, <NUM>, and <NUM>. For example, the overlapping regions <NUM>, <NUM>, and <NUM> (as illustrated by the hashmarks) illustrate regions covered by two imaging channels, and the overlapping region <NUM> illustrates a region covered by all three imaging channels. By using this pattern of overlap, the central region of the posterior segment is covered by all three imaging channels. Additionally, as explained below, the use and orientation of the three imaging channels permits an imaging device to image all three channels via a handheld device without reorienting the imaging device relative to the eye.

In some embodiments, each of the imaging channels include an individual imaging system with an imaging sensor, filters, etc. The imaging systems may be a smaller scale compared to typical fundus cameras. For example, the three imaging channels together may fit into a single hand-held device. In these and other embodiments, the three imaging channels may be offset from each other about the center of the imaging device and may be angled to cover the corresponding region <NUM>, <NUM>, or <NUM>. For example, the imaging systems may be offset from each other by one hundred and twenty degrees about the center point of the imaging device. In another embodiment, the imaging systems may be offset from the central axis of the imaging device by different or variable angles, 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 may be combined with an imaging channel that is on-axis relative to the device and/or the optical axis of the eye.

<FIG> and <FIG> illustrate a single imaging channel. <FIG> illustrate systems 200a and 200b of the optical traces <NUM> of the imaging path for the single imaging channel. <FIG> illustrates various portions of the imaging system <NUM> of the single imaging channel, such as lenses, windows, sensors, etc..

As illustrated in <FIG>, the optical traces <NUM> illustrate the imaging optical path as it passes through the anterior segment of the eye to image the region <NUM> of the posterior segment of the eye.

As illustrated in <FIG>, the imaging system <NUM> illustrates the optical traces <NUM> of imaging of the posterior segment. In the example illustrated in <FIG>, not covered by the claimed invention, the imaging system <NUM> may include a single imaging channel <NUM>. The single imaging channel <NUM> may include a glass window <NUM>, one or more glass lenses <NUM>, one or more polarizers <NUM>, one or more relay lenses <NUM>, one or more camera sensors <NUM>, and a camera aperture <NUM>. To facilitate understanding of the location and interaction of the various components of the single imaging channel <NUM>, the optical traces <NUM> illustrate a path from the retina of the eye to the camera sensor <NUM>.

As illustrated in <FIG>, tracing from the back wall of the eye at the retina, the optical traces <NUM> pass through the posterior lens and pass out at the anterior lens of the eye. Where the optical traces <NUM> pass out of the anterior lens and into the comea is the entrance/exit point for the imaging path to/from the inside of the eye for the imaging system <NUM>. As the optical traces <NUM> pass through the cornea, they then pass through a glass window <NUM> of the single imaging channel <NUM> at an end of the single imaging channel <NUM> proximate the eye. The glass window <NUM> may be the physical interface between the imaging device and the eye, and may be shaped with a curvature that is shaped to interface with the eye (e.g., with a curvature that matches an average eye curvature). In some embodiments, the glass window <NUM> may be oriented and aligned with a center of the eye and may be of a size that each of the multiple imaging channels may pass through the glass window <NUM>, rather than including a glass window for each channel. Additionally or alternatively, each of the multiple imaging channels may include their own glass window. In some embodiments, the glass window <NUM> may be positioned in direct contact with the comea with or without a coupling gel or fluid, while in other embodiments the glass window <NUM> may be positioned some distance away from the cornea.

After passing through the glass window <NUM>, the optical traces <NUM> may pass through one or more glass lenses <NUM>, such as the glass lens <NUM>354a and the glass lens <NUM>354b. The initial glass lenses <NUM> may cause the optical traces <NUM> from the single imaging channel <NUM> to form at an intermediate image that may be located at about one third of the length of the imaging path for the single imaging channel <NUM>. In some embodiments, the single imaging channel <NUM> may be oriented approximately twenty five degrees off of the center axis of the eye and/or the center line of the multi-channel imaging device, although any position, such as between five and forty-five degrees off of the center axis are contemplated. In these and other embodiments, the angle may be modified based on the entrance pupil position and/or the mechanical mounting of the single channels <NUM> within the multi-channel imaging device.

The optical traces <NUM> may continue on through the single imaging channel <NUM> to pass through a cleanup polarizer <NUM>. The cleanup polarizer <NUM> may be configured to act as a polarization filter such that any light reflected back towards the camera sensor <NUM> from surfaces within the single imaging channel <NUM> from an orthogonally polarized illumination source may be filtered out while allowing the unpolarized light scattered off of the retina to pass through the cleanup polarizer <NUM> for imaging. In some embodiments, the polarized illumination source may be oriented using a filter or other feature. In some embodiments, the illumination source and/or the cleanup polarizer <NUM> may be tunable.

The optical traces <NUM> may continue on through the single imaging channel <NUM> to pass through one or more relay lenses 358which may include individual relay lenses or any system of relay lenses. While illustrated as a single relay lens <NUM>, any number of reflective or refractive optical elements may be included. As illustrated in <FIG>, there is one relay system (e.g., the relay lens <NUM>) and camera (the camera sensor <NUM> and/or the camera aperture <NUM>) per objective and the relay system may be aligned to the objective. The present disclosure may be multiple cameras with relays, each oriented toward the intermediate image in a patterned or random arrangement.

As the relay lens <NUM> begins to focus the beams of the single imaging channel <NUM>, the optical traces <NUM> may pass through the camera aperture <NUM> and arrive at the camera sensor <NUM> for capturing an image of the posterior segment of the eye. In some embodiments, the intermediate image plane may be aligned to a plane of the camera sensor <NUM>. The camera aperture <NUM> may be aligned with the plane of the camera sensor <NUM> and may be conjugate to the system entrance pupil (e.g., the entrance pupil position illustrated in <FIG>).

As illustrated in <FIG>, the single imaging channel <NUM> is offset from the center of the eye such that, according to the invention, multiple such single channels are disposed within the same single imaging device.

<FIG> illustrates a multi-channel imaging system <NUM>. <FIG> illustrates a side view of the multi-channel imaging system <NUM>, <FIG> illustrates a top-down view of the multi-channel imaging system <NUM>, <FIG> illustrates a front view of the multi-channel imaging system <NUM> (e.g., from the eye looking out towards the multi-channel imaging system), and <FIG> illustrates a back view of the multi-channel imaging system <NUM>.

As illustrated in <FIG>, the first imaging channel 410a may include the optical traces 412a to illustrate the imaging of the first region 414a, the second imaging channel 410b may include the optical traces 412b to illustrate the imaging of the second region 414b, and the third imaging channel 410c may include the optical traces 412c to illustrate the imaging of the third region 414c. While illustrated as three equally-spaced channels, any number of channels and spacing of those channels may be included. For example, two, four, five, six, or any number of channels may be used. As another example, rather than being equally distributed, the channels may be arranged in a varied or weighted arrangement, rather than equally distributed.

According to the invention, because the plurality of illustrated imaging channels converge on a single point, there is overlap at the apex of the three imaging channels. To address the overlap, the imaging channels may be truncated symmetrically and mounted against a symmetrical three-section wall <NUM>. The different sections of the three-section wall <NUM> function as axial baffles to block light from crossing between the different channels. In some embodiments, the imaging channels may be truncated in an asymmetric manner and mounted against an asymmetric wall <NUM>. In some embodiments, the wall <NUM> may contain within it optical illumination and/or imaging channels that are separate from those described herein. In some embodiments, if more than three channels are used the wall <NUM> may be a multi-sectioned wall with a same number of sections as there are channels.

In some embodiments, the glass lenses of the individual channels may be individually cut and mounted so as to be separated by the three-section wall <NUM>. Additionally or altematively, the glass lenses may be mounted without the three-section wall <NUM>. In these and other embodiments, the glass lenses across the distinct channels may be molded together as a single component and/or be mounted as separate components.

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

<FIG> illustrate various aspects of an illumination system associated with the multi-channel imaging system <NUM>. Each channel utilizes an illuminating system to facilitate illuminating the posterior segment of the eye for imaging. <FIG> illustrates a top down view of the multi-channel imaging system <NUM>, <FIG> illustrates a side view of the multi-channel imaging system <NUM>, <FIG> illustrates a front view of the multi-channel imaging system <NUM> (e.g., from the eye looking out towards the multi-channel imaging system <NUM>), and <FIG> illustrates a back view of the multi-channel imaging system <NUM> (e.g., looking towards the eye from the back of the multi-channel imaging system <NUM>). As illustrated in <FIG>, each respective channel includes an illuminating portion <NUM> (such as the illuminating portions 510a, 510b, and 510c). The illuminating portions <NUM> include LEDs <NUM>, or any other light emitting element. Additionally, the illuminating portions may include one or more lenses or filters <NUM> for aligning, shaping, and/or directing the light emitted from the LEDs <NUM>. In some embodiments, the filter <NUM> may include a polarizing filter such that the illumination light directed towards the eye may be polarized in the same direction to allow filtering of certain undesirable polarizations of light, such as specular reflections from the objective lenses (e.g., the glass lenses <NUM>). Stated another way, by polarizing the illumination light, any reflectance from the lenses or other elements of the imaging device would retain their polarization and thus be filterable by a polarizing filter in the imaging channel (e.g., the cleanup polarizer <NUM> in <FIG>), while allowing the scattered illumination on the retina that is travelling back along the imaging channel and thus used in imaging the posterior segment of the eye to pass through the polarizing filter. In some embodiments, polarization may be left out of the design of an imaging device and scattered light may be managed by other means, such as in the optical design of the imaging device or in software post-processing of the images acquired.

In some embodiments, the camera sensor and/or aperture may be oriented directly in line with the center line of the illuminating portion <NUM>. In these and other embodiments, the camera sensor may be located within a cylindrical chamber, and the LEDs <NUM> may be located outside of the cylindrical chamber. In these and other embodiments, the walls of the cylindrical chamber may act to prevent the illumination from the LEDs <NUM> from bleeding into the image capturing of the camera device. Stated another way, the LEDs <NUM> may be located offset from the center line of the illuminating portion <NUM> while the camera sensor is in line with the center line.

<FIG> illustrates a three-section wall <NUM> (that may be similar or comparable to the three-section wall <NUM> of <FIG>) and the glass lenses <NUM> (that may be similar or comparable to the lenses and/or windows <NUM> and/or <NUM> of <FIG>) within a nose cone portion <NUM> of the imaging device.

Using the imaging devices <NUM>, various portions of the posterior segment of the eye are illuminated at different times and along different paths to avoid illumination light interfering with the imaging path. For example, overlap between the illumination path to the posterior segment and an imaging path back from the posterior segment may cause diffuse scatter from ocular surfaces which may present as haze in a captured image.

<FIG> illustrate illumination patterns of a given region of the posterior segment of the eye for imaging. The gridlines represent the same gridlines as used in <FIG>. The dark blue region represents the various regions covered by the field-of-view illustrated in <FIG>. <FIG> illustrate how various portions of a given region are illuminated by different illuminating elements to avoid contamination of the imaging path by the illumination path. By illuminating different regions at different times, each portion is illuminated separately and the images may be combined to cover the entire region, and thus the entire wide field-of-view. The grid lines in <FIG> illustrate the posterior segment projected outward from the fovea. An inner radial portion <NUM> may illuminate from approximately <NUM>-<NUM> degrees from the fovea, an outer radial portion <NUM> may illuminate from approximately <NUM>-<NUM> degrees from the fovea, and a medial portion <NUM> may illuminate from approximately minus <NUM> - positive <NUM> degrees from the fovea, as well as the overlapping regions between the channels (e.g., regions <NUM>, <NUM>, <NUM>, and <NUM> of <FIG>).

The various portions <NUM>, <NUM>, and <NUM> may be illuminated and oriented in a different manner than illustrated in <FIG> that avoids interference on both the posterior and anterior surfaces of the crystalline lens and comea of the eye that would interfere with the imaging channel of the portion being illuminated and imaged. In some embodiments, the various portions <NUM>, <NUM>, and <NUM> may be illuminated one at a time for all three channels at the same time (e.g., the inner radial portion <NUM> for all three channels while an image is captured, the outer radial portion <NUM> for all three channels while an image is captured, and the medial portion <NUM> for all three channels while an image is captured), separately (e.g., the inner radial portion <NUM> for one channel may be illuminated while an image is captured for the illuminated portion of the posterior segment by one of the channels, etc.), or any combination or variation thereof.

<FIG> illustrates an example of illumination system <NUM> for illuminating an inner radial portion of the posterior segment of the eye. The illumination system <NUM> may include a base component <NUM> and a nose cone component <NUM>.

As illustrated in <FIG>, the base component <NUM> may include an LED <NUM> (or other light emitting device) and an associated aperture. The base component <NUM> may also include an illumination condenser system <NUM>, and a baffle and prepolarizer <NUM>. The base component <NUM> may additionally include a camera component <NUM> with a camera sensor <NUM> and a casing <NUM>. The camera sensor <NUM> may be disposed within the casing <NUM>, which may function to prevent light from the LED <NUM> from impacting the image capturing by the camera sensor <NUM>.

In some embodiments, the illumination condenser system <NUM> may include two elements (e.g., four surfaces) patterned symmetrically about the plane bisecting the imaging channel and retina. In these and other embodiments, the illumination condenser system <NUM> may include one or more passive refractive or reflective optical elements, or active elements, such as a reflective MEMS micromirror array, or transmissive spatial light modulator, to enable beam control and steering.

As illustrated in <FIG>, the plane in which the LED <NUM> is positioned and the illumination condenser system <NUM> may be positioned orthogonal to the channel axis (e.g., the axis along which the optical traces of the imaging channel are directed to the camera sensor <NUM>), such that the plane in which the LED <NUM> is positioned and the illumination condenser system <NUM> may be mounted around the casing <NUM>. It will be appreciated that the LED <NUM> and the illumination condenser system <NUM> may be placed anywhere in space such that the illumination path for the inner radial segment does not interfere with the imaging path for that segment on any ocular surfaces.

In some embodiments, the illumination condenser system <NUM> may be aligned and configured to image the comea to the aperture plane. In these and other embodiments, such an imaging location may further be based on the properties of an objective lens system <NUM> (which may be similar or comparable to the glass lenses <NUM> of <FIG>). For example, as illustrated in <FIG>, the illumination rays may travel through the illumination condenser system to be directed by the objective lens system <NUM> such that the illumination is approximately at its narrowest point in the cornea, thus reducing and/or minimizing interference with the rays of the imaging channel passing back through the cornea. While articulated in terms of the illumination rays imaging at the cornea, the LED <NUM> and associated aperture, the illumination condenser system <NUM>, and/or the objective lens system <NUM> may be configured such that the illumination rays may be configured to image at any location between the comea and the posterior crystalline lens of the eye along an axis that is non-overlapping with the imaging path for the radial segment being illuminated. In these and other embodiments, the aperture size and/or position of the aperture associated with the LED <NUM> may be selected to confine the path of the illumination rays through an exit pupil such that the illumination rays do not interfere with the path of the imaging rays when imaging the portion and/or region of the posterior segment that is being imaged.

In some embodiments, the baffles associated with the illumination channel may be placed and/or configured to trap stray light on the posterior (e.g., on the other side of the illumination condenser system <NUM> from the LED <NUM>) and anterior (e.g., on the same side as the LED <NUM>) sides of the illumination condenser system <NUM>. Additionally or alternatively, the baffles may be placed and/or configured to trap stray light between elements in the illumination condenser system <NUM>. In some embodiments, the baffles may be moveable within the device <NUM>. For example, the baffles may be mechanized and/or motorized such that their position may be adjusted to alter the illumination optics for different eyes and/or different applications. In some embodiments, the casing <NUM> may function as a baffle to trap such stray light. Additionally or alternatively, the three-section wall of the imaging device may operate as a baffle to block certain stray light (e.g., the three-section wall <NUM> of <FIG>).

In some embodiments, the pre-polarizer <NUM> may 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 <NUM>) maintain their state of polarization. Such an arrangement allows a cleanup polarizer in the imaging path to reject specularly reflected light as such light maintains polarization on reflection (e.g., may be filtered by the cleanup polarizer <NUM>). Additionally, such an arrangement may permit non-polarized light, such as the illumination light scattered by the retina tissue and travelling along the imaging channel, to pass through the cleanup polarizer for imaging.

<FIG> illustrate the imaging system <NUM> generating the imaging rays for illuminating the inner radial portion of the posterior segment. <FIG> illustrates a side view of the imaging system <NUM>, <FIG> illustrates a top-down view of the imaging system <NUM>, <FIG> illustrates a front view of the imaging system <NUM> (e.g., from the eye looking out towards the multi-channel imaging system), and <FIG> illustrates a back view of the multi-channel imaging system <NUM>.

As illustrated in <FIG>, in some embodiments, all three channels may illuminate simultaneously such that the inner radial portions for all three imaging channels may be illuminated at the same time. For example, all three imaging channels may illuminate and image all three imaging channels at the inner radial portion of the posterior segment at the same time. Additionally or altematively, the inner radial portion for each imaging channel may be independently or sequentially illuminated and imaged, for example, three distinct images for each of the inner radial portions for each of the imaging channels may be taken at different times.

<FIG> illustrates an example of illumination system <NUM> for illuminating an inner radial portion and an outer radial portion of the posterior segment of the eye. The illumination system <NUM> may include a base component <NUM> and a nose cone component <NUM>. The illumination system <NUM> may be similar or comparable to the illumination system <NUM> illustrated in <FIG>. The illumination system <NUM> may include a distinct LED <NUM> and associated aperture that may be different or distinct from the LED <NUM> of <FIG>, where the LED <NUM> may be configured to illuminate the outer radial portion and the LED <NUM> may be configured to illuminate the inner radial portion of the posterior segment. In these and other embodiments, the illumination system <NUM> may include all of the components illustrated in <FIG> as well as those illustrated in <FIG>, such that the illumination system <NUM> may illuminate the inner radial segment and the outer radial segment. The components that are similarly numbered may operate or function in the same or similar manner as the components as described above with respect to <FIG>.

The elements of <FIG> may be similar or comparable to those of <FIG>, serving similar functions although illuminating a different portion of the posterior segment of the eye. For example, the base component <NUM> may be similar or comparable to the base component <NUM> of <FIG> (e.g., may include an LED <NUM> similar or comparable to the LED <NUM> (or other light emitting device) and an associated aperture). The base component <NUM> may also include an illumination condenser system <NUM> that may be similar or comparable to the illumination condenser system <NUM>. The base component <NUM> may also include a baffle and/or prepolarizer <NUM> that may be similar or comparable to the baffle and/or prepolarizer <NUM>. The base component <NUM> may additionally include a camera component <NUM> that may be similar or comparable to the camera component <NUM>, including a camera sensor <NUM> comparable or similar to the camera sensor <NUM> and casing <NUM> similar or comparable to the casing <NUM>.

As illustrated in <FIG>, the illumination beams <NUM> illuminating the outer radial segment and the illumination beams <NUM> illuminating the inner radial segment are illustrated as being active simultaneously. As seen in <FIG>, the combination of the illumination beams <NUM> and <NUM> consume more space within the anterior segment of the eye, increasing the likelihood of illumination interfering with imaging of the posterior segment of the eye. In these and other embodiments, if the orientation and/or alignment of the illumination beams <NUM> and <NUM> (e.g., via the apertures, illumination condenser system <NUM>, and/or objective lens system <NUM>) is such that both segments may be imaged without interference in the imaging channel, both may be simultaneously illuminated and imaged. Additionally or alternatively, the inner radial segment and the outer radial segment may be sequentially illuminated such that the two segments may be independently imaged where a smaller portion of the space within the anterior segment of the eye is consumed by the illumination beams.

<FIG> illustrate the imaging system <NUM> generating the imaging rays for illuminating the outer radial portion of the posterior segment. <FIG> illustrates a side view of the imaging system <NUM>, <FIG> illustrates a top-down view of the imaging system <NUM>, <FIG> illustrates a front view of the imaging system <NUM> (e.g., from the eye looking out towards the multi-channel imaging system), and <FIG> illustrates a back view of the multi-channel imaging system <NUM>.

As illustrated in <FIG>, in some embodiments, all three channels may illuminate simultaneously such that the outer radial portions for all three imaging channels may be illuminated at the same time. For example, all three imaging channels may illuminate and image all three imaging channels at the outer radial portion of the posterior segment at the same time. Additionally or altematively, the outer radial portion for each imaging channel may be independently or sequentially illuminated and imaged, for example, three distinct images for each of the outer radial portions for each of the imaging channels may be taken at different times.

<FIG> illustrate the imaging system <NUM> generating the imaging rays for illuminating the medial portion of the posterior segment. <FIG> illustrates a side view of the imaging system <NUM>, <FIG> illustrates a top-down view of the imaging system <NUM>, <FIG> illustrates a front view of the imaging system <NUM> (e.g., from the eye looking out towards the multi-channel imaging system), and <FIG> illustrates a back view of the multi-channel imaging system <NUM>.

As illustrated in <FIG>, in some embodiments, all three channels may illuminate simultaneously such that the medial portions for all three imaging channels may be illuminated at the same time. For example, all three imaging channels may illuminate and image all three imaging channels at the medial portion of the posterior segment at the same time. Additionally or altematively, the medial portion for each imaging channel may be independently or sequentially illuminated and imaged, for example, three distinct images for each of the medial portions for each of the imaging channels may be taken at different times.

In these and other embodiments, the imaging system <NUM> for the medial segment may include and/or utilize a similar or comparable illumination condenser system such as those illustrated in <FIG> and <FIG>. Additionally or altematively, the imaging system <NUM> for the medial segment may include and/or utilize a baffle and/or prepolarizer of <FIG> and <FIG>.

In some embodiments, a given medial portion may be illuminated by two neighboring channels, rather than the actual imaging channel. For example, with a three channel imaging system, as an initial channel images, the other two channels may illuminate the medial portion as it is imaged by the initial channel. In these and other embodiments, a series of images may be captured as one channel images and the other two channels illuminate in a rotating or sequential manner. For example, with a first, second, and third channel, the first channel may image while the second and third channels illuminate, followed by the second channel imaging while the first and third channels illuminate, followed by the third channel imaging while the first and second channels illuminate.

<FIG> illustrate the imaging system <NUM> generating the imaging rays for illuminating the outer radial portion, the inner radial portion, and the medial portion of the posterior segment. <FIG> illustrates a side view of the imaging system <NUM>, <FIG> illustrates a top-down view of the imaging system <NUM>, <FIG> illustrates a front view of the imaging system <NUM> (e.g., from the eye looking out towards the multi-channel imaging system), and <FIG> illustrates a back view of the multi-channel imaging system <NUM>.

As illustrated in <FIG>, rays for illuminating all three portions are illustrated, as well as the rays for imaging the posterior segment. For example, the rays for illuminating the outer radial portion (red), the inner radial portion (green), and the medial portion (magenta) are illustrated in conjunction with the rays for imaging (blue) the posterior segment.

<FIG> illustrates an imaging system <NUM> for guiding placement of an associated imaging device relative to the eye. For example, imaging system <NUM> may include one or more LEDs <NUM> that may be configured to provide reflection and/or scattering from surfaces of the eye, such as the cornea, crystalline lens, and/or retina, such that an operator of an imaging device may orient the imaging device correctly upon the eye. As another example, the imaging system <NUM> may include an illumination condenser system <NUM> that may direct or shape the guidance illumination. In these and other embodiments, the illumination condenser system <NUM> may be bisected by the plane that bisects the imaging channel and the retina. Additionally, the imaging system <NUM> may utilize a nose cone section <NUM>, including an objective lens system <NUM>, for directing guidance rays <NUM> to the center of the eye beginning at equidistant positions about the center of the eye. For example, as illustrated in <FIG>, each of the guidance rays <NUM> from each of the three channels may combine near the center of the eye such that the reflectance of each of the multiple guidance rays <NUM> may be oriented around the center of the eye by an operator of the imaging system <NUM>.

In these and other embodiments, the guidance rays <NUM> may consume a substantial portion of the space through which the imaging rays may pass in the anterior segment of the eye in order to allow the imaging device to be guided in position with respect to the eye to facilitate imaging. In these and other embodiments, imaging and/or illumination of the retina may occur after the guidance has been completed such that the consumption of the substantial portion of the space does not impact the imaging that occurs after the guidance of the imaging device.

<FIG> illustrates a side view of the imaging system <NUM>, <FIG> illustrates a top-down view of the imaging system <NUM>, <FIG> illustrates a front view of the imaging system <NUM> (e.g., from the eye looking out towards the multi-channel imaging system), and <FIG> illustrates a back view of the multi-channel imaging system <NUM>.

<FIG> illustrates an example arrangement <NUM> of condensers. For example, the arrangement <NUM> includes inner radial segment condensers <NUM>, outer radial segment condensers <NUM>, medial segment condensers <NUM>, and a guidance condenser <NUM>.

As illustrated in <FIG>, each of the condensers <NUM>, <NUM>, <NUM>, and <NUM> may be oriented around a central region within which the rays of the imaging channel may be directed. For each of the condensers <NUM>, <NUM>, <NUM>, and <NUM> may be aligned symmetrically about a plane bisecting the imaging channel and the retina (as illustrated by the green arrow).

In some embodiments, the inner radial segment condensers <NUM> and/or the outer radial segment condensers <NUM> may be oriented along an outer edge of the imaging device (e.g., among the three imaging channels, the inner radial segment condensers <NUM> and/or the outer radial segment condensers <NUM> may be located on the side away from the other imaging channels). In some embodiments, the medial segment condensers <NUM> and/or the guidance condensers <NUM> may be oriented along an inner edge of the imaging device (e.g., among the three imaging channels, the medial segment condensers <NUM> and/or the guidance condensers <NUM> may be located on the side proximate to the other imaging channels). Using such an arrangement, the inner and outer radial segment illumination may project further out towards the outer portions of radial segments of the eye. In these and other embodiments, the medial segment condensers <NUM> and the guidance condensers <NUM> may be configured to direct the illumination towards the middle of the eye.

<FIG> illustrates an example set <NUM> of imaging channels, 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 may be individually imaged and/or illuminated, including illuminating a specific portion as guided by one or more of the condensers illustrated in the present disclosure.

<FIG> illustrates an example imaging device <NUM> including a fixation system that generates fixation rays <NUM> of illumination upon which the eye will focus during operation of the imaging device <NUM>. As illustrated in <FIG>, the fixation system may be positioned and oriented proximate the center of the imaging device <NUM> or along a central axis of the imaging device <NUM>, with imaging and illumination channels positioned around the fixation system. For example, the fixation system may be on the same axis as the eye is focused, while the imaging channels are oriented around the central channel. In some embodiments, the fixation system may be located within one or more of the optical imaging systems rather than outside of the optical imaging systems.

The fixation system may include an LED <NUM>, an aperture <NUM>, and a lens <NUM> to direct the fixation rays <NUM> towards the retina of the eye. The LED <NUM> may be any device configured to emit a beam of light. The LED <NUM> may be selected to limit an amount of scatter into other lenses or portions of the imaging device <NUM>.

In some embodiments, the LED <NUM>, the aperture <NUM>, and the lens <NUM> may be selected to provide a focused beam of light to the eye (represented by the fixation rays <NUM>). In these and other embodiments, the fixation rays <NUM> may convene past the aperture <NUM> into a beam that projects through a focusing chamber <NUM>. In some embodiments, the aperture(s) may create a focused pattern of fixation light, thereby creating a discrete fixation pattern for the eye to view.

The focusing chamber <NUM> may be a chamber with light absorbing regions and materials within the chamber. The chamber may include an opening proximate the region where the lens <NUM> and the LED <NUM> cause the beams to coalesce and may include a pinhole opening <NUM> on the opposite side of the focusing chamber <NUM>. In some embodiments, the opening near the LED <NUM> may also be a pinhole opening. In these and other embodiments, by using the focusing chamber <NUM>, any light beams from the LED <NUM> that are not narrowly directed towards the retina may be absorbed within the focusing chamber <NUM>. In this way, a highly focused fixation beam may be generated upon which the eye may focus during use. Because the fixation rays <NUM> are focused to a narrow beam, the size of the fixation system is minimized such that most of the volume of the imaging device <NUM> is available for the imaging channels. According to such an arrangement, a clear line-of-sight may exist between the LED <NUM> and the retina of the eye.

In some embodiments, one or more imaging channels may share the central axis with the fixation system. For example, a medial illuminating and imaging channel for illuminating and imaging the medial portion of the posterior segment may share the central axis of the imaging device <NUM>. 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.

In some embodiments, a set of optical components (such as the aperture <NUM>, the lens <NUM>, and/or other components) may be selected, designed, and/or positioned to image the aperture <NUM> onto the retina of the eye, through the clear line of sight enabled by the pinhole opening exiting the focusing chamber <NUM>, such that the eye may see and focus on a resolvable spot, which may be used during image capture as a fixation target for the eye, such that the ocular surfaces of the eye, such as the crystalline lens, are in a fixed position while the eye is focused on the resolvable spot, thereby reducing variation in the position and imaging properties of the eye during image capture.

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

Generally, the processor may include any suitable special-purpose or general-purpose computer, computing entity, or processing device including various computer hardware or software modules and may be configured to execute instructions stored on any applicable computer-readable storage media. For example, the processor may 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 circuitry configured to interpret and/or to execute program instructions and/or to process data.

It is understood that the processor may include any number of processors distributed across any number of networks or physical locations that are configured to perform individually or collectively any number of operations described herein. In some embodiments, the processor may interpret and/or execute program instructions and/or processing data stored in the memory. By interpreting and/or executing program instructions and/or process data stored in the memory, the device may perform operations, such as the operations performed by the retinal imaging device described in the present disclosure.

The memory may include computer-readable storage media or one or more computer-readable storage mediums for carrying or having computer-executable instructions or data structures stored thereon. Such computer-readable storage media may be any available media that may be accessed by a general-purpose or special-purpose computer, such as the 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 disk storage, magnetic disk storage or other magnetic storage devices, flash memory devices (e.g., solid state memory devices), or any other storage medium which may be used to carry or store desired program code in the form of computer-executable instructions or data structures and which may be accessed by a general-purpose or special-purpose computer. Combinations of the above 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 that were found to fall outside the scope of patentable subject matter in the Federal Circuit decision of In re Nuijten, <NUM> F. 3d <NUM> (Fed. In some embodiments, computer-executable instructions may include, for example, instructions and data configured to cause the processor to perform a certain operation or group of operations as described in the present disclosure.

In accordance with common practice, the various features illustrated in the drawings may not be drawn to scale. The illustrations presented in the present disclosure are not meant to be actual views of any particular apparatus (e.g., device, system, etc.) or method, but are merely idealized representations that are employed to describe various embodiments of the disclosure. Accordingly, the dimensions of the various features may be arbitrarily expanded or reduced for clarity. Thus, the drawings may not depict all of the components of a given apparatus (e.g., device) or all operations of a particular method.

Terms used herein and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including, but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes, but is not limited to," etc.).

Additionally, if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations.

In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." or "one or more of A, B, and C, etc." is used, in general 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 interpreted to mean a value within <NUM>% of actual value.

Further, any disjunctive word or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" should be understood to include the possibilities of "A" or "B" or "A and B.

However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and/or "an" should be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations.

Additionally, the use of the terms "first," "second," "third," etc., are not necessarily used herein to connote a specific order or number of elements. Generally, the terms "first," "second," "third," etc., are used to distinguish between different elements as generic identifiers. Absence a showing that the terms "first," "second," "third," etc., connote a specific order, these terms should not be understood to connote a specific order. Furthermore, absence a showing that the terms "first," "second," "third," etc., connote a specific number of elements, these terms should not be understood to connote a specific number of elements. For example, a first widget may be described as having a first side and a second widget may be described as having a second side. The use of the term "second side" with respect to the second widget may be to distinguish such side of the second widget from the "first side" of the first widget and not to connote that the second widget has two sides.

Claim 1:
A device (<NUM>, <NUM>) for illuminating a posterior segment of an eye, including:
a plurality of channels (410a, 410b, 410c, 510a, 510b, 510c), each of the plurality of channels including:
a first region (414a) illumination path; and
a second region (414b) illumination path,
wherein the first region illumination path and the second region illumination path are illuminated at different times such that a first region and a second region are imaged without interference from a non-illuminated illumination path, and
characterised in that the plurality of channels converge at a single point proximate the eye, the device further comprising a multi-sectioned wall (<NUM>) disposed at the single point, the multi-sectioned wall preventing light from crossing between the plurality of channels.