WO2020060486A1

WO2020060486A1 - Mobile eye-imaging device for detecting eye pathologies

Info

Publication number: WO2020060486A1
Application number: PCT/SG2019/050463
Authority: WO
Inventors: Yang Yu; David Chen; Clement Woon Teck TAN; Chee Yuen Cheng; Saw Soon YONG
Original assignee: Ngee Ann Polytechnic; National University Hospital Singapore Pte Ltd
Current assignee: Ngee Ann Polytechnic; National University Hospital Singapore Pte Ltd
Priority date: 2018-09-17
Filing date: 2019-09-13
Publication date: 2020-03-26
Anticipated expiration: 2021-03-17
Also published as: SG10201808021VA

Abstract

A mobile eye imaging device for detecting eye pathologies includes an imaging camera with a processor, a light source, one or more optical elements, a mirror for directing incident light from the light source into an eye, a housing assembly and a mounting assembly. The housing assembly includes at least one magnet and a lens held in a hole formed through the housing assembly, wherein the housing assembly is configured to hold the light source and the mirror, and to direct the incident light from the light source along an optical axis through the one or more optical elements and onto the mirror reflecting the incident light at a predefined angle relative to the optical axis, wherein the one or more optical elements filter or shape the incident light for illuminating the eye with a predefined illumination pattern. The imaging camera may be a smartphone camera and the one or more optical elements may include an optical slit.

Description

MOBILE EYE-IMAGING DEVICE FOR DETECTING EYE PATHOLOGIES

FIELD OF THE DISCLOSURE

The present disclosure relates to ophthalmic diagnostic devices, and more particularly to mobile eye-imaging devices for detecting eye pathologies.

BACKGROUND

Ophthalmic pathologies represent up to five percent of medical complaints by a patient to a primary care physician. In developing countries or in remote locations, there may be a limited availability of ophthalmic diagnostic tools, such as ophthalmic slit lamps, for example, available to the physician for adequate primary assessment in a primary care setting.

In addition, tools that do exist in such remote locations would not be able to provide physicians with the ability to automatically diagnose ophthalmic diseases.

Mobile communication devices such as smartphones and their cameras are increasingly being utilized as a companion-imaging tool for physicians for use in a wide variety of medical areas.

Thus, there may be a desire for low-cost ophthalmic diagnostic device adapters that may be used in conjunction with mobile communication devices for providing physicians in remote locations to perform a more accurate initial assessment of patients with ophthalmic complaints and diagnose ophthalmic diseases, in the absence of a primary care setting.

SUMMARY

There is thus provided, in accordance with some embodiments of the present disclosure, a mobile eye imaging device for detecting eye pathologies may include an imaging camera with a processor, a light source, one or more optical elements, a mirror for directing incident light from the light source into an eye, a housing assembly and a mounting assembly. The housing assembly may include at least one magnet and a lens held in a hole formed through the housing assembly. The housing assembly may be configured to hold the light source and the mirror and to direct the incident light from the light source along an optical axis through the one or more optical elements and onto the mirror reflecting the incident light at a predefined angle relative to the optical axis, wherein the one or more optical elements filter or shape the incident light for illuminating the eye with a predefined illumination pattern. The mounting assembly removably attachable to the housing assembly by the at least one magnet for holding the imaging camera may be positioned substantially opposite to the lens held in the hole, wherein reflected light from the eye is coupled by the lens into the imaging camera for capturing images of the eye.

Furthermore, in accordance with some embodiments of the present disclosure, the predefined angle may include a range of 35 to 55 degrees relative to the optical axis.

Furthermore, in accordance with some embodiments of the present disclosure, the one or more optical elements may be selected from the group consisting of a blue cobalt filter, a blue light emitting diode, lenses, mirrors, an optical slit, a light diffuser, and a light condenser.

Furthermore, in accordance with some embodiments of the present disclosure, the mobile eye imaging device may include an intensity control knob for controlling an intensity of the incident light directed to the eye.

Furthermore, in accordance with some embodiments of the present disclosure, the imaging camera may include a smartphone camera.

Furthermore, in accordance with some embodiments of the present disclosure, the processor may be configured to assess pathologies in the eye from the captured images of the eye.

Furthermore, in accordance with some embodiments of the present disclosure, at least one optical element from the one or more optical elements may include an optical slit and the predefined illumination pattern may include a slit lamp pattern illuminating the eye.

Furthermore, in accordance with some embodiments of the present disclosure, the reflected light from the eye captured by the imaging camera in response to the slit lamp pattern may include colored bands in the captured image of the eye corresponding to the incident light reflected from a cornea, an iris, and a lens of the eye.

Furthermore, in accordance with some embodiments of the present disclosure, the processor may be configured to estimate intensities of the reflected light in the colored bands by counting the pixels in the captured image for each colored band. Furthermore, in accordance with some embodiments of the present disclosure, the processor may be configured to detect the likelihood of acute primary angle closure in the eye from the estimated intensities of the reflected light in each colored band.

There is further provided, in accordance with some embodiments of the present disclosure, a mobile eye imaging slit lamp device for detecting eye pathologies may include an imaging camera, a light source, one or more optical elements including an optical slit, a mirror for directing incident light from the light source into an eye, a housing assembly, a mounting assembly, and a processor. The housing assembly may include at least one magnet and a lens held in a hole formed through the housing assembly. The housing assembly may be configured to hold the light source and the mirror and to direct the incident light from the light source along an optical axis through the one or more optical elements and onto the mirror reflecting the incident light at a predefined angle relative to the optical axis, wherein the eye is illuminated with a slit lamp illumination pattern. The mounting assembly may be removably attachable to the housing assembly by the at least one magnet for holding the imaging camera positioned substantially opposite to the lens held in the hole, wherein reflected light from the eye is coupled by the lens into the imaging camera for capturing images of the eye. The processor may be configured to estimate intensities of the reflected light from colored bands in the captured image of the eye in response to the slit lamp pattern, each colored band corresponding to the incident light reflected from a cornea, an iris, an anterior surface of the lens of the eye, and a posterior surface of the lens of the eye, to use the estimated intensities to compute a distance A between the cornea to the anterior surface of the lens and a distance B between the anterior surface and the posterior surface of the lens, and to compute a ratio A/B indicative of a likelihood of a disease in the eye when the ratio A/B is smaller than a predefined threshold.

Furthermore, in accordance with some embodiments of the present disclosure, the processor may be configured to estimate intensities of the reflected light in the colored bands by counting the pixels in the captured image for each colored band.

Furthermore, in accordance with some embodiments of the present disclosure, the imaging camera may be a smartphone camera.

Furthermore, in accordance with some embodiments of the present disclosure, the processor may be a processor of a smartphone. BRIEF DESCRIPTION OF THE DRAWINGS

In order for the embodiments of the present disclosure to be better understood and for its practical applications to be appreciated, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as examples only and in no way limit the scope of the embodiments of the present disclosure. Like components are denoted by like reference numerals.

Fig. 1 schematically illustrates an eye-imaging device for imaging an eye of a subject, in accordance with some embodiments of the present disclosure;

Fig. 2 schematically illustrates a block diagram of an eye-imaging device used as a slit lamp apparatus, in accordance with some embodiments of the present disclosure;

Fig. 3 schematically illustrates a block diagram of circuitry in a housing assembly and in an imaging device, in accordance with some embodiments of the present disclosure;

Fig. 4A schematically illustrates an isotropic top view of a mobile eye imaging device, in accordance with some embodiments of the present disclosure;

Fig. 4B schematically illustrates a cutout view of an optical design of a mobile eye imaging device, in accordance with some embodiments of the present disclosure;

Fig. 4C schematically illustrates an exploded top view of a mobile eye imaging device, in accordance with some embodiments of the present disclosure;

Fig. 4D schematically illustrates an exploded bottom view of a mobile eye imaging device, in accordance with some embodiments of the present disclosure;

Fig. 5 schematically illustrates reflected light from anatomical features in an eye in response to incident light illuminating the eye obliquely, in accordance with some embodiments of the present disclosure;

Fig. 6A schematically illustrates a first embodiment of a captured image of an eye, in according with some embodiments of the present disclosure; and

Fig. 6B schematically illustrates a second embodiment of a captured image of an eye, in according with some embodiments of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the disclosure. However, it will be understood by those of ordinary skill in the art that the embodiments of the disclosure may be practiced without these specific details. In other instances, well- known methods, procedures, components, modules, units and/or circuits have not been described in detail so as not to obscure the embodiments of the disclosure.

Although embodiments of the disclosure are not limited in this regard, discussions utilizing terms such as, for example, “processing,” “computing,” “calculating,” “determining,” “establishing”, “analyzing”, “checking”, or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulates and/or transforms data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer’s registers and/or memories or other information non-transitory storage medium (e.g., a memory) that may store instructions to perform operations and/or processes. Although embodiments of the disclosure are not limited in this regard, the terms“plurality” and“a plurality” as used herein may include, for example,“multiple” or“two or more”. The terms“plurality” or“a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, or concurrently. Unless otherwise indicated, use of the conjunction“or” as used herein is to be understood as inclusive (any or all of the stated options).

Embodiments of the present disclosure herein describe a mobile eye-imaging device for detecting eye pathologies. The mobile eye-imaging device may include a mobile imaging camera, such as a smartphone camera, for example, that may be mounted on a mounting assembly. A housing assembly may include at least one light source, such as a light emitting diode, a mirror, and one or more optical components. The incident light from the light source may be directing by the one or more optical components and the mirror into an eye of a subject, such as a patient. The one or more optical components may be used to filter or spatially shape the incident light into a predefined illumination pattern, such as a slit-lamp illumination pattern, which may be coupled to the eye of the subject. The mounting assembly holding the mobile imaging camera may be removably attached to the housing assembly, which may include a lens for directing reflected light from the subject's eye into the mobile imaging camera for capturing images of the subject's eye while illuminated with the predefined illumination pattern. The captured images may include still photographs and/or videos.

In some embodiments of the present disclosure, the mobile eye imaging device, such as a smartphone camera, for example, may include a processor (e.g., the processor of the smartphone) configured to execute a code such as an application (e.g., app) for analyzing the captured images of the eye, so as to determine if the eye is normal or dysfunctional. The ophthalmologist using the mobile eye-imaging device may observe the subject's eye on the screen or display of the imaging camera, and may position the mobile eye imaging device so as to direct the incident light with the predefined illumination pattern into a particular region of the eye at a particular angle.

In some embodiments of the present disclosure, the user may observe the eye on the screen of the imaging camera, for example, or use the application executed by the processor to analyze the captured images of the eye for dysfunctions. In other embodiments, the ophthalmologist may couple a cobalt blue filter in the housing assembly into the incident light beam for example to view the subject's eyes with the cobalt blue light after the subject's cornea is dyed with fluorescein to assess if corneal epithelial defects are present.

In some embodiments of the present disclosure, the user may use an optical slit in the housing assembly, which may be coupled into the optical path of the incident light from the at least optical light source, so as to form a slit lamp illumination pattern. The imaging camera may then be used to capture images of the anterior segment of the eye when illuminated with the slit-lamp illumination pattern. The processor of the imaging camera or the smartphone may then analyze the captured images of the eye under slit lamp illumination, so as to assess the likelihood of acute primary angle closure in the subject's eye.

In some embodiments of the present disclosure, the mobile eye-imaging device described herein solves a problem for providing a mobile-handheld eye diagnostic instrument, which may be used to form a variety of illumination patterns. The mobile eye-imaging device may be used for assessing or diagnosing a variety of common anterior segment pathologies of the eye and allowing a more thorough assessment of common anterior eye pathologies. This may include, for example, a characterization of anterior segment pathologies including corneal (keratitis), lens (lens subluxation), bulbar (episcleritis, scleritis), and eyelids (meibomian gland disease). The mobile eye-imaging device as described herein may allow for assessment of anterior chamber depth, and thus differentiation between common causes of red eyes (conjunctivitis, episcleritis) and potentially vision-threatening causes of red eyes (angle closure, scleritis).

The mobile eye-imaging device may also provide a potential for teleophthalmology, where the images from the mobile eye-imaging device may be uploaded to a secure server for cloud-based storage for sharing of the captured eye images between primary care and tertiary care providers. For example, the captured images such as digital images and/or videos may be transmitted securely through the cloud server for real time assessment by an ophthalmologist in a tertiary center (tele-ophthalmology).

Fig. 1 schematically illustrates an eye-imaging device 10 for imaging an eye 25 of a subject 12, in accordance with some embodiments of the present disclosure. Eyeimaging device 10 may include a housing assembly 1 15 removably attachable to a mounting assembly 130, configured to hold an imaging device 15 such as a smartphone camera, for example, for imaging eye 25 on a touchscreen 20. The user of the eye-imaging device 10, such as an ophthalmologist may snap pictures or capture images of eye 25 in any suitable orientation such as in either portrait or landscape mode depending on the user's preference. However, acquiring images in a landscape mode (e.g., oriented horizontally as shown in Fig. 1) may be more suitable for one-handed operation, as well as maximizing the captured image area of eye 25.

Fig. 2 schematically illustrates a block diagram of eye-imaging device 10 used as a slit lamp apparatus, in accordance with some embodiments of the present disclosure. Housing assembly 1 15 may include a slit image generator, such as an optical slit 60, through which incident light may propagate along an optical axis 64. The optical slit image pattern may then be reflected by a mirror 45 into eye 25. In some embodiments mirror 45 may be a double-sided reflecting mirror. The reflected incident light axis 65 may form an angle f with the optical axis 64. In some embodiments, angle f may be in a range of 35-55 degrees, but angle f may typically be 45 degrees. The reflected light from eye 25 from sclera 30, an iris 35, and a pupil 40 (e.g., from the lens of the eye) in response to the illumination pattern applied to the eye along optical path (incident light axis 65) may be coupled through a lens 50, such as a macro lens, into an imaging camera 55, such as a cellphone camera 55 (e.g., rear side built-in camera of a smartphone). Imaging camera 55, for example, may be mounted onto mounting assembly 130, which may be removably attached to housing apparatus 1 15 on the opposite side of macro lens 50.

When eye-imaging device 10 may be used as a slit lamp apparatus, the incident light with the slit lamp illumination pattern may be reflected by mirror 45 as a 45° angled slit beam coupled to eye 25, so as to allow optimal cross-sectional evaluation of cornea, anterior chamber, and lens for assessing if any pathologies exist. The slit beam may be oriented vertically across eye 25 with the phone being held in landscape orientation where the slit beam may illuminate an optical section of the anterior chamber structures including the cornea, anterior chamber, iris 35, and the lens of the eye via pupil 40.

In some embodiments of the present disclosure, eye-imaging device 10 may include a switchable LED white slit beam, a diffuse LED white light mode, and a diffuse cobalt blue light. A single switch may be used to toggle between diffuse white LED light, slit beam and cobalt blue light. In other embodiments, the light source module such as a light emitting diode may include may include an optical slit or alternatively, the optical slit may be placed in any suitable position along optical axis 64. Eye-imaging device 10 may be operated in either well-lit and/or in dim environments.

In multiple embodiments of the present disclosure, eye-imaging device 10 may be used as a slit lamp mode for assessment of anterior chamber depth, conjunctival, episcleral and scleral structures. Eye-imaging device 10 may be used for assessment of tear film height. Diffuse beam high magnification assessment of ocular adnexa may include lid margins, Meibomian glands, and tear film. A cobalt blue filter may be used in the assessment of corneal pathologies (with the aid of fluorescein dye, separately provided).

Fig. 3 schematically illustrates a block diagram of circuitry 10A in housing assembly 1 15 and in imaging device 15, in accordance with some embodiments of the present disclosure. Circuitry 10A may be placed in any suitable position within housing assembly 1 15 of eye-imaging device 10. Circuitry 10 A may include a light emitting diode (LED) 100, LED driver circuity 1 10 with an intensity control module 105 controlled by an external knob, and power circuitry and interface 101.

Circuitry 10A in housing assembly 1 15 may be powered by circuitry 10B in imaging camera 15 such as a smartphone, via a cable 120 coupled to power circuitry and interface 90 in imaging camera 15. Circuitry 10B may include a battery 95 for powering the circuitry coupled to power circuitry and interface 90, a processor 65 executing an application 70 and coupled to a memory 75, a camera interface 85 for relaying the captured images by imaging camera 55 to processor 65, an input device 86, an output device 87, and a communication interface 80 for communicating with other computing systems such as a server (e.g., remote cloud server) over a wireless and/or wired communication network. In other embodiments, eye-imaging device 10 may be powered externally either through the smartphone charging port (e.g., power circuitry and interface 90), or through an external battery pack (e.g., a power-bank) when there is no internal battery 95. A typical electrical specification for the eye-imaging device operation may be 3.3 to 5 Volts at 1 Amp (e.g., for cellphone compatibility).

Circuitry 10A and 10B may be configured to detect and assess eye pathologies using mobile eye imaging device 10. Circuitry 10B includes a processor 65. Processor 65 may include one or more processing units, e.g. of one or more computers. Processor 65 may be configured to operate in accordance with programmed instructions stored in memory 75. Processor 65 may be capable of executing application 70 for detecting and assessing eye pathologies by analyzing captured images and/or videos of eye 25 using mobile eye imaging device 10.

Processor 65 may communicate with output device 87. For example, in some embodiments where a digital camera may be used as imaging device 15 coupled to a laptop or desktop computer, for example, output device 87 may include a computer monitor or screen. Processor 65 may communicate with a screen of output device 87 to display the captured image of eye 25. In another example, output device 87 may include a printer, display panel, speaker, or another device capable of producing visible, audible, or tactile output. Similarly, processor 65 may communicate with input device 86. For example, input device 86 may include one or more of a keyboard, keypad, or pointing device for enabling a user to inputting data or instructions for operation of processor 65.

In some embodiments of the present disclosure, input device 86 and output device 87 may be realized as touchscreen 20 on a smartphone.

Processor 65 may communicate with memory 75. Memory 75 may include one or more volatile or nonvolatile memory devices. Memory 75 may be utilized to store, for example, programmed instructions for operation of processor 65, data or parameters for use by processor 65 during operation, or results of operation of processor 65, such as for storing the captured images and/or video of eye 25 as well as storing data from analyses using the stored captured images and/or video.

In operation, processor 65 may execute a method for detecting and assessing eye pathologies by analyzing captured images and/or videos of eye 25 using mobile eye imaging device 10. Fig. 4 A schematically illustrates an isotropic top view of a mobile eye imaging device 200, in accordance with some embodiments of the present disclosure.

Fig. 4B schematically illustrates a cutout view of an optical design 233 of mobile eye imaging device 200, in accordance with some embodiments of the present disclosure.

Fig. 4C schematically illustrates an exploded top view of mobile eye imaging device 200, in accordance with some embodiments of the present disclosure.

Fig. 4D schematically illustrates an exploded bottom view of mobile eye imaging device 200, in accordance with some embodiments of the present disclosure.

Mobile eye imaging device 200 may include a housing assembly 215 and a mounting assembly 230 for holding imaging device 15. Mobile eye imaging device 200 may have typical dimensions (length, width, and height) of 168 x 135 x 30 mm, for example. Mounting assembly 230 may include a metal plate 235, a first mounting holder 232A and a second mounting holder 232B, each with a beveled edge 252. Imaging device 15 with a camera 55 such as a smartphone may be attached to metal plate 235 with first mounting holder 232A and second mounting holder 232B with beveled edges 252 used for catching an edge of imaging device 15. Screws (not shown) placed in screw holes 245 may be used to affix imaging device 15 to metal plate 135 using first mounting holder 232A and second mounting holder 232B. A groove 247 in second mounting holder 232B may permit the position of second mounting holder 232B to be adjusted to any suitable dimension of imaging device 15.

Optical design 233 within the region of the dotted line of Fig. 4A as further shown in Fig. 4B illustrates the one or more optical elements placed along optical axis 64 from light source 201 to mirror 45. The one or more optical elements may include a condensing lens 260, optical filter shaping elements held in a slide selector assembly 265 with a finger tab 266, a first imaging lens 270, and a second imaging lens 275. Mirror 45 may be held in grooves 246 by pins formed on mirror housing 45 (not shown), by a lateral force applied by lower portion 215B of housing assembly 215 on the casing of the mirror, for example, or by any suitable method for holding mirror 45 to housing assembly 215. In some embodiments, groove 246 may be used as a slider track for mirror 45 so as to change its position of mirror 45 on the slider track. Additionally, mirror 45 may be easily replaced with a different angled reflector.

In some embodiments of the present disclosure, the optical elements for shaping or filtering the incident light from light source 201 may be mounted in slide selector assembly 265. These optical elements may include optical slit 60 and a white diffuse filter 264. The user may choose which optical element to use by sliding the slide selector assembly 265 using finger tab 266.

In some embodiments of the present disclosure, light source 201 may be located in a light housing assembly 212 with a second finger tab 21 1 as shown in Fig. 4C. In alternative embodiments, second finger tab 21 1 may be modified, for example, into a slider switch similar to slide selector assembly 265 (e.g., finger tab 266), a depressive button, and/or a rotating wheel. A cobalt blue filter may also be located in light housing assembly 212 (not shown in the inset) which may be switching into place by the user using second finger tab 21 1 so as to allow the user to choose to direct either white light or blue light into eye 25, or alternatively light source 201 may provide the cobalt blue light (425 nm).

In some embodiments of the present disclosure, housing assembly 215 may be formed from an upper portion 215A and a lower portion 215B. Lower portion 215B may include light source 201 (such as an LED), one or more optical elements, macro lens 50 held within a hole 51 formed through the top to the bottom of lower portion 215B, and mirror 45 held within grooves 246 formed in lower portion 215B. As shown in Fig. 4D, lower portion 215B may include magnets 255. Metal plate 235 of mounting assembly 230 may be formed from any suitable metal which may be attracted to magnets 255 so as to allow mounting assembly 230 to be removably attachable to the bottom side of lower portion 215B as shown. Additionally, since the mounting assembly is removably attachable to the housing assembly, this allow's the user to manually adjust the position of camera 55 on imaging device 15 to align with the position of macro lens 50 independent of where camera 55 (e.g., the camera lens) may be located on the body of imaging device 15, such as a smartphone.

In some embodiments of the present disclosure, the one or more optical components may be held in grooves 256 formed in upper portion 215 A (see Fig. 4D) and lower portion 215B of housing assembly 215 such that when upper portion 215A and lower portion 215B may be affixed to one another by screws (not shown) placed in screw holes 245, 295, grooves 256 may hold the optical elements fixed in place in housing assembly 215 so as to maintain precision alignment of the optical elements along optical axis 64 from light source 201 to mirror 45.

In some embodiments of the present disclosure, circuitry 1 15C may be placed in any suitable position in housing assembly 215 and cable 120 may be connected to power circuitry interface 101 at a connector port 216 formed in housing assembly 1 15. In some embodiments, housing assembly 215 may include a knob 240 coupled to intensity control circuitry module 105, so as to allow the user to control the intensity of incident light from light source 201. The light intensity may be controlled in steps or continuously by rotating knob 240.

In some embodiments of the present disclosure, the specification of lens 275 in mobile eye imaging device 200, respectively, as shown in Table I below may be:

Table I - Example specifications of Lens 275

In some embodiments of the present disclosure, the specification of lens 270 in mobile eye imaging device 200, respectively, as shown in Table II below may be:

Table II - Example specifications of Lens 270

In some embodiments of the present disclosure, the specification of condensing lens 260 in mobile eye imaging device 200, respectively, may be:

Diameter: 12.7 mm

Coating: AR Coating 350-700 nm

Substrate: N-BK7

EFL: 20 mm

In some embodiments of the present disclosure, the specification of mirror 45 in mobile eye imaging device 200. respectively, as shown in Table III below may be:

Table III - Example Specifications of Mirror 45

In some embodiments of the present disclosure, the specification of magnets 255 in mobile eye imaging device 200, respectively, as shown in Table IV below may be:

Table IV - Example specifications of Magnets 255

In some embodiments of the present disclosure, the working distance between eye 25 and macro lens 50 in both the first embodiment of mobile eye imaging device 10 shown in Fig. 1 and the second embodiment of mobile eye imaging device 200 shown in Figs. 4A-4D, may be typically 21 mm, in contrast to working distances of 65-100 mm in a slit lamp instrument found, for example, in a tertiary eye clinic. A working distance of 21 mm, for example, may strike a balance between device handling and image acquisition, as it would be close enough to permit the capture of anterior segment details, including measurements for the diagnosis of acute primary angle closure, without getting unnecessarily close to be obstructed by the subject’s facial features (e.g., nose bridge, orbital rims), for example.

Furthermore, in a slit lamp mode having incident light in a slit lamp illumination pattern leaving the mobile imaging device at an angle f=45 degrees and coupled to the patient’s eye obliquely may allow capture of anterior segment features used for evaluating acute primary angle closure. The position and/or orientation of the incident light on the subject’s eye may change dynamically as the user of the device (e.g., ophthalmologist) moves the device with the user’s hand.

In some embodiments of the present disclosure, mobile eye imaging device 200 may be configured to assess a variety of eye pathologies. Mobile ey¾ imaging device 200 may be used to detect foreign objects in the surface of eye 20, scratches or other problems with the surface of the cornea, and/or irritation of the cornea due to the use of contact lenses or severe dry eyes. Eye 25 of subject 12 may be stained with fluorescein dye. Subject 12 may be asked to blink so as to spread the dye so as to coat the tear film covering the surface of the cornea. The user of mobile eye imaging device 200 may use finger tab 266 and second finger tab 21 1 to form a cobalt blue illumination pattern that may be directed to illuminate eye 25.

If there are abnormalities in the eye, the fluorescein dye sticks to the regions of structural abnormalities, which fluoresce under cobalt blue light illumination, which may be easily visible on touchscreen 20 to the user, such as the ophthalmologist. Furthermore, the ophthalmologist may snap a picture or film a video (e.g., capture images) of eye 25 using imaging camera 55 on imaging device 15 under cobalt blue light illumination which are relayed via camera interface 85 to application 70 executed by processor 65. Processor 65 may be configured to analyze the captured images of eye 25 so as to provide to the ophthalmologist a spatial mapping of the structural abnormalities in eye 25. Additionally, and/or optionally, processor 65 may be configured to identify the type of structural abnormalities in eye 25 of subject 12.

In some embodiments of the present disclosure, mobile eye imaging device 200 may be configured to use a slit lamp illumination to assess an additional variety of eye pathologies. For example, as a patient ages, the lens may thicken with age. As a result of lens thickening, the distance from the cornea to the anterior surface of the lens decreases, while the distance from the anterior surface to the posterior surface of the lens increases. Stated differently, the ratio between the distance front the cornea to the anterior surface of the lens to the distance from the anterior surface to the posterior surface of the lens subsequently decreases as the angle becomes narrower, which subsequently indicates an increased risk for angle closure glaucoma. This ratio or index may be assessed using mobile eye imaging device 200 as described below.

Fig. 5 schematically illustrates reflected light from anatomical features in eye 25 in response to incident light illuminating eye 25 obliquely, in accordance with some embodiments of the present disclosure. Incident light generated in mobile eye imaging device with a slit lamp illumination pattern, for example, may be coupled obliquely to eye 25 along reflected incident light axis 65 as shown in Fig. 5.

In some embodiments of the present disclosure, due to the geometry of the angle f in mobile eye imaging device, typically 45 degrees, between optical axis 64 and incident light axis 65 reflected from mirror 45, the incident light may propagate out of the device and strike the eye of the subject obliquely. In response, the reflected light from eye 25 may exit the eye with approximate 45 degrees relative to incident light axis 65 that may be collected in macro lens 50 and coupled to imaging camera 55. This oblique illumination effect may cause the generation of separately distinguishable reflection bands from cornea 305, iris 35, and lens 315 of eye 25 that may be captured in images or videos in imaging camera 55.

In some embodiments of the present disclosure, the separately distinguishable reflection bands may refer herein to reflection bands appearing with different colors that are distinguishable on touchscreen 20, as well as in the images and/or videos captured by imaging device 15. For example, in response to the incident white-light slit lamp illumination pattern as the user moves the slit across the subject’s eye: a reflection 320 from cornea 305 may appear as a blue colored band, a reflection 325 from iris 35 may appear as a yellow colored band, and a reflection 330 from lens 315 of eye 25 may appear as a green colored band emanating from pupil 40.

In some embodiments of the present disclosure, application 70 executed by processor 65 may be configured to estimate the intensity of the reflected light of each of the imaged colored bands by counting the colored pixels in the captured image or video within each of the imaged colored bands.

Fig. 6A schematically illustrates a first embodiment of a captured image of eye 25, in according with some embodiments of the present disclosure. When the user of mobile eye imaging device 200 directs incident light onto eye 25 with a slit lamp illumination pattern to the left of pupil 40, two lines or bands of reflected light may appear: reflection 320 (e.g., a blue colored line denoted with a thick dotted line) and reflection 325 (e.g., a yellow colored line denoted with a thin dotted line). These reflections may be captured on display (e.g., touchscreen 20) for analysis.

Fig. 6B schematically illustrates a second embodiment of a captured image of eye 25, in according with some embodiments of the present disclosure. When the user of mobile eye imaging device 200 directs incident light onto eye 25 with a slit lamp illumination pattern inside the left edge of pupil 40, four lines of reflected light may appear reflection 320 from cornea 305 (e.g., a blue colored line denoted with a thick dotted line), reflection 325 from iris 35 (e.g., a yellow colored line denoted with a thick dotted line), reflection 326 from the anterior part of lens 315 (a light blue line denoted as a solid line in pupil 40) and reflection 330 from the posterior lens surface (e.g., a green colored line denoted with a thin dotted line in pupil 40). These reflections may be captured on display (e.g., touchscreen 20) for analysis. The embodiments shown in Figs. 6A and 6B are merely for visual clarity and not by way of limitation of the embodiments of the present disclosure. The user may direct the slit lamp beam in any suitable position and/or orientation onto eye 25, which may generate multiple reflected lines in multiple respective colors.

In some embodiments of the present disclosure, application 70 executed by processor 65 may estimate a distance A between cornea 305 to the anterior surface of lens 315 and a distance B between to the anterior and posterior surfaces of lens 3 15. Processor 65 may estimate distance A (e.g., from reflections 320 and 326) and distance B (e.g., from reflections 326 and 330) using the estimated light intensity of the reflected light for each of the imaged colored bands by from the captured image or video of eye 25 under slit lamp illumination.

In some embodiments of the present disclosure, application 70 executed by processor 65 may compute a likelihood of acute primary angle closure in eye 25 when a calculated ratio of A/B decreases below a predefined threshold (e.g., from the estimated intensities of the reflected light in each colored band). A higher likelihood of acute primary angle closure is indicative of a higher likelihood of subject 12 developing angle closure glaucoma.

In some embodiments of the present disclosure, a mobile eye imaging device for detecting eye pathologies may include an imaging camera with a processor, a light source, one or more optical elements, a mirror for directing incident light from the light source into an eye, a housing assembly and a mounting assembly. The housing assembly may include at least one magnet and a lens held in a hole formed through the housing assembly. The housing assembly may be configured to hold the light source and the mirror and to direct the incident light from the light source along an optical axis through the one or more optical elements and onto the mirror reflecting the incident light at a predefined angle relative to the optical axis, wherein the one or more optical elements filter or shape the incident light for illuminating the eye with a predefined illumination pattern. The mounting assembly removably attachable to the housing assembly by the at least one magnet for holding the imaging camera may be positioned substantially opposite to the lens held in the hole, wherein reflected light from the eye is coupled by the lens into the imaging camera for capturing images of the eye.

In some embodiments of the present disclosure, the predefined angle may include a range of 35 to 55 degrees relative to the optical axis.

In some embodiments of the present disclosure, the one or more optical elements may be selected from the group consisting of a blue cobalt filter, a blue light emitting diode, lenses, mirrors, an optical slit, a light diffuser, and a light condenser.

In some embodiments of the present disclosure, the mobile eye imaging device may include an intensity control knob for controlling an intensity' of the incident light directed to the eye.

In some embodiments of the present disclosure, the imaging camera may include a smartphone camera.

In some embodiments of the present disclosure, the processor may be configured to assess pathologies in the eye from the captured images of the eye.

In some embodiments of the present disclosure, at least one optical element from the one or more optical elements may include an optical slit and the predefined illumination pattern may include a slit lamp pattern illuminating the eye.

In some embodiments of the present disclosure, the reflected light from the eye captured by the imaging camera in response to the slit lamp pattern may include colored bands in the captured image of the eye corresponding to the incident light reflected from a cornea, an iris, and a lens of the eye.

In some embodiments of the present disclosure, the processor may be configured to estimate intensities of the reflected light in the colored bands by counting the pixels in the captured image for each colored band. In some embodiments of the present disclosure, the processor may be configured to detect the likelihood of acute primary angle closure in the eye from the estimated intensities of the reflected light in each colored band.

In some embodiments of the present disclosure, a mobile eye imaging slit lamp device for detecting eye pathologies may include an imaging camera, a light source, one or more optical elements including an optical slit, a mirror for directing incident light from the light source into an eye, a housing assembly, a mounting assembly, and a processor. The housing assembly may include at least one magnet and a lens held in a hole formed through the housing assembly. The housing assembly may be configured to hold the light source and the mirror and to direct the incident light from the light source along an optical axis through the one or more optical elements and onto the mirror reflecting the incident light at a predefined angle relative to the optical axis, wherein the eye is illuminated with a slit lamp illumination pattern. The mounting assembly may be removably attachable to the housing assembly by the at least one magnet for holding the imaging camera positioned substantially opposite to the lens held in the hole, wherein reflected light from the eye is coupled by the lens into the imaging camera for capturing images of the eye. The processor may be configured to estimate intensities of the reflected light from colored bands in the captured image of the eye in response to the slit lamp pattern, each colored band corresponding to the incident light reflected from a cornea, an iris, an anterior surface of a lens of the eye, and a posterior surface of the lens of the eye, to use the estimated intensities to compute a distance A between the cornea to the anterior surface of the lens and a distance B between the anterior surface and the posterior surface of the lens, and to compute a ratio A/B indicative of a likelihood of a disease in the eye when the ratio A/B is smaller than a predefined threshold.

In some embodiments of the present disclosure, the processor may be configured to estimate intensities of the reflected light in the colored bands by counting the pixels in the captured image for each colored band.

In some embodiments of the present disclosure, the imaging camera may be a smartphone camera.

In some embodiments of the present disclosure, the processor may be a processor of a smartphone.

Different embodiments are disclosed herein. Features of certain embodiments may be combined with features of other embodiments; thus certain embodiments may be combinations of features of multiple embodiments. The foregoing description of the embodiments of the disclosure has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed. It should be appreciated by persons skilled in the art that many modifications, variations, substitutions, changes, and equivalents are possible in light of the above teaching. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the disclosure.

While certain features of the disclosure have been illustrated and described herein, many modifications, substitutions, changes, and equivalents will now occur to those of ordinary skill in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modi fications and changes as fall within the true spirit of the disclosure.

Claims

1. A mobile eye imaging device for detecting eye pathologies, comprising:

an imaging camera comprising a processor;

a light source;

one or more optical elements;

a mirror directing incident light from the light source into an eye;

a housing assembly, comprising at least one magnet and a lens held by the housing assembly, and configured to hold the light source and the mirror and to direct the incident light from the light source along an optical axis through the one or more optical elements and onto the mirror reflecting the incident light at a predefined angle relative to the optical axis, wherein the one or more optical elements filter or shape the incident light thereby illuminating the eye with a predefined illumination pattern; and

a mounting assembly removably attachable to the housing assembly by the at least one magnet holding the imaging camera positioned substantially opposite to the lens held by the housing, wherein reflected light from the eye is coupled by the lens into the imaging camera capturing images of the eye.

2. The mobile eye imaging device according to claim 1 , wherein the predefined angle comprises a range of 35 to 55 degrees relative to the optical axis.

3. The mobile eye imaging device according to claim 1, wherein the one or more optical elements is selected from the group consisting of a blue cobalt filter, a blue light emitting diode, lenses, mirrors, an optical slit, a light diffuser, and a light condenser.

4. The mobile eye imaging device according to claim 1, further comprising an intensity control knob controlling an intensity of the incident light directed to the eye.

5. The mobile eye imaging device according to claim 1, wherein the imaging camera comprises a smartphone camera.

6. The mobile eye imaging device according to claim 1, wherein the processor is configured to assess pathologies in the eye from the captured images of the eye.

7. The mobile eye imaging device according to claim 1, wherein at least one optical element from the one or more optical elements comprises an optical slit and the predefined illumination pattern comprises a slit lamp pattern illuminating the eye.

8. The mobile eye imaging device according to claim 7, wherein the reflected light from the eye captured by the imaging camera in response to the slit lamp pattern comprises colored bands in the captured images of the eye corresponding to the incident light reflected from a cornea, an iris, and a lens of the eye.

9. The mobile eye imaging device according to claim 8, wherein the processor is configured to estimate intensities of the reflected light in the colored bands by counting pixels in the captured images for each colored band.

10. The mobile eye imaging device according to claim 9, wherein the processor is configured to detect the likelihood of acute primary angle closure in the eye from the estimated intensities of the reflected light in each colored band.

11. A mobile eye imaging slit lamp device for detecting eye pathologies, comprising: an imaging camera;

a light source;

one or more optical elements including an optical slit;

a mirror directing incident light from the light source into an eye;

a housing assembly, comprising at least one magnet and a lens held within the housing assembly, and holding the light source and the mirror and to direct the incident light from the light source along an optical axis through the one or more optical elements and onto the mirror reflecting the incident light at a predefined angle relative to the optical axis, wherein the eye is illuminated with a slit lamp illumination pattern;

a mounting assembly removably attachable to the housing assembly by the at least one magnet holding the imaging camera positioned substantially opposite to the lens held in the hole, wherein reflected light from the eye is coupled by the lens into the imaging camera capturing images of the eye; a processor configured to estimate intensities of the reflected light from colored bands in the captured images of the eye in response to the slit lamp pattern, each colored band corresponding to the incident light reflected from a cornea, an iris, an anterior surface of a lens of the eye, and a posterior surface of the lens of the eye, to use the estimated intensities to compute a distance A between the cornea to anterior surface of the lens and a distance B between the anterior surface and the posterior surface of the lens, and to compute a ratio A/B indicative of a likelihood of a disease in the eye when the ratio A/B is smaller than a predefined threshold.

12. The mobile eye imaging device according to claim 11, wherein the processor estimates intensities of the reflected light in the colored bands by counting pixels in the captured images for each colored band.