CATRA: Interactive Measuring and Modelling of Cataracts
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CATRA: Interactive Measuring and Modelling of Cataracts

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CATRA Presentation at SIGGRAPH 2011.

CATRA Presentation at SIGGRAPH 2011.

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  • CATRA is a Snap-On eyepiece for mobile phones that measures and quantifies cataracts in the human eye.The patient looks tru it, respond to few patterns that are drawn on the screen, and the app generates, for the first time, maps to show occluders and their scatering profile.
  • Last year we presented NETRA, which is also a hardware app for phones but designed to measure refractive error.Although CATRA may look similar to NETRA, we had to re-desing optics and interaction procedures in order to create a map, instead of just showing a number.
  • We’ve been working with NGO’s on NETRA, and they reminded us that although refractive error is the second leading cause of preventable blindness, cataract is the first one. We ended up realizing that we actually were targeting one of the most prevalent diseases on this planet. In fact, allof us will have cataracts if we live long enough.
  • Well, cataracts are these clouds you may see in someone's eye which reflect and scatter light as it goes through on of these white blobs.For the subject's view, they create glare and blurriness.
  • Cataracts are detected, measured and diagnosed through this device.It is called slit-lamp microscope and is essentially a searching platform for doctors. Clinicians will change the several degrees of freedom this device has to manually search for cataracts in one's eye.This device has really not changed for several decades…
  • Conceptually speaking, this device is very simple. It shines a slit of light into the eye, which gets reflected in the cataract and goes back to the viewer.Clinician will se a white blob and will subjectively rate from 1 to 4 according to his notion of severity. 3 and 4 are advanced cases of the disease and suggest surgery. As you may see on this image, this method works on what we call back scattering analysis. Clinician relies on the reflex of the scattering spot which may not represent the actual effects cataracts are creating on the subject's view.
  • Instead of relying on someone else’s judgement of severity, CATRA works with forward scattering analysis.This snap-on can be seen as a light-field display, which when placed up close, scans the lens of the eye section by section. So, by relying on the ability to show the scattering profile of a section of the lens, we built interactive techniques to transform the visual information the subject is seen into quantifiable data.
  • We propose 4 maps to model occluders and replace the currently used subjective evaluation, that one from 1 to 4. The first map is what we call an opacity map. It consists of a binary information (has or has not) cataracts per section of the lens. It tell us position, size and shape of the occluders.The attenuation map is a density test per section of the eye. It tell us, how reflexive and transmissive an occluded section is. The third map is what we call contrast map. A contrast test is made per section of the eye, and tell us how big is the spreading of light from each section. The fourth map holds the point spread function per section of the eye. This four maps are divided into occlusion and scattering analisis
  • Based on these maps, we can simulate an individual cataract-affected vision and the progress of the disease
  • Based on these maps, we can simulate an individual cataract-affected vision and the progress of the disease
  • Based on these maps, we can simulate an individual cataract-affected vision and the progress of the disease
  • Now, notice that these maps are measuring a region that has about 3mm in diameter. Each section has only 6mmAnd thus any small variation on the position of the device, face or gazing will make the software miss a cataract spot.
  • We though a lot about it, and after several iterations, we came up with a design that relies on forward scattering and always projects patterns on fovea, so the subject will not gaze Our design is essentially a modified 3D display. We have two LCDs and a light box behind them, LCDs work as programmable masks, and an additional lens, placed one focal length from the parallax barrier. This setup allows us, for instance, to open a pinhole in LCD2 and 3 pixels on LCD1, and light rays coming out of the device will pass trough 3 testing regions on the crystallin lens and converge to a single point in the fovea. With this setup, we can alternate among testing sections without breaking the subject's visual point of reference. It does not matter which position of the lens we are testing, the subject will always see a green steady dot.
  • The intuition of this design relies on the role of each LCD. Each pixel on LCD1 represents a position on the crystalline, or a testing site. Each pixel on LCD2 is mapped to a position onto de fovea. So, if we want to draw visual stimulus, we draw it on LCD2, if we want to test different positions, we change LCD1.
  • Here is an example on a subject with cataracts. With our setup it is possible to shine a light ray that hits the cataract spot. Cataract will reflect and scatter light and a small amount of the scattered energy will reach the retina.
  • If the scattering is too big or the cataract is too reflexive, we can trade resolution for brightness and open neighbor pixels on LCD1 to create collimated beams of light, increasing the testing site and also the amount of energy been focused into a single point in the retina. This tool allows us to play with the scattering element and identify its properties without changing the users point of reference.
  • Well, the eye as any other imaging device has a point spread function. If the eye does not have cataracts, it PSF is a peak.
  • In case of mild cataracts, this peak decreases and the PSF assumes a gaussian profile.
  • In advanced cases of the disease, you cannot even see a peak al all. At this stage, the subject will not be able to notice objects in front of him.
  • In this work, we want to map what is on the aperture of the eye, in order to estimate the point spread function and thus compute a visual representation for an individual cataract affected eye. In order to do so, we have to figure out values for sigma and the peak of the point spread function. This values are estimated through 5 interactive techniques that run in sequence.
  • The first technique is a binary test for the presence of cataracts. So, yes or no if the subject has cataracts.
  • Although we’ve shown the single-LCD mobile phone based solution, we’re now going to move on to the general design. In our optical design, we open a pinhole in the center of LCD2 and we keep moving a pixel on LCD1. When this scanning procedure hits a cataract spot, the dot disappears and the subject realizes he has something blocking his view.
  • In a 2D example, we have a moving dot on screen, a pinhole open on LCD2, this will scan the lens of the eye and the subject will notice a difference between occluded and clear paths.
  • In a 2D example, we have a moving dot on screen, a pinhole open on LCD2, this will scan the lens of the eye and the subject will notice a difference between occluded and clear paths.
  • In a 2D example, we have a moving dot on screen, a pinhole open on LCD2, this will scan the lens of the eye and the subject will notice a difference between occluded and clear paths.
  • Let's say the subject has cataracts and thus we move forward to our maps.
  • The first one is the opacity map. Tell us the position, size and density of the cataract. GROUP AGAIN
  • On the optical scheme, it is exact the same procedure as before, a pinhole on LCD2 and a moving pattern on LCD1. However, the pattern on LCD1 moves slower and when the scanning process hit a cataract, the dot fades away and subject presses a button. By marking all regions the dot faded, app computes an opacity map.
  • Since now we know where cataracts are, we can now compute what are their densities.
  • Since now we know where cataracts are, we can now compute what are their densities.This will tell us how reflexive they are.
  • Now we alternate pixels on LCD1 in such a way that one point will hit a cataract spot and the second is a clear path. Subject see both alternating on his view and will decrease the intensity of the clear path, by pressing buttons on the phone, in order to match the occluded one.
  • In essence, subject will decrease brightness up to the point he does not notice any difference between patterns.
  • Again on 2D, we have alternating patterns on LCD1, still a pinhole on LCD2 and the subject will change the brightness of the clear path in order to math the intensity of the occluded path on his retina. By executing this procedure for all sections, we built an attenuation map.
  • Again on 2D, we have alternating patterns on LCD1, still a pinhole on LCD2 and the subject will change the brightness of the clear path in order to math the intensity of the occluded path on his retina. By executing this procedure for all sections, we built an attenuation map.
  • Each value on this map is an estimation for the peak of the gaussian PSF function.
  • Each value on this map is an estimation for the peak of the gaussian PSF function.
  • The fourth map is what we call a contrast map.We will conduct contrasts sensitivity tests per section of the eye. We will show a low contrast letter C, which may be rotated, and the subject will answer where C is pointing to when he notice it.
  • C is drawn on LCD2 and a pixel is opened on LCD1 which will make C go thought the cataract spot. Subject increases the contrast of C up to the point he notice where C is pointing to, in this case, he presses the right key.
  • Subject increases the contrast of C up to the point he notice where C is pointing to, in this case, he presses the right key.
  • Subject increases the contrast of C up to the point he notice where C is pointing to, in this case, he presses the right key.
  • Subject increases the contrast of C up to the point he notice where C is pointing to, in this case, he presses the right key.
  • The contrast map tell us sigma for the gaussian PSF function.
  • The contrast map tell us sigma for the gaussian PSF function.
  • The fifth test is computes a point spread function per section of the eye.
  • Just like the attenuation map, we have alternating points on LCD1, one for an occluded path and the other for a clear one. The pinhole on LCD2 for the clear path is changed for a gaussian,
  • which peak is read from the attenuation map. Subject will only increase sigma to match the point spread function that is been created by the occluded path. When he finishes, the drawing on LCD2 is the actual point spread function of the sub-aperture.
  • which peak is read from the attenuation map. Subject will only increase sigma to match the point spread function that is been created by the occluded path. When he finishes, the drawing on LCD2 is the actual point spread function of the sub-aperture.
  • which peak is read from the attenuation map. Subject will only increase sigma to match the point spread function that is been created by the occluded path. When he finishes, the drawing on LCD2 is the actual point spread function of the sub-aperture.
  • PSF maps also estimate sigma, but there is a difference between the sigma from a PSF map and from the contrast map.
  • PSF maps also estimate sigma, but there is a difference between the sigma from a PSF map and from the contrast map.
  • If respective attenuation value is high subject may not be able to match the point spread function accurately. So, the contrast map replaces the PSF matching.
  • And thus our algorithm follows these steps, one after the other, with a decision point after the brightness test. In the remaining of the talk, Erick will show our prototypes, validations and how to compute an individual cataract affected view.
  • Thanks Vitor…Here is the first prototype. It is composed of a DLP projector with a diffuser, a pinhole mask, and an eyepiece where the subject should look into. Interaction is made though the keys of a laptop.
  • ThanksVitor.We’ve built several prototypes…
  • This one is made of a pair of stacked LCDs. We disassembled and re-builtthese high-contrast monochromaticmedical displays.Interaction is made though a keyboard.
  • This one is made of a pair of stacked LCDs. We disassembled and re-builtthese high-contrast monochromaticmedical displays.Interaction is made though a keyboard.
  • This one is made of a pair of stacked LCDs. We disassembled and re-builtthese high-contrast monochromaticmedical displays.Interaction is made though a keyboard.
  • The simplest possible setup, you already saw it, a clip-on for mobile phones with a pinhole mask on top of the display. This mobile phone prototype can only generate opacity and attenuation maps. With the stacked LCDs one, we implemented the full interactive procedure.
  • We validated our method in 3 steps.Firstly we validated the technique itself, and how accurate our interactive method can be under a highly controlled environment.We added diffusers to camera lenses to simulate cataracts and computed, in this example, attenuation and point spread function maps.
  • Here is another example: a picture of the simulated cataracts, opacity map, and the measured attenuation map, which was created by taking per-section pictures and summing up pixels on the resulting image. The estimated attenuation map matches the actual value.
  • In the second step, we validated alignment and gaze control.So, if you’re a young graduate student without cataracts, how would you do the experimentation? I, for instance, don’t have cataracts…Guess what, we SCRATCHED these contact lenses to create simulations for advanced, mild and early cataracts, and we wore them, er… Vitor did, since I wasn’t brave enough.For instance, we could successfully measure the size of a simulated cataract of about 0.5mm^2 as 0.45mm^2.WHOLE FACE PICTURES INSTEAD
  • In the last step, we tested how elderly subjects interacted with our device. 18 people took the test: 5 of them had early cataracts, all confirmed through our method; and 1 individual discovered he had cataracts with our device, which was confirmed afterwards by an ophthalmologist.
  • Well, now that we know how to measure approximate point spread functions per sub-aperture, we can build a single point spread function for the eye by summing up all of them. However, because of cataracts, eye’s PSFs are depth dependent
  • , so for scenes with objects out of focus, there is a shift to be applied for each sub-aperture PSF that is proportional to the distance from the focal plane.
  • So, here is a scenario for our rendering.
  • A photography taken with a cataract-affected lens
  • And a simulation using our estimated PSFs.
  • Based on these estimated PSFs, we can simulate the progress of cataract-affected vision.
  • Based on these estimated PSFs, we can simulate the progress of cataract-affected vision.
  • Based on these estimated PSFs, we can simulate the progress of cataract-affected vision.
  • In some out of focus objects, you may even see the cataract shape inside the bokeh effect.
  • Our technique has a few limitations.It requires active user participation, so if the user cannot understand our procedures, he may not get reliable results.We need a clear path in the lens in order to estimate the attenuation, contrast and PSF of occluded paths.Retinal diseases may change the results as well.
  • Just like last year's NETRA, that now is in the hands of 29 field testers, we plan to run field and clinical tests using our devices through partnerships with doctors in several institutions.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • Integrating optics, computer graphics and interactive techniques can address this worldwideproblem.So, because NETRA and CATRA are portable, low-cost, and easy to build and use, we created an initiative called EyeNETRA.com to spread these hardware apps. We aim to increase the accessibility for eye care in remote parts of the world.These hardware apps will empower millions of people through patient centric ecosystems that start with diagnosis and awareness.
  • We thank all collaborators and doctors we have been working with. Thanks for our sponsors and...
  • In summary, we have introduced a co-design of optics and interactive techniquesfor measuring cataracts which works with forward scattering analysis and holds gaze through foveal projection…We proposed 4 quantitative maps to replace the subjective evaluation doctors currently use...And we developed the first simulation for an individual cataract-affected vision.
  • Thank you.
  • So, feel free to visit our website and
  • Cataracts are the leading cause of avoidable blindness worldwide.
  • Find a more impactful thing.
  • Be very concentrated in a single region.
  • You may try to attach a camera recalibrate it to take a picture.
  • There are three main types of cataracts:Nuclear, that grows from the center of the lens towards its periphery and is associated with the aging process. Subcapsular, mostly caused by diabetes, grows above the “capsule” that holds the lens in place. Cortical spreads all over the lens periphery and grows inwards its center.Each one of these scatters light differently. Common visual effects are glare, diffraction rings and overall blurriness. Pupil size determines the strength of the effects. While for nuclear and sub-capsular smaller pupils increase effects, for cortical they decrease and the pupil constricts.
  • Nuclear cataracts are highly reflexive
  • while sub-capsular and cortical are mostly transmissive.
  • Which means that Nuclear Cataracts are easyer to identify through a backscattering evaluation. While may others require techniques such as retro-illumination or OCTs to be identified.
  • We developed CATRA, an interactive technique to measure cataract opacities. Instead of relying on backscattering and someone else’s judgement of severity, we use a dual stack lcd display to scan the lens and show to the user the point spread function of each section of his eye.
  • In this paper, we introduce a new approach, called CATRA, a co-design of optics and interactive techniques to measure and quantify cataracts. It works on forward scattering analysis, the inverse of the previous one, to assess the severity of the disease. In the simplest form factor, it can be built as a low-cost clip-on for mobile phones. This clip-on creates a light-field display, which when placed up to the eye, can scan the lens of the eye section by section.
  • A patient will look close, he will se a steady green dot, if this dot fades away, subject presses a button. By compiling buttons pressed, the app builds
  • A patient will look close, he will se a steady green dot, if this dot fades away, subject presses a button. By compiling buttons pressed, the app builds scattering maps, who will show size, position and density of cataracts. This computational ophthalmology approach is intriguingly accurate and low-cost.

CATRA: Interactive Measuring and Modelling of Cataracts Presentation Transcript

  • 1. CATRA: Interactive Measuring and Modeling of Cataracts
    Vitor F. Pamplona Erick B. Passos Jan Zizka Manuel M. Oliveira Everett Lawson Esteban CluaRameshRaskar
    MIT Media Lab – Camera Culture
  • 2. CATRA: Quantitative Maps for
    Self-assessment of Early Cataracts
  • 3. NETRA: Near Eye Tool for Refractive Assessment
    Vitor Pamplona , Ankit Mohan, Manuel Oliveira, RameshRaskar, ACM SIGGRAPH 2010
  • 4. Main Cause of Preventable Blindness
  • 5.
  • 6. Slit-Lamp Microscope
  • 7.
  • 8. Computational Ophthalmology
  • 9. Observing Sub-aperture
    Scattering Profile
    (Point Spread Function)
    Clear Section
    Cataract-Affected Section
    Subject’s View
  • 10. Four Stages of Interaction
    Occlusion
    Scattering
    Opacity Map
    (position, size)
    Attenuation Map
    (brightness)
    Contrast Map
    (contrast)
    PSF Map
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
  • 11.
  • 12.
  • 13.
  • 14. Four Stages of Interaction
    Occlusion
    Scattering
    Opacity Map
    (position, size)
    Attenuation Map
    (brightness)
    Contrast Map
    (contrast)
    PSF Map
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    0.6mm
    C
    C
    C
    3mm
  • 15. ForwardScatteringSensedonFovea
    Testing
    Sections
    Projection on the Fovea
    LCD1
    Lens
    LCD2
    Light Box
  • 16. ForwardScatteringSensedonFovea
    Testing
    Sections
    Projection on the Fovea
    LCD1
    Lens
    LCD2
    Light Box
  • 17. Testing Sections of the Eye Lens
    LCD1
    Lens
    LCD2
  • 18. Trading Resolution for Brightness
    Testing Section
    Collimated Beams
    LCD1
    Lens
    LCD2
  • 19. Healthy Eye Point Spread Function = Peak
    Eye
    Visual Representation
    PSF
  • 20. Mild Cataracts Point Spread Function
    Eye
    Visual Representation
    PSF
  • 21. Advanced Cataracts Point Spread Function
    Eye
    Visual Representation
    PSF
  • 22. CATRA: Measuring, Modeling and Simulation
    σ
    Peak
    and simulate vision
    We want to map the aperture
    to estimate PSF
  • 23. Cataract Screening
    Presence of Cataracts
    (Binary Answer)
  • 24. Detecting the Presence of Cataracts
    Moving patterns
    on LCD1
    LCD1
    LCD2
  • 25. Detecting the Presence of Cataracts
    LCD1
    LCD2
  • 26. Detecting the Presence of Cataracts
    LCD1
    LCD2
    Eye lens
  • 27. Detecting the Presence of Cataracts
    LCD1
    LCD2
    Eye lens
    Perceived Image
  • 28. Cataract Screening
    Presence of Cataracts
    (Binary Answer)
  • 29. Interactive Techniques and Maps
    Presence of Cataracts
    (Binary Answer)
    Position, Size and Shape
    (Opacity Map)
  • 30. Estimating an Opacity Map
    Moving patterns
    on LCD1
    LCD1
    LCD2
  • 31. Interactive Techniques and Maps
    Presence of Cataracts
    (Binary Answer)
    Position, Size and Shape
    (Opacity Map)
  • 32. Interactive Techniques and Maps
    Brightness Test
    (Attenuation Map)
    Presence of Cataracts
    (Binary Answer)
    Position, Size and Shape
    (Opacity Map)
  • 33. Estimating Attenuation Maps
    Decreasing
    Brightness
    on the clear path
    LCD1
    LCD2
  • 34. Estimating Attenuation Maps
    Decreasing
    Brightness
    on the clear path
    Same Perceived
    Brightness
    LCD1
    LCD2
  • 35. Estimating Attenuation Maps
    Decreasing Intensity
    of the Clear Path
    To Match Brightness
    Perceived Image
    LCD1
    LCD2
    Eye
  • 36. Estimating Attenuation Maps
    Decreasing Intensity
    of the Clear Path
    To Match Brightness
    Perceived Image
    LCD1
    LCD2
    Eye
  • 37. Interactive Techniques and Maps
    Brightness Test
    (Attenuation Map)
    Presence of Cataracts
    (Binary Answer)
    Position, Size and Shape
    (Opacity Map)
  • 38. Interactive Techniques and Maps
    Brightness Test
    (Attenuation Map)
    Presence of Cataracts
    (Binary Answer)
    Position, Size and Shape
    (Opacity Map)
    Peak
  • 39. Interactive Techniques and Maps
    Brightness Test
    (Attenuation Map)
    Presence of Cataracts
    (Binary Answer)
    C
    C
    C
    C
    C
    C
    C
    C
    Position, Size and Shape
    (Opacity Map)
    Sub-aperture
    Contrast Test
    (Contrast Map)
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
  • 40. Contrast Test
    Increasing Contrast
    Perceived Image
    LCD1
    LCD2
    Eye
    Rotated Low Contrast Letter C
  • 41. Contrast Test
    Increasing Contrast
    Perceived Image
    LCD1
    LCD2
    Eye
    Rotated Low Contrast Letter C
  • 42. Contrast Test
    Increasing Contrast
    Perceived Image
    LCD1
    LCD2
    Eye
    Rotated Low Contrast Letter C
  • 43. Contrast Test
    Increasing Contrast
    Perceived Image
    LCD1
    LCD2
    Eye
    Rotated Low Contrast Letter C
    Press the right key
  • 44. Interactive Techniques and Maps
    Brightness Test
    (Attenuation Map)
    Presence of Cataracts
    (Binary Answer)
    C
    C
    C
    C
    C
    C
    C
    C
    Position, Size and Shape
    (Opacity Map)
    Sub-aperture
    Contrast Test
    (Contrast Map)
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
  • 45. Interactive Techniques and Maps
    Brightness Test
    (Attenuation Map)
    Presence of Cataracts
    (Binary Answer)
    C
    C
    C
    C
    C
    C
    C
    C
    Position, Size and Shape
    (Opacity Map)
    Sub-aperture
    Contrast Test
    (Contrast Map)
    C
    C
    C
    C
    C
    σ
    C
    C
    C
    C
    C
    C
    C
    C
  • 46. Interactive Techniques and Maps
    Brightness Test
    (Attenuation Map)
    Sub-aperture
    PSF Match
    (PSF Map)
    Presence of Cataracts
    (Binary Answer)
    C
    C
    C
    C
    C
    C
    C
    C
    Position, Size and Shape
    (Opacity Map)
    Sub-aperture
    Contrast Test
    (Contrast Map)
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
  • 47. Point Spread Function Matching
    Perceived Image
    LCD1
    LCD2
    Eye
  • 48. Point Spread Function Matching
    Perceived Image
    LCD1
    LCD2
    Eye
  • 49. Point Spread Function Matching
    Perceived Image
    LCD1
    LCD2
    Eye
  • 50. Point Spread Function Matching
    Perceived Image
    LCD1
    LCD2
    Eye
    Sub-aperture
    Point Spread Function
  • 51. Interactive Techniques and Maps
    Brightness Test
    (Attenuation Map)
    Sub-aperture
    PSF Match
    (PSF Map)
    Presence of Cataracts
    (Binary Answer)
    C
    C
    C
    C
    C
    C
    C
    C
    Position, Size and Shape
    (Opacity Map)
    Sub-aperture
    Contrast Test
    (Contrast Map)
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
  • 52. Interactive Techniques and Maps
    Brightness Test
    (Attenuation Map)
    Sub-aperture
    PSF Match
    (PSF Map)
    Presence of Cataracts
    (Binary Answer)
    C
    C
    C
    C
    C
    C
    C
    C
    Position, Size and Shape
    (Opacity Map)
    Sub-aperture
    Contrast Test
    (Contrast Map)
    C
    C
    C
    C
    C
    σ
    C
    C
    C
    C
    C
    C
    C
    C
  • 53. Contrast Tests when High-Attenuated
    Brightness Test
    (Attenuation Map)
    C
    C
    C
    High Attenuation
    Low Attenuation
    C
    C
    C
    C
    C
    Sub-aperture
    Contrast Test
    (Contrast Map)
    Sub-aperture
    PSF Match
    (PSF Map)
    Peak
    C
    C
    C
    C
    C
    Peak
    C
    C
    C
    C
    C
    C
    C
    C
  • 54. Reducing Search Space for PSF
    Brightness Test
    (Attenuation Map)
    Sub-aperture
    PSF Match
    (PSF Map)
    Presence of Cataracts
    (Binary Answer)
    Low Attenuation
    C
    C
    C
    C
    C
    C
    C
    C
    Position, Size and Shape
    (Opacity Map)
    Sub-aperture
    Contrast Test
    (Contrast Map)
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    High Attenuation
    C
    C
    C
  • 55. DLP-Mask Prototype
    High Contrast
    DLP Projector
    Mask
    Lens
    Eye
  • 56.
  • 57. Dual Monitor Stack
  • 58. Dual Monitor Stack
  • 59. Dual Monitor Stack
    Lens
    Medical Monochrome Monitors
    LCD Stack
  • 60. Cell Phone Prototype
    Lens
    Pinhole
    Mask
  • 61. Validation using Cameras
    Thin Diffuser to Simulate Cataracts
    Estimated Attenuation Map
    Estimated PSF Map
  • 62. Validation using Cameras
    Estimated
    Opacity Map
    Measured Attenuation
    (Pictures)
    Estimated
    Attenuation
    (User Interaction)
    Simulated Cataract
  • 63. Scratching Contact Lenses
    Advanced
    Cataracts
    Mild
    Cataracts
    Early
    Cataracts
    Measured: 0.5mm2
    Estimated: 0.45mm2
  • 64. Elderly Evaluation
  • 65. Rendering Cataract Effects
  • 66. Eye’s PSF = Summation of Sub-aperture PSF’s
    For the point of
    focus only
  • 67. Depth-dependent PSF
    Far
    Closer
    Focal Point
  • 68. Scene for Simulation
    Depth Map
  • 69. Picture with Cataract Lenses
  • 70. Simulation with Estimated PSF
  • 71.
  • 72.
  • 73.
  • 74. Bokeh Effect
  • 75. Limitations
    Active user participation
    One clear light path
    Retinal diseases
    Patience and concentration
    are required to follow steps
  • 76. Future Clinical Tests
    Clinical Testing Partners
    for CATRA
    Last year’s NETRA Prototypes
    (29 partners in 14 countries)
  • 77.
  • 78.
  • 79.
  • 80.
  • 81.
  • 82.
  • 83.
  • 84.
  • 85.
  • 86.
  • 87.
  • 88.
  • 89.
  • 90.
  • 91.
  • 92.
  • 93.
  • 94. Acknowledgments
    Bruce
    Sherleen
    Shrikant
    Don
    Rob
    Caio
    Tiago
    Tyler
    Fabiano
  • 95. Computational Ophthalmology
    A Co-design of Optics and CG for Measuring Cataracts
    Forward Scattering
    Foveal Image
    Four-stage Interactive Maps
    A Radar for the Cloud Cover
    Better than Subjective Rating
    Simulation of an individual’s cataract-affected eye
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
  • 96. CATRA: Quantitative Maps for
    Self-assessment of Early Cataracts
    More at: eyecatra.com
  • 97.
  • 98. Mass-use Devices  Scientific Instruments
  • 99. EyeNETRA Initiative
  • 100. EyeCATRA.com
    C
    C
    C
    LCD2
    LCD1
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
    C
  • 101. NETRA Near Eye Tool for Refractive Assessment
    Vitor Pamplona, Ankit Mohan, Manuel Oliveira, Ramesh Raskar SIGGRAPH 2010
  • 102. Preventable Blindness
  • 103.
  • 104.
  • 105. Cataract Types
    Nuclear
    Sub-capsular
    Cortical
  • 106. Cataract Types
    Nuclear
    Sub-capsular
    Cortical
  • 107. Cataract Types
    Nuclear
    Sub-capsular
    Cortical
  • 108. Cataract Types
    Easier to detect
    Nuclear
    Sub-capsular
    Cortical
  • 109.
  • 110. CATRA: Quantitative Maps for
    Self-assessment of Early Cataracts
    Unique mappingtool for
    size and density of eye opacities