Upload
vitor-pamplona
View
49.574
Download
1
Tags:
Embed Size (px)
DESCRIPTION
Our Presentation at ACM SIGGRAPH 2010.
Citation preview
MIT media lab camera culture EyeNetra.com
1
NETRA: Interactive Display for Estimating Refractive
Errors and Focal RangeVitor Pamplona Ankit Mohan Manuel M. Oliveira Ramesh Raskar
MIT media lab camera culture EyeNetra.com
2
NETRA: Near Eye Tool for Refractive Assessment
Vitor Pamplona Ankit Mohan Manuel M. Oliveira Ramesh Raskar
MIT media lab camera culture EyeNetra.com
Challenge
6.5 Billion people
4.5B have a cell phone
2B haverefractive errors
0.6B have URE
NETRA at LVP Eye Institute
MIT media lab camera culture EyeNetra.com
4
Computational Photography
Optometry/Opthalmalogy
Measure .. Overcome Limitations .. Extend Abilities
MIT media lab camera culture EyeNetra.com
Phoropter
Snellen chart
Trial lenses
Reading Charts• Accuracy
– Sharpness Estimation is subjective– Brightness affects results– Pupil size variation and DoF
• Cost– Trial Lens Set > $150– Bulky
Retino scope w/
Lenses
Auto-refracto-
meter
Chart with
Lenses
In-Focus: Focometer Optiopia
Solo-health: EyeSite
NETRA
Technology Shining Light plus lenses
Fundus Camera
Moving lenses + target
Moving lenses + target
Reading chart on monitor
Cellphone + eyepiece
Cost to buy $2,000* ~$10,000 ~$100 ~$495 ~$200 -- $30
Cost per test ~$36 ~$36 ~$5 -- -- -- ~$1
Data capture No Comp. No No No Comp. Phone
Mobility <500g >10Kg 2kg 1kg <5kg >10Kg <100g
Speed Fast Fast Medium Medium -- Fast Fast
Scalability No No No Yes Probably No Yes
Accuracy 0.15 0.15 0.5 0.75 -- -- <0.5
Self evaluation No No Yes Yes Yes Yes Yes
Electricity Req No Yes No No -- Yes No
Astigmatism Yes Yes Yes/No No -- Yes Yes
Network No Yes No No No Yes Yes
Training High High High Medium Medium Low Low
* Phoropter-based: $5,000.00
Needs expert, Moving parts, Shining lasers
MIT media lab camera culture EyeNetra.com
7
Shack-Hartmann Wavefront Sensor
Expensive; Bulky, Requires trained professionals
Wavefront aberrometer
MIT media lab camera culture EyeNetra.com
8
Shack-Hartmann ~ Lightfields
Levoy et al 2009 Zhang and Levoy 2009: Observable Light Field
Oh, Raskar, Barbastathis 2009: Augmented Light Field
Shack-Hartmann Wavefront Sensor
Laser
Sensor Microlens Array
Planar Wavefront
Shack & Platt 1971Liang et al 1994
David Williams et al, Rochester
Spot Diagram
MIT media lab camera culture EyeNetra.com
9
Laser
Sensor
Displacement = Local Slope
of the Wavefront
Spot Diagram
Shack-Hartmann Wavefront Sensor
MIT media lab camera culture EyeNetra.com
10
NETRA = Inverse of Shack-Hartmann
Spot Diagram on LCD
Cell Phone Display
Eye Piece
MIT media lab camera culture EyeNetra.com
11
Spot Diagram on LCD
Inverse of Shack-HartmannUser interactively creates the Spot Diagram
Displace 25 points but 3 parameters
MIT media lab camera culture EyeNetra.com
12
Infinity
Optometry
Human Eye
Infinity
Subject can focusat infinity
10cm
Normal Vision
Accommodation Range
MIT media lab camera culture EyeNetra.com
13
Myopia (nearsightedness)
Infinity
Subject cannot focusat far distances
10cm
Normal Vision
Myopia
Accommodation Range
Infinity
Shifted Accommodation Range
MIT media lab camera culture EyeNetra.com
14
Myopia Correction
Infinity
Subject can focusat infinity
10cm
Normal Vision
Myopia
Accommodation Range
Infinity
Human Eye
Shifted Accommodation Range
MIT media lab camera culture EyeNetra.com
16
Hyperopia (farsightedness)
Infinity 10cm
Normal Vision
Myopia
Hyperopia
Wrong focal point
Accommodation Range
Infinity
Human Eye
MIT media lab camera culture EyeNetra.com
17Infinity
Accommodation Range
10cm
Normal Vision
Myopia
Hyperopia
‘Beyond’Infinity
Human Eye
Hyperopia (farsightedness)
MIT media lab camera culture EyeNetra.com
19
Refractive Errors and Shifted Range
Perfect vision
Myopia
Hyperopia
10cmInfinity
Need to measure
1m 33cm Distance
MIT media lab camera culture EyeNetra.com
20
Refractive Errors and Shifted Range
Perfect vision
Myopia
Hyperopia
10cmInfinity
10D0D
Diopter = 1/Distance
3D1D
1m 33cm
-1D-3D
Distance
Diopter
MIT media lab camera culture EyeNetra.com
21
Eye
Relaxed Eye with Myopia
Blurred point
Red pointat infinity
perfect vision
myopia
hyperopia
~10cminfinity
Focusing Range
MIT media lab camera culture EyeNetra.com
22
Eye
Relaxed Eye with Myopia
Distinctimage points
perfect vision
myopia
hyperopia
~10cminfinity
Focusing Range
Pinholes
Red pointat infinity
Scheiner’s Principle
MIT media lab camera culture EyeNetra.com
23
Eye
Relaxed Eye with Myopia
Virtual red pointat infinity
perfect vision
myopia
hyperopia
~10cminfinity
Focusing Range
A
B
Distinctimage points
Display
MIT media lab camera culture EyeNetra.com
24
Relaxed Eye with Myopia
A
B
perfect vision
myopia
hyperopia
~10cminfinity
Focusing Range
Virtual red pointat finite distance
Move spots towards each
other
Display
Eye
Distinctimage points
MIT media lab camera culture EyeNetra.com
25
B
A
Points overlap
Relaxed Eye with Myopia
Display
perfect vision
myopia
hyperopia
~10cminfinity
Focusing Range
Eye
Virtual red pointat finite distance
Move spots towards each
other
MIT media lab camera culture EyeNetra.com
26
B
A
Points overlap
Relaxed Eye with Myopia
Display
perfect vision
myopia
hyperopia
~10cminfinity
Focusing Range
Eye
Virtual red pointat finite distance
Move spots towards each
other
d
MIT media lab camera culture EyeNetra.com
27
Points overlap
Relaxed Eye with Myopia
perfect vision
myopia
hyperopia
~10cminfinity
Focusing Range
Eye
d
d
1
Point at infinity
MIT media lab camera culture EyeNetra.com
29
Distinctimage points
Relaxed Eye with Hyperopia
perfect vision
myopia
hyperopia
~10cminfinity
Focusing Range
A
B
Display
Virtual red pointat infinity
Eye
MIT media lab camera culture EyeNetra.com
30
Points overlap
Relaxed Eye with Hyperopia
Virtual point“beyond” infinity
Move spots away from each other
perfect vision
myopia
hyperopia
~10cminfinity
Focusing Range
Display
A
B
Display
MIT media lab camera culture EyeNetra.com
31
Points overlap
Relaxed Eye with Hyperopia
Virtual point“beyond” infinity
Move spots away from each other
perfect vision
myopia
hyperopia
~10cminfinity
Focusing Range
MIT media lab camera culture EyeNetra.com
32
NETRA: Using pinholes
Patterns on an LCD
Pinhole array
MIT media lab camera culture EyeNetra.com
33
f
Patterns on an LCD
Microlens array
NETRA: Using Lens to Increase Light
tda
fc
2
t
a
Pixel Pitch
Virtual Depth
MIT media lab camera culture EyeNetra.com
34
Interactive Method
Farthest Focal Point(myopia, hyperopia)
MIT media lab camera culture EyeNetra.com
35
Interactive Method
Farthest Focal Point(myopia, hyperopia)
MIT media lab camera culture EyeNetra.com
36
Interactive Method
Farthest Focal Point(myopia, hyperopia)
MIT media lab camera culture EyeNetra.com
37
Overview• Inverse of Shack Hartmann Wavefront Sensor
• Hi-res displays + interaction• Measuring Spherical Error
• No moving parts, lasers• Blur -> Alignment problem• ~ Lightfield Display for Single Eye
• Astigmatism• Novel Patterns• Focal Range• User Study
MIT media lab camera culture UFRGS EyeNetra.com
38
Astigmatism: angle-dependent refractive error
http://www.elizabethpope.co.uk/eyeinfo/astigmatism.html
MIT media lab camera culture UFRGS EyeNetra.com
39
Astigmatism: angle-dependent refractive error
http://www.elizabethpope.co.uk/eyeinfo/astigmatism.html
MIT media lab camera culture UFRGS EyeNetra.com
40
Astigmatism: angle-dependent refractive error
http://www.elizabethpope.co.uk/eyeinfo/astigmatism.html
MIT media lab camera culture UFRGS EyeNetra.com
41
Refractive Power as a Function of Angle
Cylinder SphereAxis Cyl.Unknowns:
SCP )(sin( 2
MIT media lab camera culture UFRGS EyeNetra.com
42
Astigmatism
Cross or points may never meet with a 1d search !
MIT media lab camera culture UFRGS EyeNetra.com
43
Astigmatism
Lines reduce the problem to a 1d search
MIT media lab camera culture UFRGS EyeNetra.com
44
Interactive Method
Farthest Focal Point(myopia, hyperopia, astigmatism)
MIT media lab camera culture UFRGS EyeNetra.com
45
Interactive Method
Farthest Focal Point(myopia, hyperopia, astigmatism)
MIT media lab camera culture UFRGS EyeNetra.com
46
Interactive Method
Farthest Focal Point(myopia, hyperopia, astigmatism)
MIT media lab camera culture UFRGS EyeNetra.com
47
Interactive Method
Farthest Focal Point(myopia, hyperopia, astigmatism)
MIT media lab camera culture UFRGS EyeNetra.com
48
Interactive Method
Farthest Focal Point(myopia, hyperopia, astigmatism)
MIT media lab camera culture UFRGS EyeNetra.com
49
Evaluation Prototype
LCD Display
Minification
Camera simulatesthe perfect eye
Trial lenses simulate lens
aberration
MIT media lab camera culture UFRGS EyeNetra.com
50
Subjective Validation: User Study
MIT media lab camera culture UFRGS EyeNetra.com
51
Measuring the Accommodation Range
Perfect vision
~10cmInfinity
Myopia
Hyperopia
Step 1: Far limit Step 2: Near limit
MIT media lab camera culture UFRGS EyeNetra.com
52
Measuring the Accommodation Range
Perfect vision
~10cmInfinity
Myopia
Hyperopia
Step 1: Far limit Step 2: Near limit
MIT media lab camera culture UFRGS EyeNetra.com
53
Measuring the Accommodation Range
Perfect vision
~10cmInfinity
Myopia
Hyperopia
Step 1: Far limit Step 2: Near limit
MIT media lab camera culture UFRGS EyeNetra.com
54
Points overlap
A
B
Display
Virtual Point at the far limit
Relaxed Eye
MIT media lab camera culture UFRGS EyeNetra.com
55
Points overlap
A
B
Display
Accommodated Eye
Virtual pointgetting closer
Move points towards each other
Subject Accommodates to fix the “blur”
MIT media lab camera culture UFRGS EyeNetra.com
56
Points overlap
A
B
Display
Accommodated Eye
Virtual pointgetting closer
Move points towards each other
Subject Accommodates to fix the “blur”
MIT media lab camera culture UFRGS EyeNetra.com
57
Points overlap
A
B
Display
Accommodated Eye
Virtual pointgetting closer
Move points towards each other
Subject cannot accommodate more than the previous point
MIT media lab camera culture UFRGS EyeNetra.com
58
Patterns for Alignment Task
Displayed
Subject view
Displayed
Subject view
Visual Cryptography
A B A B A B A B A B
A B A B A B A B A B
[NaorShamir94]
MIT media lab camera culture UFRGS EyeNetra.com
59
Patterns for Alignment Task
Displayed
Subject view
Displayed
Subject view
Visual Cryptography
A B A B A B A B
A B A B A B A B A B
A B
[NaorShamir94]
MIT media lab camera culture UFRGS EyeNetra.com
gh
ghh
Subject View as Convolution
Subject’ s View
Subject’ s View
Display
g h
S
S
MIT media lab camera culture UFRGS EyeNetra.com
Viewmaster prototype
+3D to -5D with accommodation61
Subject View
h - Jittered Pinholes
G(-5D) G(0D) G(+5D)
Scaled Patterns
MIT media lab camera culture UFRGS EyeNetra.com
62
Summary of Interaction
Farthest Point(myopia, hyperopia, astigmatism)
Nearest Point(presbyopia)
Accommodation Range
MIT media lab camera culture UFRGS EyeNetra.com
63
Limitations
• Children• Ability to align lines
• Single Eye test– Other eye for convergence-forced accommodation
• Resolution is a function of the display DPI– Samsung Behold II – 160 DPI – 0.35D– Google Nexus One – 250 DPI – 0.2D– Apple iPhone 4G – 326 DPI – 0.14D
MIT media lab camera culture UFRGS EyeNetra.com
64
Future Work• Clinical research for an optometry device
– Side-by-side validation tests– Field trials – Tests for cataract, lazy eye, etc
• Opportunity to monitor one’s eyesight– Diabetes/Glucose non-invasive meter– Unstable lens prescriptions
• Distribution in Developing Countries– Software app for free– Eyepiece blueprint to NGOs for <$1– More at EyeNetra.com
MIT media lab camera culture UFRGS EyeNetra.com
65
Future Work• Multi-focus display without moving parts
– [Akeley04][Rolland00][Hua09] [Barsky04]
• Personalized devices (clear without glasses) – Alarm Clock – Cell phones– eReaders
Inju Fernando Meyer
MIT media lab camera culture UFRGS EyeNetra.com
66
Acknowledgements
• Volunteers• Dr. Joseph Ciolino (MGH Mass Eye and Ear Inst.)• Dr. Fuentanta Vera Diaz (Schepens Eye Research Inst.)• Dr. James Kobler (MGH Mass Eye and Ear Inst.)• Dr. Shrikant Bhardwaj, (LV Prasad Eye Institute, India)
Sponsors• CNPq-Brazil• Alfred P. Sloan Research Fellowship• Google • Samsung
MIT media lab camera culture UFRGS EyeNetra.com
67
NETRA: Display for Eye Refraction Tests
• Inverse of Shack-Hartmann wavefront aberrometer– High-resolution displays and user interaction
• Focal Parameters– Myopia, Hyperopia, Astigmatism– Focal range
• Thermometer for the eye– Measurement not prescription– Promote Self Awareness
• Impact in Developing Countries– 600 Million without corrective glasses– $1 cost, easy to deploy
MIT media lab camera culture UFRGS EyeNetra.com
68
NETRA: Interactive Display for Estimating Refractive Errors and Focal Range
Vitor Pamplona Ankit Mohan Manuel M. Oliveira Ramesh Raskar