Hyperspectral imaging system for the dynamic recording of...
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Hyperspectral imaging system for the dynamic recording of the ocular fundus Preliminary Results Tommaso Alterini
Transcript of Hyperspectral imaging system for the dynamic recording of...
Hyperspectral imaging systemfor the dynamic recording of the ocular fundus
Preliminary ResultsTommaso Alterini
• Aim of the project
• The fundus camera prototype:
• Design
• Illumination
• Experimental set-up
• Preliminary results
• Work in progress
Outline
• Resolution (≈ 15 µm)
• Field Of View (>30°)
• Color (RGB) Imaging
• Specific static spectral filters
Color image
Red-free image
Aim of the project
Hyperpectralimaging
ColorImaging
Aim of the project
Development of a fast and broad bandhyperspectral fundus camera to investigate both the spatial
and spectral properties of the ocular fundus
• Extension to the NIR range(Up to 1.3 μm).
• Increase the number of spectral bands.
• Fast acquisition and illumination system
• Hyperspectral clinical diagnosis of retinal disease
Broad band and high speed hyperspectral imaging.
SpectralExtension
Well knownspectral range
Aim of the project
The fundus camera design
CMOS
InGaAs
0.9-1.3 µm detection
0.4 -0.9 µmdetection
EYE
Light source
Anti-backreflectionsstops
System Specs:• FOV = 30°• ~ 10 µm resolution• ≥ ±10 D refraction correction • Fast LED-based sequential illumination • 15 spectral channels:
410 nm, 460 nm, 490 nm, 520 nm, 585 nm, 620 nm, 660 nm,720 nm, 810 nm, 850 nm, 940 nm, 1050 nm, 1140 nm, 1200 nm, 1300 nm.
• Two detection arms:CMOS camera VIS (16 bits, 2048x2048 pixels)InGaAs camera NIR (12 bits, 640x512 pixels)
BLACKMASK
DIFFUSER
Retinal plane illumination
Eye pupilplane
Dichroichmirror
The fundus camera design
ObjectiveArtificial
eye
InGaAs Camera
CMOS Camera
Anti-backreflections
stops
Dichroic mirrors
Pupil separation
mirror
Illumination arm
Detection arms
The fundus camera prototype
Preliminary results
Artificial Eye
LED LED +polarizersRing mask + White source
BLACKMASK
DIFFUSER
LED LED +polarizers
Preliminary results
Artificial Eye
Ring mask + White source
Preliminary results
Artificial Eye
LED LED +polarizersRing mask + White source
Preliminary results
Artificial Eye
LED LED +polarizersRing mask + White source
Preliminary results
1050 nm670 nm
Human Retina
Work in progress
• Hard-implementation of all 16 wavelengths LEDs.
• Improvement of illumination homogeneity and efficiency by means of precise system adjustment:
- holed mirror in place of an elliptical mirror- illumination module with smaller LEDs and optimized arrangement- homogeneity and reduce parasites lights.
Work in progress
• Implementation of robust and fast software for synchronized acquisition and post processing.
• Working with Pablo we are developing image restoration algorithms to reduce the shadow effects and increase illumination homogeneity.
