Dr. Alfredo Dubra Profile

Dr. Alfredo Dubra

Professor at Stanford University

SPIE Involvement:

Author | Science Fair Judge

Area of Expertise:

Retinal imaging , Adaptive optics , Imaging

Websites:

Company Website

Publications (22)

Proceedings Article | 13 March 2024 Presentation

Artificial intelligence improves pixel resolution of cones from sparsely sampled AOOCT

Vineeta Das, Andrew Bower, Nancy Aguilera, Joanne Li, Zhuolin Liu, Daniel Hammer, Alfredo Dubra, Johnny Tam

Proceedings Volume PC12824, PC1282410 (2024) https://doi.org/10.1117/12.3000362

KEYWORDS: Cones, Pixel resolution, Artificial intelligence, Visualization, Transformers, Retina, Resolution enhancement technologies, Network architectures, Modeling, In vivo imaging

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SPIE Journal Paper | 13 December 2022 Open Access

Special Section Guest Editorial: Advances in Optical Measurements and Instrumentation for Ophthalmology and Optometry

Daniel Malacara-Hernández, Alfredo Dubra, Jim Schwiegerling, Pablo Artal, Yobani Mejía, Eva Acosta Plaza

OE, Vol. 61, Issue 12, 121801, (December 2022) https://doi.org/10.1117/12.10.1117/1.OE.61.12.121801

KEYWORDS: Ophthalmology, Eye, Optometry, Optical testing, Optical engineering, Optical coherence tomography, Wavefront sensors, Visualization, Technology, Physiology

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Proceedings Article | 7 March 2022 Presentation

Dynamic imaging of vitreous cortex hyalocytes using adaptive optics scanning light ophthalmoscopy in human subjects

Richard Rosen, Justin Migacz, Oscar Otero-Marquez, Davis Zhou, Maria Castanos-Toral, Kara Rickford, Rebecca Zhou, Brian Murillo, Alexander Pinhas, Rishard Weitz, Nripun Sredar, Alfredo Dubra, Toco Chui

Proceedings Volume 11941, 1194103 (2022) https://doi.org/10.1117/12.2610678

KEYWORDS: Adaptive optics, Vitreous, Optical coherence tomography, Human subjects, Ophthalmoscopy, Scanning laser ophthalmoscopy, Cell mechanics, Visualization, Video processing, Video

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Proceedings Article | 5 March 2021 Presentation

A two-layer Shack-Hartmann wavefront sensor model of the human and mouse retinas

Vyas Akondi, Alfredo Dubra

Proceedings Volume 11623, 116230D (2021) https://doi.org/10.1117/12.2583667

KEYWORDS: Wavefront sensors, Retina, Eye models, Monochromatic aberrations, Optical sensors, Gaussian optics, Backscatter

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Proceedings Article | 5 March 2021 Poster + Presentation

Correction of dynamic aberration in resonant optical scanners using tilted optics

Xiaojing Huang, Alfredo Dubra

Proceedings Volume 11623, 116231M (2021) https://doi.org/10.1117/12.2583648

KEYWORDS: Monochromatic aberrations, Reflectivity, Wavefronts, Mirrors, Distortion, Scanners, Relays, Optical scanning, Optical components, Wavefront aberrations

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Proceedings Article | 5 March 2021 Presentation

Surpassing the resolution limit of adaptive optics imaging in the living human eye by combining annular pupil illumination with sub-Airy disk confocal pinhole detection

Rongwen Lu, Nancy Aguilera, Tao Liu, Jianfei Liu, John Giannini, Joanne Li, Andrew Bower, Alfredo Dubra, Johnny Tam

Proceedings Volume 11623, 116230B (2021) https://doi.org/10.1117/12.2583069

KEYWORDS: Confocal microscopy, Image resolution, Eye, Adaptive optics, Rods, Cones, Resolution enhancement technologies, Point spread functions, 3D metrology, Spatial resolution

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Proceedings Article | 9 March 2020 Presentation

In vivo quantification of Bruch's membrane in humans with visible light OCT (Conference Presentation)

Tingwei Zhang, Aaron Kho, Vyas Akondi, Alfredo Dubra, Vivek Srinivasan

Proceedings Volume 11218, 112180H (2020) https://doi.org/10.1117/12.2546437

KEYWORDS: In vivo imaging, Visible radiation, Optical coherence tomography

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SPIE Journal Paper | 9 December 2019 Open Access

Special Section Guest Editorial: Advances in Retinal Imaging

Ji Yi, Alfredo Dubra, Sina Farsiu

NPh, Vol. 6, Issue 04, 041101, (December 2019) https://doi.org/10.1117/12.10.1117/1.NPh.6.4.041101

KEYWORDS: Retinal scanning, Optical coherence tomography, Retina, Image quality, Visible radiation, Oxygen, Tissue optics, Nerve, Biology, Ecosystems

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Proceedings Article | 3 April 2018 Paper

Visible light optical coherence microscopy imaging of the mouse cortex with femtoliter volume resolution

Conrad Merkle, Shau Poh Chong, Aaron Kho, Jun Zhu, Oybek Kholiqov, Alfredo Dubra, Vivek Srinivasan

Proceedings Volume 10483, 104831X (2018) https://doi.org/10.1117/12.2292125

KEYWORDS: Visible radiation, Image resolution, Objectives, Optical coherence tomography, Imaging systems, Confocal microscopy, Tissue optics, In vivo imaging, Skull, Scattering

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Proceedings Article | 5 March 2018 Paper

New clinical opportunities for retinal vascular imaging: adaptive optics to OCT angiography

Richard Rosen, Toco Chui, Rishard Weitz, Alfredo Dubra, Joseph Carroll, Patricia Garcia, Alexander Pinhas, Nicole Scripsema, Shelley Mo, Steven Agemy, Brian Krawitz

Proceedings Volume 10591, 1059102 (2018) https://doi.org/10.1117/12.2304296

KEYWORDS: Capillaries, Optical coherence tomography, Angiography, Adaptive optics, Scanning laser ophthalmoscopy, Visualization, Retinal scanning, Vascular imaging, Retina, Image resolution

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Proceedings Article | 24 March 2016 Paper

A fully automatic framework for cell segmentation on non-confocal adaptive optics images

Jianfei Liu, Alfredo Dubra, Johnny Tam

Proceedings Volume 9785, 97852J (2016) https://doi.org/10.1117/12.2217191

KEYWORDS: Image segmentation, Adaptive optics, Eye, Retina, Cones, Detection and tracking algorithms, Automatic tracking, Image processing, Signal processing, Ophthalmology

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Proceedings Article | 24 March 2016 Paper

Computer-aided detection of human cone photoreceptor inner segments using multi-scale circular voting

Jianfei Liu, Alfredo Dubra, Johnny Tam

Proceedings Volume 9785, 97851A (2016) https://doi.org/10.1117/12.2216929

KEYWORDS: Cones, Image segmentation, Eye, Adaptive optics, Human vision and color perception, Retina, Computer-aided diagnosis, Blood vessels, Detection and tracking algorithms, Feature extraction, Confocal microscopy, Visualization, Algorithm development

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Proceedings Article | 7 March 2014 Paper

Optical design of a broadband scanning adaptive optics ophthalmoscope for the mouse eye

Yusufu Sulai, Alfredo Dubra

Proceedings Volume 8978, 89780E (2014) https://doi.org/10.1117/12.2041993

KEYWORDS: Adaptive optics, Mirrors, Eye, Spherical lenses, Telescopes, Wavefronts, Retina, Wavefront sensors, Reflectivity, Optical design

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Proceedings Article | 24 February 2012 Paper

Low bandwidth eye tracker for scanning laser ophthalmoscopy

Zachary Harvey, Alfredo Dubra, Nathan Cahill, Sonia Lopez Alarcon

Proceedings Volume 8314, 831450 (2012) https://doi.org/10.1117/12.911661

KEYWORDS: Eye, Motion estimation, Filtering (signal processing), Signal to noise ratio, Adaptive optics, Raster graphics, Human subjects, Image registration, Scanners, Optical scanning

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Proceedings Article | 16 February 2011 Paper

Advanced capabilities of the multimodal adaptive optics imager

Daniel Hammer, R. Ferguson, Mircea Mujat, David Biss, Nicusor Iftimia, Ankit Patel, Emily Plumb, Melanie Campbell, Jennifer Norris, Alfredo Dubra, Toco Chui, James Akula, Anne Fulton

Proceedings Volume 7885, 78850A (2011) https://doi.org/10.1117/12.876579

KEYWORDS: Optical coherence tomography, Scanning laser ophthalmoscopy, Adaptive optics, Imaging systems, Raster graphics, Video, Multichannel imaging systems, Image registration, Scanners, Doppler effect

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Proceedings Article | 3 December 2009 Paper

First-order design of off-axis reflective ophthalmic adaptive optics systems using afocal telescopes

Armando Gómez-Vieyra, Alfredo Dubra, David Williams, Daniel Malacara-Hernández

Proceedings Volume 7499, 74990F (2009) https://doi.org/10.1117/12.845198

KEYWORDS: Monochromatic aberrations, Adaptive optics, Mirrors, Telescopes, Reflector telescopes, Reflectivity, Eye, Off axis mirrors, Spherical lenses, Fluctuations and noise

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Proceedings Article | 30 December 2008 Paper

Optimization of the temporal performance of a deformable mirror for use in ophthalmic applications

Erika Odlund, Maurice Navarro, Emeric Lavergne, Franck Martins, Xavier Levecq, Alfredo Dubra

Proceedings Volume 7139, 713912 (2008) https://doi.org/10.1117/12.814906

KEYWORDS: Actuators, Linear filtering, Capacitors, Adaptive optics, Mirrors, Wavefronts, Electronic filtering, Digital filtering, Photovoltaics, Monochromatic aberrations

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Proceedings Article | 6 February 2008 Paper

MEMS in adaptive optics scanning laser ophthalmoscopy: achievements and challenges

A. Dubra, D. Gray, J. I. Morgan, D. Williams

Proceedings Volume 6888, 688803 (2008) https://doi.org/10.1117/12.771747

KEYWORDS: Microelectromechanical systems, Luminescence, Reflectivity, Adaptive optics, Mirrors, Eye, In vivo imaging, Sensors, Retinal scanning, Scanners

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Proceedings Article | 8 June 2006 Paper

Hysteresis compensation in PZT bimorph mirrors: Preisach's classical and non-linear models

Alfredo Dubra, John Massa, Carl Paterson

Proceedings Volume 6018, 60181E (2006) https://doi.org/10.1117/12.669384

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Proceedings Article | 6 July 1999 Paper

Laser and optics in Uruguay

Alfredo Dubra, Jose Ferrari, Erna Frins, Arturo Lezama, Cristina Masoller

Proceedings Volume 3572, (1999) https://doi.org/10.1117/12.358436

KEYWORDS: Laser optics, Semiconductor lasers, Spectroscopy, Optical fibers, Polarization, Interferometry, Absorption, Laser stabilization, Rubidium, Transient nonlinear optics

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SPIE Journal Paper | 1 July 1999

Space integrating joint transform correlator using a moving grating

Jose Ferrari, Alfredo Dubra, Daniel Perciante, Ben Rodriguez

OE, Vol. 38, Issue 07, (July 1999) https://doi.org/10.1117/12.10.1117/1.602270

KEYWORDS: Optical correlators, Ronchi rulings, Joint transforms, Spatial light modulators, Photodetectors, Modulation, Sensors, Image processing, Fourier transforms, Electronic filtering

SPIE Journal Paper | 1 October 1998

Nonlinear joint transform correlator using one-dimensional Fourier transformation

Ben Rodriguez, Alfredo Dubra, Carlos Martinez, Gonzalo Escuder, Jose Ferrari

OE, Vol. 37, Issue 10, (October 1998) https://doi.org/10.1117/12.10.1117/1.601809

KEYWORDS: Joint transforms, Optical correlators

Showing 5 of 22 publications

Conference Committee Involvement (1)

Optical Coherence Imaging Techniques and Imaging in Scattering Media II

25 June 2017 | Munich, Germany

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