Dr. Bahram Khoobehi Profile

Dr. Bahram Khoobehi

Physicist/Professor at Retina Health Ctr

SPIE Involvement:

Author

Publications (12)

Proceedings Article | 13 March 2013 Paper

A virtual size-variable pinhole for single photon confocal microscopy

Guangjun Gao, Bahram Khoobehi

Proceedings Volume 8573, 85730A (2013) https://doi.org/10.1117/12.2000240

KEYWORDS: Confocal microscopy, Zoom lenses, Surface plasmons, Imaging systems, Sensors, Single photon, Interference (communication), Signal detection, Objectives, Relays

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Proceedings Article | 3 February 2012 Paper

Determination of oxygen saturation of the optic nerve head and overlying artery and vein using a snapshot multi-spectral imaging system

Bahram Khoobehi, Alexander Eaton, Hussein Wafapoor, Paul Fournier, Kim Firn, Matt Peters, Ellie Rodebeck, Brian Templet

Proceedings Volume 8229, 822906 (2012) https://doi.org/10.1117/12.910030

KEYWORDS: Oxygen, Veins, Algorithm development, Tissues, Arteries, Retina, Blood, Optic nerve, Head, Image segmentation

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Proceedings Article | 3 February 2012 Paper

Spectral reflectance of the ocular fundus as a diagnostic marker for cerebral malaria

Xun Liu, David Rice, Bahram Khoobehi

Proceedings Volume 8229, 82290H (2012) https://doi.org/10.1117/12.905763

KEYWORDS: Oxygen, Reflectivity, Blood, Diagnostics, Hyperspectral imaging, Absorption, Pathology, Retina, Curium, Luminescence

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Proceedings Article | 3 February 2012 Paper

Snapshot hyperspectral imaging to measure oxygen saturation in the retina using fiber bundle and multi-slit spectrometer

Bahram Khoobehi, Aurash Khoobehi, Paul Fournier

Proceedings Volume 8229, 82291E (2012) https://doi.org/10.1117/12.910056

KEYWORDS: Spectroscopy, Oxygen, Hyperspectral imaging, Cameras, Eye, Diffraction gratings, Retina, Spectrographs, Tissues, Spatial resolution

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Proceedings Article | 24 February 2009 Paper

A simple model of oxygen diffusion out of the retinal artery

J. Beach, J. Ning, B. Khoobehi, D. Rice

Proceedings Volume 7163, 71630S (2009) https://doi.org/10.1117/12.809408

KEYWORDS: Oxygen, Diffusion, Arteries, Blood, Tissues, Velocity measurements, Blood circulation, Eye, Hyperspectral imaging, Radium

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Proceedings Article | 18 February 2009 Paper

Oxygen saturation changes in the optic nerve head during acute intraocular pressure elevation in monkeys

Bahram Khoobehi, Hiroyuki Kawano, Jinfeng Ning, Claude Burgoyne, David Rice, Fareeha Khan, Hilary Thompson, James Beach

Proceedings Volume 7163, 716320 (2009) https://doi.org/10.1117/12.809512

KEYWORDS: Oxygen, Mercury, Eye, Arteries, Blood, Veins, Optic nerve, Tissues, Head, Blood circulation

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Proceedings Article | 13 February 2009 Paper

Angiogram, fundus, and oxygen saturation optic nerve head image fusion

Hua Cao, Bahram Khoobehi

Proceedings Volume 7182, 71821U (2009) https://doi.org/10.1117/12.809537

KEYWORDS: Image fusion, Oxygen, Angiography, Optic nerve, Head, Detection and tracking algorithms, Eye, Cameras, Image registration, Spectrographs

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Proceedings Article | 29 March 2007 Paper

Retinal oxygen saturation evaluation by multi-spectral fundus imaging

Bahram Khoobehi, Jinfeng Ning, Elise Puissegur, Kimberly Bordeaux, Madhusudhanan Balasubramanian, James Beach

Proceedings Volume 6511, 65110B (2007) https://doi.org/10.1117/12.710030

KEYWORDS: Oxygen, Retina, Arteries, Tissues, Veins, Cameras, Eye, Image registration, Blood, Reflectivity

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Purpose: To develop a multi-spectral method to measure oxygen saturation of the retina in the human eye. Methods: Five Cynomolgus monkeys with normal eyes were anesthetized with intramuscular ketamine/xylazine and intravenous pentobarbital. Multi-spectral fundus imaging was performed in five monkeys with a commercial fundus camera equipped with a liquid crystal tuned filter in the illumination light path and a 16-bit digital camera. Recording parameters were controlled with software written specifically for the application. Seven images at successively longer oxygen-sensing wavelengths were recorded within 4 seconds. Individual images for each wavelength were captured in less than 100 msec of flash illumination. Slightly misaligned images of separate wavelengths due to slight eye motion were registered and corrected by translational and rotational image registration prior to analysis. Numerical values of relative oxygen saturation of retinal arteries and veins and the underlying tissue in between the artery/vein pairs were evaluated by an algorithm previously described, but which is now corrected for blood volume from averaged pixels (n > 1000). Color saturation maps were constructed by applying the algorithm at each image pixel using a Matlab script. Results: Both the numerical values of relative oxygen saturation and the saturation maps correspond to the physiological condition, that is, in a normal retina, the artery is more saturated than the tissue and the tissue is more saturated than the vein. With the multi-spectral fundus camera and proper registration of the multi-wavelength images, we were able to determine oxygen saturation in the primate retinal structures on a tolerable time scale which is applicable to human subjects. Conclusions: Seven wavelength multi-spectral imagery can be used to measure oxygen saturation in retinal artery, vein, and tissue (microcirculation). This technique is safe and can be used to monitor oxygen uptake in humans. This work is original and is not under consideration for publication elsewhere.

SPIE Journal Paper | 1 September 2005 Open Access

Algorithms for automated oximetry along the retinal vascular tree from dual-wavelength fundus images

Harihar Narasimha-Iyer, James Beach, Bahram Khoobehi, Jinfeng Ning, Hiroyuki Kawano, Badrinath Roysam

JBO, Vol. 10, Issue 05, 054013, (September 2005) https://doi.org/10.1117/12.10.1117/1.2113187

KEYWORDS: Image segmentation, Oxygen, Arteries, Veins, Oximetry, Image processing algorithms and systems, Blood, Algorithm development, Retina, Reconstruction algorithms

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