Towards simultaneous Talbot bands based optical coherence tomography and scanning laser ophthalmoscopy imaging

by Manuel J. Marques, Adrian Bradu, Adrian Gh. Podoleanu
Abstract:
We report a Talbot bands-based optical coherence tomography (OCT) system capable of producing longitudinal B-scan OCT images and en-face scanning laser ophthalmoscopy (SLO) images of the human retina in-vivo. The OCT channel employs a broadband optical source and a spectrometer. A gap is created between the sample and reference beams while on their way towards the spectrometerrqs dispersive element to create Talbot bands. The spatial separation of the two beams facilitates collection by an SLO channel of optical power originating exclusively from the retina, deprived from any contribution from the reference beam. Three different modes of operation are presented, constrained by the minimum integration time of the camera used in the spectrometer and by the galvo-scannersrq scanning rate: (i) a simultaneous acquisition mode over the two channels, useful for small size imaging, that conserves the pixel-to-pixel correspondence between them; (ii) a hybrid sequential mode, where the system switches itself between the two regimes and (iii) a sequential “on-demand” mode, where the system can be used in either OCT or SLO regimes for as long as required. The two sequential modes present varying degrees of trade-off between pixel-to-pixel correspondence and independent full control of parameters within each channel. Images of the optic nerve and fovea regions obtained in the simultaneous (i) and in the hybrid sequential mode (ii) are presented.
Reference:
Towards simultaneous Talbot bands based optical coherence tomography and scanning laser ophthalmoscopy imaging (Manuel J. Marques, Adrian Bradu, Adrian Gh. Podoleanu), In Biomed. Opt. Express, volume 5, 2014.
Bibtex Entry:
@article{Marques2014Towards,
	abstract = {We report a Talbot bands-based optical coherence tomography (OCT)
	system capable of producing longitudinal B-scan OCT images and en-face
	scanning laser ophthalmoscopy (SLO) images of the human retina in-vivo.
	The OCT channel employs a broadband optical source and a spectrometer.
	A gap is created between the sample and reference beams while on
	their way towards the spectrometer{rq}s dispersive element to create
	Talbot bands. The spatial separation of the two beams facilitates
	collection by an SLO channel of optical power originating exclusively
	from the retina, deprived from any contribution from the reference
	beam. Three different modes of operation are presented, constrained
	by the minimum integration time of the camera used in the spectrometer
	and by the galvo-scanners{rq} scanning rate: (i) a simultaneous
	acquisition mode over the two channels, useful for small size imaging,
	that conserves the pixel-to-pixel correspondence between them; (ii)
	a hybrid sequential mode, where the system switches itself between
	the two regimes and (iii) a sequential ``on-demand'' mode, where
	the system can be used in either OCT or SLO regimes for as long as
	required. The two sequential modes present varying degrees of trade-off
	between pixel-to-pixel correspondence and independent full control
	of parameters within each channel. Images of the optic nerve and
	fovea regions obtained in the simultaneous (i) and in the hybrid
	sequential mode (ii) are presented.},
	author = {<b>Manuel J. Marques</b> and Adrian Bradu and Adrian Gh. Podoleanu},
	journal = {Biomed. Opt. Express},
	month = {April},
	number = {5},
	owner = {manuel},
	pages = {1428--1444},
	timestamp = {2014.04.11},
	title = {{Towards simultaneous Talbot bands based optical coherence tomography and scanning laser ophthalmoscopy imaging}},
	volume = {5},
	year = {2014}
}