Multiple Scattering Analysis of Retinal Blood Oximetry

Cohen, Allen J.; Laing, Ronald A.

doi:10.1109/tbme.1976.324650

Cited by 33 publications

(24 citation statements)

References 14 publications

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“…Also, the human retinal vein oxyhemoglobin saturation is thought to be ∼60%. 1,13,14,16,27,40,41 We estimated the oxyhemoglobin saturation in the enucleated swine retinal vein and in the in vivo human retinal vein using the calibration line from our intravitreal retinal illumination experiments 1 and the measured minima in Fig. 6.…”

Section: Discussionmentioning

confidence: 99%

“…The calculated oxyhemoglobin saturation in the enucleated swine vessel was very near 0 as expected (-1 ± 2.0% Sat), and the human vein oxyhemoglobin saturation (63 ± 2.3% Sat) was also in the range reported elsewhere. 1,13,14,16,27,40,41 …”

Section: Discussionmentioning

confidence: 99%

“…When a small spot of laser light is directed onto a blood vessel in the eye, there are many possible paths it can traverse. [26][27][28][29][30] Two paths of particular interest for this discussion are: (i) light specularly reflected from the blood vessel (also known as a glint) and (ii) laterally scattered light that has interacted with the red blood cell-packaged hemoglobin in the vessel and scattered back out of the eye. Figure 1(a) shows an example of the specular vessel glint path and Fig.…”

Section: Specular Vessel Glintmentioning

confidence: 99%

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Retinal oximeter for the blue-green oximetry technique

et al. 2011

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Abstract. Retinal oximetry offers potential for noninvasive assessment of central venous oxyhemoglobin saturation (SO 2 ) via the retinal vessels but requires a calibrated accuracy of ± 3% saturation in order to be clinically useful. Prior oximeter designs have been hampered by poor saturation calibration accuracy. We demonstrate that the bluegreen oximetry (BGO) technique can provide accuracy within ± 3% in swine when multiply scattered light from blood within a retinal vessel is isolated. A noninvasive on-axis scanning retinal oximeter (ROx-3) is constructed that generates a multiwavelength image in the range required for BGO. A field stop in the detection pathway is used in conjunction with an anticonfocal bisecting wire to remove specular vessel reflections and isolate multiply backscattered light from the blood column within a retinal vessel. This design is tested on an enucleated swine eye vessel and a retinal vein in a human volunteer with retinal SO 2 measurements of ∼1 and ∼65%, respectively. These saturations, calculated using the calibration line from earlier work, are internally consistent with a standard error of the mean of ± 2% SO 2 . The absolute measures are well within the expected saturation range for the site (-1 and 63%). This is the first demonstration of noninvasive on-axis BGO retinal oximetry. C 2011 Society of Photo-Optical Instrumentation Engineers (SPIE).

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Specular Vessel Glintmentioning

confidence: 99%

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Retinal oximeter for the blue-green oximetry technique

et al. 2011

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“…Further studies have been made for four decades to overcome the difficulties of the fundus photographic method such as nonlinear sensor (photographic film), eye movement during lengthy measurements, small areas measured at one time, and optical complexities within eye. Researchers also have attempted to include blood scattering in the measurements by adding the scattering factor to the Beer-Lambert equation 2,3,4,5,6 . Hickam (1963) 1 developed retinal vessel oximetry using a modified fundus camera that acquired dual quasi-monochromatic fundus photographs at the wavelengths of 640 and 800nm.…”

Section: Introductionmentioning

confidence: 99%

Spectroscopic imaging of the retinal vessels using a new dual-wavelength

Rasta

Manivannan

Sharp

2009

Clinical and Biomedical Spectroscopy

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This study aimed to investigate the feasibility of non-invasive evaluating vessel blood oxygenation in the human eye using a dual-wavelength confocal scanning laser ophthalmoscope (cSLO). A cSLO prototype was adapted to use a new combination of two red and infrared wavelengths simultaneously performing a spectral analysis of the status of retinal blood vessel to give the ability to image perfusion in the human eye. This technique was evaluated using measurements made on normal volunteers' eyes. The reproducibility of the measurements of reflected light from the eye was investigated. Spectral measurements of light reflected from retinal vessels were determined and liner relationship of oxygen saturation of blood and spectral transmittance based on Beer-Lambert law was defined. The relative oxygen levels of retinal blood vessels (artery and vein) were successfully determined using these two wavelengths. The technique showed promise in the determination of the relative oxygen saturation levels of the retina in amongst eye subjects.

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“…[1][2][3][4] A non-invasive measurement technique for SpO 2 is especially useful in clinical applications. [5][6][7][8][9][10] Spectroscopic oximetry has been studied for long by many research groups. [11][12][13][14][15][16][17] For optical oximetry, retina is attractive measurement site from a technological view point because retinal vessels can be directly measured unlike other sites where vessels are embedded under the skin tissue.…”

Section: Introductionmentioning

confidence: 99%

PLS regression approach for oxygen saturation in spectroscopic fundus images

2006

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Two-dimensional distribution of oxygen saturation levels across the human retina is predicted by measuring the multispectral images. A liquid crystal tunable filter is used to scan wavelength ranging from 500 to 700 nm to acquire the multispectral images with the spectral resolution of 20 nm. After preprocessing reflected spectra at every pixel to cancel common offsets and amplifications, the partial least squares regression is adopted to estimate the oxygen saturation levels at each pixel point. All the resulted response values compose the oxygen saturation level map. The effects of preprocessing types on the predicted oxygen saturation levels are also discussed.

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Multiple Scattering Analysis of Retinal Blood Oximetry

Cited by 33 publications

References 14 publications

Retinal oximeter for the blue-green oximetry technique

Retinal oximeter for the blue-green oximetry technique

Spectroscopic imaging of the retinal vessels using a new dual-wavelength

PLS regression approach for oxygen saturation in spectroscopic fundus images

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