Conference proceeding
Detection of low-amplitude in vivo intrinsic signals from an optical imager of retinal function
Proceedings of SPIE, Vol.6138(1), pp.61380F-61380F-12
Ophthalmic Technologies XVI
02/09/2006
DOI: 10.1117/12.652263
Abstract
In the early stages of some retinal diseases, such as glaucoma, loss of retinal activity may be difficult to detect with today's clinical instruments. Many of today's instruments focus on detecting changes in anatomical structures, such as the nerve fiber layer. Our device, which is based on a modified fundus camera, seeks to detect changes in optical signals that reflect functional changes in the retina. The functional imager uses a patterned stimulus at wavelength of 535nm. An intrinsic functional signal is collected at a near infrared wavelength. Measured changes in reflectance in response to the visual stimulus are on the order of 0.1% to 1% of the total reflected intensity level, which makes the functional signal difficult to detect by standard methods because it is masked by other physiological signals and by imaging system noise. In this paper, we analyze the video sequences from a set of 60 experiments with different patterned stimuli from cats. Using a set of statistical techniques known as Independent Component Analysis (ICA), we estimate the signals present in the videos. Through controlled simulation experiments, we quantify the limits of signal strength in order to detect the physiological signal of interest. The results of the analysis show that, in principle, signal levels of 0.1% (-30dB) can be detected. The study found that in 86% of the animal experiments the patterned stimuli effects on the retina can be detected and extracted. The analysis of the different responses extracted from the videos can give an insight of the functional processes present during the stimulation of the retina.
Details
- Title: Subtitle
- Detection of low-amplitude in vivo intrinsic signals from an optical imager of retinal function
- Creators
- Eduardo S Barriga - Univ. of New MexicoDan T'so - Upstate Medical Univ./SUNYMarios Pattichis - Univ. of New MexicoYoung Kwon - Univ. of IowaRandy Kardon - Univ. of IowaMichael Abramoff - Univ. of IowaPeter Soliz - VisionQuest Biomedical
- Resource Type
- Conference proceeding
- Publication Details
- Proceedings of SPIE, Vol.6138(1), pp.61380F-61380F-12
- Conference
- Ophthalmic Technologies XVI
- DOI
- 10.1117/12.652263
- ISSN
- 0277-786X
- Language
- English
- Date published
- 02/09/2006
- Academic Unit
- Electrical and Computer Engineering; Roy J. Carver Department of Biomedical Engineering; Ophthalmology and Visual Sciences; Iowa Neuroscience Institute; Fraternal Order of Eagles Diabetes Research Center
- Record Identifier
- 9984060899402771
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