Spectrally tunable light source based on a digital micromirror device for retinal image contrast enhancement

Abstract

Different optical methods for retinal imaging provide a significant improvement for image analysis and help with data interpretation. The use of tunable light sources, which have been optimized for contrast enhancement of various retinal features or lesions in retinal images, could simplify the eye fundus examination through enhanced image quality. In this study, we have developed and described a research prototype which consists of a spectrally tunable light source based on a digital micromirror device which is further coupled to a fundus camera. The overall aim of this construction was to generate illuminations optimized for enhanced retinal image feature visibility. The optimized illumination conditions were compared to traditional red-free imaging and the measurements were executed for an artificial eye followed by in vivo measurements of the eyes of three volunteers. In all cases, the retinal image contrast was observed to improve compared to the traditional red-free imaging. Depending on the observed retinal feature, the perceptual improvements in the contrast varied from a few percent to nearly 70 percent.

A 380-1100nm spectrum matching light source with high spectral resolution, throughput, speed, and stability

“…It offers a full wavelength range (380nm to 1100nm) of spectral matching with high spectral power. The source can be a valuable tool for ambient sensor or image sensor calibration [8,15,23,24], display calibration, hyperspectral imaging, spectroscopy [3,4,16,24], healthcare [12,14], radiometry [2,18,19,21], diagnostics and biomedical-related applications [7,9,12,20,22], which also need to consider the ambient light or NIR light effects and simulate the detailed spectral profiles of arbitrary light sources with more extended wavelength range and high fidelity.…”

“…This wavelength range extension makes it possible for spectral matching in silicon detectors sensitive range of both Visible and NIR with reasonable flux and spectral resolution. As the spectra of Visible and NIR on DMD [11,12,13,14] are from individual input channels and spatially separated (see Fig. 1) on different sections of the same DMD with a clear gap in between, each spectrum can be individually controlled to simulate visible light only (380nm to 800nm), NIR light only (680nm to 1100nm) or full spectral range (380nm to 1100nm) with spectra overlapping from 680nm to 800nm.…”

Application of digital micromirror devices (DMD) in biomedical instruments

“…It is employed to evaluate symptoms of various retinal vascular diseases or eye diseases such as glaucoma and retinal detachment. Piotr B 72,73 used DMD to achieve optimal illumination for diabetic retinopathy detection. Spe-ci¯cally, the team designed an illuminate pattern, which was realized with DMD, to be projected on the retina.…”