Abstract: A portable, lightweight digital imaging device uses a slit scanning arrangement to obtain an image of the eye, in particular the retina.

Abstract: A new model based on ray tracing is developed to estimate power spectral properties in laser Doppler velocimetry of retinal vessels and to predict the effects of laser beam size and eccentricity as well as absorption of laser light by oxygenated and reduced hemoglobin. There is described the model and show that it correctly converges to the traditional rectangular shape of the Doppler shift power spectrum, given the same assumptions, and that reduced beam size and eccentric alignment cause marked alterations in this shape. The changes in the detected total power of the Doppler-shifted light due to light scattering and absorption by blood can also be quantified with this model and may be used to determine the oxygen saturation in retinal arteries and veins. The potential of this approach is that it uses direct measurements of Doppler signals originating only from moving red blood cells. The invention opens new avenues for retinal vessel oximetry.

Abstract: A portable, lightweight digital imaging device uses a slit scanning arrangement to obtain an image of the eye, in particular the retina.

Abstract: A new model based on ray tracing is developed to estimate power spectral properties in laser Doppler velocimetry of retinal vessels and to predict the effects of laser beam size and eccentricity as well as absorption of laser light by oxygenated and reduced hemoglobin. There is described the model and show that it correctly converges to the traditional rectangular shape of the Doppler shift power spectrum, given the same assumptions, and that reduced beam size and eccentric alignment cause marked alterations in this shape. The changes in the detected total power of the Doppler-shifted light due to light scattering and absorption by blood can also be quantified with this model and may be used to determine the oxygen saturation in retinal arteries and veins. The potential of this approach is that it uses direct measurements of Doppler signals originating only from moving red blood cells. The invention opens new avenues for retinal vessel oximetry.

Abstract: An apparatus is provided for the measurement of the velocity of blood flowing within a blood vessel of an eye wherein the apparatus includes a light source for producing a source beam of light and an optical element for applying the source beam of light to the blood vessel to permit the blood flowing within the blood vessel to scatter a portion of the source beam of light and produce bidirectional scattered beams. A detector system for detecting the bidirectional scattered beams provides signals representative of the scattered beams. The light source and the detector system are disposed in a confocal relationship. An output representative of the velocity of the blood flow velocity is produced in accordance with the signals. The light source and the detector system include respective pinholes wherein the respective pinholes are disposed in the confocal relationship. The blood vessel is conjugate with the respective pinholes of the light source and the detector system.