Wide-field retinal imaging system
A retinal imager for imaging a retina of an eye includes an illumination source operable to generate illumination light and a beam splitter operable to receive the illumination light and direct the illumination light along an optical axis. The retinal imager also includes a field lens disposed along the optical axis and an objective lens disposed along the optical axis and operable to contact a cornea of the eye. An aerial image is formed adjacent to the field lens. The retinal imager further includes an image sensor and one or more lenses disposed along the optical axis between the beam splitter and the image sensor. The one or more lenses are operable to form a sensor image at the image sensor.
1. A retinal imager for imaging a retina of an eye, the retinal imager comprising:
a housing containing an optical system comprising:
an illumination source operable to generate illumination light;
a beam splitter operable to receive the illumination light and direct the illumination light along an optical axis;
a field lens disposed along the optical axis;
an image sensor;
an objective lens disposed along the optical axis and operable to contact a cornea of the eye, wherein the objective lens is operable to inject the illumination light into the eye as an illumination ring; and
an imaging lens group disposed along the optical axis between the beam splitter and the image sensor, wherein the imaging lens group is operable to form a sensor image at the image sensor and wherein an entrance pupil and the illumination ring are located at different positions along the optical axis.
2. The retinal imager of claim 1 , wherein the illumination source is disposed inside the housing.
3. The retinal imager of claim 1 , wherein the imaging lens group is disposed inside the housing.
4. The retinal imager of claim 1 , wherein the objective lens is mounted at a periphery of the housing.
5. The retinal imager of claim 1 , wherein the housing includes a grip operable to be held by a hand of a user.
6. The retinal imager of claim 1 , wherein a second beam splitter is operable to be positioned within the imaging lens group.
7. The retinal imager of claim 6 , wherein an optical coherence tomography (OCT) beam train is optically coupled to the second beam splitter.
8. The retinal imager of claim 7 , wherein the OCT beam train is mounted on an outer surface of the housing.
9. The retinal imager of claim 7 , wherein OCT beam train is disposed inside the housing.
10. The retinal imager of claim 7 , wherein the OCT beam train comprises a micro-electromechanical system (MEMS) mirror, and where a pupil is formed on the MEMS mirror.
11. The retinal imager of claim 7 , wherein a single fiber is utilized to transmit and receive light propagating along the OCT beam train.
12. The retinal imager of claim 1 , wherein the housing further comprises an input/output (I/O) connection.
13. The retinal imager of claim 12 , wherein the I/O connection is coupled to a communications cable being operable to communicate power and communications with optical elements disposed within the housing.
14. The retinal imager of claim 1 , wherein an aerial image is formed adjacent to the field lens.
15. The retinal imager of claim 14 , wherein the aerial image comprises an object for the sensor image at the image sensor.
16. The retinal imager of claim 14 , wherein the aerial image is formed between the field lens and the beam splitter, and wherein the objective lens is further operable to receive reflected light from a retina and the aerial image is formed by the reflected light.
17. The retinal imager of claim 1 , wherein the objective lens comprises a single element objective lens, and wherein the illumination light is injected into the eye through the single element objective lens.
18. The retinal imager of claim 1 , wherein the sensor image comprises a central area, wherein the central area us circular, and wherein the sensor image further comprises an annular area surrounding the central area.
19. The retinal imager of claim 18 , wherein a periphery of the central area forms a common border with an inner periphery of the annular area.
20. The retinal imager of claim 18 , wherein the sensor image further comprises three azimuthal segments.