Through focus retinal image capturing
View Patent ↗An apparatus for producing a non-mydriatic fundus image is disclosed. The apparatus can include a processor and memory, as well as an illumination component and a camera with a variable focus lens. The apparatus can be configured to adjust the focus of the lens to a plurality of different diopter ranges and capture at least one image at each of the plurality of different diopter ranges. A method for capturing a non-mydriatic image of a fundus is also disclosed. The method can include setting a depth of field, dividing the depth of field into a plurality of zones, adjusting a variable focus lens of a camera to focus on each of the plurality of zones, and capturing at least one image at each of the plurality of zones.
1. An apparatus for producing a non-mydriatic fundus image, comprising:
a processor and a memory;
an illumination component including a visible light source and operatively coupled to the processor;
a camera including a lens and operatively coupled to the processor; and
a display coupled to the memory and to the processor,
wherein the memory stores instructions that, when executed by the processor, cause the apparatus to:
set a depth of field for capturing a plurality of images of a fundus, the depth of field being set by defining lower and upper diopters;
divide the depth of field into a plurality of different diopter ranges, wherein the depth of field and number of diopter ranges are adjustable;
adjust the lens to each of the plurality of different diopter ranges, the lens being set to each diopter range without regard to focus of features shown by the lens;
capture, using the camera, a plurality of images of a fundus, wherein the camera captures at least one image within each of the plurality of different diopter ranges;
illuminate, using the illumination component, visible light during the capture of the plurality of images;
after capturing each of the plurality of images of the fundus:
evaluate each of the plurality of images of the fundus; and
based on the evaluation of each of the plurality of images of the fundus, determine a representative image of the fundus from the plurality of images; and
display the representative image of the fundus.
2. The apparatus of claim 1 , wherein the instructions further cause the apparatus to: adjust the focus of the lens and capture the plurality of images until images have been captured in a depth of field from −10 diopters to +10 diopters.
3. The apparatus of claim 2 , wherein each adjustment of the focus is by +/−1 diopter.
4. The apparatus of claim 2 , wherein each adjustment of the focus is by +/−2 diopters.
5. The apparatus of claim 2 , wherein the images are captured sequentially in less than about 150 milliseconds.
6. A method for capturing a non-mydriatic image of a fundus, comprising:
setting a depth of field for capturing a plurality of images of a fundus, the depth of field being set by defining lower and upper diopters;
dividing the depth of field into a plurality of zones, each zone comprising a diopter range within the depth of field, wherein the depth of field and number of zones are adjustable;
adjusting a lens of a camera on each of the plurality of zones, the lens being set to each diopter range without regard to focus of features shown by the lens;
capturing at least one image within each of the plurality of zones;
after capturing each image within each of the plurality of zones, displaying each image captured at each of the plurality of zones to a user;
prompting the user for a representative image; and
receiving selection of the representative image from the user.
7. The method of claim 6 , wherein the depth of field is from −10 diopters to +10 diopters.
8. The method of claim 7 , wherein the depth of field is divided into 5 equal zones.
9. The method of claim 7 , wherein the depth of field is divided into 10 zones.
10. The method of claim 6 , wherein a light source is illuminated throughout the capture of each image in each zone.