Fundus imaging system
A fundus imaging system includes: an image sensor array, where the image sensor array includes monochrome photodiodes and global shutter control, an illumination unit with one or more light-emitting diodes that have one or more dies, a computing system including a processor and memory, one or more lenses, one or more reflective mirrors, and a display. In an example method of use, a clinician positions a patient, initiates a focal adjustment, initiates a retinal imaging process, and the same or a different clinician views the image. In some embodiments, the imaging system is configured to analyze the image and identify detected physical attributes in the image relating to the diagnosis and treatment of diabetic retinopathy.
1. A non-mydriatic fundus imaging system, comprising:
an image sensor array capable of global reset operations, the global reset operations including exposing each pixel of a plurality of rows of pixels substantially simultaneously;
an illumination unit operatively coupled to the image sensor array, wherein the illumination unit includes a multi-die light emitting diode;
a timing unit operatively coupled to the image sensor array and the illumination unit and configured to simultaneously expose each pixel of the plurality of rows of pixels of the image sensor array during an exposure period;
a processor; and
memory storing instructions that, when executed by the processor, cause the non-mydriatic fundus imaging system to:
capture a plurality of images in a first image capture mode;
process at least a portion of the plurality of images to determine a position of a pupil of a subject; and
capture an image in a second image capture mode when the position of the pupil is substantially aligned with an optical axis of the non-mydriatic fundus imaging system;
wherein the first image capture mode comprises a first resolution and a first illumination condition;
wherein the second image capture mode comprises a second resolution and a second illumination condition;
wherein the second resolution is greater than or equal to the first resolution; and
wherein the second illumination condition is brighter than the first illumination condition.
2. The non-mydriatic fundus imaging system according to claim 1 , the image sensor array including a two-dimensional monochrome complementary metal-oxide-semiconductor.
3. The non-mydriatic fundus imaging system according to claim 1 , the second image capture mode including overdrive of the multi-die light emitting diode during the global reset operations.
4. The non-mydriatic fundus imaging system according to claim 3 , the illumination unit being configured to emit monochrome light for less than 2 milliseconds during the second image capture mode.
5. The non-mydriatic fundus imaging system according to claim 4 , the illumination unit being configured to cause the multi-die light emitting diode to, consecutively, illuminate red light only, illuminate green light only, and illuminate blue light only.
6. The non-mydriatic fundus imaging system according to claim 4 , the illumination unit being configured to cause the multi-die light emitting diode to illuminate red, green and blue simultaneously.
7. The non-mydriatic fundus imaging system according to claim 1 , the image sensor array further being capable of global transfer operations, the global transfer operations including simultaneously ceasing exposure of each pixel in the image sensor array.
8. The non-mydriatic fundus imaging system according to claim 7 , the global transfer operations further including transferring charge from each pixel in the image sensor array into opaque shielded storage.
9. The non-mydriatic fundus imaging system according to claim 8 , the image sensor array further being capable of sequential readout operations.
10. A method for producing an image of a fundus, the method comprising:
illuminating a light emitting diode, the light emitting diode being a multi-color die LED, wherein illuminating the light emitting diode includes emitting monochrome light for less than 2 milliseconds;
activating a shutter of an image sensor array capable of exposing each pixel of a plurality of rows of pixels substantially simultaneously; and
storing an image readout from the plurality of rows of pixels.
11. The method according to claim 10 , further comprising initiating global transfer operations, including simultaneously ceasing exposure of each pixel in the image sensor array.
12. The method according to claim 11 , the initiating global transfer operations further including transferring charge from each pixel in the image sensor array into opaque shielded storage.
13. The method according to claim 11 , further comprising initiating sequential readout operations.
14. The method according to claim 10 , wherein illuminating the light emitting diode includes illuminating red light only, illuminating green light only, and illuminating blue light only; and
further comprising capturing an image during each of illuminating red light only, illuminating green light only, and illuminating blue light only.
15. A non-mydriatic fundus imaging system, comprising:
an image sensor array, configured for:
global reset operations, the global reset operations including exposing each pixel of a plurality of rows of pixels substantially simultaneously,
global transfer operations, the global transfer operations including simultaneously ceasing exposure of each pixel in the image sensor array and transferring charge from each pixel in the image sensor array into opaque shielded storage; and
sequential readout operations;
an illumination unit operatively coupled to the image sensor array, the illumination unit including a multi-die light emitting diode;
a timing unit operatively coupled to the image sensor array and the illumination unit and configured to simultaneously expose a full frame of pixels of the image sensor array during an exposure period;
a processor; and
memory storing instructions that, when executed by the processor, cause the non-mydriatic fundus imaging system to:
capture a plurality of images in a first image capture mode;
process at least a portion of the plurality of images to determine a position of a pupil of a subject;
capture an image in a second image capture mode when the position of the pupil is substantially aligned with an optical axis of the non-mydriatic fundus imaging system,
the first image capture mode comprises a first resolution and a first illumination condition;
the second image capture mode comprises a second resolution and a second illumination condition;
the second resolution is greater than or equal to the first resolution; and
the second illumination condition is brighter than the first illumination condition
the image sensor array including a two-dimensional monochrome complementary metal-oxide-semiconductor; and
the illumination unit being configured to emit monochrome light for less than 2 milliseconds during the second image capture mode.