System and method for retinal imaging

1 . A system to capture a stabilized retinal image of an eye of a subject by a handheld retinal imaging device, the system comprising:

the handheld retinal imaging device; and

an external computing device configured to:

receive a user selection from a user, the user selection comprising a type of image to be captured;

convey data on an initial position of a fixation stimulus on a fixation screen based on the user selection;

receive video data of the eye of the subject from a camera and position data from a 3-D accelerometer, and display a video based on the video data received from the camera;

calculate, during the display of the video, an updated two-dimensional position for the fixation stimulus on the fixation screen, wherein to calculate the updated two-dimensional position, the external computing device is configured to:

detect, using artificial intelligence techniques applied to one or more frames of the video, a location of an optic disc relative to a region corresponding to the user-selected type of image; and

project movement indicated by the 3-D accelerometer into coordinates of the fixation screen;

dynamically reposition the fixation stimulus on the fixation screen in real time to the updated two-dimensional position to guide the subject's gaze and maintain the user-selected type of image;

determine that a stable image condition is satisfied based on the one or more frames and the position data; and

responsive to the stable image condition convey a trigger to a light source of the handheld retinal imaging device for illuminating the eye of the subject for a predefined duration, and convey a trigger to the camera for capturing the stabilized retinal image illuminated by the light source.

2 . The system of claim 1 , wherein the data on the initial position of the fixation stimulus on the fixation screen is determined by the external computing device based on the user selection and corresponding predetermined data loaded on the external computing device.

3 . The system of claim 1 , wherein the user selection is a type of image selected from a group of types of images, including macula-centered, optic disc-centered, peripheral up, peripheral down, peripheral left diagonal, and peripheral right diagonal.

4 . The system of claim 1 , wherein the handheld retinal imaging device comprises:

an infrared light source configured to illuminate the eye of the subject, through illuminating optics configured for illuminating the eye of the subject;

the source of visible light configured to illuminate the eye of the subject, through the illuminating optics, for the predefined duration, based on the trigger received from the external computing device;

the fixation screen configured to display the fixation stimulus for the subject to gaze at during the use of the handheld retinal imaging device, the position of the fixation stimulus on the fixation screen being based on an input received from the external computing device; and

the 3-D accelerometer configured to sense data corresponding to a movement of the handheld retinal imaging device and convey it to the external computing device; and

the camera configured to:

capture the video data of the eye of the subject and convey the video data to the external computing device; and

capture the retinal image of the eye of the subject, based on the trigger received from the external computing device, and convey retinal image data to the external computing device.

5 . The system of claim 4 , wherein the locations of the infrared light source and the source of visible light are interchanged with corresponding changes to the illuminating optics.

6 . A method for capturing a stabilized retinal image of an eye of subject using a handheld retinal imaging device, the method comprising:

a step of receiving, by an external computing device, a user input on a type of image to be captured;

a step of conveying, by the external computing device, data to a fixation screen on an initial position of a fixation stimulus on the fixation screen;

a step of receiving, by the external computing device, video data of the eye of the subject from a camera of the handheld retinal imaging device, and data on a position of the handheld retinal imaging device, from a 3-D accelerometer of the handheld retinal imaging device, and displaying a video based on the video data provided by the camera;

a step of calculating, by the external computing device, during the display of the video, an updated two-dimensional position for the fixation stimulus on the fixation screen by:

a step of detecting, using artificial intelligence techniques applied to one or more frames of the video, a location of an optic disc relative to a region corresponding to the type of image; and

a step of projecting movement indicated by the 3-D accelerometer into coordinates of the fixation screen;

a step of dynamically repositioning the fixation stimulus on the fixation screen in real time to the updated two-dimensional position to guide the subject's gaze and maintain the type of image;

a step of determining that a stable image condition is satisfied based on the one or more frames and the position data;

a step of conveying, by the external computing device, in response to the stable image condition, a trigger to a light source to illuminate the eye of the subject for a predefined duration, and conveying a trigger to the camera for capturing the stabilized still retinal image illuminated by the light source; and

a step of displaying, by the external computing device, the stabilized retinal image on a display device and storing image data in a memory of the external computing device.