US 12,213,736 B2
Eye-imaging apparatus and method employing sequential flashing of illumination light in synchronization with the operation of an image sensor
Yan Zhou, Pleasanton, CA (US); Willem Crone, Malin, OR (US); and John Allison, Middleton, WI (US)
Assigned to Natus Medical Incorporated, Middleton, WI (US)
Filed by Natus Medical Incorporated, Middleton, WI (US)
Filed on Nov. 10, 2023, as Appl. No. 18/506,322.
Application 18/506,322 is a continuation of application No. 16/948,992, filed on Oct. 8, 2020, granted, now 11,864,833.
Claims priority of provisional application 62/913,706, filed on Oct. 10, 2019.
Prior Publication US 2024/0074660 A1, Mar. 7, 2024
Int. Cl. A61B 3/10 (2006.01); A61B 3/00 (2006.01); A61B 3/117 (2006.01); A61B 3/12 (2006.01); A61B 3/125 (2006.01); A61B 3/14 (2006.01); F21V 8/00 (2006.01); G02C 7/04 (2006.01)
CPC A61B 3/14 (2013.01) [A61B 3/0008 (2013.01); A61B 3/1208 (2013.01); A61B 3/1241 (2013.01); A61B 3/125 (2013.01); G02B 6/0008 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An eye-imaging apparatus comprising:
a light source comprising a red light source, a green light source, and a blue light source, with each color light source being individually operable;
one or more optical lenses defining an imaging path for light reflected from an eye of a patient, including a front optical element;
a light guide cable positioned next to the light source and configured to transmit light emitted from the light source and emit light from an emitting end to illuminate the eye of the patient, the emitting end being positioned proximate to the front optical element; and
a one-chip color image sensor positioned in the imaging path and comprising a shutter, the color image sensor being operable to:
independently measure red light, green light, and blue light in the imaging path; and
transmit measured red light in a red channel, measured green light in a green channel, and measured blue light in a blue channel;
wherein the light source is operated to sequentially flash the red light source, the green light source, and the blue light source in synchronization with the operation of the image sensor;
wherein the color image sensor is operable to capture one of a red image, a green image, and a blue image in synchronization with the color flashed by the light source;
wherein the color image sensor is configured to transmit the red image on the red channel, the green image on the green channel, and the blue image on the blue channel;
wherein the red image, the green image, and the blue image are transmitted by the color image sensor one at a time on the respective red channel, green channel, and blue channel;
wherein the synchronization is implemented in that the light source flashing is on when the shutter of the image sensor is open and the light source flashing is off when the shutter of the image sensor is closed; and
wherein an averaged amount of light output from each flashing is controlled through pulse width modulation (PWM) having a duty cycle, a pulse peak value, and a pulsing frequency, with the pulsing frequency being at least 10 times a frame rate of the image sensor.