System and method for assessment of retinal and choroidal blood flow noninvasively using color amplification

A system for assessing retinal and choroidal blood flow in a subject, comprising:

• an ocular lens for viewing a fundus of an eye of the subject;
• a light source for illuminating the fundus of the eye of the subject;
• a digital video camera in optical communication with the ocular lens for imaging the fundus of the eye of the subject;
• a biosensor for sensing a pulse waveform of the subject;
• a trigger;
• a computer in communication with the digital video camera, the biosensor, and the trigger, the computer configured for:
• recording input frames received from the digital video camera and pulse waveform data from the biosensor in response to an input from the trigger;
• defining a low-pass frequency and a high-pass frequency by a lowest time and a highest time between heart beats in the pulse waveform data;
• stabilizing each of the input frames utilizing subpixel phase correlation with a reference frame;
• enhancing contrast of each of the input frames utilizing contrast limited adaptive histogram equalization (CLAHE);
• separating each of the input frames into sub-channels;
• conducting on each sub-channel eulerian video magnification for color amplification using the inputs of image sampling rate, the low-pass frequency, the high-pass frequency, and an amplification factor;
• reconstructing the amplified sub-channels into output frames;
• and
• combining the output frames with the input frames, resulting in enhanced frames demonstrating retinal and choroidal blood flow and tissue perfusion;
• and
• a display for displaying the enhanced frames.