The automated vision testing system uses gesture input by drawing letters in space.

Abstract

The invention relates to an automated visual acuity measurement system using gesture input to draw letters in space with the index finger in front of a camera. The system comprises hardware components including: a visual acuity measurement screen, an input screen positioned next to or integrated with the measurement screen to display the drawing strokes in real time, and a camera facing the user to capture images of hand movement. In terms of data processing, the system integrates specialized modules: a module to display medical-standard Latin characters such as Sloan or Snellen; a module for hand recognition and extraction of the coordinates of the index finger and thumb tips from the camera image; a module to control the drawing state based on the distance between these two finger tips; a module to draw the trajectory of the index finger movement by connecting consecutive coordinate points; an optical character recognition module to convert the drawing stroke trajectory into the corresponding letter; and a module to compare the results with the original character for automatic scoring.This invention, in the field of ophthalmic diagnostic devices, human-machine interaction based on computer vision, and digital signal processing, allows the subject to input answers remotely without direct assistance from a doctor or technician.

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