Line-Scan Eye Tracking for Low-Latency Optical Beam Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current eye tracking systems for ophthalmology face challenges in accurately tracking the motion of the human eye during optical treatments or measurements, especially when landmarks are absent or when high latency is introduced, which can lead to errors in positioning directed beams like in photocoagulation and optical coherence tomography.
Innovation Solution
A line-scan imaging system that provides real-time tracking of eye motion by comparing current image lines with previously recorded lines, allowing for shifts and rotations, and using this information to correct the placement of optical beams, thereby reducing latency and eliminating the need for specific landmarks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two-dimensional image frames are used for tracking, then real-time display for operator orientation is achieved, but latency increases to approximately 1/30 of one second
Solution Approach 1:
The patent segments the image acquisition process by using a line-scan camera that captures one line of the image at a time at approximately 10 kHz, rather than capturing complete two-dimensional frames at 30 Hz. This segmentation allows tracking data to be obtained much more frequently, reducing latency while maintaining tracking accuracy through continuous line-by-line comparison with reference frames.
2Speed
If a dithered tracking beam is used, then tracking speed reaches 2-10 kHz, but an separate optical scanning system is required
Solution Approach 1:
The patent merges the tracking function with the existing line-scan ophthalmoscope system. The same line-scan camera used for obtaining a real-time view of the subject is also used for tracking by comparing current lines with reference lines. This eliminates the need for a separate dithered tracking beam system while achieving comparable tracking speeds of approximately 10 kHz.
3Measurement precision
If landmark-based tracking is used, then tracking reference points are available, but tracking fails when landmarks are absent or unclear
Solution Approach 1:
The patent implements self-service tracking by using the image data itself for tracking purposes. The line-scan camera captures lines that are then compared with reference lines to determine subject motion. The tracking system serves itself by utilizing the same imaging data that provides the real-time view, eliminating dependence on specific landmarks and allowing tracking to proceed using any visible features in the image lines.
Data Source
AI summary
A line scan imager is used to determine the motion of a subject. Each line of image data from the line scan imager is compared with a reference image. The location of a matching line in the reference image reveals the displacement of the subject. The current subject displacement can be determined based on each line of image data. The resulting displacement information can be used to correctly place other optical beams on the subject. The method can be applied to tracking the human eye to facilitate measurement, imaging, or treatment with a beam of optical radiation.