Adaptive Eye Gaze Fixation Detection Using Dynamic Thresholds

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Solution Overview

Problem

Current eye gaze tracking systems rely on fixed thresholds for fixation detection, which are not universally applicable and require manual tuning, leading to inaccuracies and limitations in implementing a 'plug and play' system due to variations in user behavior and content.

Innovation Solution

An adaptive eye-tracking system that calculates saccade estimates from gaze noise values and uses percentile statistics to determine fixation thresholds dynamically, allowing for automatic adjustment based on collected data, thereby eliminating the need for manually set thresholds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If fixed thresholds are used for fixation detection, then the system is simpler to implement, but the measurement precision deteriorates due to inability to adapt to individual variations and content types

Engineering Contradiction:
Improvethreshold setting complexityVSAvoidfixation detection accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by transitioning from fixed, static thresholds to adaptive, dynamic thresholds that automatically adjust based on the specific user and content being analyzed. The system calculates optimal thresholds in real-time using statistical methods (percentiles) applied to the gaze data itself, allowing the fixation detection parameters to evolve and adapt to individual variations and different content types, thereby resolving the contradiction between simplicity and precision.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements parameter changes by modifying the threshold values dynamically based on statistical analysis of the gaze data. Instead of using predetermined fixed values, the system computes thresholds as a function of the data characteristics (using percentile statistics), allowing the parameters to change adaptively to match the specific conditions, thus improving measurement precision without requiring complex manual configuration.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If manually tuned thresholds are used, then the fixation detection can be optimized for specific cases, but the adaptability deteriorates requiring re-tuning for different users and content

Engineering Contradiction:
Improvefixation detection accuracyVSAvoiduniversal applicability
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The patent applies self-service by enabling the system to automatically determine optimal thresholds without requiring manual intervention or expert tuning. The algorithm autonomously analyzes the gaze data, computes statistical percentiles, and establishes appropriate fixation thresholds based on the inherent characteristics of the data being analyzed. This self-adjusting capability allows the system to adapt to different users and content types automatically, achieving both high precision and universal applicability.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent implements universality by creating a threshold determination method that works across diverse scenarios without requiring case-specific calibration. The statistical approach (using percentile-based thresholds) is content-agnostic and user-agnostic, making the same algorithm applicable to different users, different content types, and different viewing conditions, thereby achieving universal applicability while maintaining optimization for each specific case.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Measurement precision

If small spatial thresholds are used, then the fixation detection precision is improved, but the productivity deteriorates due to increased false negatives and missed fixations

Engineering Contradiction:
Improvespatial threshold precisionVSAvoidfixation detection efficiency
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent applies feedback by using the statistical properties of the actual gaze data to inform and adjust the threshold selection. The system calculates percentiles based on the distribution of gaze positions and uses this feedback to set thresholds that are optimized for the specific data being analyzed. This data-driven feedback mechanism ensures that thresholds are neither too small (causing false negatives) nor too large (reducing precision), thereby maintaining both precision and productivity.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS7556377B2System and method of detecting eye fixations using adaptive thresholds
Publication Date: 2009.07.07 GOOGLE LLC
  • US7556377B2 patent drawing
  • US7556377B2 patent drawing
  • US7556377B2 patent drawing

AI summary

A system and method of adaptively establishing fixation thresholds for eye-gaze tracking data and identifying fixations within the eye-gaze tracking data are disclosed. Eye-gaze tracking data is collected. A saccade estimate may be calculated using a percentile statistic of the changes in eye-gaze position. Fixations may be determined by comparing the saccade estimates with the changes in eye-gaze positions over time windows.