Hybrid Eye Tracking System Switching Between VOG and EOG Sensors

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional eye tracking systems face high power consumption and latency due to the use of video oculography (VOG) cameras, which are inefficient in terms of power usage and computational processing.

Innovation Solution

The implementation of a hybrid eye tracking system that dynamically switches between VOG and electrooculography (EOG) sensors, using EOG sensors for power-efficient and low-latency eye direction prediction, and activating VOG sensors only when necessary for accurate tracking, such as through a trigger-based or keyframe-based mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If video oculography (VOG) cameras are used for eye tracking, then accurate eye position detection is achieved, but power consumption and latency increase

Engineering Contradiction:
Improveeye position detection accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system dynamically switches between VOG and EOG modes based on operational requirements. During calibration or when high precision is needed, VOG is activated. During normal operation or when power saving is prioritized, EOG is used. This dynamic adaptation resolves the contradiction by allowing the system to optimize between accuracy and power consumption in different contexts.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the operational parameters of the eye tracking mechanism by switching between two distinct sensing modes (VOG and EOG) with different power consumption characteristics. This parameter change allows the system to select the appropriate mode based on whether accuracy or power efficiency is the priority at any given moment.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If video oculography (VOG) cameras are used for eye tracking, then accurate eye position detection is achieved, but processing latency increases

Engineering Contradiction:
Improveeye position detection accuracyVSAvoidprocessing latency
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system dynamically selects between VOG and EOG based on whether high precision or low latency is the priority. EOG provides faster, lower-latency detection suitable for real-time responses, while VOG provides higher precision when needed. This dynamic selection resolves the contradiction by allowing the system to optimize for speed when necessary.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses periodic switching between VOG and EOG modes, activating VOG only when high precision is required (such as during calibration or specific interaction moments) and using EOG for continuous low-latency tracking. This periodic activation of the higher-precision mode reduces overall latency while maintaining accuracy when needed.

Inventive Principle:
Principle #19Periodic action

3Use of energy by moving object

If EOG sensors are used for eye direction prediction, then power consumption is reduced, but tracking accuracy may be compromised

Engineering Contradiction:
Improvepower consumptionVSAvoideye tracking accuracy
Core Design Contradiction:
Use of energy by moving objectVSMeasurement precision

Solution Approach 1:

The system dynamically switches to VOG mode when high tracking accuracy is required, such as during calibration phases or when precise eye position data is needed for specific interactions. During normal operation, EOG maintains acceptable accuracy with lower power consumption. This dynamic switching resolves the contradiction by allowing the system to prioritize accuracy only when necessary.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system periodically activates VOG to recalibrate or verify eye position data obtained from EOG. This periodic high-precision measurement ensures that the lower-power EOG mode maintains sufficient accuracy over time, resolving the contradiction by intermittently correcting for EOG's lower precision.

Inventive Principle:
Principle #19Periodic action

4Measurement precision

If VOG sensors are activated continuously, then accurate eye tracking is maintained, but power consumption increases

Engineering Contradiction:
Improveeye tracking accuracyVSAvoidpower consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by stationary object

Solution Approach 1:

The system activates VOG periodically rather than continuously, specifically during calibration phases or when high-precision tracking is required. Between these periodic activations, EOG maintains eye tracking with minimal power consumption. This periodic activation strategy resolves the contradiction by limiting high-power operation to only when necessary.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts its operational mode based on real-time requirements, switching from continuous VOG operation to intermittent EOG operation when high precision is not immediately needed. This dynamic adaptation allows the system to maintain accuracy when required while minimizing power consumption during normal operation.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach reduces power consumption and latency while maintaining accurate eye tracking, allowing for efficient operation in devices like head-mounted displays and near-to-eye systems.

Implementation Method 1

electrooculography (EOG) sensors, using EOG sensors for power-efficient and low-latency eye direction prediction

Methodology Applied
Scientific EffectElectrooculography (EOG):

Implementation Method 2

Light (e.g., infrared light) illuminates an eye and is reflected from the eye. A video camera senses the reflected light and records images of the eye.

Methodology Applied
Scientific EffectLight reflection: Reflection

Data Source

PatentEP3559788B1Eye tracking system with low-latency and low-power
Publication Date: 2024.03.06 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP3559788B1 patent drawingFigure 1
  • EP3559788B1 patent drawingFigure 2
  • EP3559788B1 patent drawingFigure 3

AI summary

Disclosed are an apparatus and a method of low-latency, low-power eye tracking. In some embodiments, the eye tracking method operates a first sensor having a first level of power consumption that tracks positions of an eye of a user. In response to detection that the eye does not change position for a time period, the method stops operation of the first sensor and instead operates a second sensor that detects a change of position of the eye. The second sensor has a level of power consumption lower than the level of power consumption of the first sensor. Once the eye position changes, the first sensor resumes operation.