Foam Earpiece Electrodes for Camera-Free Eye Tracking
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Solution Overview
Problem
Conventional video-based eye tracking requires a camera pointed at the user's face, limiting application possibilities, while traditional EOG methods using sticky electrodes are inconvenient.
Innovation Solution
An eye-tracking system using compressible and electrically conducting foam electrodes on earpieces for reliable skin contact, combined with signal processing to determine gaze direction, compatible with various devices like headphones and smart glasses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If video-based eye tracking is used to determine gaze direction, then measurement precision is improved, but device complexity and ease of operation worsen due to requiring a camera pointed at the user's face
Solution Approach 1:
The patent replaces the optical/mechanical camera-based eye tracking system with an electrical/electrophysiological EOG measurement system. Instead of using a camera to capture video images of the eyes and process them through image analysis algorithms, the invention uses electrodes to measure the electrical dipole potential of the corneo-retinal dipole, thereby determining gaze direction through electrical signals rather than optical imaging.
2Measurement precision
If sticky silver-chloride electrodes are used for EOG measurement, then measurement precision is improved, but ease of operation worsens due to inconvenience of placement
Solution Approach 1:
The patent changes the physical and material parameters of the electrodes from traditional sticky silver-chloride electrodes to compressible and electrically conducting foam materials. This material substitution maintains the electrical conductivity needed for EOG measurement while dramatically improving ease of placement and user comfort, allowing the electrodes to be integrated into earpieces without requiring sticky adhesives or complex placement procedures.
3Ease of operation
If compressible and electrically conducting foam electrodes are used on earpieces, then ease of operation is improved, but measurement precision may worsen due to distance from eye orbit
Solution Approach 1:
The patent makes the earpiece device multi-functional by integrating both audio delivery and EOG-based eye tracking capabilities into a single wearable device. The earpieces serve dual purposes: delivering audio content to the user and housing electrodes that measure eye movement signals, thereby eliminating the need for separate eye tracking equipment while maintaining measurement accuracy through the electrical properties of the foam electrodes.
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
Provides accurate gaze direction estimation with improved comfort and versatility, enabling applications such as presentation control, AR/VR enhancement, and active dialog enhancement.
Implementation Method 1
a set of electrodes arranged on each earpiece, such that they, in use, are placed in contact with the user's skin, each electrode comprising a patch of compressible and electrically conducting foam material, configured to provide a reliable electrical connection with the skin
Implementation Method 2
each electrode comprising a patch of compressible and electrically conducting foam material
Implementation Method 3
Electro-oculography (EOG) is the measurement of the electrical dipole potential of the corneo-retinal dipole of the eyeball (difference in electrical charge between the cornea and the retina). When the eyes move in the orbit, the dipole rotates. This electrical potential can be measured using a set of electrodes placed near the orbit and can be used to estimate the eye position.
Data Source
AI summary
A system for determining a direction of gaze of a user, comprising a set of electrodes arranged on earpieces, each electrode comprising a patch of compressible and electrically conducting foam material. The system further includes circuitry connected to the electrodes and configured to receive a set of voltage signals from a set of electrodes arranged on an audio endpoint worn by a user, multiplex said voltage signals into an input signal, remove a predicted central voltage from said input signal, to provide a detrended signal, and determine said gaze direction based on said detrended signal. Such conducting foam materials provide satisfactory bio-sensing performance for a wide range of compression levels and over time. In the case of on-ear headphones, the foam electrodes may be integrated in the cuffs with little or no effect on the comfort level.