Eye Gesture Detection Using Laser Feedback Interferometry

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Solution Overview

Problem

Existing eye gesture recognition systems are complex, energy-intensive, and have limited temporal resolution, often relying on camera-based or sensor systems with high complexity and energy consumption.

Innovation Solution

A method utilizing laser feedback interferometry to determine optical path length, signal-to-noise ratio, and eye velocity from a single measurement sample, enabling efficient and low-energy eye gesture recognition without the need for continuous tracking.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If camera-based systems or electrical sensors are used for eye tracking, then eye gesture recognition is achieved, but device complexity and energy consumption increase

Engineering Contradiction:
Improveeye gesture recognition accuracyVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical camera-based systems and electrical sensors with an optical measurement system using laser feedback interferometry. This substitution reduces device complexity while maintaining eye gesture recognition capability through optical path length and Doppler shift measurements.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts only the essential measurement parameters (optical path length and eye velocity) needed for eye gesture recognition, eliminating unnecessary components of traditional eye tracking systems. This extraction approach simplifies the overall system while preserving core functionality.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If camera-based systems or electrical sensors are used for eye tracking, then eye gesture recognition is achieved, but energy consumption increases

Engineering Contradiction:
Improveeye gesture recognition accuracyVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces energy-intensive camera-based systems and electrical sensors with a low-power optical measurement system. The laser feedback interferometry method consumes significantly less energy while achieving the same eye gesture recognition accuracy, making it suitable for portable and wearable devices.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If traditional eye tracking systems are used, then eye position is tracked, but temporal resolution is limited

Engineering Contradiction:
Improvetemporal resolutionVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent utilizes the natural vibration and movement of the eye to generate Doppler shifts in the backscattered laser radiation. By measuring these frequency shifts, the system achieves high temporal resolution in eye velocity measurement without requiring complex scanning mechanisms or high-speed cameras.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The patent employs laser feedback interferometry where the backscattered light from the eye feeds back into the laser cavity, creating interference patterns that encode information about optical path length changes and eye velocity. This feedback mechanism enables precise, high-temporal-resolution measurements with minimal system complexity.

Inventive Principle:
Principle #23Feedback

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

Enables precise and efficient eye gesture recognition with high temporal resolution, allowing for zero or negative latency in gesture recognition and using simple, cost-effective components with low energy consumption.

Implementation Method 1

Through a process called laser feedback interferometry, the emitted laser beam is superimposed on the backscattered radiation, resulting in interference radiation. This resulting interference radiation can be detected and analyzed

Methodology Applied
Scientific EffectLaser feedback interferometry: Interference

Implementation Method 2

The eye velocity is determined based on a Doppler shift of the emitted and backscattered radiation, also determined by laser feedback interferometry

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentEP4327155B1Method for detecting gestures of an eye
Publication Date: 2026.04.15 ROBERT BOSCH GMBH
  • EP4327155B1 patent drawingFigure 1~2
  • EP4327155B1 patent drawingFigure 3
  • EP4327155B1 patent drawingFigure 4a~4c

AI summary

The invention relates to a method for detecting gestures of an eye (10), having the steps of emitting at least one laser beam (1) onto the eye (10), ascertaining an individual measurement sample with current values for: an optical wavelength (2) of the emitted laser beam (1); a signal-noise ratio of radiation scattered back by the eye (10); and the speed of the eye (10); and detecting an eye gesture on the basis of the individual measurement sample, wherein the optical wavelength (2) is ascertained on the basis of a laser feedback interferometry of the emitted laser beam with the radiation scattered back by the eye (10), and the eye speed is ascertained on the basis of a Doppler effect of the emitted and back-scattered radiation, said Doppler effect being ascertained using the laser feedback interferometry.