Wearable device for detecting the eye movement of a user

Patent metadata

Field	Value
Publication number	US-2025072808-A1
Application number	US-202418804589-A
Country	US
Kind code	A1
Filing date	Aug 14, 2024
Priority date	Aug 28, 2023
Publication date	Mar 6, 2025
Grant date	—

Abstract

A wearable device for detecting a user's eye movement having a first movement sensor with electrodes aligned with each other along a first movement axis, a second movement sensor with electrodes aligned with each other along a second movement axis transverse to the first movement axis, and a control circuit coupled to the electrodes and configured to acquire electrostatic charge variation signals indicative of differences between the electrostatic charge variations detected by the electrodes of the movement sensors; detect an event indicative of respective displacements of the eyes along the movement axis; and determine the movement of the eyes based on of the event confirmation.

First claim

What is claimed is:

1 . A circuit for detecting a movement of a first eye and a second eye of a user, the circuit comprising:
a first movement sensor comprising a first electrode and a second electrode aligned along a first movement axis, spaced apart by a first distance, positionable proximate to the first eye, and configured to detect, respectively, a first electrostatic charge variation and a second electrostatic charge variation generated by the movement of the first eye along the first movement axis; a second movement sensor comprising a third electrode and a fourth electrode aligned along a second movement axis, spaced apart by a second distance, positionable proximate to the second eye, and configured to detect, respectively, a third electrostatic charge variation and a fourth electrostatic charge variation generated by the movement of the second eye along the second movement axis, the second movement axis being transverse to the first movement axis; and a control circuit coupled to the first movement sensor and the second movement sensor, the control circuit configured to:
acquire a first electrostatic charge variation signal indicative of a difference between the first electrostatic charge variation and the second electrostatic charge variation,
acquire a second electrostatic charge variation signal indicative of a difference between the third electrostatic charge variation and the fourth electrostatic charge variation,
detect, starting from the first electrostatic charge variation signal and the second electrostatic charge variation signal, an event indicative of eye displacement along the first movement axis or the second movement axis, and
determine the movement of the first eye and the second eye based on the event.

2 . The circuit of claim 1 , further comprising a sensor configured to detect speech-related activity by the user, wherein the control circuit is configured to:
compute a modulus signal from the first electrostatic charge variation signal and the second electrostatic charge variation signal and accounting for the speech-related activity, wherein accounting for the speech-related activity comprises:
removing speech-related artifacts from the first electrostatic charge variation signal and the second electrostatic charge variation signal before computing the modulus signal,
updating a threshold value used to detect the event by adding an offset value to the threshold value in response to detecting the speech-related activity; and
determine an angle at which the first eye and the second eye are directed based on the modulus signal.

3 . The circuit of claim 1 ,
wherein the first movement axis and the second movement axis are orthogonal to each other, or wherein the first movement axis is parallel to a longitudinal axis of the user's face, wherein the second movement axis is parallel to, or coincident with, a transverse axis of the user's face, wherein the longitudinal axis is equidistant from the first eye and the second eye, and wherein the transverse axis passes through the first eye and the second eye.

4 . The circuit of claim 1 ,
wherein the first electrode and the second electrode extend from sides opposite to each other of the first eye along the first movement axis, and wherein the third electrode and the fourth electrode extend from sides opposite to each other of the second eye along the second movement axis.

5 . The circuit of claim 1 ,
wherein the first movement sensor further comprises a fifth electrode and a sixth electrode aligned along a first parallel movement axis transverse or orthogonal to the first movement axis, spaced apart by a third distance, positionable proximate to the first eye, and configured to detect, respectively, a fifth electrostatic charge variation and a sixth electrostatic charge variation generated by the movement of the first eye along the first parallel movement axis, wherein the second movement sensor further comprises a seventh electrode and an eighth electrode aligned along a second parallel movement axis transverse or orthogonal to the second movement axis, spaced apart by a fourth distance, positionable proximate to the second eye, and configured to detect, respectively, a seventh electrostatic charge variation and an eighth electrostatic charge variation generated by the movement of the second eye along the second parallel movement axis, the second parallel movement axis being transverse or orthogonal to the first parallel movement axis, wherein the control circuit is configured to:
acquire a third electrostatic charge variation signal indicative of a difference between the fifth electrostatic charge variation and the sixth electrostatic charge variation,
acquire a fourth electrostatic charge variation signal indicative of a difference between the seventh electrostatic charge variation and the eighth electrostatic charge variation,
detect, starting from the third electrostatic charge variation signal and the fourth electrostatic charge variation signal, a second event indicative of eye displacement along the first parallel movement axis or the second parallel movement axis, and
determine the movement of the first eye and the second eye based on the second event.

6 . The circuit of claim 1 , wherein the first electrode, the second electrode, the third electrode, and the fourth electrode are releasably fixed to the user's skin.

7 . The circuit of claim 1 , wherein the circuit is hosted by a wearable device, the wearable device being an eyewear device, a wearable eyeglass device, a smart wearable eyeglass device, a headset, or an augmented reality headset.

8 . A wearable device, comprising:
a frame; and a circuit for detecting a movement of a first eye and a second eye of a user, the circuit arranged on the frame and comprising: a first movement sensor comprising a first electrode and a second electrode aligned along a first movement axis, spaced apart by a first distance, positionable proximate to the first eye, and configured to detect, respectively, a first electrostatic charge variation and a second electrostatic charge variation generated by the movement of the first eye along the first movement axis, a second movement sensor comprising a third electrode and a fourth electrode aligned along a second movement axis, spaced apart by a second distance, positionable proximate to the second eye, and configured to detect, respectively, a third electrostatic charge variation and a fourth electrostatic charge variation generated by the movement of the second eye along the second movement axis, the second movement axis being transverse to the first movement axis, and a control circuit coupled to the first movement sensor and the second movement sensor, the control circuit configured to:
acquire a first electrostatic charge variation signal indicative of a difference between the first electrostatic charge variation and the second electrostatic charge variation;
acquire a second electrostatic charge variation signal indicative of a difference between the third electrostatic charge variation and the fourth electrostatic charge variation;
detect, starting from the first electrostatic charge variation signal and the second electrostatic charge variation signal, an event indicative of eye displacement along the first movement axis or the second movement axis; and
determine the movement of the first eye and the second eye based on the event.

9 . The wearable device of claim 8 ,
wherein the frame comprises a first support portion and a second support portion coupled to each other and configured to, respectively, face the first eye and the second eye, wherein the first electrode and the second electrode are fixed to the firs

Assignees

• St Microelectronics Int Nv

Inventors

• Alessi Enrico Rosario
• Baldacchino Daniele
• Passaniti Fabio
• Dellutri Michele Alessio

Classifications

• A61B5/7267

  involving training the classification device · CPC title

• A61B5/4803

  Speech analysis specially adapted for diagnostic purposes · CPC title

• A61B5/721

  using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured · CPC title

• A61B5/1114

  Tracking parts of the body · CPC title

• A61B3/113

  for determining or recording eye movement · CPC title