Capacitive gaze tracking for auto-accommodation in a contact lens

Patent metadata

Field	Value
Publication number	US-9442310-B2
Application number	US-201414587639-A
Country	US
Kind code	B2
Filing date	Dec 31, 2014
Priority date	Jun 13, 2014
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

A method of capacitive gaze detection for accommodation includes monitoring at least one capacitance value of a capacitive sensor system disposed within a contact lens. The at least one capacitance value varies in response to changes in a gazing direction of a cornea upon which the contact lens is removeably mounted. The changes in the gazing direction of the cornea are detected in real-time based upon changes in the at least one capacitance value. An accommodation actuator disposed within the contact lens is manipulated to automatically change an optical power of the contact lens in response to detecting changes in the gazing direction.

First claim

What is claimed is:

1. A method, comprising:
monitoring at least one capacitance value of a capacitive sensor system disposed within a contact lens, wherein the at least one capacitance value varies in response to changes in a gazing direction of a cornea upon which the contact lens is removeably mounted;
detecting, in real-time, the changes in a gazing direction of the cornea based upon changes in the at least one capacitance value; and
manipulating an accommodation actuator disposed within the contact lens to automatically change an optical power of the contact lens in response to detecting changes in the gazing direction,
wherein detecting the changes in the gazing direction of the cornea based upon changes in the at least one capacitance value comprises associating different values of the at least one capacitance value with different gazing positions of the cornea.

2. The method of claim 1 , wherein the different values of the at least one capacitance value are related to the different gazing positions of the cornea based at least in part upon eyelid coverage of the capacitive sensor system.

3. The method of claim 1 , further comprising:
determining that the cornea is looking down and towards the nose based at least in part upon the at least one capacitance value; and
controlling an amount of accommodation provided by the accommodation actuator to improve near-field focus for reading.

4. The method of claim 1 , further comprising:
determining that the cornea is looking substantially forward based at least in part upon the at least one capacitance value; and
controlling an amount of accommodation provided by the accommodation actuator to improve far-field focus.

5. The method of claim 1 , wherein the accommodation actuator is disposed across a central region of the contact lens and wherein manipulating the accommodation actuator comprises manipulating a refractive index of the accommodation actuator.

6. The method of claim 1 , wherein the capacitive sensor system comprises a plurality of discrete capacitors distributed peripherally to the accommodation actuator within the contact lens.

7. The method of claim 6 , wherein the contact lens comprises a rotationally stable contact lens, the method further comprising:
associating calibration capacitance values of specific ones of the discrete capacitors with particular gazing directions.

8. The method of claim 6 , wherein the contact lens comprises a non-rotationally stable contact lens, the method further comprising:
performing an orientation calibration to determine a rotational position of the contact lens; and
temporarily associating calibration capacitance values of specific ones of the discrete capacitors with particular gazing directions.

9. The method of claim 8 , further comprising:
tracking a rotational drift of the contact lens based upon changes in the capacitance values of the discrete capacitors; and
updating the temporary associations between the calibration capacitance values of the specific ones of the discrete capacitors and the particular gazing directions to account for the rotational drift.

10. The method of claim 1 , further comprising performing a gaze detection calibration to account for different user eyelid shapes, wherein the gaze detection calibration includes:
measuring the at least one capacitance value of a capacitive sensor system while the cornea is looking in a plurality of different gazing directions or looking at a plurality of different focal distances; and
storing the at least one capacitance value for each of the plurality of different gazing directions or focal distances as calibration data associated with the different gazing directions or the different focal distances.

11. A contact lens, comprising:
a capacitive sensor system disposed within the contact lens, wherein the capacitive sensor system has at least one capacitance value that varies with changes in a gazing direction of a cornea when the contact lens is removeably mounted over the cornea;
an accommodation actuator disposed within the contact lens and located to overlay at least a central portion of the cornea when the contact lens is so mounted; and
a controller disposed within the contact lens and electrically connected to the capacitive sensor system and the accommodation actuator, wherein the controller includes logic that when executed by the controller causes the controller to perform operations including:
monitoring the at least one capacitance value;
detecting, in real-time, the changes in a gazing direction of the cornea based upon changes in the at least one capacitance value; and
electrically manipulating the accommodation actuator to automatically change an optical power of the contact lens in response to detecting changes in the gazing direction,
wherein detecting the changes in the gazing direction of the cornea based upon changes in the at least one capacitance value comprises associating different values of the at least one capacitance value with different gazing positions of the cornea.

12. The contact lens of claim 11 , wherein the different values of the at least one capacitance value are related to the different gazing positions of the cornea based at least in part upon eyelid coverage of the capacitive sensor system.

13. The contact lens of claim 11 , wherein the controller includes further logic that when executed by the controller causes the controller to perform operations including:
determining that the cornea is looking down and towards the nose based at least in part upon the at least one capacitance value; and
controlling an amount of accommodation provided by the accommodation actuator to improve near-field focus for reading.

14. The contact lens of claim 11 , wherein the controller includes further logic that when executed by the controller causes the controller to perform operations including:
determining that the cornea is looking substantially forward based at least in part upon the at least one capacitance value; and
controlling an amount of accommodation provided by the accommodation actuator to improve far-field focus.

15. The contact lens of claim 11 , wherein the accommodation actuator is disposed across a central region of the contact lens and wherein electrically manipulating the accommodation actuator comprises manipulating a refractive index of the accommodation actuator.

16. The contact lens of claim 15 , wherein the accommodation actuator comprises an electro-active optical material.

17. The contact lens of claim 15 , wherein the accommodation actuator comprises a liquid crystal cell.

18. The contact lens of claim 15 , wherein the capacitive sensor system comprises a plurality of discrete capacitors distributed peripherally to the accommodation actuator within the contact lens.

19. The contact lens of claim 18 , wherein the contact lens comprises a rotationally stable contact lens and wherein the controller includes further logic that when executed by the controller causes the controller to perform operations including:
associating calibration capacitance values of specific ones of the discrete capacitors with particular gazing directions.

20. The contact lens of claim 18 , wherein the contact lens comprises a non-rotationally stable contact lens and wherein the controller includes further logic that when executed by the controller causes the controller to perform operations including:
performing an orientation calibration to determine a rotational position of the contact lens; and
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Assignees

• Verily Life Sciences Llc

Inventors

• Biederman William J
• Yeager Daniel J
• Otis Brian
• Pletcher Nathan

Classifications

• G02C7/04

  Contact lenses for the eyes (disinfection or sterilisation of contact lenses A61L12/00) · CPC title

• A61B3/113

  for determining or recording eye movement · CPC title

• G02C7/083 Primary

  Electrooptic lenses · CPC title