Miniature electric field detector

Patent metadata

Field	Value
Publication number	US-2024407699-A1
Application number	US-202418810810-A
Country	US
Kind code	A1
Filing date	Aug 21, 2024
Priority date	Mar 15, 2019
Publication date	Dec 12, 2024
Grant date	—

Abstract

According to various aspects, a sensor system is provided comprising a first substrate configured to be coupled to a user, an electric field detector to detect a user electric field and comprising a second substrate, a proof mass positioned above the second substrate, one or more electrodes coupled to the second substrate, and a control circuit coupled to the one or more electrodes, the control circuit being configured to determine a change in capacitance between the proof mass and each electrode responsive to torsional movement of the proof mass responsive to the electric field, and a controller coupled to the first substrate and being configured to receive, from the detector, information indicative of each change in capacitance between the proof mass and each electrode, and determine, based on the information, characteristics of the electric field in at least two dimensions.

First claim

What is claimed is:

1 . A sensor system incorporated within a headset comprising:
a first substrate configured to be coupled to a user; an electric field detector to detect an electric field generated by the user, the electric field detector being coupled to the first substrate and comprising: a second substrate; a proof mass positioned above the second substrate; one or more electrodes coupled to the second substrate; and a control circuit coupled to the one or more electrodes, the control circuit being configured to determine a respective change in capacitance between the proof mass and each respective electrode of the one or more electrodes responsive to torsional movement of the proof mass in response to the electric field; and a controller coupled to the first substrate and to the electric field detector, the controller being configured to:
receive, from the electric field detector, information indicative of each respective change in capacitance between the proof mass and each respective electrode of the one or more electrodes; and
determine, based on the information indicative of each respective change in capacitance between the proof mass and each respective electrode, characteristics of the electric field in at least two dimensions.

2 . The sensor system of claim 1 , wherein the electric field detector is removably coupled to the first substrate.

3 . The sensor system of claim 2 , further comprising an adhesive coupled to the first substrate, the first substrate being configured to be removably coupled to the user.

4 . The sensor system of claim 1 , further comprising an electric dipole coupled to the proof mass, the electric dipole being polarized along a polarization axis.

5 . The sensor system of claim 4 , wherein the proof mass is configured to:
rotate about a first torque axis orthogonal to the polarization axis responsive to the electric field having a first vector component aligned with a first electric field axis, the first electric field axis being orthogonal to the polarization axis and the first torque axis; and rotate about a second torque axis orthogonal to the polarization axis responsive to the electric field having a second vector component aligned with a second electric field axis, the second electric field axis being orthogonal to the polarization axis and the second torque axis, wherein the second torque axis is parallel to the first electric field axis and the first torque axis is parallel to the second electric field axis.

6 . The sensor system of claim 5 , wherein the one or more electrodes includes a first set of one or more electrodes and a second set of one or more electrodes, the control circuit being configured to:
determine a first change in capacitance between the proof mass and the first set of one or more electrodes responsive to torsional movement of the proof mass about the first torque axis; and determine a second change in capacitance between the proof mass and the second set of one or more electrodes responsive to torsional movement of the proof mass about the second torque axis.

7 . The sensor system of claim 6 , wherein the controller is further configured to determine, based on the first change in capacitance and the second change in capacitance, characteristics of the electric field along the first electric field axis and the second electric field axis.

8 . The sensor system of claim 4 , wherein the electric dipole includes a dielectric material, and wherein the control circuit is configured to selectively polarize the dielectric material along a first polarization axis and a second polarization axis, the first polarization axis being orthogonal to the second polarization axis.

9 . The sensor system of claim 8 , the proof mass being configured to:
rotate about a first torque axis orthogonal to the first polarization axis responsive to receiving the electric field along a first electric field axis, the first electric field axis being orthogonal to the first polarization axis and the first torque axis; rotate about a second torque axis orthogonal to the first polarization axis responsive to receiving the electric field along a second electric field axis, the second electric field axis being orthogonal to the first polarization axis and the second torque axis; and
rotate about a third torque axis orthogonal to the second polarization axis responsive to receiving the electric field along a third electric field axis, the third electric field axis being orthogonal to the second polarization axis and the third torque axis,
wherein the first torque axis is parallel to the second electric field axis and one of the third electric field axis and the second polarization axis, the second torque axis is parallel to the first electric field axis and one of the third electric field axis and the second polarization axis, and the third torque axis is parallel to the first polarization axis.

10 . The sensor system of claim 9 , wherein the one or more electrodes includes a first set of one or more electrodes, a second set of one or more electrodes, and a third set of one or more electrodes, the control circuit being configured to:
determine a first change in capacitance between the proof mass and the first set of one or more electrodes responsive to torsional movement of the proof mass about the first torque axis; determine a second change in capacitance between the proof mass and the second set of one or more electrodes responsive to torsional movement of the proof mass about the second torque axis; and determine a third change in capacitance between the proof mass and the third set of one or more electrodes responsive to torsional movement of the proof mass about the third torque axis.

11 . The sensor system of claim 10 , wherein the controller is further configured to determine, based on the first change in capacitance, the second change in capacitance, and the third change in capacitance, characteristics of the electric field along the first electric field axis, the second electric field axis, and the third electric field axis.

12 . The sensor system of claim 8 , further comprising a first set of polarization electrodes and a second set of polarization electrodes coupled to the dielectric material, the first set of polarization electrodes being positioned along the first polarization axis and the second set of polarization electrodes being positioned along the second polarization axis.

13 . The sensor system of claim 12 , wherein the control circuit is configured to:
generate a first voltage difference across the first set of polarization electrodes to polarize the dielectric material along the first polarization axis; and generate a second voltage difference across the second set of polarization electrodes to polarize the dielectric material along the second polarization axis.

14 . The sensor system of claim 13 , wherein generating the first voltage difference includes applying a first voltage to the first set of polarization electrodes at a first frequency, and wherein generating the second voltage difference includes applying a second voltage to the second set of polarization electrodes at a second frequency, the first frequency being different than the second frequency.

15 . The sensor system of claim 1 , wherein the electric field detector is configured to detect an electric field generated by a brain of the user.

16 . The sensor system of claim 1 , wherein the controller is configured to determine characteristics of the electric field in three orthogonal dimensions.

17 . The s

Assignees

• Charles Stark Draper Laboratory Inc

Inventors

• Bickford James A
• Wheeler Jesse J
• Golmon Stephanie Lynne

Classifications

• A61B5/291

  for electroencephalography [EEG] · CPC title

• A61B5/341

  Vectorcardiography [VCG] · CPC title

• A61B5/282

  Holders for multiple electrodes (for introduction into the body A61B5/287) · CPC title

• A61B2562/0214

  Capacitive electrodes · CPC title

• A61B2562/028

  Microscale sensors, e.g. electromechanical sensors [MEMS] · CPC title