Compensation magnetic field generator for a magnetic field measurement system

Patent metadata

Field	Value
Publication number	US-11293999-B2
Application number	US-202016862946-A
Country	US
Kind code	B2
Filing date	Apr 30, 2020
Priority date	May 3, 2019
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

A magnetic field generator includes a first planar substrate, a second planar substrate positioned opposite to the first planar substrate and separated from the first planar substrate by a gap, a first wiring set on the first planar substrate, a second wiring set on the second planar substrate, and one or more interconnects between the first planar substrate and the second planar substrate. The one or more interconnects electrically connect the first wiring set with the second wiring set to form a continuous electrical path. The continuous electrical path forms a conductive winding configured to generate, when supplied with a drive current, a first component of a compensation magnetic field configured to actively shield a magnetic field sensing region located in the gap from ambient background magnetic fields along a first axis that is substantially parallel to the first planar substrate and the second planar substrate.

First claim

What is claimed is:

1. A magnetic field generator comprising:
a first planar substrate;
a second planar substrate positioned opposite to the first planar substrate and separated from the first planar substrate by a gap,
a first wiring set disposed on the first planar substrate,
a second wiring set disposed on the second planar substrate,
a third wiring set disposed on the first planar substrate,
a fourth wiring set disposed on the second planar substrate, and
one or more interconnects positioned between the first planar substrate and the second planar substrate and that electrically connect the first wiring set with the second wiring set to form a first continuous electrical path and that electrically connect the third wiring set with the fourth wiring set to form a second continuous electrical path,
wherein the first continuous electrical path forms a first conductive winding configured to generate, when supplied with a first drive current, a first component of a compensation magnetic field configured to actively shield a magnetic field sensing region located in the gap from ambient background magnetic fields along a first axis that is substantially parallel to the first planar substrate and the second planar substrate, and
wherein the second continuous electrical path forms a second conductive winding configured to generate, when supplied with a second drive current, a second component of the compensation magnetic field configured to actively shield the magnetic field sensing region from the ambient background magnetic fields along a second axis that is substantially parallel to the first planar substrate and the second planar substrate and orthogonal to the first axis.

2. The magnetic field generator of claim 1 , wherein the first component of the compensation magnetic field is configured to actively shield the magnetic field sensing region by reducing or canceling a first component of the ambient background magnetic field, the first component of the ambient background magnetic field being along the first axis.

3. The magnetic field generator of claim 2 , wherein the first component of the compensation magnetic field is substantially equal and opposite to the first component of the ambient background magnetic field.

4. The magnetic field generator of claim 1 , wherein the one or more interconnects comprises an elastomeric connector that is anisotropically conductive.

5. The magnetic field generator of claim 4 , wherein the elastomeric connector is configured to maintain a minimum spacing between the first planar substrate and the second planar substrate.

6. The magnetic field generator of claim 1 , wherein each of the first planar substrate and the second planar substrate comprises a printed circuit board.

7. The magnetic field generator of claim 1 , wherein a winding pattern of the first conductive winding includes a first counter-winding configured to reduce a spatial extent of a first fringe magnetic field generated by the first conductive winding.

8. The magnetic field generator of claim 1 , further comprising:
a first gradient wiring and a second gradient wiring disposed on the first planar substrate; and
a third gradient wiring and a fourth gradient wiring disposed on the second planar substrate;
wherein
the one or more interconnects electrically connect the first gradient wiring with the third gradient wiring to form a first additional continuous electrical path, the additional continuous electrical path forming a first gradient conductive winding,
the one or more interconnects electrically connect the second gradient wiring with the fourth gradient wiring to form a second additional continuous electrical path, the second additional continuous electrical path forming a second gradient conductive winding, and
the first gradient conductive winding and the second gradient conductive winding are configured to generate, when supplied with different drive currents, a first gradient component of the compensation magnetic field configured to actively shield the magnetic field sensing region from ambient background magnetic fields that linearly vary along the first axis.

9. The magnetic field generator of claim 1 , wherein the second component of the compensation magnetic field is configured to actively shield the magnetic field sensing region by reducing or canceling a second component of the ambient background magnetic fields, the second component of the ambient background magnetic fields being along the second axis.

10. The magnetic field generator of claim 9 , wherein the second component of the compensation magnetic field is substantially equal and opposite to the second component of the ambient background magnetic fields.

11. The magnetic field generator of claim 1 , wherein:
the first wiring set and the third wiring set are formed on a first surface of the first planar substrate and are electrically insulated from one another, and
the second wiring set and the fourth wiring set are formed on a first surface of the second planar substrate and are electrically insulated from one another.

12. The magnetic field generator of claim 1 , wherein:
the first wiring set is formed on a first surface of the first planar substrate,
the third wiring set is formed on a second surface of the first planar substrate,
the second wiring set is formed on a first surface of the second planar substrate, and
the fourth wiring set is formed on a second surface on the second planar substrate.

13. The magnetic field generator of claim 1 , further comprising:
a first gradient wiring and a second gradient wiring disposed on the first planar substrate; and
a third gradient wiring and a fourth gradient wiring disposed on the second planar substrate;
wherein
the one or more interconnects electrically connect the first gradient wiring with the third gradient wiring to form a first additional continuous electrical path, the additional continuous electrical path forming a first gradient conductive winding,
the one or more interconnects electrically connect the second gradient wiring with the fourth gradient wiring to form a second additional continuous electrical path, the second additional continuous electrical path forming a second gradient conductive winding, and
the first gradient conductive winding and the second gradient conductive winding are configured to generate, when supplied with different drive currents, a first gradient component of the compensation magnetic field configured to actively shield the magnetic field sensing region from ambient background magnetic fields that linearly vary along the first axis.

14. The magnetic field generator of claim 13 , further comprising:
a fifth gradient wiring and a sixth gradient wiring disposed on the first planar substrate; and
a seventh gradient wiring and an eighth gradient wiring disposed on the second planar substrate;
wherein
the one or more interconnects electrically connect the fifth gradient wiring with the seventh gradient wiring to form a third additional continuous electrical path, the third additional continuous electrical path forming a third gradient conductive winding,
the one or more interconnects electrically connect the sixth gradient wiring with the eighth gradient wiring to form a fourth additional continuous electrical path, the fourth additional continuous electrical path forming a fourth gradient conductive winding, and
the third gradient conductive winding and the fourth gradient conductive winding are configured to generate, when supplied with different drive currents, a second gradient component of the compensation magnetic field configured to ac

Assignees

• Hi Llc

Inventors

• Alford Jamu
• Henninger Michael
• Garber Stephen
• Gormley Jeffery Kang
• Decker Dakota Blue
• Homan Scott Michael
• Lasser Teague
• Ledbetter Micah
• Leung Jerry
• Mohseni Hooman
• Pratt Ethan
• Seidman Scott Jeremy
• Siepser Benjamin

Classifications

• A61B5/6802

  Sensor mounted on worn items · CPC title

• G01R33/025

  Compensating stray fields {(G01R33/0017 takes precedence)} · CPC title

• H01F27/2866

  Combination of wires and sheets · CPC title

• A61B2562/0223

  Magnetic field sensors · CPC title

• G01R33/26

  using optical pumping · CPC title