Segmented magnets

• US 9,999,380 B1
• Filed: 09/22/2015
• Issued: 06/19/2018
• Est. Priority Date: 09/22/2014
• Status: Active Grant

• Current Assignee: Verily Life Sciences LLC (Alphabet Inc.)
• Original Assignee: Verily Life Sciences LLC (Alphabet Inc.)
• Inventors: Demas, Vasiliki, Bajaj, Vikram Singh
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US14/861,901
• Time in Patent Office: 1,001 Days
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61N 2/06 using magnetic fields produced by permanent magnets A61N2/12 takes precedence
• CPC Class Codes: H01F 2003/103 Magnetic circuits with permanent magnets
• CPC Class Codes: H01F 3/10 Composite arrangements of magnetic circuits
• CPC Class Codes: H01F 7/0231 Magnetic circuits with PM for power or force generation

Abstract

A variety of wearable magnetic assemblies are provided that are configured to produce magnetic fields having high field magnitudes and/or high field gradients. Such magnetic assemblies include a plurality of magnetic segments arranged in a linear array. Individual magnetic segments of the magnetic array can each include multiple magnetic elements. An individual magnetic segment can include elements that have similar shape, size, composition, and relative location to elements of neighboring magnetic segments while having magnetic moments that are antiparallel to the magnetic moments of corresponding elements of the neighboring magnetic segments. These wearable magnetic assemblies are configured to exert forces on magnetic particles disposed in a portion of subsurface vasculature to attract, slow, speed, separate, or otherwise influence the magnetic particles in various applications. The magnetic particles can be configured to bind to an analyte of interest.

Claims

1. A device comprising:

a magnetic assembly comprising a plurality of magnetic segments, wherein the plurality of magnetic segments are arranged in a linear array, wherein the magnetic segments are separated from each other by respective specified distances, wherein each magnetic segment comprises two or more magnetic elements each having a respective magnetic moment, wherein the magnetic assembly is configured to be positioned proximate to an external body surface such that the magnetic assembly exerts a magnetic force on magnetic particles in a portion of subsurface vasculature proximate to the external body surface, wherein a first magnetic segment of the plurality of magnetic segments is next to a second magnetic segment of the plurality of magnetic segments, and wherein the magnetic moments of respective first and second magnetic elements of the first magnetic segment are each oriented antiparallel to the magnetic moments of respective corresponding first and second magnetic elements of the second magnetic segment, wherein the magnetic particles are configured to bind to an analyte;

and a detector, wherein the detector is configured to detect one or more properties of the analyte bound to the magnetic particles, or an energy emitter, wherein the energy emitter is configured to emit energy into the subsurface vasculature sufficient to alter one or more properties of the analyte bound to the magnetic particles.

2. The device of claim 1, wherein the magnetic force is an attractive magnetic force, and wherein the attractive magnetic force is sufficient to collect the magnetic particles in the portion of subsurface vasculature proximate to the magnetic assembly.

3. The device of claim 1, wherein the magnetic particles include first magnetic particles and second magnetic particles, wherein the magnetic assembly exerts a magnetic force on magnetic particles that are disposed in the portion of subsurface vasculature including a first magnetic force on the first magnetic particles and a second magnetic force on the second magnetic particles, and wherein the first magnetic force and the second magnetic force are sufficiently different to cause separation of the first magnetic particles and the second magnetic particles.

4. The device of claim 1, wherein the first magnetic segment of the magnetic assembly comprises a first magnetic element having a first magnetic moment oriented substantially into the external body surface when positioned proximate the external body surface.

5. The device of claim 4, wherein the first magnetic segment of the magnetic assembly comprises at least three magnetic elements, wherein the first magnetic element of the at least three magnetic elements is adjacent to a second magnetic element of the at least three magnetic elements, wherein the second magnetic element is adjacent to a third magnetic element of the at least three magnetic elements, wherein the second and third magnetic elements have respective second and third magnetic moments, wherein the second magnetic moment is substantially perpendicular to the first magnetic moment, wherein the third magnetic moment is substantially perpendicular to the second magnetic moment, wherein the third magnetic moment is substantially antiparallel to the first magnetic moment.

6. The device of claim 5, wherein the at least three magnetic elements are permanent magnets, and wherein the at least three magnetic elements have a cross-sectional shape in a plane substantially perpendicular to a long axis of the linear array of magnetic segments, wherein the cross-sectional shape is narrower proximate to the external body surface.

7. The device of claim 5, wherein the first magnetic segment of the magnetic assembly comprises three magnetic elements, wherein the second magnetic moment is configured to be oriented substantially into the external body surface, and wherein the first magnetic segment further comprises:

a layer of high-permeability material, wherein the layer of high-permeability material partially encloses the three magnetic elements, wherein the layer of high-permeability material is disposed on a first side of the three magnetic elements of the magnetic assembly, wherein the first side is configured to be an opposite side of the three magnetic elements from the external body surface, wherein the layer of high-permeability material is disposed on a side of the third magnetic element opposite the second magnetic element, and wherein the layer of high-permeability material is disposed on a side of the first magnetic element opposite the second magnetic element.

8. The device of claim 5, wherein the first magnetic segment of the magnetic assembly comprises an axial magnetic element having a magnetic moment configured to be oriented substantially into the external body surface, wherein the axial magnetic element has a central axis parallel to the magnetic moment of the axial magnetic element, wherein the first magnetic segment further comprises a plurality of radial magnetic elements having respective magnetic moments oriented toward the central axis, and wherein the plurality of radial magnetic elements are disposed proximate to and surrounding the axial magnetic element.

9. The device of claim 1, wherein the first magnetic segment of the magnetic assembly further comprises a focusing pole comprised of high-permeability material, wherein the focusing pole is disposed on a first side of the first magnetic segment, wherein the first side is a side of the first magnetic segment configured to be proximate the external body surface, wherein the focusing pole has a first cross-sectional area proximate to the first side of the first magnetic segment, wherein the focusing pole has a second cross-sectional area farther from the first side of the first magnetic segment, and wherein the second cross-sectional area is less than the first cross-sectional area.

10. The device of claim 1, further comprising a spacer comprised of a low-permeability material, wherein the spacer is disposed between the first and second magnetic segments.

11. The device of claim 1, wherein the magnetic assembly has a first side configured to be proximate the external body surface and a second side opposite the first side, and wherein the magnetic assembly comprises a layer of high-permeability material disposed on the second side.

12. The device of claim 1, wherein the magnetic assembly has a concave surface, the external body surface has a convex surface, and the concave surface is configured to at least partially enclose the convex surface, and wherein at least two magnetic elements of the two or more magnetic elements of the first magnetic segment are disposed on the concave surface.

13. The device of claim 12, wherein the first magnetic segment comprises four magnetic elements disposed on the concave surface, wherein each of the four magnetic elements has a respective magnetic moment that is configured to be substantially perpendicular to a respective local external body surface, wherein a first magnetic element of the four magnetic elements has a magnetic moment configured to be pointing into the respective local external body surface, wherein a second magnetic element of the four magnetic elements has a magnetic moment pointing configured to be away from the respective local external body surface, wherein the second magnetic element is proximate to the first magnetic element, wherein a third magnetic element of the four magnetic elements has a magnetic moment configured to be pointing into the respective local external body surface, wherein the third magnetic element is proximate to the second magnetic element, wherein the third magnetic element is disposed opposite the first magnetic element relative to the second magnetic element, wherein the magnetic moment of the third magnetic element is substantially antiparallel to the magnetic moment of the second magnetic element, wherein a fourth magnetic element of the four magnetic elements has a magnetic moment configured to be pointing away from the respective local external body surface, wherein the fourth magnetic element is proximate to the third magnetic element, wherein the fourth magnetic element is disposed opposite the second magnetic element relative to the third magnetic element, and wherein the first magnetic segment further comprises:

a layer of high-permeability material, wherein the layer of high-permeability material has a concave shape, wherein the four magnetic elements have respective first sides configured to be proximate the respective local external body surfaces, wherein the four magnetic elements have respective second sides opposite the respective first sides, and wherein the layer of high-permeability material is disposed on the respective second sides.

14. A method, comprising:

positioning a device comprising a magnetic assembly proximate to an external body surface that is proximate to a portion of subsurface vasculature, wherein the magnetic assembly comprises a plurality of magnetic segments, wherein the plurality of magnetic segments are arranged in a linear array, wherein the magnetic segments are separated from each other by respective specified distances, wherein each magnetic segment comprises two or more magnetic elements each having a respective magnetic moment, wherein a first magnetic segment of the plurality of magnetic segments is next to a second magnetic segment of the plurality of magnetic segments, and wherein the magnetic moments of respective first and second magnetic elements of the first magnetic segment are each oriented antiparallel to the magnetic moments of respective corresponding first and second magnetic elements of the second magnetic segment; and

exerting, by the magnetic assembly in the positioned device, a magnetic force on magnetic particles disposed in the portion of subsurface vasculature.

15. The method of claim 14, further comprising introducing the magnetic particles into the portion of subsurface vasculature.

16. The method of claim 14, wherein the magnetic particles are configured to bind to an analyte, wherein the device further comprises an energy emitter configured to emit energy into the portion of subsurface vasculature, wherein exerting a magnetic force onto the magnetic particles comprises exerting an attractive magnetic force, wherein the attractive magnetic force is sufficient to collect the magnetic particles in the portion of subsurface vasculature proximate to the magnetic assembly, and further comprising:

emitting energy into the portion of subsurface vasculature, wherein the energy emitted into the portion of subsurface vasculature is sufficient to modify one or more properties of the analyte bound to the magnetic particles that are disposed in the portion of subsurface vasculature.

17. The method of claim 14, wherein the magnetic particles are configured to bind to an analyte, wherein the analyte has a biological effect, wherein the analyte has a first rate of clearance, wherein the first rate of clearance is a rate of transport of the analyte out of the portion of subsurface vasculature when the device is not disposed on the external body surface proximate to the portion of subsurface vasculature, wherein exerting a magnetic force onto magnetic particles that are disposed in the portion of subsurface vasculature comprises exerting an attractive magnetic force, wherein the attractive magnetic force is sufficient to collect the magnetic particles in the portion of subsurface vasculature proximate to the magnetic assembly, wherein the analyte has a second rate of clearance, wherein the second rate of clearance is a rate of transport of the analyte out of the portion of subsurface vasculature when the device is disposed on the external body surface proximate to the portion of subsurface vasculature such that the magnetic assembly of the device exerts an attractive magnetic force on the magnetic particles sufficient to collect the magnetic particles in the portion of subsurface vasculature proximate to the magnetic assembly, and wherein the second rate of clearance is less than the first rate of clearance.

18. The method of claim 14, wherein the magnetic particles are configured to bind to an analyte, wherein the device further comprises a detector configured to detect one or more properties of the analyte bound to the magnetic particles that are disposed in the portion of subsurface vasculature, wherein exerting a magnetic force onto the magnetic particles comprises exerting an attractive magnetic force, wherein the attractive magnetic force is sufficient to collect the magnetic particles in the portion of subsurface vasculature proximate to the magnetic assembly, and further comprising:

detecting one or more properties of the analyte bound to the magnetic particles that are disposed in the portion of subsurface vasculature.