Systems and devices for detecting coronary artery disease using magnetic field maps

Abstract

A magnetic field, such as an electromagnetic field or a magnetocardiogram, associated with tissue of the individual, a portion of the individual's body, or the individual's entire body is sensed.SOLUTION: (a) identifying first negative and positive electromagnetic dipoles in a first electromagnetic field map associated with a heart of an individual at a first time, (b) identifying second negative and positive electromagnetic dipoles in a second electromagnetic field map associated with the heart of the individual at a second time, (c) determining a first angle based on the first negative and positive electromagnetic dipoles, and (d) determining a second angle based on the second negative and positive electromagnetic dipoles; And (e) determining the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on whether (i) the first angle differs from the second angle by at least 100 degrees or (ii) the third electromagnetic dipole is present in the first or second electromagnetic field map.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] cross reference

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 030,536, filed May 27, 2020, which is incorporated herein by reference in its entirety. [Background technology]

[0002]

[0002] Dynamic magnetic fields are associated with certain mammalian tissues, for example, tissues whose physiology is driven by action potentials. Changes in the structure or function of a particular tissue can be reflected in changes in the magnetic fields associated with and / or generated by that tissue. Summary of the Invention

[0003] Described herein are systems, devices, and methods for sensing magnetic fields, such as electromagnetic fields ("EMF") or magnetocardiograms ("MCG"), associated with tissue of an individual, a portion of an individual's body, and / or the entire body of an individual. Non-limiting examples of tissues with which magnetic fields may be associated and sensed using the systems, devices, and methods described herein include blood, bone, lymph, CSF, and organs, including the heart, lungs, liver, kidneys, and skin. In some embodiments, the devices and systems described herein sense magnetic field signals associated with a portion of an individual's body, such as the individual's torso, or magnetic fields associated with the entire body of an individual.

[0004] Described herein is a device for sensing magnetic field data associated with an individual, the device comprising: a mobile base unit; an arm having a proximal end and a distal end, the proximal end being movably coupled to the mobile base unit such that the arm moves with at least one degree of freedom relative to the mobile base unit; and an array of one or more optically excited magnetometers coupled to the distal end of the arm, the optically excited magnetometer array configured to sense magnetic fields associated with the individual. In some embodiments, the device comprises a shield configured to attenuate one or more magnetic fields associated with an environment. In some embodiments, the shield is configured to house a portion of the individual's body associated with the magnetic field data. In some embodiments, the portion of the individual's body associated with the magnetic field is the individual's chest. In some embodiments, the arm of the device or system comprises a joint configured to articulate the arm. In some embodiments, the optically excited magnetometer array is movably coupled to the distal end such that the optically excited magnetometer moves with at least one degree of freedom relative to the arm. In some embodiments, the optically excited magnetometer is part of an array. In some embodiments, the array is positioned to conform to a unique portion of the individual's body. In some embodiments, the device comprises a processor and a non-transitory computer-readable medium, the non-transitory computer-readable medium including a computer program configured to cause the processor to receive magnetic field data sensed by the optically excited magnetometer and filter the magnetic field data. In some embodiments, the device comprises a gradiometer, and the computer program causes the processor to filter the data by canceling out magnetic fields associated with the environment. In some embodiments, the computer program causes the processor to filter the data by subtracting a frequency-based measurement from the magnetic field data. In some embodiments, the computer program causes the processor to generate a visual representation of the magnetic field data including a waveform.

[0005] Also described herein is a method for sensing magnetic field data associated with an individual. The method includes positioning a mobile electromagnetic sensing device near an individual, positioning an arm of the mobile electromagnetic sensing device coupled to a base unit near an optically excited magnetometer that is near a portion of the individual's body associated with magnetic field data, and sensing the magnetic field data. In some embodiments, the method includes shielding at least a portion of the individual from a magnetic field associated with an environment. In some embodiments, the shield is configured to house the portion of the individual's body associated with the magnetic field data. In some embodiments, the portion of the individual's body associated with the magnetic field is the individual's chest. In some embodiments, the arm of the device or system comprises a joint configured to articulate the arm. In some embodiments, the optically excited magnetometer is movably coupled to the arm such that the optically excited magnetometer moves with at least one degree of freedom relative to the arm. In some embodiments, the optically excited magnetometer is part of an array. In some embodiments, the array is positioned to conform to a specific portion of the individual's body.

[0006] In some embodiments, the method includes generating a visual representation of the magnetic field data including a waveform. In some embodiments, the method includes generating a visual representation of the magnetic field data including two-dimensional cubic interpolation between two or more sensors in the magnetometer array for each timestamp of the recorded data. In some embodiments, the visual representation includes color values ​​associated with the magnetic field values ​​displayed in two-dimensional (2D) space. In some embodiments, playing the successive visual representations of the sensed magnetic field data includes a dynamic 2D animation summarizing the electromagnetic activity detected from the individual.

[0007]

[0007] Also described herein is a system for determining the possible presence of coronary artery disease in an individual, the system comprising: (1) a sensing device configured to sense a magnetic field associated with the individual, the sensing device comprising a movable base unit, an arm having a proximal end and a distal end, the proximal end coupled to the movable base unit by a first joint, the first joint configured to allow the arm to move with at least one degree of freedom relative to the movable base unit, and an array of one or more optically excited magnetometers coupled to the distal end of the arm, the array of one or more optically excited magnetometers configured to sense the magnetic field associated with the individual; and (2) a non-transitory computer-readable medium encoded with a computer program comprising instructions executable by a processor, the instructions causing the processor to receive from the sensing device a first magnetic field associated with the individual's heart at a first time, and generating a first electromagnetic field map based on a first magnetic field associated with the individual's heart at a second time from the sensing device, and identifying a first negative electromagnetic dipole and a first positive electromagnetic dipole in the first electromagnetic field map; receiving a second magnetic field associated with the individual's heart at a second time from the sensing device; generating a second electromagnetic field map based on the second magnetic field associated with the individual's heart at the second time, and identifying a second negative electromagnetic dipole and a second positive electromagnetic dipole in the second electromagnetic field map; and a non-transitory computer-readable medium configured to: determine a first angle based on the first negative electromagnetic dipole and the first positive electromagnetic dipole; determine a second angle based on the second negative electromagnetic dipole and the second positive electromagnetic dipole; and determine a probable presence of coronary artery disease in the individual if the first angle differs from the second angle by at least 100 degrees or if a third electromagnetic dipole is present in the first or second electromagnetic field map.

[0008] In some embodiments, the coronary artery disease comprises myocardial ischemia. In some embodiments, the coronary artery disease comprises myocardial ischemia associated with epicardial coronary artery disease. In some embodiments, the coronary artery disease comprises myocardial ischemia without epicardial coronary artery disease. In some embodiments, the sensing device comprises a shield configured to shield the device from one or more environmental magnetic fields. In some embodiments, the shield is configured to at least partially surround a portion of the individual's body associated with the magnetic field. In some embodiments, the portion of the individual's body associated with the magnetic field comprises at least one of the individual's chest. In some embodiments, the shield comprises two or more layers. In some embodiments, each of the two or more layers has a thickness of 0.1 to 10 millimeters. In some embodiments, the shield comprises permalloy or mu-metal. In some embodiments, the arm comprises a proximal segment and a distal segment, a second joint positioned between the proximal segment and the distal segment, and the distal segment configured to articulate relative to the proximal segment. In some embodiments, the one or more arrays of optically excited magnetometers are movably coupled to the distal end of the arm such that the one or more arrays of optically excited magnetometers move with at least one degree of freedom relative to the arm. In some embodiments, the one or more arrays of optically excited magnetometers comprise at least three optically excited magnetometers. In some embodiments, the one or more arrays of optically excited magnetometers are positioned to match a generalized contour of a portion of an individual's body.

[0009] In some embodiments, the computer program includes instructions configured to cause the processor to further filter the sensed magnetic field. In some embodiments, the system further comprises a gradiometer, and the computer program includes instructions configured to cause the processor to filter the sensed magnetic field by canceling out the magnetic field sensed by the gradiometer. In some embodiments, the computer program includes instructions configured to cause the processor to filter the sensed magnetic field by subtracting a frequency-based measurement from the magnetic field. In some embodiments, the computer program includes instructions configured to further cause the processor to generate a visual representation of the magnetic field including a waveform.

[0010]

[0010] In some embodiments, the computer program includes instructions configured to cause the processor to further determine the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on (iii) parameters selected from the group consisting of dipole parameters, integrated MCD parameters, integrated ECD parameters, mean PCD parameters, equal integral parameters, field map correlation parameters, R_peak pegged dipole parameters, pseudocurrent arrow parameters, extremal circle parameters, phase space embedded parameters using delta coordinates, and phase space embedded parameters using time delay coordinates, or (iv) visualizations selected from the group consisting of STAG plots, T_peak MFM plots, field map animations, pseudocurrent density arrows, MCD plots, and ECD plots.

[0011]

[0011] In some embodiments, the computer program includes instructions configured to cause the processor to further determine the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on the parameters.

[0012]

[0012] In some embodiments, the computer program includes instructions configured to cause the processor to further determine the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on the visualization.

[0013]

[0013] In some embodiments, the presence of coronary artery disease in an individual is determined based on the presence of at least one abnormality among: (i) whether the first angle differs from the second angle by at least 100 degrees; (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map; (iii) the parameters; and (iv) the visualization.

[0014] In some embodiments, the presence of coronary artery disease in the individual is determined based on (i) whether the first angle differs from the second angle by at least 100 degrees, (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map, and (iii) whether a parameter and (iv) the visualization is determined based on the presence of at least two abnormalities.

[0015]

[0015] Also described herein is a method for determining the possible presence of coronary artery disease in an individual, the method comprising the steps of positioning a mobile electromagnetic sensing device near the individual; positioning an arm of the mobile electromagnetic sensing device coupled to an array of one or more optically excited magnetometers near the individual's heart; receiving from the mobile electromagnetic sensing device a first magnetic field associated with the individual's heart at a first time; generating a first electromagnetic field map based on the first magnetic field associated with the individual's heart at the first time; identifying a first negative electromagnetic dipole and a first positive electromagnetic dipole in the first electromagnetic field map; and receiving from the mobile electromagnetic sensing device a first magnetic field associated with the individual's heart at a second time. The method includes receiving a second magnetic field associated with the person's heart; generating a second electromagnetic field map based on the second magnetic field associated with the individual's heart at a second time; identifying a second negative electromagnetic dipole and a second positive electromagnetic dipole in the second electromagnetic field map; determining a first angle based on the first negative electromagnetic dipole and the first positive electromagnetic dipole and a second angle based on the second negative electromagnetic dipole and the second positive electromagnetic dipole; and determining a possible presence of coronary artery disease in the individual if the first angle differs from the second angle by at least 100 degrees or if a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map.

[0016] In some embodiments, the coronary artery disease comprises myocardial ischemia. In some embodiments, the coronary artery disease comprises myocardial ischemia associated with epicardial coronary artery disease. In some embodiments, the coronary artery disease comprises myocardial ischemia without epicardial coronary artery disease. In some embodiments, the method further comprises shielding at least a portion of the individual from one or more environmental magnetic fields using a shield. In some embodiments, the shield is configured to at least partially surround a portion of the individual's body associated with the magnetic field. In some embodiments, the portion of the individual's body associated with the magnetic field is at least a portion of the individual's chest. In some embodiments, the shield comprises two or more layers. In some embodiments, each of the two or more layers has a thickness of 0.1 to 10 millimeters. In some embodiments, the shield comprises permalloy or mu-metal. In some embodiments, the arm includes a proximal segment and a distal segment, a second joint positioned between the proximal segment and the distal segment, and the distal segment configured to articulate relative to the proximal segment. In some embodiments, the array of one or more optically excited magnetometers is movably coupled to a distal end of the arm such that the array of one or more optically excited magnetometers moves with at least one degree of freedom relative to the arm. In some embodiments, the array of one or more optically excited magnetometers comprises at least three optically excited magnetometers. In some embodiments, the array of one or more optically excited magnetometers is positioned to match a generalized contour of a portion of the individual's body.

[0017] In some embodiments, the method further includes filtering the first magnetic field and / or the second magnetic field. In some embodiments, the filtering includes canceling out the magnetic field sensed by the gradiometer. In some embodiments, the filtering includes subtracting a frequency-based measurement from the first magnetic field and / or the second magnetic field.

[0018] In some embodiments, the method further comprises: (iii) embedding a parameter selected from the group consisting of a dipole parameter, an integrated MCD parameter, an integrated ECD parameter, an average PCD parameter, an isointegral parameter, a field map correlation parameter, an R_peak pegged dipole parameter, a pseudocurrent arrow parameter, an extremum circle parameter, a phase space embedding parameter using delta coordinates, and a phase space embedding parameter using time delay coordinates. or (iv) determining the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on a visualization selected from the group consisting of a STAG plot, a T_peak MFM plot, a field map animation, a pseudo current density arrow, an MCD plot, and an ECD plot.

[0019] In some embodiments, the method further comprises determining the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on the parameter.

[0020] In some embodiments, the method further includes determining the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on the visualization.

[0021]

[0021] In some embodiments, the method further includes determining the presence of coronary artery disease in the individual based on the presence of at least one abnormality from among (i) whether the first angle differs from the second angle by at least 100 degrees, (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map, (iii) the parameters, and (iv) the visualization.

[0022]

[0022] In some embodiments, the method further includes determining the presence of coronary artery disease in the individual based on the presence of at least two abnormalities from among: (i) whether the first angle differs from the second angle by at least 100 degrees; (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map; (iii) the parameters; and (iv) the visualization.

[0023]

[0023] Also described herein is a method for determining the possible presence of coronary artery disease in an individual, the method including the steps of identifying a first negative electromagnetic dipole and a first positive electromagnetic dipole in a first electromagnetic field map associated with the individual's heart at a first time, identifying a second negative electromagnetic dipole and a second positive electromagnetic dipole in a second electromagnetic field map associated with the individual's heart at a second time, determining a first angle based on the first negative electromagnetic dipole and the first positive electromagnetic dipole, determining a second angle based on the second negative electromagnetic dipole and the second positive electromagnetic dipole, and determining that there is a possible presence of coronary artery disease in the individual if the first angle differs from the second angle by at least 100 degrees or if a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map.

[0024] In some embodiments, the coronary artery disease comprises myocardial ischemia. In some embodiments, the coronary artery disease comprises myocardial ischemia associated with epicardial coronary artery disease. In some embodiments, the coronary artery disease comprises myocardial ischemia without epicardial coronary artery disease. In some embodiments, the method further comprises recording an electrocardiogram of the individual. In some embodiments, the first angle comprises a peak R depolarization angle at a first time, the first time being the time at which an R wave is recorded on the electrocardiogram. In some embodiments, the second angle comprises a peak T repolarization angle at a second time, the second time being the time at which a T wave is recorded on the electrocardiogram. In some embodiments, the third electromagnetic dipole is present in the second electromagnetic field map. In some embodiments, the coronary artery disease comprises an occlusion of the left anterior descending artery. In some embodiments, the first angle is determined by determining a first line passing through both the first negative electromagnetic dipole and the first positive electromagnetic dipole and determining the angle between the first line and a horizontal axis. In some embodiments, the second angle is determined by determining a second line passing through both the second negative electromagnetic dipole and the second positive electromagnetic dipole and determining the angle between the second line and a horizontal axis. In some embodiments, a coronary artery in the individual is determined. The possible presence of arterial disease is determined when the first angle differs from the second angle by between 100 degrees and 170 degrees.

[0025] In some embodiments, the individual has a normal electrocardiogram while experiencing chest pain, or a normal troponin level while experiencing chest pain. In some embodiments, the individual has a positive stress test or an abnormal echocardiogram. In some embodiments, the method further includes performing a stress test if the first angle is different from the second angle or if a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map. In some embodiments, the method further includes sensing a first electromagnetic field associated with the individual's heart at a first time and sensing a second electromagnetic field associated with the individual's heart at a second time, wherein the first electromagnetic field map includes a representation of the first electromagnetic field and the second electromagnetic field map includes a representation of the second electromagnetic field. In some embodiments, the method further includes determining the likelihood of the presence of a conduction abnormality in the individual's heart if the first positive electromagnetic dipole and the second negative electromagnetic dipole have the same location, or if the first negative electromagnetic dipole and the second positive electromagnetic dipole have the same location. In some embodiments, the method further includes administering a treatment for coronary artery disease to the individual in response to determining the likelihood of the presence of coronary artery disease (e.g., a pathophysiology that induces ischemia) in the individual. In some embodiments, the treatment includes a daily prescription of aspirin or ibuprofen. In some embodiments, the treatment includes blood pressure lowering agent administration. In some embodiments, the treatment includes lipid lowering agent administration. In some embodiments, the treatment includes cardiac catheterization. In some embodiments, the treatment includes surgical intervention. In some embodiments, the method further includes performing (a)-(e) by a computer.

[0026]

[0026] In some embodiments, the method further includes determining the presence, absence, or possibility of coronary artery disease in the individual based at least in part on (iii) parameters selected from the group consisting of dipole parameters, integrated MCD parameters, integrated ECD parameters, mean PCD parameters, equal integral parameters, field map correlation parameters, R_peak pegged dipole parameters, pseudocurrent arrow parameters, extremal circle parameters, phase space embedded parameters using delta coordinates, and phase space embedded parameters using time delay coordinates, or (iv) visualization selected from the group consisting of STAG plots, T_peak MFM plots, field map animations, pseudocurrent density arrows, MCD plots, and ECD plots.

[0027] In some embodiments, the method further comprises determining the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on the parameter.

[0028]

[0028] In some embodiments, the method further includes determining the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on the visualization.

[0029]

[0029] In some embodiments, the method further includes determining the presence of coronary artery disease in the individual based on the presence of at least one abnormality from among (i) whether the first angle differs from the second angle by at least 100 degrees, (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map, (iii) the parameters, and (iv) the visualization.

[0030] In some embodiments, the method further comprises determining whether (i) the first angle differs from the second angle by at least 100 degrees; (ii) whether the first electromagnetic field map or the second electromagnetic field map is greater than or equal to 100 degrees; determining the presence of coronary artery disease in the individual based on the presence of at least two abnormalities from (iii) the parameters, and (iv) the visualization; whether a third electromagnetic dipole is present within the parameter; and

[0031]

[0031] Also described herein is a non-transitory computer-readable medium including machine-executable code that, when executed by one or more computer processors, implements a method for determining the likelihood of the presence of coronary artery disease in an individual, the method including the steps of identifying a first negative electromagnetic dipole and a first positive electromagnetic dipole in a first electromagnetic field map associated with the individual's heart at a first time; identifying a second negative electromagnetic dipole and a second positive electromagnetic dipole in a second electromagnetic field map associated with the individual's heart at a second time; determining a first angle based on the first negative electromagnetic dipole and the first positive electromagnetic dipole; determining a second angle based on the second negative electromagnetic dipole and the second positive electromagnetic dipole; and determining that there is a likelihood of coronary artery disease in the individual if the first angle differs from the second angle by at least 100 degrees or if a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map.

[0032] In some embodiments, the coronary artery disease comprises myocardial ischemia. In some embodiments, the coronary artery disease comprises myocardial ischemia associated with epicardial coronary artery disease. In some embodiments, the coronary artery disease comprises myocardial ischemia without epicardial coronary artery disease.

[0033]

[0033] This specification also describes a non-transitory computer-readable medium containing machine-executable code that, when executed by one or more computer processors, implements any of the methods described above or elsewhere in this specification.

[0034] Also described herein is a system comprising one or more computer processors and a computer memory coupled to the one or more computer processors, the computer memory including machine-executable code that, when executed by the one or more computer processors, implements any of the methods described above or elsewhere herein.

[0035]

[0035] Additional aspects and advantages of the present disclosure will become readily apparent to those skilled in the art from the following detailed description, in which only exemplary embodiments of the present disclosure are shown and described. As will be understood, the present disclosure is capable of other and different embodiments, and its several details are capable of modification in various obvious respects, all without departing from the present disclosure. Accordingly, the drawings and description should be regarded as illustrative in nature, and not as restrictive. Incorporation by Reference

[0036] All publications, patents, and patent applications mentioned herein are incorporated by reference herein to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. In the event that the publications and patents or patent applications incorporated by reference conflict with the disclosure contained herein, the present specification is intended to supersede and / or take precedence over any such conflicting material.

[0036]

[0037] The present patent application file contains at least one drawing executed in color. Copies of this patent application publication with color drawing(s) will be provided by the Patent and Trademark Office upon request and payment of the necessary fee.

[0037]

[0038] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings (as defined herein). See also "figure" and "FIG." [Brief explanation of the drawings]

[0038] [Figure 1]

[0039] FIG. 2 illustrates an example of a sensor array, a shield, and a base unit. [Figure 2]

[0040] FIG. 10 is a diagram illustrating an example of a shield. [Figure 3]

[0041] FIG. 10 illustrates an example of a shield and a base unit. [Figure 4]

[0042] FIG. 1 illustrates an example of a sensor array operably coupled to a base unit. [Figure 5]

[0043] FIG. 1 illustrates an example of a sensor array operably coupled to an arm. [Figure 6]

[0044] FIG. 1 illustrates an example of a sensor array operably coupled to a base unit. [Figure 7]

[0045] FIG. 1 illustrates an example of a sensor array operably coupled to an arm of a base unit. [Figure 8]

[0046] FIG. 1 illustrates a computer system programmed or otherwise configured to implement the methods provided herein. [Figure 9A]

[0047] 9A and 9B show an example of a shield, with the shield in Fig. 9A positioned to show the open end and interior volume of the shield. [Figure 9B] 9A and 9B show an example of a shield, the shield in Fig. 9A being positioned to show the closed end of the shield having a tapered or conical shape. [Figure 10A]

[0048] 1A and 1B show two different cross-sectional views of a shield. [Figure 10B] 1A and 1B show two different cross-sectional views of a shield. [Figure 11A]

[0049] FIG. 10 is a diagram illustrating an example of a shield. [Figure 11B]FIG. 10 is a diagram illustrating an example of a shield. [Figure 11C] FIG. 10 is a diagram illustrating an example of a shield. [Figure 11D] FIG. 10 is a diagram illustrating an example of a shield. [Figure 11E] FIG. 10 is a diagram illustrating an example of a shield. [Figure 11F] FIG. 10 is a diagram illustrating an example of a shield. [Figure 11G] FIG. 10 is a diagram illustrating an example of a shield. [Figure 11H] FIG. 10 is a diagram illustrating an example of a shield. [Figure 11I] FIG. 10 is a diagram illustrating an example of a shield. [Figure 12A]

[0050] FIG. 10 illustrates an example of an external support for a shield. [Figure 12B] FIG. 10 illustrates an example of an external support for a shield. [Figure 13]

[0051] FIG. 10 is a diagram illustrating an example of a hook. [Figure 14A]

[0052] FIG. 1 illustrates a mobile cart device. [Figure 14B] FIG. 1 illustrates a mobile cart device. [Figure 15A]

[0053] FIG. 1 illustrates a mobile cart device. [Figure 15B] FIG. 1 illustrates a mobile cart device. [Figure 15C] FIG. 1 illustrates a mobile cart device. [Figure 16]

[0054] FIG. 1 illustrates an example of a device in use in a magnetically shielded environment. [Figure 17]

[0055] FIG. 10 shows an example of an individual sliding into a shield. [Figure 18]

[0056] FIG. 1 illustrates an example of an embodiment of a shield comprising three mu metal layers (the three innermost layers) and one aluminum alloy layer (the outer layer). [Figure 19]

[0057] FIG. 10 shows a plot of magnetic field measurements along the centerline of the shield. [Figure 20]

[0058] FIG. 1 is a diagram illustrating an example of a sensor array. [Figure 21]

[0059] FIG. 10 shows an example of a 3D rendering of a sensor head cage attached to the bed of a shield. [Figure 22]

[0060] FIG. 10 illustrates an exemplary layout of one inner coil positioned on one embodiment of a shield. [Figure 23]

[0061] 1A and 1B illustrate an exemplary layout of an outer coil positioned on one embodiment of a shield. [Figure 24]

[0062] FIG. 1 illustrates a typical balance function. [Figure 25]

[0063] FIG. 1 illustrates an exemplary method for assessing the presence of coronary artery disease (e.g., myocardial ischemia with or without associated epicardial coronary artery disease) in an individual. [Figure 26A]

[0064] 26A shows an example of how the methods and systems of the present disclosure can be used to analyze electrical currents in an organ or tissue of interest (e.g., the heart) and determine its associated magnetic field, including a depiction of Ampere's Law (FIG. 26A), as well as an example of a magnetic field map generated from the electrical currents (FIG. 26B). [Figure 26B] 26A shows an example of how the methods and systems of the present disclosure can be used to analyze electrical currents in an organ or tissue of interest (e.g., the heart) and determine its associated magnetic field, including a depiction of Ampere's Law (FIG. 26A), as well as an example of a magnetic field map generated from the electrical currents (FIG. 26B). [Figure 27A]

[0065] 27A and 27B show an example of how the methods and systems of the present disclosure can be used to analyze electrical currents in a target organ or tissue (e.g., the heart) and determine its associated magnetic field, including a depiction of peak R depolarization angle 2702 (FIG. 27A) and a depiction of peak T repolarization angle 2704 (FIG. 27B), where an increase in the RT angle gap indicates cardiac ischemia in the target heart. [Figure 27B] 27A and 27B show an example of how the methods and systems of the present disclosure can be used to analyze electrical currents in a target organ or tissue (e.g., the heart) and determine its associated magnetic field, including a depiction of peak R depolarization angle 2702 (FIG. 27A) and a depiction of peak T repolarization angle 2704 (FIG. 27B), where an increase in the RT angle gap indicates cardiac ischemia in the target heart. [Figure 28]

[0066] A diagram showing how the heart generates electricity, including (1) a depolarizing ion flow (non-energy dependent) in which sodium slows entering the cell and potassium leaves the cell, (2) a large amount of calcium enters the cell, (3) calcium stops entering the cell and potassium leaves the cell, and (4) a repolarizing ion flow (highly energy dependent) in which the balance of ions inside and outside the cell is restored (repolarized), and heart attack / ischemic cells in which damaged cells become stuck (depolarized) in section 3 and are unable to contract. [Figure 29]

[0067] FIG. 1 shows a "Wiggers Diagram" depicting the cardiac cycle, showing ventricular volumes, ventricular pressures, aortic pressures, and atrial pressures, demonstrating that electrical generation precedes mechanical function of the heart. [Figure 30]

[0068] FIG. 1 illustrates an example of an assessment of patient inspiration using the systems, devices, and methods of the present disclosure, including a stress-tested patient, an MCG-negative or MCG-positive patient, an ST-negative or ST-positive patient, and a CA-positive or CA-negative patient. [Figure 31]

[0069] FIG. 1 illustrates an example workflow for chest pain triage according to clinical standards of care. [Figure 32]

[0070] FIG. 1 illustrates an example of an improved workflow for chest pain triage in accordance with the systems, devices, and methods of the present disclosure. [Figure 33]

[0071] Figure 1 shows an example of output data obtained using the disclosed method and system presented to a physician for interpretation as a set of 36 superimposed waveforms of magnetic field strength versus time for a single cardiac cycle. Each individual waveform represents the magnetic field magnitude normal to the chest wall measured a few centimeters (inches) above the torso. The system acquires data from 36 sensors arranged in a uniform 6x6 grid, so each dark circle shown in the map below represents a "true data point" and is color-coded to represent the magnetic field direction and strength. All information represented by the "sea of ​​color" in the magnetic field map (MFM) outside the 36 grid points is interpolated using data from these grid points. [Figure 34]

[0072] FIG. 1 illustrates an example of output data obtained using the disclosed method and system after drawing a waveform pattern that resembles a conventional form of voltage presentation of an electrocardiogram (ECG). [Figure 35A]

[0073] FIG. 10 shows an example of an R-peak magnetic field map of a subject that is interpreted as having a normal (e.g., non-ischemic) result and has consistent vectors between the positive and negative electromagnetic dipoles during the R-peak compared to the T-peak. [Figure 35B] FIG. 10 shows an example of a T-peak magnetic field map of a subject that is interpreted as having a normal (e.g., non-ischemic) result, with consistent vectors between the positive and negative electromagnetic dipoles during the R-peak compared to the T-peak. [Figure 36A]

[0074] FIG. 10 shows an example of an R-peak magnetic field map of a subject that is interpreted as having a normal (e.g., non-ischemic) result and shows a 180 degree reversal of the vectors between the positive and negative electromagnetic dipoles during the R-peak compared to the T-peak. [Figure 36B]FIG. 10 shows an example of a T-peak magnetic field map of a subject that is interpreted as having a normal (e.g., non-ischemic) result and shows a 180 degree reversal of the vectors between the positive and negative electromagnetic dipoles during the R-peak compared to the T-peak. [Figure 37A]

[0075] A figure showing an example of an R-peak magnetic field map of a subject that is interpreted as having an abnormal (e.g., ischemic) result and in which there are multiple electromagnetic dipoles completely surrounding a positive electromagnetic dipole in the T-peak magnetic field map. [Figure 37B] FIG. 10 shows an example of a T-peak magnetic field map of a subject that is interpreted as having an abnormal (e.g., ischemic) result and in which there are multiple electromagnetic dipoles completely surrounding a positive electromagnetic dipole in the T-peak magnetic field map. [Figure 38A]

[0076] FIG. 10 shows an example of an R-peak magnetic field map of a subject that is interpreted as having an abnormal (e.g., ischemic) result and shows electromagnetic dipole movement where the vector between the positive and negative electromagnetic dipoles during the R-peak compared to the T-peak exceeds 100 degrees. [Figure 38B] FIG. 10 shows an example of a T-peak magnetic field map of a subject that is interpreted as having an abnormal (e.g., ischemic) result and shows electromagnetic dipole movement where the vector between the positive and negative electromagnetic dipoles during the R-peak compared to the T-peak exceeds 100 degrees. DETAILED DESCRIPTION OF THE INVENTION

[0039]

[0077] While various embodiments are shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. It will be understood that various alternatives to the embodiments herein may also be employed.

[0040]

[0078] As used herein, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Any reference herein to "or" is intended to include "and / or" unless specifically stated otherwise.

[0041]

[0079] As used herein, the term "about" is intended to mean from a referenced numerical indication plus or minus 15% of the referenced numerical indication.

[0080] Device and system for sensing magnetic fields

[0081] Described herein are devices and systems configured to sense magnetic fields associated with one or more tissues, one or more body parts, one or more organs, or the entire body of an individual. Non-limiting examples of organs and organ systems having magnetic fields sensed by the devices and systems described herein include the brain, heart, lungs, kidneys, liver, spleen, pancreas, esophagus, stomach, small intestine, and colon, the endocrine system, respiratory system, cardiovascular system, genitourinary system, nervous system, vascular system, lymphatic system, and digestive system. Non-limiting examples of tissues having magnetic fields sensed by the devices and systems described herein include inflamed tissue (including areas of inflamed tissue), blood vessels and the blood flowing therein, lymphatic vessels and the lymph flowing therein, bone, and cartilage. The sensed magnetic field data is further processed to determine, or to assist a user (e.g., a healthcare provider) in determining, the condition of one or more tissues, one or more body parts, one or more organs, or the entire body of an individual associated with the sensed magnetic field. For example, in some embodiments, the devices described herein may be used to detect, for example, The devices described herein are used to determine a prognosis for an individual, such as predicting the likelihood that the individual will exhibit a disease or condition, based on one or more magnetic fields sensed using the device. For example, in some embodiments, the devices described herein are used to determine a diagnosis, such as confirming or providing a diagnosis to an individual regarding a disease or condition, based on one or more magnetic fields sensed using the device. For example, in some embodiments, the devices described herein are used to provide monitoring, such as monitoring the progression of a disease or condition in an individual, monitoring the effectiveness of a treatment provided to the individual, or a combination thereof, based on one or more magnetic fields sensed using the device. It should be understood that the devices and systems described herein are suitable for measuring magnetic fields associated with any type of tissue.

[0042]

[0082] In some embodiments of the devices and systems described herein, sensed magnetic field data associated with the heart is used to generate a magnetocardiogram. In these embodiments of the devices and systems described herein, the devices and systems are utilized, for example, as magnetocardiographs, which are passive, non-invasive bioelectrical measurement tools intended to detect, record, and display magnetic fields naturally generated by the electrical activity of the heart.

[0043]

[0083] In some embodiments, the devices or systems described herein are configured to measure one or more biomarkers in addition to the magnetic field. Non-limiting examples of biomarkers that may be sensed in addition to the magnetic field using embodiments of the devices and systems described herein include body temperature, heart rate, blood pressure, an echocardiogram (ECG), a magnetic field, or any combination thereof.

[0044]

[0084] In some embodiments, the individual to whom the magnetic field is sensed is healthy. In some embodiments, the individual to whom the magnetic field is sensed is an individual suspected of having a condition or disease. In some embodiments, the individual to whom the magnetic field is sensed is an individual who has previously been diagnosed with a condition or disease.

[0045]

[0085] In some embodiments, the condition or disease identified in the individual is a cardiac condition or disease, hi some embodiments, the cardiac condition or disease identified in the individual comprises rheumatic heart disease, hypertensive heart disease, ischemic heart disease, cerebrovascular disease, inflammatory heart disease, valvular heart disease, aneurysm, stroke, atherosclerosis, arrhythmia, hypertension, angina pectoris, coronary artery disease, coronary heart disease, increased demand ischemia, heart attack, cardiomyopathy, pericardial disease, congenital heart disease, heart failure, or any combination thereof.

[0046]

[0086] In some embodiments, the devices described herein include one or more sensors. In some embodiments, two or more sensors are arranged in a sensor array. In some embodiments, the devices described herein include an electromagnetic shield, and some embodiments of the devices described herein do not include a shield.

[0047]

[0087] In some embodiments, the systems described herein comprise any of the devices described herein and one or more local and / or remote processors. Sensor and sensor array for sensing magnetic fields

[0088] In some embodiments of the devices and systems described herein, the devices include a sensor such as an optically excited magnetometer (OPM) as a measurement tool, and in some embodiments, such a sensor utilizes a non-radioactive, stand-alone alkali metal cell coupled to a closed excitation laser and photodetector setup to measure small magnetic fields. In some embodiments of the devices and systems described herein, the devices and The system utilizes an n×n array (or grid) or alternative geometric configuration of OPMs to collect magnetic field data at n distinct locations across a portion of an individual's body, such as the chest area, and in some embodiments, such data is digitized using pickup electronics.

[0048]

[0089] OPMs are typically configured to utilize a non-radioactive, free-standing alkali-metal cell coupled to a closed excitation laser and photodetector setup to measure small magnetic fields. Compared to superconducting quantum interference devices (SQUIDs), which are also typically used to detect these biomagnetic fields, OPM sensors are significantly smaller and typically do not require the use of cryogenic cooling.

[0049]

[0090] The Earth's magnetic field is naturally present everywhere on Earth, with an amplitude of approximately 50 microtesla. OPM performance is enhanced in the presence of Earth's ambient magnetic field in at least two exemplary ways. In a first OPM enhancement technique, a reference value representing the Earth's magnetic field is used as part of vector subtraction to isolate signals of interest within the OPM. Another technique involves the use of a gradiometer for active noise cancellation for the OPM.

[0050]

[0091] The sensor array configuration utilized in some embodiments of the devices and systems described herein includes a custom array configuration. In some embodiments, the sensor array configuration is customized to an individual's anatomy. In some embodiments, the sensor array configuration is customized to an individual's location to be measured, such as a chest location or a head location. In some embodiments, the sensor array configuration is customized to the type of measurement the device is programmed to acquire. In some embodiments, the sensor array configuration is customized to be operably coupled to a shield and / or arm. In some embodiments, the sensor array configuration is interchangeable with different array configurations that a user can alternate between. In some embodiments, the array configuration includes an arc (e.g., a generally curved shape), has a depth, and includes a radius of about 20 cm to about 50 cm or about 10 cm to about 60 cm. In some embodiments, an array configuration, such as an arc configuration, includes one or more variable inter-magnetometer distances and variable sensor densities. In some embodiments, the array configuration includes a concave structure (e.g., a concave structure configured to wrap or form around a body region, such as the head or chest). One or more magnetometers are positioned on at least a portion of the surface of the concave structure. In some embodiments, the concave array configuration includes one or more variable inter-magnetometer distances and variable sensor densities.

[0051]

[0092] In some embodiments, the sensor array is nxn sensors. In some embodiments, the sensor array is a 2D rectangular array, such as a 2x2 array or a 4x4 array. In some embodiments, the sensor array is a 2D non-rectangular array, such as a 2x1 array or a 4x1 array. In some embodiments, the sensor array is a circular or semicircular array, such as a 3D array of sensors positioned in an arc or concave structure. In some embodiments, the sensor array is a 2D or 3D array. In some embodiments, the sensors of the sensor array have x, y, and z coordinates. In some embodiments, the array comprises a single sensor, such as nxn = 1x1. In some embodiments, the array comprises two sensors, such as nxn = 2x1. In some embodiments, the array comprises three sensors. In some embodiments, the array comprises four sensors. In some embodiments, the array comprises nine sensors. In some embodiments, the array comprises 16 sensors. In some embodiments, the array comprises 25 sensors. In some embodiments, the array comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, The sensor array may comprise 45, 46, 47, 48, 49, 50, or more sensors. In some embodiments, the sensor array comprises 8 sensors. In some embodiments, the sensor array comprises 16 sensors. In some embodiments, the sensor array comprises a single sensor housed within a single housing. In some embodiments, the sensor array comprises multiple sensors housed within a single housing, such as a housing with multiple or variable sensor configurations. In some embodiments, the sensor array comprises multiple sensors housed within multiple housings. In some embodiments, the sensor array comprises multiple sensors, each housed within a separate housing. In some embodiments, the first sensor and the second sensor of the sensor array are different. In some embodiments, the first sensor and the second sensor of the sensor array are the same. In some embodiments, each sensor of the sensor array is unique. In some embodiments, each sensor of the sensor array is identical. In some embodiments, some of the sensors in the sensor array are unique. In some embodiments, some of the sensors in the sensor array are identical. The spatial positioning of the sensors in the sensor array may be adjustable, such as by a user, or automated by a controller. In some embodiments, the spatial positioning of the sensors in the sensor array is fixed. In some embodiments, the number of sensors in the sensor array is selected based on the application. In some embodiments, the number of sensors in the sensor array is selected based on the type of measurement or the location of the measurement. In some embodiments, the array comprises a single channel array or a multi-channel array. In some embodiments, increasing the number of sensors in the sensor array increases the resolution of the measurements obtained by the array. In some embodiments, the sensor arrays of sensors are densely packed, such as substantially adjacent or proximate to one another. The arrays of sensors are sparsely spaced, such as with spaces between them. In some embodiments, some of the sensors in the sensor array are densely packed. In some embodiments, some of the sensors in the sensor array are sparsely spaced or densely spaced.In some embodiments, the center points of any two sensors in a densely packed portion of sensors are spaced less than about 5, 4.5, 4, 3.5, 3, 2.5, 2, 1.5, 1, 0.5, or 0.1 centimeters (cm) apart. In some embodiments, the center points of densely packed sensors are spaced about 0.1 cm to about 2.0 cm, or about 0.1 cm to about 1.5 cm, or about 1.0 cm to about 2.0 cm apart. In some embodiments, the center points of any two sensors in a sparsely packed portion of sensors are spaced more than about 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 8, or 10 cm apart. In some embodiments, the center points of sparsely packed sensors are spaced about 1.5 cm to about 3 cm, or about 2 cm to about 5 cm, or about 2.5 cm to about 8 cm apart. In some embodiments, the center point is the location of the center of the sensor, such as a central axis. In some embodiments, the center point of the circular sensor is the center point to which all other edge points are equidistant.

[0052]

[0093] In some embodiments, a densely packed array exhibits an inter-magnetometer spacing of less than 1.5 cm, and a magnetometer spacing of greater than about 1.5 cm constitutes a sparsely packed array.

[0053]

[0094] In some embodiments, the housing is configured to house a sensor or a sensor array of sensors. In some embodiments, the housing is configured to house a single configuration of sensor spacing within the housing. In some embodiments, the housing is configured to house multiple configurations of sensor spacing within the housing. In some embodiments, the housing accommodates (i) adjustments to sensor spacing, such as dense or sparse spacing, or (ii) changes to the number of sensors in the array. In some embodiments, the housing is a common housing for multiple arrays and array configurations.

[0054]

[0095] In some embodiments, the sensor is configured to sense the presence of a magnetic field or measure a parameter of the magnetic field. In some embodiments, the sensor comprises a sensitivity to the magnetic field of about 10 femtotesla per root Hertz (fT / √Hz). In some embodiments, the sensor comprises a sensitivity of about 1 fT / √Hz to about 20 fT / √Hz. In some embodiments, the sensor comprises a sensitivity of about 5 fT / √Hz to about 15 fT / √Hz. In some embodiments, the sensor comprises a sensitivity of about 0.1 fT / √Hz to about 30 fT / √Hz. In some embodiments, the sensor comprises a sensitivity of about 0.5 fT / √Hz to about 12 fT / √Hz. In some embodiments, the sensor comprises a sensitivity of about 1 fT / √Hz to about 15 fT / √Hz. In some embodiments, the sensor comprises a sensitivity of about 0.001, 0.005, 0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 fT / √Hz.

[0055]

[0096] In some embodiments, the sensor does not require a cooling element, such as cryogenic cooling, to collect measurements. In some embodiments, the sensor collects measurements over a temperature range of about -30 degrees Fahrenheit (-1.111°C) to about 110 degrees Fahrenheit (43.33°C). In some embodiments, the sensor collects measurements over a temperature range of about 50 degrees Fahrenheit (10°C) to about 110 degrees Fahrenheit (43.33°C). In some embodiments, the sensor collects measurements over a period of about 1 second to about 5 hours without the need for a cooling element. In some embodiments, the sensor collects measurements over a period of about 1 second to about 1 hour without the need for a cooling element. In some embodiments, the sensor collects measurements over a period of about 1 second to about 30 minutes without the need for a cooling element.

[0056]

[0097] In some embodiments, the noise source comprises a magnetic field strength. In some embodiments, the strength of the magnetic field of the noise source is measured in units of Tesla (T). In some embodiments, the noise, such as ambient noise, comprises a magnetic field strength of less than about 100 nanotesla (nT). In some embodiments, the noise comprises a magnetic field strength of less than about 1000 nT. In some embodiments, the noise comprises a magnetic field strength of less than about 500 nT. In some embodiments, the noise comprises a magnetic field strength of less than about 200 nT. In some embodiments, the noise comprises a magnetic field strength of less than about 120 nT. In some embodiments, the noise comprises a magnetic field strength of less than about 80 nT. In some embodiments, the noise source, such as the Earth's magnetic field, comprises a magnetic field strength of about 50 microtesla (mT). In some embodiments, the noise comprises a magnetic field strength of between about 40 mT and about 60 mT. In some embodiments, the noise comprises a magnetic field strength of between about 10 mT and about 100 mT. In some embodiments, the noise includes amplitude components, frequency components, or a combination thereof, and in some embodiments includes both noise sources, direct current (DC), alternating current (AC), or a combination of the two. Electromagnetic shielding

[0098] Some embodiments of the devices and systems described herein are configured to provide electromagnetic shielding to reduce or eliminate the Earth's ambient magnetic field. In some embodiments, the shields described herein include a metal alloy (e.g., permalloy or mu-metal) that, when annealed in a hydrogen furnace, provides very high magnetic permeability, thereby isolating the area protected by the shield (e.g., within the shield in the shape of a chamber) from the Earth's magnetic field.

[0057]

[0099] The chambers or shields described herein minimize internal magnetic fields and, in some embodiments, are constructed to have one closed end and one open end, hi some embodiments, the closed end takes the form of a flat, conical, or dome-shaped end cap.

[0058]

[0100] In some embodiments, utilizing a shield in conjunction with a sensor, such as a sensor array, provides noise reduction so that the sensor collects measurements that are substantially noise-free or have significantly reduced noise. The noise includes noise from a noise source. In some embodiments, the noise source includes high-frequency noise, such as above about 20 Hz, mid-frequency noise, such as between about 1 Hz and about 20 Hz, low-frequency noise, such as between about 0.1 Hz and about 1 Hz, or any combination thereof. In some embodiments, the noise source includes any structure containing metal. In some embodiments, the metal-containing structure includes a metal implant, such as a pacemaker, defibrillator, orthopedic implant, or dental implant. In some embodiments, the metal-containing structure includes a metal tool, a metal door, a metal chair, or the like. In some embodiments, the noise source includes the operation of a device, such as a fan, an air conditioner, or clinical equipment, or building vibration. In some embodiments, the noise source includes the operation of a power source or an electronic device, such as a monitor or a computer with a graphical user interface.

[0059]

[0101] In some embodiments, the shield or portion thereof comprises a single layer of material. In some embodiments, the shield or portion thereof comprises multiple layers of one material. In some embodiments, the shield or portion thereof comprises multiple layers, at least two of the multiple layers comprising different materials. In some embodiments, the shield or portion thereof comprises two layers. In some embodiments, the shield or portion thereof comprises three layers. In some embodiments, the shield or portion thereof comprises four layers. In some embodiments, the shield or portion thereof comprises five layers. In some embodiments, the shield or portion thereof comprises six layers.

[0060]

[0102] In some embodiments, the layer of the shield, or portion thereof, comprises a thickness of about 0.1 to about 10 millimeters. In some embodiments, the layer of the shield has a thickness of about 0.5 to about 5 millimeters. In some embodiments, the layer of the shield has a thickness of about 0.1 to about 2 millimeters. In some embodiments, the layer of the shield has a thickness of about 0.8 to about 5 millimeters. The thickness is substantially the same along the length or circumference of the shield. In some embodiments, the thickness of the layer of the shield varies along the length or circumference of the shield.

[0061]

[0103] In some embodiments, the shield comprises multiple layers. In some embodiments, a space exists between at least two of the multiple layers. In some embodiments, a space exists between each of the multiple layers. In some embodiments, a space exists between some of the multiple layers. In some embodiments, a first layer of the shield is configured to be adjacent to a second layer of the shield. In some embodiments, the first layer of the shield is configured to be attached or bonded to the second layer of the shield. In some embodiments, the first layer of the shield is configured to be positioned about 0.1 inches to about 5 inches from the second layer. In some embodiments, the first layer of the shield is configured to be positioned about 1 inch to about 3 inches from the second layer. In some embodiments, the first layer of the shield is configured to be positioned about 1 inch to about 20 inches from the second layer. In some embodiments, the first layer of the shield is configured to be positioned between about 1 inch and about 10 inches from the second layer.

[0062]

[0104] In some embodiments, the length of the shield, such as the inner length or outer length, is about 2 times the inner diameter of the shield. In some embodiments, the length of the shield is about 0.5 to about 3 times the inner diameter of the shield. In some embodiments, the length of the shield is about 1 to about 3 times the inner diameter of the shield. In some embodiments, the length of the shield is about 1.5 to about 3 times the inner diameter of the shield.

[0063]

[0105] In some embodiments, the length of the shield is such that it accommodates at least a portion of an individual. In some embodiments, the length of the shield is configured to accommodate the individual. In some embodiments, the diameter of the shield, such as the inner diameter, is configured to accommodate at least a portion of the individual. In some embodiments, the diameter of the shield, such as the inner diameter, is configured to accommodate the individual. In some embodiments, the individual is a human subject. In some embodiments, the human subject is an adult subject, a pediatric subject, or a neonatal subject.

[0064]

[0106] In some embodiments, the length of the shield is between about 40 inches and about 100 inches. In some embodiments, the length of the shield is between about 50 inches and about 90 inches. In some embodiments, the length of the shield is between about 40 inches and about 150 inches. In some embodiments, the length of the shield is between about 60 inches and about 90 inches.

[0065]

[0107] In some embodiments, the diameter of the shield is between about 40 inches and about 60 inches. In some embodiments, the diameter of the shield is between about 45 inches and about 55 inches. In some embodiments, the diameter of the shield is between about 50 inches and about 70 inches.

[0066]

[0108] In some embodiments, the shield, or a portion thereof, is configured in a substantially cylindrical shape. In some embodiments, the shield, or a portion thereof, is configured in a substantially conical shape. In some embodiments, the shield comprises a first end and a second end. In some embodiments, the first end of the shield comprises a substantially cylindrical shape and the second end of the shield comprises a conical shape. In some embodiments, the shield is configured such that the first end has a tapered, e.g., gradually tapered, cylindrical shape to the second end, which has a conical shape.

[0067]

[0109] In some embodiments, the shield includes an interior volume configured to accommodate placement of an individual, a sensor, or a combination thereof. When an individual is placed within the interior volume of the shield, it may be desirable to reduce the interior volume overburden. For example, providing a shield with a tapered or conical end reduces the interior volume overburden, improves spatial uniformity of measurements taken by the sensor, reduces noise, or any combination thereof.

[0068]

[0110] In some embodiments, measurements collected from the sensor are collected from inside the interior volume of the shield. In some embodiments, the measurements are collected in the absence of the individual. In some embodiments, the measurements are collected in the presence of the individual. In some embodiments, the shield includes a portion of the interior volume that has greater spatial uniformity or a greater amount of noise reduction compared to a different portion. For example, a tapered or conical end of the interior volume has more spatial uniformity of measurements, noise reduction, or both compared to a cylindrical end. In some embodiments, the individual is positioned within the interior volume of the shield such that an area of ​​the subject desired to be measured by the sensor is positioned within a portion of the interior volume that has more spatial uniformity of measurements, noise reduction, or both.

[0069]

[0111] In some embodiments, noise reduction and quality of measurements within the interior volume of the shield are altered by varying the length of the shield, varying the diameter of the shield, or varying the shape of the shield (e.g., tapering), each of which may be altered independently or collectively to optimize noise reduction or improve the quality of measurements obtained by the sensor.

[0070]

[0112] In some embodiments, the shield comprises a coil, such as a Helmholtz coil. In some embodiments, the coil generates a current within the coil. In some embodiments, adding a coil to the shield improves the quality of the measurements (e.g., spatial uniformity of the measurements), reduces noise, or a combination thereof. In some embodiments, the shield comprises multiple coils. In some embodiments, the shield comprises a single coil. In some embodiments, the shield comprises two coils. In some embodiments, the shield comprises three coils. In some embodiments, the shield comprises between one and three coils. In some embodiments, the coil is positioned within a portion of the shield. In some embodiments, the coil is positioned within a portion of the shield where the measurements are made. In some embodiments, the position of the coil is adjustable, such as by a controller or a user. In some embodiments, the position of the coil is adjusted for each measurement of the sensor. In some embodiments, the position of the coil is pre-programmed depending on the type of measurement of the sensor. In some embodiments, the position of the coil is adjustable with an accuracy of between about 0.1 inches and about 5 inches. In some embodiments, the coil provides feedback to a user or controller that the coil has achieved a desired position. In some embodiments, feedback from the coil to the user or controller occurs before, during, or after the sensor measurement, hi some embodiments, feedback from the coil confirms that a desired location (such as a location corresponding to the location of an individual desired to be measured) has been reached.

[0071]

[0113] In some embodiments, the shield is modular. In some embodiments, the shield or a portion thereof is disposable. In some embodiments, the shield is configured to receive at least a portion of an individual, at least a portion of the sensor array, or a combination thereof. In some embodiments, the portion of the individual comprises a head, an arm, or a leg disposed within an interior volume of the shield. In some embodiments, the portion of the individual comprises an individual's torso to head or torso to feet. In some embodiments, the shield is non-modular. In some embodiments, the shield is configured to interact with one or more modular units. For example, a modular unit, such as a base unit, is modular and configured to be adjusted in relation to a stationary or non-modular shield.

[0072]

[0114] In some embodiments, the shield or a portion thereof is configured for the comfort of the subject. In some embodiments, the shield or a portion thereof is configured with illumination, for example, in some embodiments, the interior volume of the shield comprises an illumination source. In some embodiments, the shield or a portion thereof is configured with ventilation, such as one or more ports or openings, for example, one or more openings positioned on the interior surface of the shield.

[0073]

[0115] In some embodiments, the shield comprises a single material. In some embodiments, the shield comprises two or more materials. In some embodiments, the shield, or a portion thereof, comprises a metal, a metal alloy, or a combination thereof. In some embodiments, the shield, or a portion thereof, comprises permalloy or mu-metal. In some embodiments, the shield, or a portion thereof, comprises aluminum, copper, gold, iron, nickel, platinum, silver, tin, zinc, or any combination thereof. In some embodiments, the shield, or a portion thereof, comprises brass, bronze, steel, chromoly, stainless steel, titanium, or any combination thereof.

[0074]

[0116] In some embodiments, the shield or a portion thereof is made of nickel, iron, or and combinations thereof. In some embodiments, the shield, or portion thereof, comprises about 70% to about 90% nickel by weight. In some embodiments, the shield, or portion thereof, comprises about 75% to about 85% nickel by weight. In some embodiments, the shield, or portion thereof, comprises about 10% to about 30% iron by weight. In some embodiments, the shield, or portion thereof, comprises about 15% to about 25% iron by weight. In some embodiments, the shield, or portion thereof, comprises about 70% to about 90% nickel by weight and about 10% to about 30% iron by weight. In some embodiments, the shield, or portion thereof, comprises about 40% to about 60% nickel by weight and about 50% to about 60% iron by weight. In some embodiments, the shield, or portion thereof, comprising permalloy or mu-metal also comprises one or more additional elements, such as molybdenum.

[0075]

[0117] In some embodiments, the shield, or portions thereof, comprises a material having a high magnetic permeability. For example, in some embodiments, the material comprises a relative permeability of about 50,000 to about 900,000, as compared to, for example, steel, which has a relative permeability of about 4,000 to about 12,000. In some embodiments, the material comprises a relative permeability of about 75,000 to about 125,000. In some embodiments, the material comprises a relative permeability of about 400,000 to about 800,000. In some embodiments, the material comprises a relative permeability greater than about 50,000. In some embodiments, the material comprises a relative permeability greater than about 75,000. In some embodiments, the material comprises a relative permeability greater than about 100,000. In some embodiments, the material comprises a relative permeability greater than about 200,000. In some embodiments, the material comprises a relative permeability greater than about 300,000. In some embodiments, the material comprises a relative permeability greater than about 400,000. In some embodiments, the material comprises a relative permeability greater than about 500,000. In some embodiments, the material comprises a relative permeability greater than about 600,000. In some embodiments, the material comprises a relative permeability between about 80,000 and about 900,000. In some embodiments, the material comprises a relative permeability between about 400,000 and about 800,000.

[0076]

[0118] In some embodiments, the shield is in the shape of a monolith. In some embodiments, the shield is formed from multiple subcomponents configured together. In some embodiments, the shield is 3D printed. In some embodiments, the shield comprises a material formed in a hydrogen furnace, e.g., the shield comprises one or more materials annealed in a hydrogen furnace.

[0077]

[0119] Described herein are devices and systems configured to sense magnetic fields associated with, for example, tissue, body parts, or organs of an individual. In some embodiments of the devices and systems described herein, the device for sensing the magnetic field comprises a mobile base unit and one or more magnetic field sensors. In some embodiments of the devices and systems described herein, the device for sensing the magnetic field comprises a mobile base unit, one or more magnetic field sensors, and a shield for shielding ambient electromagnetic noise.

[0078]

[0120] In some embodiments of the devices and systems described herein, the device for sensing a magnetic field comprises a mobile base unit configured for portability. In some embodiments, the mobile base unit comprises wheels or tracks, and the mobile base unit is moved on the wheels or tracks across a surface. In some embodiments, the mobile base unit is handheld. In some embodiments, the mobile base unit is configured with a housing that houses electronic components.

[0079]

[0121] In some embodiments of the devices and systems described herein, the device for sensing a magnetic field comprises one or more magnetic sensors, such as, for example, one or more OPMs. Equipped with a field sensor.

[0080]

[0122] In some embodiments of the devices and systems described herein, the device for sensing the magnetic field comprises one or more coupling mechanisms for receiving and coupling to one or more sensors. In some embodiments of the systems and devices described herein, the device for sensing the magnetic field comprises one or more arms or extensions that connect to a mobile base unit. In some embodiments of the devices and systems described herein, the device for sensing the magnetic field includes one or more extensions or arms configured to move, rotate, and / or articulate to position the one or more sensors to sense the magnetic field in proximity to an individual whose magnetic field is to be sensed.

[0081]

[0123] In some embodiments, a device or system described herein comprises a mechanical housing comprising one or more non-ferrous materials, such as, for example, aluminum alloy, rubber, plastic, wood, or any combination thereof, to minimize the amount of interference seen in the biomagnetic signals from the device or system itself. Illustrative Embodiments

[0124] 1 shows an exemplary embodiment of a device 100 for sensing magnetic fields as described herein that includes a shield 107. The device 100 for sensing magnetic fields includes the shield 107 and one or more sensors 106 (such as optically excited magnetometers). In some embodiments, two or more sensors 106 are arranged in an array.

[0082]

[0125] The shield 107 includes an open end 109 and a closed end 108. In some embodiments, the open end 109 is positioned adjacent to the closed end 108. In some embodiments, the open end 109 is positioned opposite the closed end 108. In some embodiments, the shield 107 comprises one or more openings. The one or more openings in the shield 107 are configured to receive at least a portion of the base unit 101, at least a portion of the individual 114, at least a portion of the one or more sensors 106, or any combination thereof.

[0083]

[0126] For example, shield 107 comprises an opening, such as recessed opening 113, configured to receive a portion of base unit 101. In some embodiments, shield 107 comprises opening 115 configured to receive at least a portion of base unit 101, at least a portion of individual 114, at least a portion of one or more sensors 106, or any combination thereof. Shield 107 includes an inner surface 110. In some embodiments, inner surface 110 in some embodiments comprises a coating. In some embodiments, inner surface 110 of shield 107 defines an interior volume of the shield. The interior volume of shield 107 is a volume in which a portion of individual 114, a portion of a sensor, a portion of base unit 101, or any combination thereof is received. Shield 107 comprises shield portion 116 configured to house components of a device for sensing a magnetic field, such as an electronic screwdriver. In some embodiments, shield portion 116 comprises a drawer, a shelf, a cabinet, a compartment, or a section of shield 107. In some embodiments, the shield portion 116 is positioned on a side portion of the shield. In some embodiments, the shield portion 116 is positioned on a bottom portion of the shield 107.

[0084]

[0127] In some embodiments, a device 100 for sensing magnetic fields described herein comprises a base unit 101. In the exemplary embodiment shown in Figure 1, the base unit 101 comprises a bed or gurney on which an individual 114 lies.

[0085]

[0128] In some embodiments, a device 100 for sensing a magnetic field described herein is operably coupled to a base unit 101. In some embodiments, a shield 107 is configured to receive a portion of the base unit 101. For example, in some embodiments, a recessed opening in the shield 107 is configured to receive at least a portion of the base unit 101, as shown in FIG. 1 . In some embodiments, the base unit 101 is directly attachable to one or more sensors 106.

[0086]

[0129] In some embodiments, the base unit 101 is configured as a stationary base unit 101. In some embodiments, the base unit 101 is configured as a mobile base unit 101. In some embodiments, the shield 107 is movable relative to the base unit 101. In some embodiments, the base unit 101 is movable relative to the shield 107. In some embodiments, the base unit 101 and the shield 107 are movable relative to each other.

[0087]

[0130] In the exemplary embodiment shown in FIG. 1 , the base unit 101 is configured as a mobile base unit 101. In some embodiments, the mobile base unit 101 is configured to move in one or more degrees of freedom (e.g., relative to the shield 107). In some embodiments, the mobile base unit 101 is configured to move along the x-axis, the y-axis, the z-axis, or any combination thereof. In some embodiments, the mobile base unit 101 comprises one or more rolling elements, such as wheels (113 a, 113 b), rollers, conveyor belts, or any combination thereof, configured to provide movement of the base unit 101 or a portion thereof. In some embodiments, the base unit 101 comprises one rolling element. In some embodiments, the base unit 101 comprises two rolling elements. In some embodiments, the base unit 101 comprises three rolling elements. In some embodiments, the base unit 101 comprises four rolling elements. In some embodiments, the base unit 101 comprises five or more rolling elements. In some embodiments, the rolling elements are positioned at one or both ends of the base unit 101. In some embodiments, the base unit 101 comprises a non-rotating element configured to be received in a track or channel such that the base unit 101 is movable along the track or channel. In some embodiments, the track or channel is positioned adjacent to the shield 107 such that the base unit 101 is movable along the track or channel toward the shield, away from the shield, or both.

[0088]

[0131] In some embodiments, the base unit 101 comprises one or more pivots (102a, 102b). In some embodiments, the base unit 101 comprises one pivot. In some embodiments, the base unit 101 comprises two pivots. In some embodiments, the base unit 101 comprises three or more pivots. In some embodiments, the pivots 102a, 102b are configured to allow movement of the base unit 101, such as by accommodating an individual positioned on the base unit 101. In some embodiments, the pivots 102a, 102b are configured to allow movement of the base unit 101, such as to position the base unit 101 within an interior volume of the shield 107. In some embodiments, the pivots 102a, 102b are configured to provide movement of the base unit 101 that provides one or more degrees of freedom.

[0089]

[0132] In some embodiments, one or more sensors 106 are operably coupled to the arm 103. In some embodiments, the arm 103 is a movable arm 103. In some embodiments, the device has an extendable arm 103, with the sensor array 106 housed at the end of the extendable arm 103. In some embodiments, any type of O A PM is used as one or more of the one or more sensors 106. In some embodiments, the arm 103 is movable with at least one degree of freedom. In some embodiments, the arm 103 comprises a joint 104 configured to provide movement to the arm 103. In some embodiments, the arm 103 comprises two or more joints 104. In some embodiments, the arm 103 comprises two joints 104. In some embodiments, the arm 103 is operably coupled to the one or more sensors 106 and the base unit 101, as shown in FIG. 1 . The arm 103 is operably coupled to the base unit 101 by a beam 105, as shown in FIG. 1 .

[0090]

[0133] In some embodiments, a device 100 for sensing a magnetic field described herein comprises a computer processor 112, as shown in Figure 1. In some embodiments, the computer processor 112 comprises a graphical user interface. In some embodiments, the computer processor 112 comprises a touch screen.

[0091]

[0134] 1, the device for sensing a magnetic field 100 includes a stand 111 configured to receive, for example, a computer processor 112. In some embodiments, the stand 111 is positioned adjacent to the shield 107 or the base unit 101 of the device for sensing a magnetic field 100. In some embodiments, the stand 111 is integral with or attachable to the shield 107 or the base unit 101 of the device for sensing a magnetic field 100.

[0092]

[0135] In some embodiments of device 100 shown in Figure 1, the device is essentially stationary. It should be understood that other embodiments of device 100 (and systems) described herein are configured to be mobile.

[0093]

[0136] In some embodiments, device 100 includes a compartment 116 or tabletop to house the electronics, computer interface, and power source; in other embodiments, device 100 includes a separate unit connected to the first component by wiring to house these components. In some embodiments, device 100 requires power via an electrical outlet. In some embodiments, a standard operating procedure involves extending the device's arm 103 and lowering the base of sensor unit 106 to a position, such as within 2 centimeters of the skin surface of an individual (such as the chest, head, or other area of ​​interest of individual 114). In some embodiments, device 100 is calibrated using a software application provided on or separately from the device. In some embodiments, the biomagnetic signal of interest is displayed and recorded for immediate or later analysis.

[0094]

[0137] In some embodiments, operation of the device (or system) 100 described herein is controlled using a software user interface (UI), a manual UI, or a combination UI including software and manual elements. In some embodiments, the UI is installed in situ on an attached computer. Use of the device is directed by a medical professional, such as a physician, to determine further information about an individual's symptoms. Within the UI, user preferences and acquisition parameters, including sampling rates and axis operations of the device or system, are selected. From the software user interface, magnetic field signals from the individual, such as signals corresponding to the individual's heart, are displayed and saved to a file. In some embodiments, the device or system is configured to measure cardiac electrical activity and create a waveform similar to an electrocardiogram that can demonstrate points of interest within the cardiac cycle.

[0095]

[0138] One or more sensors 106 are arranged in an array, with one or more optically excited magnetometers outputting one or more waveforms. In some embodiments, the array outputs one waveform per sensor in the array. In some embodiments, the individual waveforms of the individual sensors are combined into a single waveform. In some embodiments, the array outputs a single waveform that includes a combination of waveforms from each sensor in the array. In some embodiments, the magnetic field data is visualized as a series of 2D images made from interpolated magnetic field values ​​between the sensors. In some embodiments, the array comprises at least one OPM and at least one other type of magnetometer. In some embodiments, the array comprises only OPMs.

[0096]

[0139] In some embodiments, the shield 107 is housed in a shroud structure, and in some embodiments, the overall length of the device is at least about 2.25 meters (m) in length, with the perforation opening (or opening inner diameter) being about 0.8 m.

[0097]

[0140] In some embodiments, a base unit 101, such as a bed platform on which the subject is positioned, is used to insert the individual into the shield 107. During use of the device, a flexible articulated arm 103 with xyz translational motion is configured to occupy any point within a semicircle defined by the entire arm length at the extension and is used to position an array of n optically excited magnetometers in a wide range of geometries on or near a portion of the individual (such as the chest, head, or other organ of the individual 114) using a standard set of operating procedures based on the organ of interest, symptom or disease of interest, or a combination thereof. In some embodiments, the sensor array is then powered on, and at least a portion of the subject, at least a portion of the base unit 101 (e.g., bed platform), or a combination thereof, is slid into the shield 107. A provided computer application is used to quickly calibrate the sensors, and then display and record the magnetic field of the organ of interest, or a combination thereof, for immediate or later analysis. In some embodiments, the electronic drivers for the sensors are housed under the shield 107 portion of the device 100 or in an adjacent cart with computer control.

[0098]

[0141] In some embodiments, the system includes a touchscreen computer interface (such as a graphical user interface) housed on the side of the device itself or on said adjacent cart.

[0099]

[0142] As shown in FIG. 2 , in some embodiments, the shield comprises a shield frame 200. In some embodiments, the shield frame 200 provides a macrostructure or shape for the shield. In some embodiments, the shield frame 200 is positioned on an inner or outer surface of the shield. In some embodiments, the shield frame 200 is configured to receive one or more portions of a base unit. In some embodiments, the shield frame 200 includes an open end 201 and a closed end 203. In some embodiments, an opening 202 is positioned at the open end 201, such as an opening configured to receive a portion of the base unit. In some embodiments, an opening, such as a recessed opening 204, is positioned at the open end 201 or the closed end 203 and configured to receive a portion of the base unit. In some embodiments, the shield frame 200 comprises separate elements operably connected to form the shield frame 200, or in some embodiments, the shield frame 200 comprises a single monolithic frame or a 3D printed frame. In some embodiments, the shield frame 200 comprises one or more layers.

[0100]

[0143] As shown in Figure 3, an exemplary embodiment of a device or system 300 described herein includes a shield 301. The shield 301 has a closed end 302 and an open end 303. 3. In some embodiments, open end 303 of shield 301 is positioned opposite closed end 302 of shield 301. In some embodiments, open end 303 of shield 301 is positioned adjacent closed end 302 of shield 301. In some embodiments, open end 303 is configured to position a sensor, an individual 305, a base unit 306 (such as a mobile base unit), or any combination thereof, within the interior volume of shield 301. In some embodiments, shield 301 includes an interior surface 304. In some embodiments, interior surface 304 of shield 301 spatially defines the interior volume of shield 301. In some embodiments, interior surface 304 is configured to interface with individual 305. In some embodiments, interior surface 304 comprises ventilation or lighting to accommodate individual 305. In some embodiments, base unit 306 comprises one or more pivots, such that one or more portions of base unit 306 are adjustable. For example, in some embodiments, the base unit 306 comprises a first pivot 307 and a second pivot 308. In some embodiments, the pivots are configured to adjust the position of the base unit 306 relative to the shield 301. In some embodiments, the pivots are configured to adjust the position of the base unit 306 relative to the interior volume of the shield 301. In some embodiments, the base unit 306 comprises one, two, three, four, five, six, seven, eight, or more pivots. In some embodiments, the pivots provide one or more degrees of freedom of movement. In some embodiments, the pivots provide bending movement. In some embodiments, the pivots provide rotational movement. In some embodiments, the pivots provide extension movement. In some embodiments, the base unit 306 comprises a base 309. In some embodiments, the base 309 is configured to support a portion of the base unit 306 that holds the individual 305, the sensor, the sensor array, or a combination thereof.In some embodiments, base 309 is configured to fit into opening 310 in shield 301, such that a portion of base unit 306 that holds individual 305, an array, or a combination thereof, moves in and out of the interior volume of shield 301. In some embodiments, the interior volume of shield 301 comprises structure 311, such as a track or channel or rod or protrusion, configured to receive a portion of base unit 306 (such as a portion associated with individual 305, a sensor, or both) as it moves in and out of the interior volume of shield 301.

[0101]

[0144] As shown in FIG. 4, an example device or system 400 described herein includes a base unit 412 (such as a mobile base unit 412) and one or more sensors, which in some embodiments comprise an array of sensors 401 (such as optically excited magnetometers).

[0102]

[0145] In some embodiments, device 400 comprises a structure 402 such as a handle, beam, or rod, or protrusion configured to allow a user to adjust the position of array 401 .

[0103]

[0146] In some embodiments, device 400 comprises one or more pivots (such as 403 or 408). In some embodiments, the pivots adjust the position of base unit 412 or its subcomponents, the position of array 401, or a combination thereof. In some embodiments, the pivots (403 or 408) are adjusted manually, automatically, or a combination thereof. In some embodiments, the pivots (403 or 408) are adjusted by a user, a controller, or a combination thereof. In some embodiments, the pivots (403 or 408) are configured to provide one or more degrees of freedom of movement. In some embodiments, the pivots (403 or 408) provide bending movement. In some embodiments, the pivots (403 or 408) provide extension movement. In some embodiments, the pivots (403 or 408) , providing rotational motion.

[0104]

[0147] In some embodiments, the base unit 412 comprises one or more compartments (such as 410 or 411). In some embodiments, the base unit 412 comprises a single compartment. In some embodiments, the base unit 412 comprises two compartments. In some embodiments, the base unit 412 comprises multiple compartments. In some embodiments, the base unit 412 comprises three compartments. In some embodiments, the first compartment and the second compartment are different. In some embodiments, the first compartment and the second compartment are the same. In some embodiments, the first compartment is larger in size than the second compartment. In some embodiments, the first compartment is positioned adjacent to the second compartment. In some embodiments, the first compartment is positioned above the second compartment. In some embodiments, the first compartment is positioned within the second compartment. In some embodiments, the compartments are configured to house one or more components. For example, the compartment is configured to house a power source, so the base unit 412 is not limited to remaining near a wall outlet or external power source. In some embodiments, the compartment is configured to house a computer including an operating system, a database, a monitor, a graphical user interface, or any combination thereof. In some embodiments, the compartment is configured to house one or more sensors or housings for sensors.

[0105]

[0148] In some embodiments, the base unit 412 comprises one or more compartments (such as 409 or 410). In some embodiments, the base unit 412 comprises a single compartment. In some embodiments, the base unit 412 comprises two compartments. In some embodiments, the base unit 412 comprises multiple compartments. In some embodiments, the base unit 412 comprises three compartments. In some embodiments, the first compartment and the second compartment are different. In some embodiments, the first compartment and the second compartment are the same. In some embodiments, the first compartment is larger in size than the second compartment. In some embodiments, the first compartment is positioned adjacent to the second compartment. In some embodiments, the first compartment is positioned above the second compartment. In some embodiments, the first compartment is positioned within the second compartment. In some embodiments, the compartments are configured to house one or more components. For example, the compartment is configured to house a power source, so the base unit 412 is not limited to remaining near a wall outlet or external power source. In some embodiments, the compartment is configured to house a computer including an operating system, a database, a monitor, a graphical user interface, or any combination thereof. In some embodiments, the compartment is configured to house one or more sensors or housings for sensors.

[0106]

[0149] In some embodiments, the base unit 412 includes a surface 409, such as a flat surface. The surface 409 is configured to hold a computer or other components of the system. In some embodiments, the base unit 412 includes one or more rolling elements (e.g., 414a or 414b). In some embodiments, the rolling elements include wheels (414a, 414b), rollers, conveyor belts, or any combination thereof configured to provide movement of the base unit 412. In some embodiments, In some embodiments, base unit 412 comprises arm 413. In some embodiments, one end of arm 413 is configured to attach to array of sensors 401. In some embodiments, a second end of arm 413 is configured to attach to base unit 412, e.g., at compartment 410 or 411 or surface 409. In some embodiments, arm 413 is adjustable. For example, arm 413 is extendable in its length, e.g., first portion 405 of arm 413 extends from second portion 407 of arm 413. In some embodiments, first portion 405 or second portion 407 of arm 413 comprises a locking element (e.g., a knob or protrusion or pin-in groove) to secure arm 413 or first portion 405 or second portion 407 of arm 413 in an extended, bent, or folded position.

[0107]

[0150] In some embodiments, pivot 408 is positioned at first end 405 of arm 413, second end 407 (shown in FIG. 4 ) of arm 413, or a combination thereof. In some embodiments, pivot 403 is positioned at an end of arm 413 adjacent to array 401. In some embodiments, pivot 408 is positioned at an end of arm 413 adjacent to compartment 410 or 411 or surface 409. In some embodiments, base unit 412 comprises wiring 404, such as one or more wires. Wiring 404 is configured to attach to one or more sensors of array 401, one or more power sources of base unit 412, one or more computers of base unit 412, or any combination thereof. In some embodiments, base unit 412 comprises wire securing element 406 (such as a tie or latch or hook) for securing one or more wires to base unit 412. In some embodiments, the wire fixation element 406 is positioned on the arm 413 of the base unit 412. In some embodiments, the wire fixation element 406 is positioned within a compartment of the base unit 412. In some embodiments, the wire fixation element 406 is positioned proximal to the array 401, proximal to an extension point of the arm 413, proximal to the pivot (403 or 408), or any combination thereof.

[0108]

[0151] In some embodiments, device 400 is combined with a shield (not shown), such as, for example, a disposable shield or a modular shield. In some embodiments, the shield is separate from base unit 412. In some embodiments, the shield is associated with base unit 412, for example, attached to base unit 412 at a location proximal to array 401.

[0109]

[0152] In some embodiments, the shield is integral to device 400. In some embodiments, the shield, array 401, arm 413, or any combination thereof, is operably connected (such as by wire or wirelessly) to a controller or computer system.

[0110]

[0153] As shown in Figure 5, in some embodiments of the devices and systems described herein, an arm 500 of a mobile cart device comprises an articulation and / or extension mechanism 501. As shown in Figure 5, in some embodiments, the extension mechanism 501 comprises a telescoping housing for a portion of the arm 500 to extend in and out. In some embodiments, the articulation mechanism 501 comprises a joint.

[0111]

[0154] In some embodiments, the arm 500 comprises one or more holders 502, such as holders for securing wiring components 503 at positions on the arm 500. In some embodiments, the holders 502 are positioned at any position along the length of the arm 500. In some embodiments, the location of the holders 502 along the length of the arm 500 is adjustable. In some embodiments, a housing or tubing 504 is provided to secure one or more wiring components 503. The arm 500 is configured to accommodate a line component 503. In some embodiments, the line component 503 operably connects the sensor array to one or more components, such as a computer or a power source. In some embodiments, the arm 500 includes a first and second end. In some embodiments, the first end of the arm 500 is configured to be coupled to the sensor array 509. The first end is coupled to the sensor array by a pivot 505. In some embodiments, the pivot 505 provides one or more degrees of freedom of movement for the sensor array 509. In some embodiments, the position of the sensor array is adjusted using an actuator, such as a power button 506. In some embodiments, the actuator adjusts the linear movement of the sensor array, such as toward or away from the individual's surface. In some embodiments, the actuator has a separate power button 507. In some embodiments, the power button 506 and the power button are the same. In some embodiments, the actuator comprises a bar or handle 508. The bar is configured for manual adjustment of the position of the arm 500, the position of the sensor array, or a combination thereof.

[0112]

[0155] In some embodiments, the mobile cart device is configured to transition from the extended configuration shown in FIG. 7 to the folded configuration shown in FIG. 6. In some embodiments, the mobile cart device is configured to transition between the two configurations one or more times. In some embodiments, the mobile cart device is configured for a user to manually transition the device between the two configurations. In some embodiments, the mobile cart device is configured for automatic transition between the two configurations, such as automation by a motor system operably coupled to a controller.

[0113]

[0156] FIG. 6 illustrates an exemplary mobile cart device 600 in a folded configuration. As shown in FIG. 6, the mobile cart device 600 includes a sensor array 604, such as an optically excited magnetometer. The sensor array 604 is coupled to a first end of an arm 608. In some embodiments, the second end of the arm 608 is coupled to the vertical beam 602 or the top end of the frame at location 607. In some embodiments, this coupling includes a pivot. In some embodiments, the pivot coupling is configured to transition the device 600 from the extended configuration to the folded configuration. In some embodiments, a cross beam 601 is coupled to the arm 608 at location 609, anywhere between the first and second ends. In some embodiments, the cross beam 601 is coupled to the arm 608 at a midpoint between the first and second ends of the arm 608. In some embodiments, the cross beam 601 includes a pivot, such as a pivot positioned at a midpoint along the cross beam 601. In some embodiments, the pivots of the cross beams are configured to transition device 600 from the extended configuration to the folded configuration. In some embodiments, cross beam 601 is configured to bend or pivot such that a first end coupled to sensor array 604 is moved toward a bottom end of vertical beam 602. One or more pivots of device 600 are locked in a configuration, such as the extended or folded configuration, at positions 607 or 601 or both, such as by a locking element.

[0114]

[0157] In some embodiments, mobile cart device 600 comprises a handle 610, such as a handle coupled to arm 608. In some embodiments, handle 610 facilitates actuation of arm 608 to transition device 600 between an extended configuration and a folded configuration. In some embodiments, mobile cart device 600 comprises one or more rolling elements (such as wheels 605 and 606) configured to rotate so that mobile cart device 600 is moved. In some embodiments, mobile cart device 600 comprises one or more tethering elements (such as rubber feet 612 and 613) configured to secure mobile cart device 600 at a desired location. In some embodiments, mobile cart device 600 comprises a handle 611. In some embodiments, handle 611 is configured to actuate one or more elements of device 600. For example, handle 611 is configured to actuate arm 608 of device 600 relative to the frame. In some embodiments, handle 611 is configured to actuate sensor array 604 relative to arm 608. In some embodiments, handle 611 translates sensor array 604 toward or away from arm 608 in a linear motion. In some embodiments, handle 611 is configured to rotate. In some embodiments, handle 611 is operably coupled to drive screw 603 to convert rotational motion of handle 611 into linear motion of sensor array 604.

[0115]

[0158] FIG. 7 illustrates an exemplary mobile cart device 700 similar to FIG. 6 in an extended configuration. The device 700 includes a sensor array 701 comprising one or more optically excited magnetometers. The sensor array 701 is operably coupled to a first end of an arm 706 of the device 700 by one or more shafts (such as linear motion shaft 702). In some embodiments, a second end of the arm 706 is coupled to one or more vertical beams (such as beam 709 and beam 710) at location 707. In some embodiments, the coupling located at location 707 comprises a pivot. The coupling is configured to transition the arm 706 between an extended configuration and a folded configuration. In some embodiments, the coupling is configured to move the sensor array 701 toward and away from the vertical beams.

[0116]

[0159] In some embodiments, arm 706 comprises handle 704, handle 703, or both configured to actuate a portion of device 700. For example, handle 704 is configured to move arm 706 relative to the frame. Handle 703 is configured to move sensor array 701 relative to arm 706. In some embodiments, device 700 comprises cross beam 713. In some embodiments, a first end 705 of cross beam 713 is coupled to arm 706 at a position between the first and second ends of arm 706, e.g., at a midpoint. In some embodiments, a second end 711 of cross beam 713 is coupled to the frame, e.g., to a vertical beam or cross beam 713 positioned between two vertical beams. In some embodiments, cross beam 713 comprises pivot 708. In some embodiments, the pivot is positioned at a midpoint of cross beam 713. In some embodiments, pivot 708 is configured to flex. In some embodiments, pivot 708 is configured to transition the device between a collapsed configuration and an extended configuration. In some embodiments, pivot 708 is reversibly lockable. In some embodiments, device 700 includes one or more rolling elements, such as wheels 712, configured to move the device between locations.

[0117]

[0160] 8 illustrates an exemplary computer system 801 programmed or otherwise configured to direct the operation of a device or system described herein, including movement of a base unit, movement of a shield, movement of a mobile cart, movement of a sensor array, acquisition of measurements, comparison of measurements to reference measurements, or any combination thereof. The computer system 801 coordinates various aspects of: (a) movement of one or more device or system components, (b) operation of one or more sensors, (c) adjustment of one or more parameters of a sensor, (d) computer evaluation of one or more measurements of a device or system, (e) display of various parameters, including input parameters, results of measurements, or any combination of any of these. In some embodiments, the computer system 801 is a user's electronic device (e.g., smartphone, laptop), or in some embodiments, is located remotely relative to the electronic device. In some embodiments, the electronic device is a mobile electronic device.

[0118]

[0161] Computer system 801 includes a central processing unit (CPU, also referred to herein as a "processor" and "computer processor") 805, and in some embodiments In the figure, CPU 805 is a single-core or multi-core processor, or multiple processors for parallel processing. Computer system 801 also includes memory or memory locations 810 (e.g., random access memory, read-only memory, flash memory), an electronic storage unit 815 (e.g., a hard disk), a communication interface 820 (e.g., a network adapter) for communicating with one or more other systems, and peripheral devices 825, such as cache, other memory, data storage devices, and / or electronic display adapters. Memory 810, storage unit 815, interface 820, and peripheral devices 825 communicate with CPU 805 via a communication bus (solid lines) such as a motherboard. Storage unit 815 is configured as a data storage unit (or data repository) for storing data. Computer system 801 is operatively coupled to a computer network ("network") 830 with the aid of communication interface 820. Network 830 may be the Internet, an Internet and / or extranet, or an intranet and / or extranet in communication with the Internet. In some embodiments, network 830 is a telecommunications and / or data network. Network 830 includes one or more computer servers that enable distributed computing, such as cloud computing. In some embodiments, network 830 implements a peer-to-peer network that, with the assistance of computer system 801, enables devices coupled to computer system 801 to act as clients or servers.

[0119]

[0162] The CPU 805 is configured to execute sequences of machine-readable instructions embodied in a program or software. These instructions are stored in a memory location, such as the memory 810. These instructions are directed to the CPU 805, which then programs or otherwise configures the CPU 805 to implement the methods of the present disclosure. Examples of operations performed by the CPU 805 include fetch, decode, execute, and writeback.

[0120]

[0163] The CPU 805 is part of a circuit, such as an integrated circuit. One or more other components of the system 801 are included in the circuit. In some embodiments, the circuit is an application specific integrated circuit (ASIC).

[0121]

[0164] The storage unit 815 stores files such as drivers, libraries, and saved programs. The storage unit 815 stores user data, such as user preferences and user programs. In some embodiments, the computer system 801 includes one or more additional data storage units external to the computer system 801, such as on a remote server in communication with the computer system 801 via an intranet or the Internet.

[0122]

[0165] Computer system 801 communicates with one or more remote computer systems via network 830. For example, computer system 801 communicates with a user's remote computer system (e.g., a second computer system, a server, a smartphone, an iPad®, or any combination thereof). Examples of remote computer systems include a personal computer (e.g., a portable PC), a slate or tablet PC (e.g., an Apple® iPad®, a Samsung® Galaxy Tab), a phone, a smartphone (e.g., an Apple® iPhone®, an Android-enabled device, a Blackberry®), or a personal digital assistant. A user accesses computer system 801 via network 830.

[0123]

[0166] The methods described herein are implemented by machine (e.g., computer processor) executable code stored in electronic storage locations of computer system 801, such as memory 810 or electronic storage unit 815. The machine-executable or machine-readable code is provided in the form of software. In use, the code is executed by processor 805. In some embodiments, the code is retrieved from storage unit 815 and stored in memory 810 for ready access by processor 805. In some situations, electronic storage unit 815 is excluded and machine-executable instructions are stored in memory 810.

[0124]

[0167] Machine-readable media, such as computer-executable code, may take many forms, including but not limited to, tangible storage media, carrier wave media, or physical transmission media. Non-volatile storage media include optical or magnetic disks, such as any of the storage devices in any computer illustrated in the drawings, and used to implement, for example, databases, etc. Volatile storage media include dynamic memory, such as the main memory of such a computer platform. Tangible transmission media include coaxial cables, copper wire, and fiber optics, including the wires that comprise a bus within a computer system. Carrier-wave transmission media take the form of electric or electromagnetic signals, or acoustic or light waves such as those generated during radio frequency (RF) and infrared (IR) data communications. Thus, common forms of computer readable media include, for example, floppy disks, flexible disks, hard disks, magnetic tape, any other magnetic media, CD-ROMs, DVDs, or DVD-ROMs, any other optical media, punch cards, paper tape, any other physical storage media with patterns of holes, RAM, ROM, PROMs, and EPROMs, FLASH-EPROMs, any other memory chips or cartridges, carrier waves transporting data or instructions, cables or links transporting such carrier waves, or any other medium from which a computer reads programming code and / or data. Many of these forms of computer readable media are involved in carrying one or more sequences of one or more instructions to a processor for execution.

[0125]

[0168] In some embodiments, the computer system 801 includes or communicates with an electronic display 835 that includes a user interface (UI) 840 for providing, for example, graphs of the measured signal(s), the reference signal(s), the parameter(s) entered or adjusted by a user or controller, or any combination thereof. Examples of a UI include, but are not limited to, a graphical user interface (GUI) and a web-based user interface.

[0126]

[0169] In some embodiments, the methods and systems of the present disclosure are implemented by one or more algorithms. In some embodiments, the algorithms are implemented by software when executed by the central processing unit 805. The algorithms, for example, compare the signal to a reference signal.

[0127]

[0170] 9A-9B show an example of a shield. In some embodiments, the shield has a first end and a second end. In some embodiments, the first end of the shield includes a tapered closed end 901a or 901b. In some embodiments, the second end of the shield includes an open end 904 that is substantially cylindrical in shape. In some embodiments, the opening in the second end is configured to receive at least a portion of an individual, a sensor array, a base unit, or any combination thereof, within the shield. In some embodiments, the shield is a monolith. In some embodiments, the shield includes a first segment 901a or 901b, a second segment 902a or 902b, and a third segment 903a or 903b. In some embodiments, the shield comprises one layer. In some embodiments, the shield comprises two or more layers. In some embodiments, the shield comprises an inner layer 905. In some embodiments, the shield comprises a space 906 between two layers.

[0128]

[0171] 10A-10B show an example design of the shield shown in FIGS. 9A-9B. As shown in FIG. 10A, a cross section of the shield demonstrates one example of a suitable geometry for the shield. The shield is shown as a cylindrical section in the figure, and although the underlying support comprises nylon, the fixture and support may be constructed from any non-ferrous material known in the art. FIG. 10B shows a longitudinal view of the same sample shield. In some embodiments, as shown in FIGS. 10A-10B, the total length of the shield is about 2000 millimeters (mm) to about 2500 mm or about 2200 mm to about 2300 mm (e.g., about 2272.5 mm), the inner length is about 1500 mm to about 2000 mm or about 1700 mm to about 1800 mm (e.g., about 1750.0 mm), the diameter of the inner layer is about 500 mm to about 1000 mm or about 700 mm to about 900 mm (e.g., about 800.0 mm), the diameter of the middle layer is about 600 mm to about 1100 mm or about 800 mm to about 950 mm (e.g., about 883.0 mm), and the diameter of the outer layer is about 700 mm to about 1200 mm or about 900 mm to about 1050 mm (e.g., about 986.0 mm).

[0129]

[0172] In some embodiments, the shield comprises two or more layers and has a spacing between any two given layers. In some embodiments, the shield has a non-uniform spacing between any two layers. In some embodiments, different sets of layers have non-uniform spacing relative to each other.

[0130]

[0173] In some embodiments, the layer of the shield, or portion thereof, comprises a thickness of about 0.1 to about 10 millimeters. In some embodiments, the layer of the shield has a thickness of about 0.5 to about 5 millimeters. In some embodiments, the layer of the shield has a thickness of about 0.1 to about 2 millimeters. In some embodiments, the layer of the shield has a thickness of about 0.8 to about 5 millimeters. The thickness is substantially the same along the length or circumference of the shield. In some embodiments, the thickness of the layer of the shield varies along the length or circumference of the shield.

[0131]

[0174] In some embodiments, the shield comprises multiple layers. In some embodiments, a space exists between at least two of the multiple layers. In some embodiments, a space exists between each of the multiple layers. In some embodiments, a space exists between some of the multiple layers. In some embodiments, a first layer of the shield is configured to be adjacent to a second layer of the shield. In some embodiments, the first layer of the shield is configured to be attached or bonded to the second layer of the shield. In some embodiments, the first layer of the shield is configured to be positioned about 0.1 inches to about 5 inches from the second layer. In some embodiments, the first layer of the shield is configured to be positioned about 1 inch to about 3 inches from the second layer. In some embodiments, the first layer of the shield is configured to be positioned about 1 inch to about 20 inches from the second layer. In some embodiments, the first layer of the shield is configured to be positioned between about 1 inch and about 10 inches from the second layer.

[0132]

[0175] In some embodiments, the length of the shield, such as the inner length or the outer length, is about 2 times the inner diameter of the shield. In some embodiments, the length of the shield is about 0.5 times to about 3 times the inner diameter of the shield. In some embodiments, the length of the shield is about 1 / 2 to about 3 times the inner diameter of the shield. In some embodiments, the length of the shield is about 1 to about 3 times the inner diameter of the shield.

[0133]

[0176] In some embodiments, as shown in Figures 11A-11I, the layers of shielding are separated using spacers of variable width, height, and length depending on the application of interest. In some embodiments, the spacers used to separate the layers of shielding are in the form of arcs. In some embodiments, the spacers are used to cover a portion or the entire circumference of two consecutive layers. In some embodiments, the spacers cover only a portion of the circumference of two consecutive layers.

[0134]

[0177] In some embodiments, as shown in FIGS. 12A-12B , the shield support is fabricated from one or more pieces and configured to be operably connected (e.g., joined) by bolts, fasteners, screws, or any combination thereof. In some embodiments, the shield support is operably connected (e.g., attached) to the shield by one or more fasteners, bolts, screws, or any combination thereof. In some embodiments, the support is also attached using adhesive fasteners. In some embodiments, a shield spacer is positioned anywhere along the circumference of two consecutive layers, as seen in FIG. 12A . In some embodiments, a system of one or more hooks is operably connected (e.g., attached) to any surface of any layer of the shield by adhesive, fasteners, screws, bolts, or any combination thereof. A layer comprises a protective layer. In some embodiments, an inner layer, a middle layer, an outer layer, or any combination thereof comprises a protective layer. In some embodiments, a portion of a layer comprises a protective layer. In some embodiments, the protective layer comprises a non-ferrous material. In some embodiments, the protective layer comprises polyvinyl chloride plastic. In some embodiments, the protective layer extends over the entire inner surface of the shield. In some embodiments, the protective layer extends over a portion of the inner surface of the shield.

[0135]

[0178] FIG. 13 illustrates an exemplary hook 1300 configured to span a portion or the entire volume of a shield. In some embodiments, one or more hooks 1300 are operably connected to (e.g., hold) wires and are designed to transmit analog electrical signals, digital electrical signals, or a combination thereof. In some embodiments, one or more hooks 1300 are positioned along a single plane of the shield. In some embodiments, hooks 1300 are positioned along two or more planes of the shield. Hooks are positioned along multiple planes. In some embodiments, hooks 1300 are positioned on an inner surface of the shield. In some embodiments, hooks 1300 are positioned circumferentially around the shield in a single cross-section. In some embodiments, hooks 1300 are positioned circumferentially around the shield and continue along the length of the shield. In some embodiments, hooks 1300 are configured to hold an electrical coil system, such as an electrical coil system designed to remove accumulated magnetic fields. In some embodiments, hooks 1300 are configured to hold an electrical coil system, such as an electrical coil system designed to create a homogenous magnetic environment within the shield. In some embodiments, the electrical coil system is configured to employ the use of variable gauge wire. An exemplary wire gauge suitable for use with the devices and systems described herein is 28 AWG, as shown in FIG.

[0136]

[0179] As shown in FIGS. 14A-14B, in some embodiments, the mobile cart device is capable of operating in a non-magnetically shielded environment. In some embodiments, the computer, electronics, or a combination thereof is housed within the mobile cart device itself. In some embodiments, the electronic control module is housed within a compartment (such as a cabinet) of the mobile cart device. In some embodiments, the mobile cart is configured to be powered by a battery (such as a mobile battery). In some embodiments, the arm of the device The system is configured for motorized movement in one or more degrees of freedom.

[0137]

[0180] An example of a mobile cart device 1400 is shown in FIGS. 14A-14B. This example is similar to the example shown in FIG. 4. In some embodiments, a device or system described herein comprises a base unit (e.g., a mobile base unit) and an array of sensors (e.g., optically excited magnetometers). In some embodiments, the array of sensors is housed within a housing 1404. In some embodiments, the housing 1404 is replaceable. In some embodiments, the housing 1404 is broadly configured to accommodate two or more sensor array configurations. In some embodiments, the housing 1404 is removable and configured to be replaced with a different housing. In some embodiments, the housing 1404 comprises motor features 1403, such that the sensor array position is adjusted by pressing the motor features 1403 on the housing 1404. In some embodiments, the adjustment is automated. In some embodiments, the adjustment is performed manually by a user pressing the motor features 1403. In some embodiments, the base unit comprises a structure, such as an arm, beam, rod, or protrusion, configured to allow a user to adjust the position of the array. In some embodiments, the arm is configured to attach to the sensor array or housing 1404, such as attached to bracket 1402. In some embodiments, the arm is extendable. In some embodiments, the arm is movable with one or more degrees of freedom. In some embodiments, the position of the arm, such as its extended position, is fixed by locking component 1401. In some embodiments, locking component 1401, such as a locking solenoid, is positioned on the arm. In some embodiments, locking component 1401 is operably integrated with motor feature 1403. In some embodiments, the base unit comprises a single compartment 1405. In some embodiments, the base unit comprises two compartments. In some embodiments, the base unit comprises multiple compartments. In some embodiments, compartment 1405 is configured to house one or more components.For example, compartment 1405 is configured to house a power source, so the base unit is not limited to remaining near a wall outlet or external power source. In some embodiments, compartment 1405 is configured to house a computer including an operating system, a database, a monitor, a graphical user interface, or any combination thereof. In some embodiments, compartment 1405 is configured to house one or more sensors or housings for the sensors. In some embodiments, compartment 1405 is configured to house a power source, a computer, one or more sensors, housings for the sensors, wiring, or any combination thereof. In some embodiments, the base unit includes a surface, such as a flat surface. In some embodiments, the surface is configured to hold a computer or other components of the system. In some embodiments, the base unit comprises one or more rotating elements. In some embodiments, the rotating elements comprise wheels, rollers, conveyor belts, or any combination thereof configured to provide movement of the base unit. In some embodiments, the base unit comprises an arm. One end of the arm is configured to attach to the array of sensors. In some embodiments, the second end of the arm is configured to attach to the base unit, e.g., in compartment 1405 or on a surface. In some embodiments, the arm is adjustable. For example, the arm is extendable lengthwise, e.g., a first portion of the arm extends from a second portion of the arm. In some embodiments, the base unit comprises wiring, such as one or more wires. The wiring is configured to attach to one or more sensors of the array, one or more power sources of the base unit, one or more computers of the base unit, or any combination thereof. In some embodiments, the base unit comprises a shield, such as a disposable shield or a modular shield. In some embodiments, The shield is separate from the base unit. In some embodiments, the shield is associated with the base unit, e.g., attached to the base unit at a location proximal to the array. In some embodiments, the shield is integral to the base unit. In some embodiments, the shield, the array, the arm, or any combination thereof, is operably connected (such as by wire or wirelessly) to a controller or computer system.

[0138]

[0181] 15A is a close-up view of an example of a sensor array 1500a. In some embodiments, the sensor array 1500a comprises one or more sensor plates. For example, in some embodiments, the sensor array 1500a comprises a bottom sensor plate 1501. In some embodiments, the bottom sensor plate 1501 is secured to other sensor components by one or more mounting bolts, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 mounting bolts. In some embodiments, the sensor array 1500a comprises a top sensor plate 1502. In some embodiments, the top sensor plate 1502 is secured to other sensor components by one or more mounting bolts, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 mounting bolts. In some embodiments, the sensor array 1500a comprises one or more sensor plate standoffs 1503. For example, in some embodiments, the sensor array 1500a comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 sensor plate standoffs.

[0139]

[0182] In some embodiments, the sensor array 1500a comprises one or more sensors 1506. In some embodiments, the sensor comprises a magnetometer sensor. In some embodiments, the sensor comprises an optically excited vector magnetometer or a zero-field magnetometer. In some embodiments, the sensor comprises a superconducting quantum interference device (SQUID), an inductive pickup coil, a vibrating sample magnetometer (VSM), a pulsed field extraction magnetometer, a torque magnetometer, a Faraday force magnetometer, an optical magnetometer, or any combination thereof. In some embodiments, the sensor comprises a miniature microelectromechanical (MEMS) magnetic field sensor.

[0140]

[0183] In some embodiments, the sensors do not include housings. In some embodiments, one or more sensors 1506 of sensor array 1500a include one or more sensor housings 1504a or 1504b. For example, in some embodiments, sensor array 1500a includes 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, or 24 sensor housings. In some embodiments, sensor array 1500a includes a sensor housing for each sensor in the array. In some embodiments, sensor array 1500a includes a sensor housing for at least every other sensor in the array. In some embodiments, the sensor housings are non-adjustable. In some embodiments, the sensor housings are movable within the sensor array unit to accommodate two or more sensor array configurations. In some embodiments, the sensor housings are fixed in place by one or more mounting bolts. In some embodiments, the sensor array 1500 a is held in place by a sensor housing cap 1505 .

[0141]

[0184] In some embodiments, the sensor array 1500a comprises a handle 1510. In some embodiments, actuation of the handle 1510, such as a rotational movement, causes movement (e.g., linear movement) of the sensor array 1500a (i) away from or towards an individual, (ii) away from or towards an arm of a mobile cart device, or (iii) a combination thereof. The handle 1510 is manually operated. In some embodiments, actuation of the handle 1510 is automated. In some embodiments, when the handle 1510 is actuated, a screw 1509, such as a lead screw, In some embodiments, rotation of the screw 1509 allows movement of one or more shafts on the sensor array.

[0142]

[0185] In some embodiments, the sensor comprises an element 1512 for coupling two or more shafts 1508a or 1508b (such as shaft 1508a (such as a linear motion shaft) and shaft 1511 (such as a square motion transmission shaft) for transmission of motion (such as linear motion of the sensor array away from or towards the individual). In some embodiments, the shafts also comprise a stop element such as a dog clutch. In some embodiments, element 1512 is operably coupled to handle 1510, screw 1509, one or more shafts such as shaft 1508a and shaft 1511, or any combination thereof.

[0143]

[0186] In some embodiments, sensor array 1500a includes bracket 1507, such as a support bracket. In some embodiments, the bracket provides spatial orientation of one or more shafts and one or more screws of the sensor array relative to one another. In some embodiments, the bracket is operably coupled to shaft 1508a, shaft 1511, screw 1509, element 1512, or any combination thereof.

[0144]

[0187] In some embodiments, sensor array 1500a includes a stop 1513, such as a personal stop. In some embodiments, stop 1513 is configured to be positioned on a surface of the individual. In some embodiments, stop 1513 is configured to be positioned a specified distance from the surface of the individual. In some embodiments, stop 1513 is configured to prevent the sensor array from advancing beyond a specified position, such as the surface of the individual. In some embodiments, stop 1513 is positioned on a surface of the sensor array that is positioned closest to the subject during operation.

[0145]

[0188] An example of a mobile cart device 1500b is shown in FIG. 15B. This example is similar to the examples shown in FIGS. 6 and 7. In some embodiments, the mobile cart device 1500b comprises an arm 1514. In some embodiments, the arm 1514 comprises a first end and a second end. In some embodiments, the sensor array is coupled to the first end of the arm 1514. In some embodiments, the opposite end of the arm 1514 is coupled to a frame, the frame having a first support beam 1517a and a second support beam 1517b. In some embodiments, the opposite end of the arm 1514 is coupled to the frame at an upper bracket 1518 of the frame. In some embodiments, the mobile cart device 1500b comprises a second arm. In some embodiments, the second arm comprises a top support arm 1515 and a bottom support arm 1516. In some embodiments, the first end of the second arm is coupled to the arm 1514 at a location between the first and second ends of the arm 1514. In some embodiments, the second end of the second arm is coupled to the frame, for example, by a bracket 1519 (such as a rocker bracket) on the frame. In some embodiments, the mobile cart device 1500b comprises one or more rotating elements, such as wheels 1522. In some embodiments, the rotating elements are operably coupled to one or more axles 1521 (e.g., two rotating elements operably coupled to a single axle), one or more bearings 1523, or a combination thereof, such that rotation of the two rotating elements occurs in unison. In some embodiments, the mobile cart device 1500b comprises two rotating elements. In some embodiments, the mobile cart device 1500b comprises one rotating element. In some embodiments, the rotating element is configured to move the mobile cart device 1500b from one location to a different location. In some embodiments, the mobile cart device 1500b comprises mooring elements 1524, such as rubber feet, to moor the mobile cart device 1500b at a desired location or to prevent further movement of the rotating elements. In some embodiments, The mobile cart device 1500b includes one mooring element. In some embodiments, the mobile cart device 1500b includes two or more mooring elements, such as two or three mooring elements. One or more rotating elements, axles, mooring elements, or any combination thereof, are operably coupled to the mobile cart device 1500b by one or more fixtures 1520.

[0146]

[0189] In some embodiments, the mobile cart device 1500b switches configurations from an extended configuration (FIG. 15B) to a closed configuration (FIG. 15C). In embodiments including the extended configuration, the arms 1514 fold adjacent to the frame so that the mobile cart device can be stored or easily moved to a different location.

[0147]

[0190] In some embodiments, the performance of the magnetometer is improved by balancing. In these embodiments, a gradient of 1 nT / m is achieved within the shield. In some embodiments, balancing includes a demagnetization process.

[0148]

[0191] In some embodiments, a shield configured to utilize a balancing process comprises an arrangement of coils. Typically, the coils are arranged in one or more layers. In some embodiments, the shield comprises an inner coil layer and one or more outer coil layers, where the inner coil corresponds to the innermost layer and the outer coil corresponds to each of the outer layers.

[0149]

[0192] In some embodiments, the inner coils are distributed at 45 degrees (relative to the 90 cm diameter of the cylinder), effectively forming eight coils. The machine mounting accuracy is approximately ±2 cm per wire. Generally, many different configurations are acceptable for the outer coils. In some embodiments, the shield comprises one outer coil. In some embodiments, the shield comprises two outer coils. In some embodiments, the shield comprises three outer coils. In some embodiments, the shield comprises four outer coils. In some embodiments, the shield comprises five outer coils. In some embodiments, the shield comprises six outer coils. In some embodiments, the shield comprises seven outer coils. In some embodiments, the shield comprises eight outer coils. In some embodiments, the shield comprises nine outer coils. In some embodiments, the shield comprises ten outer coils.

[0150]

[0193] In some embodiments, at least the inner layers must be electrically isolated. In some embodiments, ESD PVC is used instead of regular plastic simply to avoid charging effects that would interfere with the magnetometer.

[0151]

[0194] Figure 22 shows an exemplary layout of one inner coil 2200 positioned on one embodiment of the shield. Figure 23 shows an exemplary layout of one outer coil 2300 positioned on one embodiment of the shield.

[0152]

[0195] In some embodiments, the connection to the amplifier (or transformer) is opened during measurements by the magnetic field probe, hi some embodiments, this is achieved using a mechanical relay.

[0153]

[0196] Wire dimensions are typically at least 2.5 mm², with 4 mm² being preferred. For test devices, we suggest a coil with 3 turns per eighth, for a total of 24 turns. We cannot estimate the permeability, but it should be comparable to Krupp Magnifer material (with which we are more familiar). Thus, 24 turns would produce approximately 1 Ohm and a saturation current of 10 A, which would result in 10 V.

[0154]

[0197] In some embodiments, the balancing sequence is a 30-second sequence with a linearly decreasing envelope from the saturated state of the inner layer. This sequence is required whenever a significant change in the magnetic field is applied. During normal operation, we believe that 1-3 times per day is reasonable. The outer shield should only be balanced once using the same amplifier (and therefore the number of turns on the coil should be similar for use with the same equipment), such as when the shield is installed or when the external magnetic field changes direction by 90 degrees.

[0155]

[0198] In some embodiments, the balancing coils are individual wires with gold-plated contacts. Due to magnetization issues, Ni substrates or coatings cannot be used for the internal connectors. In some embodiments, due to the required level of precision, the balancing coils for the outer shield can be randomly placed without special precautions, whereas the inner coils require at least six-fold symmetry for a 60 cm diameter and eight-fold symmetry for a 1 m diameter to obtain a reasonably shaped residual magnetic field due to the current distribution. For the demonstrated design, we choose brass connectors with gold coatings and no (very little) nickel intermediate layer to avoid excessive magnetization. All connectors must be placed outside the inner shield layer. Connector magnetization (at this level) is not related to the internal residual magnetic field.

[0156]

[0199] The balancing process used in some embodiments of the shield described herein is a process for bringing the magnetizable material into equilibrium with the surrounding magnetic field. In some embodiments, this is done by applying a sinusoidal current around the magnetizable material. The oscillations are very tightly centered around zero and are large enough to saturate the material in both directions. By reducing the amplitude to zero, a very low magnetic field strength is obtained outside the magnetizable material (inside the cylinder). For initial testing, a linearly decreasing envelope is useful because it is a very reliable function. This model is programmed into the balancing unit. In the future, an exponentially decreasing function may be advantageous. A pre-set function (which the user can change on the PC) is shown below:

[0157]

[0200] Figure 24 shows a typical balance function. Initially, maximum current is maintained for 10 cycles, then reduced until zero amplitude is reached. Note that at extreme performance levels, many options for variation and improvement are available.

[0158]

[0201] In some embodiments, the balanced coil is connected to the electrical equipment using twisted pair cable. No RF shielding or other precautions are required because higher frequencies are attenuated by the shielding material and the inductance of the coil configuration (mH range).

[0159]

[0202] In some embodiments, the computing device programs a sinusoidal function with an envelope function, which is converted to a voltage signal by an NI6281 data acquisition device. The voltage is fed to a voltage divider, which then drives a power amplifier. This function can be set by the user and is programmable. The timing resolution of the curve is 10 kHz.

[0160]

[0203] In some embodiments, there is a box with potentiometers inside the control box. These potentiometers can be manually adjusted to set the ratio of the DAC voltage to the current from the amplifier. This minimizes the effect of the bit size on the residual field (16 bits = 0.3 mV resolution for 20 V). From experience, this optimization relates to a residual field of less than 0.5 nT. There are two potentiometers to adjust the different currents, which can be selected via software. In noisy environments, the voltage divider box applies additional frequency filtering with capacitors. In some embodiments, bandpass filtering of the amplifier is sufficient for most applications.

[0161]

[0204] In some embodiments, the power amplifier is a four-quadrant amplifier capable of operating with large inductive loads, inherently fail-safe against erroneous operation, such as short-circuits and numerous inductive spikes. For magnetic balance, the amplifier should be used in current-controlled mode, but it can be operated in any configuration. For extreme noise requirements, it is preferable to modify the coil (cross section and number of turns) around the magnetizable material to match the amplifier's maximum power. The power is selected to be very small for extremely low-noise operation. A bandpass filter can be manually set from the front panel to reduce noise effects. The amplifier can be fully remotely controlled via a sub-D connector on the rear panel. A unique feature of this amplifier is the ability to adjust the baseline by 1% via an analog ±10V input, regardless of the signal input.

[0162]

[0205] In some embodiments, noise and drift of the magnetic field probe are a concern for performing DC measurements. In some embodiments, two 3-channel Bartington Fluxgates, model Mag03-IEL-70, with a noise amplitude (peak-to-peak) of less than 6 pT are used. Two electronics units each supply three sensors, with each flying lead sensor having a cable length of 5 m. In some embodiments, for example, the readout of one or more fluxgates is performed by an NI62811 8-bit analog input unit to provide sufficient resolution of the fluxgate analog signal (±10 V). No voltage divider is required to match this range. The USB control is only for data transfer to the PC, and the NI unit is independently grounded and has an independent power supply. In some embodiments, the readout rate is set to 625,000 samples per second.

[0163]

[0206] Evaluation of coronary artery disease

[0207] Also described herein is a method for determining the possible presence of coronary artery disease in an individual (e.g., myocardial ischemia, with or without accompanying epicardial coronary artery disease), the method comprising the steps of: identifying a first negative electromagnetic dipole and a first positive electromagnetic dipole in a first electromagnetic field map associated with the individual's heart at a first time; identifying a second negative electromagnetic dipole and a second positive electromagnetic dipole in a second electromagnetic field map associated with the individual's heart at a second time; determining a first angle based on the first negative electromagnetic dipole and the first positive electromagnetic dipole; determining a second angle based on the second negative electromagnetic dipole and the second positive electromagnetic dipole; and determining the possible presence of coronary artery disease in the individual if the first angle differs from the second angle by at least 100 degrees or if a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map.

[0164]

[0208] FIG. 25 illustrates an exemplary method 2500 for assessing the presence of coronary artery disease (e.g., myocardial ischemia with or without associated epicardial coronary artery disease) in an individual. Method 2500 may include, for each of an R-wave electromagnetic field map and a T-wave electromagnetic field map, identifying a negative electromagnetic dipole and a positive electromagnetic dipole in the electromagnetic field map (shown at 2502). Method 2500 may then include determining a peak R depolarization angle and a peak T repolarization angle based on the electromagnetic dipoles of the R-wave and T-wave electromagnetic field maps, respectively (shown at 2504). Method 2500 may then include determining an RT peak angle difference based on the absolute difference between the peak R depolarization angle and the peak T repolarization angle (shown at 2506). Method 2500 may then determine the presence of coronary artery disease (e.g., myocardial ischemia) in the individual if the RT peak angle difference is at least 100 degrees (or the electromagnetic field map has a third electromagnetic dipole). For example, this may include assessing the presence of myocardial ischemia, with or without associated epicardial coronary artery disease (as shown at 2508).

[0165]

[0209] In some embodiments, the method further includes sensing a first electromagnetic field associated with the individual's heart at a first time and sensing a second electromagnetic field associated with the individual's heart at a second time, wherein the first electromagnetic field map includes a representation of the first electromagnetic field and the second electromagnetic field map includes a representation of the second electromagnetic field.

[0166]

[0210] As one example, coronary artery disease can include cardiac ischemia (e.g., occlusion of the left anterior descending artery). As another example, coronary artery disease can include demand-increased ischemia (e.g., hyperthyroidism, malignant hypertension, tachycardia, and sepsis).

[0167]

[0211] In some embodiments, the first angle includes a peak R depolarization angle at a first time. The first time can be the time when an R wave is recorded on an electrocardiogram. For example, the peak R depolarization angle can be determined by determining a first line passing through both the first negative electromagnetic dipole and the first positive electromagnetic dipole and determining the angle between the first line and a horizontal axis.

[0168]

[0212] In some embodiments, the second angle includes a peak T repolarization angle at a second time. The second time can be the time when a T wave is recorded on an electrocardiogram. For example, the peak T repolarization angle can be determined by determining a second line that passes through both the second negative electromagnetic dipole and the second positive electromagnetic dipole and determining the angle between the second line and a horizontal axis.

[0169]

[0213] In some embodiments, a third electromagnetic dipole is present in the first or second electromagnetic field map, which is referred to as multiple electromagnetic dipoles on the first or second electromagnetic field map.

[0170]

[0214] In some embodiments, the possible presence of coronary artery disease (e.g., myocardial ischemia, with or without epicardial coronary artery disease) in an individual is determined to be present if the first angle differs from the second angle by at least 100 degrees (e.g., between 100 degrees and 170 degrees). In other words, the possible presence of coronary artery disease (e.g., myocardial ischemia, with or without epicardial coronary artery disease) can be identified as present in an individual based on an RT peak angle difference of at least 100 degrees (e.g., falling within the range of 100 degrees to 170 degrees).

[0171]

[0215] In some embodiments, the possible presence of coronary artery disease (e.g., myocardial ischemia, with or without epicardial coronary artery disease) in an individual is determined to be absent if the first angle differs from the second angle by less than 100 degrees (or the magnetic field map has a third electromagnetic dipole). In other words, the possible presence of coronary artery disease (e.g., myocardial ischemia, with or without epicardial coronary artery disease) can be identified as absent in an individual based on an RT peak angle difference of less than 100 degrees (or the magnetic field map has a third electromagnetic dipole).

[0172]

[0216] In some embodiments, the method further includes recording an electrocardiogram of the individual. The individual may have a normal electrocardiogram while experiencing chest pain, or may have normal troponin levels while experiencing chest pain. The individual may have had a positive stress test or abnormal echocardiogram findings. If possible coronary artery disease (e.g., myocardial ischemia with or without epicardial coronary artery disease) is determined for the individual (e.g., if the first angle is different from the second angle, or if the first electromagnetic field map or if a third electromagnetic dipole is present in the second electromagnetic field map), a stress test can be performed on the individual.

[0173]

[0217] In some embodiments, the method further includes determining the possible presence of a conduction abnormality in the individual's heart if the first positive electromagnetic dipole and the second negative electromagnetic dipole have the same location, or if the first negative electromagnetic dipole and the second positive electromagnetic dipole have the same location. In some embodiments, the method further includes administering to the individual a treatment for cardiac ischemia (e.g., whether or not the mechanism results in myocardial ischemia). For example, the treatment may include one or more of a daily prescription of aspirin or ibuprofen, administration of a blood pressure-lowering agent, administration of a lipid-lowering agent, cardiac catheterization, surgical intervention, or a combination thereof.

[0174]

[0218] Also described herein is a non-transitory computer-readable medium including machine-executable code that, when executed by one or more computer processors, implements a method for determining the likelihood of the presence of coronary artery disease (e.g., myocardial ischemia with or without associated epicardial coronary artery disease) in an individual, the method including the steps of identifying a first negative electromagnetic dipole and a first positive electromagnetic dipole in a first electromagnetic field map associated with the individual's heart at a first time, and identifying a second negative electromagnetic dipole and a first positive electromagnetic dipole in a second electromagnetic field map associated with the individual's heart at a second time. determining a first angle based on the first negative electromagnetic dipole and the first positive electromagnetic dipole; determining a second angle based on the second negative electromagnetic dipole and the second positive electromagnetic dipole; and determining a possible presence of coronary artery disease in the individual (e.g., myocardial ischemia with or without associated epicardial coronary artery disease) if the first angle differs from the second angle by at least 100 degrees or if a third electromagnetic dipole is present in the first or second electromagnetic field map.

[0175]

[0219] 26A-26B show an example (FIG. 26A) of how the methods and systems of the present disclosure can be used to analyze electrical currents in an organ or tissue of interest (e.g., the heart) and determine its associated magnetic field, including a depiction of Ampere's Law, as well as an example magnetic field map (FIG. 26B) generated from the electrical current. FIG. 26A shows that, according to Ampere's Law, by the right-hand rule, an electrical current I traveling through a long, straight wire generates a magnetic field B around the wire. FIG. 26B shows an example magnetic field map generated from an electrical current by the systems, devices, and methods of the present disclosure, including color-coded intensity of the current vectors indicating a negative electromagnetic dipole 2602 (shown in blue), a positive electromagnetic dipole 2604 (shown in red), and an area of ​​zero magnetic field 2606 (shown in green) corresponding to the current source. Alternatively, any color can be arbitrarily selected to represent the positive and negative electromagnetic dipoles and the color-coded intensity of the current vectors indicating the area of ​​zero magnetic field corresponding to the current source.

[0176]

[0220] Figures 27A-27B show an example of how the methods and systems of the present disclosure can be used to analyze electrical currents in a target organ or tissue (e.g., the heart) and determine its associated magnetic field, including a depiction of the peak R depolarization angle 2702 (Figure 27A) and a depiction of the peak T repolarization angle 2704 (Figure 27B), where an increase in the RT angle gap indicates cardiac ischemia in the target heart.

[0177]

[0221] As shown in Figure 27A, the peak R depolarization angle can be determined from a magnetic field map generated during the period in which the R wave (and corresponding R peak) is measured using an ECG. The R peak of the magnetic field map represents the aggregate depolarization of the heart.

[0178]

[0222] Interpretation of the magnetic field map involves the presence of positive magnetic poles (e.g., shown in red) and The method may include identifying a positive magnetic pole and a negative magnetic pole (e.g., shown in blue). For example, the positive magnetic pole may be determined as the center (e.g., center of mass) of positive magnetic field values, and the negative magnetic pole may be determined as the center (e.g., center of mass) of negative magnetic field values. A first vector may be defined between the positive magnetic pole and the negative magnetic pole for purposes of determining an angle therefrom. Alternatively, a first line, line segment, or ray may be defined between the positive magnetic pole and the negative magnetic pole for purposes of determining an angle therefrom. A second vector may be defined as a horizontal vector (e.g., having the same direction as the positive x-axis) for purposes of determining an angle therefrom. Alternatively, a second line, line segment, or ray may be defined parallel to the horizontal vector (e.g., having the same direction as the positive x-axis) for purposes of determining an angle therefrom. Without loss of generality, the second vector, line, line segment, or ray may pass through the negative magnetic pole (shown in blue). Alternatively, the second vector, line, line segment, or ray may pass through another point (e.g., any point between the positive and negative magnetic poles) without affecting the determination of the angle therefrom. The first and / or second vector may be represented using any suitable coordinate system, including, but not limited to, 2D Cartesian coordinates, 3D Cartesian coordinate systems, Cartesian coordinate systems, parametric coordinate systems, and polar coordinate systems.

[0179]

[0223] After determining the first and second vectors, a vector angle can be defined based on the positive and negative magnetic poles at a given time. The vector angle can represent the angle between the first and second vectors. The vector angle can be determined as the minimum angular change between the first and second vectors. For example, the vector angle can have a value between 0 and 360 degrees, or equivalently, can have a value added or subtracted from any integer multiple of 360 to arrive at a value between 0 and 360 degrees. As an example, the vector angle θ can be determined using the formula cos(θ) = a·b / (|a||b|), where a and b represent the first and second vectors, respectively, "·" represents the dot product of the vectors, and "||" represents the magnitude of the vector. The peak R depolarization angle can be determined as the vector angle of the magnetic field map associated with the period during which the R wave (and corresponding R peak) (which can be measured, for example, using an ECG) occurs.

[0180]

[0224] In some embodiments, a computer-implemented algorithm can be executed to determine one or more of a positive magnetic electromagnetic dipole, a negative magnetic electromagnetic dipole, a first vector, a second vector, and a vector angle based on analysis of the magnetic field map. The computer-implemented algorithm can determine the vector angle regardless of whether or not it explicitly generates one or more of the positive magnetic electromagnetic dipole, the negative magnetic electromagnetic dipole, the first vector, and the second vector.

[0181]

[0225] As shown in Figure 27B, the peak T repolarization angle can be determined from a magnetic field map generated during the period in which the T wave (and corresponding T peak) is measured using an ECG. The T peak of the magnetic field map represents the aggregate repolarization of the heart.

[0182]

[0226] Interpretation of the magnetic field map can include identifying a positive magnetic pole (e.g., shown in red) and a negative magnetic pole (e.g., shown in blue) during the duration of the T wave. For example, the positive magnetic pole can be determined as the center (e.g., center of mass) of the positive magnetic field value, and the negative magnetic pole can be determined as the center (e.g., center of mass) of the negative magnetic field value. A first vector can be defined between the positive and negative magnetic poles for purposes of determining the angle therefrom. Alternatively, a first line, line segment, or ray can be defined between the positive and negative magnetic poles for purposes of determining the angle therefrom. A second vector can be defined as a horizontal vector (e.g., having the same direction as the positive x-axis) for purposes of determining the angle therefrom. Alternatively, a horizontal vector ( For example, a second line, line segment, or ray may be defined that is parallel to the positive x-axis (e.g., having the same direction as the positive x-axis). Without loss of generality, the second vector, line, line segment, or ray may pass through the negative magnetic pole (shown in blue). Alternatively, the second vector, line, line segment, or ray may pass through another point (e.g., any point between the positive and negative magnetic poles) without affecting the determination of the angle therefrom. The first and / or second vector may be represented using any suitable coordinate system, including, but not limited to, 2D Cartesian coordinates, 3D Cartesian coordinate systems, Cartesian coordinate systems, parametric coordinate systems, and polar coordinate systems.

[0183]

[0227] After determining the first and second vectors, a vector angle can be defined based on the positive and negative magnetic poles at a given time. The vector angle can represent the angle between the first and second vectors. The vector angle can be determined as the minimum angular change between the first and second vectors. For example, the vector angle can have a value between 0 and 360 degrees, or equivalently, can have a value added or subtracted from any integer multiple of 360 to arrive at a value between 0 and 360 degrees. As an example, the vector angle θ can be determined using the formula cos(θ) = a·b / (|a||b|), where a and b represent the first and second vectors, respectively, "·" represents the dot product of the vectors, and "||" represents the magnitude of the vector. The peak T repolarization angle can be determined as the vector angle of the magnetic field map associated with the period during which the T wave (and corresponding T peak) (which can be measured, for example, using an ECG) occurs.

[0184]

[0228] Figure 28 shows how the heart generates electricity, including (1) depolarizing ion flow (non-energy dependent) where sodium slows entering the cell and potassium leaves the cell, (2) large amounts of calcium enter the cell, (3) calcium stops entering the cell and potassium leaves the cell, and (4) repolarizing ion flow (highly energy dependent) where the balance of ions inside and outside the cell is restored (repolarized), as well as heart attack / ischemic cells where damaged cells become stuck (depolarized) in section 3 and are unable to contract.

[0185]

[0229] FIG. 29 shows a "Wiggers Diagram" depicting the cardiac cycle, showing ventricular volumes, ventricular pressures, aortic pressures, and atrial pressures, demonstrating that electrical generation precedes mechanical function of the heart.

[0186]

[0230] 30 shows an example of an assessment of patient inspiration using the systems, devices, and methods of the present disclosure, including patients who underwent stress testing, MCG-negative or MCG-positive patients, ST-negative or ST-positive patients, and CA-positive or CA-negative patients. In this example, a total of 97 patients presented to an outpatient clinic and underwent stress testing for further evaluation, of which 90 patients received MCG-negative results and 7 patients received MCG-positive results.

[0187]

[0231] Of the 90 patients with negative MCG results, 81 patients received negative ST results and 9 patients received positive ST results. Of the 9 patients with positive ST results, 4 patients received positive CA results and 5 patients received negative CA results. Furthermore, of the 7 patients with positive MCG results, 4 patients received positive ST results and 3 patients received negative ST results. Of the 4 patients with positive ST results, 3 patients received positive CA results and 1 patient received negative CA results. Of the 3 patients with negative ST results, all 3 patients received negative CA results.

[0188]

[0232] As a result of the above, 81 patients were determined to be likely to be discharged early, a small number still required stress testing for unstable angina before a decision was made, and 16 false-positive cases were eliminated, leaving only 2 false-positive cases, with the remaining cases requiring treatment. Therefore, no acute ischemia qualifies for early discharge and non-urgent outpatient evaluation.

[0189]

[0233] Figure 31 shows an example workflow for chest pain triage according to clinical standards of care. After a patient with chest pain presents to the emergency department, the patient undergoes a medical history and physical examination, an ECG, and an initial troponin blood draw for troponin testing. Based on a HEART score of 7–10, the patient is then assessed for a 17% high risk of cardiac ischemia, regardless of the presence or absence of epicardial coronary artery disease (CAD). Based on a HEART score of 4–6, the patient is assessed for a 47% moderate risk of cardiac ischemia. Based on a HEART score of 0–3, the patient is assessed for a 36% low risk of cardiac ischemia. If a high-risk score is given, the patient undergoes catheterization. Conversely, if a low-risk score is given, the patient is discharged. However, approximately 70% of the time, the patient undergoes stress testing, CTA, and other cardiac imaging studies. This does not result in improved outcomes, as nearly 200,000 ACS patients in the United States are missed in the emergency department and will experience a major adverse cardiac event (MACE) within 30 days. The average time to diagnosis can take 8 to 10 hours for a HEART risk score assessment and up to 14 hours if the patient undergoes stress testing, CTA, and other cardiac imaging studies. Thus, patients are typically not discharged until 8 to 24 hours after presenting to the emergency department.

[0190]

[0234] FIG. 32 illustrates an example of an improved workflow for chest pain triage using the disclosed systems, devices, and methods. After a patient with symptoms of chest pain presents to the emergency department, the patient undergoes a medical history and physical examination, an ECG test, and an initial troponin blood draw for troponin testing. Based on a HEART score of 7 to 10, the patient is then assessed for a 17% high risk of cardiac ischemia, with or without epicardial coronary artery disease (CAD); a HEART score of 4 to 6 for a 47% moderate risk of cardiac ischemia; and a HEART score of 0 to 3 for a 36% low risk of cardiac ischemia, with or without epicardial ischemia. If a high-risk score is given, the patient is admitted to the hospital, given intravenous heparin with or without nitroglycerin, and then undergoes catheterization. Conversely, if a low or moderate-risk score is given, a negative result is confirmed using the disclosed MCG imaging and analysis systems, devices, and methods, and the patient is then discharged. This reduces the need for additional, often unnecessary, stress tests, CTAs, and other cardiac imaging studies. As a result, the disclosed MCG imaging and analysis systems, devices, and methods are positioned for low- and moderate-risk chest pain patients, for whom ACC / AHA guidelines do not require observation hospitalization and / or stress tests / CTAs. This can enable an improvement in time to discharge of 6 to 20 hours per patient. [Example]

[0191]

[0235] The following provides non-limiting examples and elements of embodiments of the methods, devices, and systems described herein.

[0236] Example 1 ● Magnetically shielded environment: including minimum dimensions of approximately 7 feet wide x 7 feet deep x 7 feet high. In some embodiments, the magnetically shielded environment has a DC shielding factor of at least about 500 at all points at least 1 foot from each surface of the magnetically shielded environment, with a minimum shielding factor of about 56 decibels (dB) from a bandwidth of about 0.1 Hz to about 500 Hz.

[0192] A cart with a computer: located outside the magnetically shielded environment. Connected to the computer are electronic control modules for the sensors that are part of the attached device. In some embodiments, each module provides power and control instructions to one sensor in the array located on the device arm. The setup 1600 in an exemplary embodiment is shown in FIG. It appears as shown in.

[0193] 16, an individual lies in a supine position on a base unit (e.g., a bed) 1607. By adjusting the arm 1605 of the mobile cart device, a sensor array 1606 is positioned adjacent to a location of the subject, such as a chest location. A shield 1603 is positioned between (i) the subject and sensor array 1606 and (ii) one or more additional devices 1601, such as an electrical device, a power source, a computer, or any combination thereof. One or more subcomponents 1602 (e.g., wiring) required to operably connect the one or more additional devices and the sensor array 1606 are housed within tubing or a cover. An opening 1604 in the shield 1603 is configured to receive the one or more subcomponents 1602 to pass through the opening 1604.

[0194] 17, in some embodiments, shield 1700 comprises two or more layers, such as first layer 1701 and second layer 1702. In some embodiments, first layer 1701 and second layer 1702 are adjacent to one another. In some embodiments, first layer 1701 and second layer 1702 are separated by a gap.

[0195] In some embodiments, the base unit (e.g., the patient's bed) is positioned within a magnetically shielded environment in which the individual is positioned (e.g., lying supine) prior to use of the device. The bed is constructed from non-ferromagnetic materials (e.g., constructed entirely from non-ferromagnetic materials) and non-permanent magnets to minimize the amount of interference that the device may read.

[0196]

[0237] Configuration: To configure the device for use, one or more of the following exemplary steps are performed. ● Ensure the device frame and sensor housing are located inside a magnetically shielded room. Keep the device in storage mode with the device arms folded.

[0197] ● Ensure that the control unit is connected to the sensor housing and device frame through one or more portals in the magnetically shielded room. ● Power on the computer interface and start the software application (e.g., Maxwell).

[0198] ● Apply power to the electronic control module. ● Position the individual on the base unit 1704 (i.e., bed) with the individual's head aligned with one side of the base unit 1704 and the individual's feet aligned with a second side of the base unit 1704, as shown in Figure 17. The magnetically shielded room has sufficient clearance to position a magnetocardiograph along at least one side of the base unit 1704.

[0199] ● The individual is positioned on the base unit 1704, which is configured such that at least a portion of the base unit 1704 is slidable in and out of the shield opening. The base unit 1704 is configured to slide on a track 1705 or may slide on one or more rollers or wheels. At least a portion of the subcomponent 1703, such as wiring, is configured to operably connect the sensor array to one or more other devices and is configured to enter at least a portion of the shield 1700. The subcomponent 1703 attaches to a hook or latch or track structure in the shield 1700.

[0200] ● Extend the arms of the frame so that they form an angle of approximately 90 degrees with respect to the vertical part of the frame that has the handle (such as a curved handle). ● Move the device towards the subject by pulling the handle on the frame. Position the device so that the sensor housing is over the subject's area of ​​interest (such as the chest area). Make small adjustments to place the square platform in an optimal position.

[0201] - Align the housing on the left side of the individual so that the right-most side of the sensor array platform is located on or proximal to, and parallel to, the individual's midline. ● The height of the sensor housing is adjusted using a lifting mechanism on the end of the arm of the frame. The sensor housing is lowered to a location over or proximal to the individual's area of ​​interest (e.g., chest). To lower the sensor housing, rotate the handle in a first direction. To raise the sensor housing, rotate the handle in a second direction.

[0202]

[0238] Start: After the frame is in place, one or more sensors are activated, preparing to record signals such as cardiac magnetic activity. To begin, the user logs into the software application (e.g., Maxwell) and selects the data acquisition module. If there is a problem with any of the following steps, the application will close and attempt to restart. If the problem persists, the computer interface will be rebooted. To begin using the device, comply with one or more of the following:

[0203] ● Ensure that connections exist to all sensors (e.g., 8 sensors) by checking the sensor status within the data acquisition software user interface. Initiate the autostart procedure with the software application by pressing "autostart" within the data acquisition software user interface. This process will calibrate the sensor or sensors for use. Before continuing, ensure that the ready indicator seen within the software UI turns green and shows a status of "ready."

[0204]

[0239] Recording: After initiation is complete, the device is ready to capture signals such as cardiac magnetic field data. Initially, one or more of the following is performed: - Select the "acquire" button within the software application. Selecting this option will display the magnetic fields collected from the sensor within the viewing window found in the acquisition software UI.

[0205] • Ensure that the magnetic fields collected are specific to signals such as cardiac electrical activity. ● Select the "record" option to save the data to a file. Select your preferences for the length of data capture period, file name, and file save location. Select "save" to begin saving to a file. In some embodiments, the application will automatically stop saving after a selected amount of time has elapsed. Files are named according to institutional policy to protect subject identification information.

[0206]

[0240] Power Down and Storage: After use of the device is complete, the system is powered down by one or more of the following: ● Close applications on your computer.

[0207] - Shut off power to the electronic control module by turning the toggle switch to the "off" position. ● Power down the computer.

[0208]

[0241] To raise the sensor platform, the handle of the device is rotated in a first direction within the magnetically shielded housing. By pulling the handle (e.g., a curved handle), the device is moved to another position so that the arm does not intersect with the subject or base unit (e.g., a bed). The extension arm is moved downward toward the ground to return the device to the stowed mode. The subject is assisted in rising from the base unit. The user, the subject, or a combination thereof, has a magnetically shielded housing.

[0209]

[0242] Example 2

[0243] Configuration: To configure the device for use, one or more of the following exemplary steps are performed.

[0210] ● Ensure that the device frame and sensor housing are free of defects or damage. ● Power up the computer interface and start the software application.

[0211] ● Apply power to the electronic control module. ● Pull the base unit (e.g., bed) out of the magnetic shielding chamber until the bed is completely outside the shielding chamber.

[0212] ● Ensure that the locking components on the sensor array and arm (such as an extension arm) are unlocked. Move the sensor array away from the base unit so that the sensor array or any part of it is not positioned above the base unit.

[0213] Assist the individual onto the surface of the base unit: Position the individual on the base unit so that their head is aligned with the hole opening and their feet are aligned with the other, as shown in FIG.

[0214] - Moving the sensor array over an area of ​​interest of an individual (such as the individual's chest). - Make adjustments to ensure the sensor array platform is correctly positioned: The housing is aligned with the left side of the object so that the right-most side of the sensor array platform is above and parallel to the centerline of the object.

[0215] - Lower the sensor array platform to adjust the height of the sensor housing: The housing is lowered to a point that can be located on or proximal to the location of interest (eg, chest) of the subject.

[0216] • Locking the pivot or articulation or extension points of the sensor array to limit the movement of the array. - Slide the base unit into the recessed opening in the shield until an external light is indicated on the device (for example, it lights up or changes color, such as becoming green).

[0217]

[0244] Start: After the frame is in place, one or more sensors are activated, preparing to record signals such as cardiac magnetic activity. To begin, log into the software application and select the data acquisition module. If there is a problem with any of the following steps, the application will close and attempt to restart. If the problem persists, the computer interface will be rebooted. To begin using the device, one or more of the following will be done:

[0218] ● Check sensor status within the data acquisition software user interface Thus, it ensures that there is a connection to one or more sensors (eg, eight sensors).

[0219] Initiate the autostart procedure with the software application by pressing "autostart" within the data acquisition software user interface. This process will calibrate the sensor or sensors for use. Before continuing, ensure that the ready indicator seen within the software UI turns green and shows a status of "ready."

[0220]

[0245] Recording: After initiation is complete, the device is ready to capture signals such as cardiac magnetic field data. Initially, it adheres to one or more of the following: - Select the "acquire" button within the software application. Selecting this option will display the magnetic fields collected from the sensor within the viewing window found on the acquisition software UI.

[0221] • Ensuring that one or more collected magnetic fields are characteristic of a signal such as cardiac electrical activity. ● Select the "record" option to save the data to a file. Select your preferences for the length of time the data is captured, the file name, and where the file is saved. Select "save" to begin saving to the file. The application will automatically stop saving after the selected amount of time has elapsed. Files are named according to institutional policy to protect subject identities.

[0222]

[0246] Power Down and Storage: After use of the device is complete, the system is powered down by one or more of the following: ● Close applications on your computer.

[0223] - Shut off power to the electronic control module by turning the toggle switch to the "off" position. ● Power down the computer.

[0224]

[0247] The base unit (e.g., a bed) is removed from the magnetically shielded chamber. One or more joints, pivots, or extensions, or combinations thereof, of the sensor array or arm are unlocked and moved away from the base unit, thus moving the motion path away from the individual. The subject is assisted in moving away from the base unit. Between use with the first subject and use with the second subject, one or more of the sensor array, the sensor housing, the inner surface of the shield, the surface of the base unit, or any combination thereof, are cleaned or disinfected.

[0225]

[0248] Example 3

[0249] Configuration: To configure the device for use, one or more of the following exemplary steps are performed.

[0226] ● Power up the computer interface and start the software application. ● Apply power to the electronic control module.

[0227] ● Position the individual on the base unit (such as a standard hospital bed) so that the individual's head is aligned with one side of the base unit and the individual's feet are aligned with a second side of the base unit, as shown in Figure 17. The operating space is sufficient clearance to position a sensor array (such as a magnetocardiograph) along at least one side of the base unit. It has.

[0228] ● Extend the device's arms and increase the height of the device by pulling up on the arms or by using the "raise / lower" buttons on the sensor array so that the sensor array is positioned above the individual.

[0229] ● Move the device towards the individual by pushing the mobile cart. Position the device so that the sensor housing is above the subject (e.g., above the subject's chest). • The height of the sensor housing is adjusted using the lifting mechanism at the end of the arm of the frame. The sensor housing is lowered to a position that is on or proximal to the point of inhalation of a normal subject (e.g., the individual's chest).

[0230] - Make adjustments to ensure the sensor array platform is correctly positioned: The housing is aligned with the left side of the object so that the right-most side of the sensor array platform is above and parallel to the centerline of the object.

[0231]

[0250] Start: After the frame is in place, one or more sensors are activated, preparing to record signals such as cardiac magnetic activity. To begin, the user logs into the software application and selects the data acquisition module. If there is a problem with any of the following steps, the application is closed and attempts to restart. If the problem persists, the computer interface is rebooted. To begin using the device, one or more of the following is done:

[0232] ● Ensure that there is a connection to one or more sensors (eg, 8 sensors) by checking the sensor status within the data acquisition software user interface.

[0233] Initiate the autostart procedure with the software application by pressing "autostart" within the data acquisition software user interface. This process will calibrate the sensor or sensors for use. Before continuing, ensure that the ready indicator seen within the software UI turns green and shows a status of "ready."

[0234]

[0251] Recording: After initiation is complete, the device is ready to capture signals such as cardiac magnetic field data. Initially, one or more of the following is performed: - Select the "acquire" button within the software application. Selecting this option will display the magnetic fields collected from the sensor within the viewing window found on the acquisition software UI.

[0235] • Ensuring that one or more collected magnetic fields are characteristic of a signal such as cardiac electrical activity. ● Select the "record" option to save the data to a file. Select your preferences for the length of time the data is captured, the file name, and where the file is saved. Select "save" to begin saving to the file. The application will automatically stop saving after the selected amount of time has elapsed. Files will be named according to institutional policy to protect subject identities.

[0236]

[0252] Power Down and Storage: After use of the device is complete, the system is powered down by one or more of the following: ● Close applications on your computer.

[0237] - Shut off power to the electronic control module by turning the toggle switch to the "off" position. ● Power down the computer.

[0238]

[0253] The device's arm is raised by pulling up on the arm or by using the "raise / lower" buttons on the sensor array so that the sensor array is above the subject's chest level. The subject is assisted in rising from the base unit.

[0239]

[0254] Example 4

[0255] Figure 18 shows an example of one embodiment of a shield comprising three mu metal layers (the innermost three layers) and one aluminum alloy layer (the outer layer). The truncated end is located on the left and the open end is located on the right. One end of the shielding cylinder is completely open, but if the sensor assembly is located far enough away from this open end, EM noise entering the shield hole through the open end will be attenuated to a level low enough that it does not affect the accuracy of magnetic field measurements obtained from an individual positioned within the shield.

[0240]

[0256] Figure 19 shows a plot of magnetic field measurements along the centerline of a shield such as that shown in Figure 18. Magnetic field levels below 50 nT are acceptable for system operation. Ambient noise attenuation was measured and is shown in Figure 19. Because the patient's head is positioned approximately at the point where the cylinder begins to taper, a location of interest, e.g., an organ of interest, such as an individual's heart, within the EM shield can be expected to be comfortably located with background noise levels (below 50 nT) that are considered acceptable for reliable device performance.

[0241]

[0257] Example 5

[0258] An example of a sensor array (sensors shown in black, cables cut for clarity) is shown in Figure 20. To precisely position the sensor array over the patient's heart, the housing can be raised, lowered, and translated laterally (shoulder to shoulder) via a manually operated gear mechanism.

[0242]

[0259] Figure 21 shows an example of a 3D rendering of a sensor head cage mounted on the bed of a shield such as the shield of Figure 18 (the patient's head should be positioned to the left and their chest should be positioned under the arch within the shield).

[0243]

[0260] Example 6

[0261] A magnetocardiogram (MCG) device (Genetesis, Inc., Mason, Ohio) was used to evaluate a population of potential acute coronary syndromes admitted for observational care, followed by normal serial troponin and electrocardiogram (ECG) evaluations, using the disclosed systems, devices, and methods. The data demonstrated 33% sensitivity, 78% specificity, 13% positive predictive value (PPV), and 92% negative predictive value (NPV) when compared with cardiac stress test-guided coronary angiography, where a positive result is defined as a stenosis of at least one epicardial coronary artery to a degree greater than 50%. These results were obtained based on the use of nonparametric qualitative interpretation (NPQI) rules instructed to researchers who interpreted the magnetic field maps. The data were consistent with the reported diagnostic accuracy of MCG using similar patient populations in terms of sensitivity (73%-98%) and specificity (41%-95%). In these various reports, it is important to note that the ischemic diagnostic pattern in MCG, despite the highly variable interpretation rules for various devices (shown in Table 1), is considered to be similar to and highly susceptible to both acute and subacute levels of cardiac ischemia. Indeed, in many studies of MCG, no ischemic MCGs have been reported in which conventional diagnostic modalities were negative. Patients with G pattern can be noted.

[0244]

[0262]

[0245] [Table 1-1]

[0246] [Table 1-2]

[0247]

[0263] MCG represents a non-invasive technique that involves measuring and recording cardiac magnetic fields generated by electrical currents resulting from cardiac muscle cell processes for depolarization and repolarization. Various detectors have been used during the development of MCG devices, but the final product is a cardiac magnetic field. Measurements of the ECG signal at multiple points simultaneously can be used to generate magnetic field maps that can be analyzed as indicators of normal and abnormal cardiac physiology. While the ECG uses a voltage assessment of cardiac electrical function, the MCG is believed to be inherently affected by both tangential and eddy currents that arise in the subepicardium and deeper myocardium due to the gradient between the electrical properties of normal and ischemic tissue, in part because these currents have no electrical equivalent.

[0248]

[0264] These results were obtained based on the use of non-parametric qualitative interpretation (NPQI) rules taught to researchers interpreting the magnetic field maps. Due to the benefits of MCG intrinsic potentials and the variability of MCG interpretation, the magnetic field maps were re-evaluated to develop parameter-based interpretation (PBI) rules for MCGs generated using the disclosed systems, devices, and methods for patients with and without cardiac ischemia, based on actual clinical outcomes. In addition, accuracy statistics were compared between the study lead, experienced MCG interpreters, and the parameter-based interpretation rules derived by the Delphi process, along with inter-rater reliability ratings.

[0249]

[0265] method

[0266] The MCG study was performed as follows. Briefly, after serial negative troponin and ECG results for acute myocardial infarction, 101 patients with potential acute coronary syndromes were admitted for observational evaluation. Four patients were directly referred for coronary angiography on clinical grounds, while the remaining 97 patients underwent cardiac stress testing. Positive patients were further assigned to coronary angiography, with or without revascularization at the discretion of the treating cardiologist. Magnetic field map results were extracted by the investigator (study lead) using the NPQI methodology and assessed based on pre-study training. A trained individual performed blinded interpretation (overreading) of the magnetic field maps using the same NPQI methodology. A separate group of individuals performed a Delphi process using three rounds of review of the magnetic field maps to compare with actual results and developed criteria for the PBI rules outlined below.

[0250]

[0267] The three sets of interpretations (Study, Overread, and PBI) were compared for sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, PPV, NPV, and accuracy. Cohen's kappa scores were calculated for PBI and each of the other two sets of interpretations. Using the rules described below, magnetic field interpretations were defined as nonischemic or ischemic. This determination was used to redefine clinical ischemia, and coronary angiographic revascularization was performed as a composite assessment of epicardial coronary artery lesions associated with cardiac ischemia. No patients had troponin levels or ECGs that were diagnostic of cardiac ischemia.

[0251]

[0268] The non-parametric qualitative interpretation (NPQI) rules are based on the following productions obtained by various MCG devices. The resulting magnetic field map is presented to the interpreting physician as a set of 36 overlapping magnetic field intensity waveforms versus time in a single cardiac cycle (shown in Figure 33). The magnetic field map is evaluated for interpretation (in place of, or in addition to, waveform analysis). The magnetic field map represents a two-dimensional (2D) representation of the sum of current vectors. Each individual waveform represents the magnetic field magnitude normal to the chest wall, measured a few centimeters (inches) above the individual's torso. The MCG imaging and analysis system acquires data from 36 sensors arranged in a uniform 6x6 grid; therefore, each dark circle shown in the map below represents a "true data point" and is color-coded to represent the magnetic field direction and strength. For example, red indicates a current vector with positive magnitude, and blue indicates a current vector with negative magnitude. All information represented by the "sea of ​​color" in the magnetic field map (MFM) outside of the 36 grid points is interpolated using data from these grid points (shown in Figure 33). For example, interpolation can be performed to upsample the image from a 6x6 pixel grid to a 50x50 pixel grid. Conventional voltage presentation of ECG The magnetic field can be depicted as a visual representation of the sensed magnetic field data, both in a waveform pattern resembling the display format (as shown in FIG. 34) and / or a separate magnetic field map demonstrating normal or ischemic patterns. For example, the waveform pattern can include a superposition of data acquired over multiple (e.g., 1,000) separate time points of a single cardiac cycle. For each separate time point, the most positive and most negative values ​​of the MCG data can be determined and used for further analysis. For example, the waveform pattern can include an R-peak depolarization time 3402 and a T-peak repolarization time 3404 (as shown in FIG. 34).

[0252]

[0269] Non-parametric qualitative interpretation (NPQI)

[0270] The field maps can be subject to non-parametric qualitative interpretation (NPQI) rules as follows: First, a scan quality assessment is performed to evaluate scan readability. Second, the MCG waveform is examined to identify P-wave deflection (which may be small), QRS complex deflection, and T-wave deflection. Using the time intervals available on the horizontal baseline, PR, QRS, and QT intervals can be measured as appropriate. The reader can specifically look for evidence of interval prolongation that may indicate conduction disease (e.g., QRS interval for evidence of bundle branch block / conduction delay), which may affect interpretation.

[0253]

[0271] Third, an evaluation of the interval between the onset of T-wave deflection and the peak of the T-wave is performed as follows. During this T-wave interval, the reader evaluates whether the magnetic pole core (e.g., a red electromagnetic dipole relative to the blue) is tightly enclosed. For example, a poorly defined magnetic pole core indicates abnormal myocardial electrical function (e.g., characteristic of cardiac ischemia in an individual). Furthermore, the stability of the vector angle between the positive and negative magnetic pole cores is determined. For example, a stable vector angle of less than 30 degrees indicates a normal finding, while a vector angle that moves or rotates over the T-wave interval indicates an abnormal finding. Furthermore, significant gaps in the magnetic field distribution (e.g., areas without net inflow or outflow of magnetic force) are identified. For example, asymmetric gaps in the cardiac magnetic field map indicate myocardial injury (e.g., characteristic of cardiac ischemia in an individual). Furthermore, magnetic pole splitting is evaluated. For example, the presence of distinct positive and negative poles during repolarization indicates a normal finding, whereas conversely, splitting of the positive or negative poles during this interval indicates an abnormal finding.

[0254]

[0272] Fourth, a diagnostic conclusion is determined using the NPQI rules as follows: A non-ischemic result (e.g., a normal result) is assigned based on the combination of the presence of a distinct magnetic core during the T wave, the stability of the vector angle between the positive and negative magnetic cores at less than 30 degrees, and the presence of distinct positive and negative magnetic poles during repolarization. Conversely, an ischemic result (e.g., an abnormal result) is assigned based on any one of the following: the presence of a poorly defined magnetic core indicating abnormal myocardial electrical function; a vector angle of at least 30 degrees, or a vector angle that moves or rotates over the T wave interval; the presence of an asymmetric gap in the cardiac magnetic field map; and splitting of the positive or negative electromagnetic dipoles.

[0255]

[0273] Parametric Based Interpretation (PBI)

[0274] Using the systems, devices, and methods of the present disclosure, magnetic field maps can be subjected to parametric-based interpretation (PBI) rules as follows: First, a scan quality assessment is performed to evaluate scan readability. Second, an assessment of the duration of the QRS complex is performed (e.g., having a duration greater than 120 milliseconds (ms)) for identification of bundle branch block. This allows for identification of the early R peak (as two are visualized by bundle branch block), which can be used to calculate angles as described below. Third, the peaks of both the R and T waves are determined.

[0256]

[0275] Third, the peaks of the R and T waves are then used to calculate the respective R and T angles as follows: First, the R wave (FIG. 27A) and T wave (FIG. 27B), respectively. The centers of the negative electromagnetic dipoles (shown in blue) and the positive electromagnetic dipoles (shown in red) corresponding to the magnetic field map are identified on the magnetic field map. For example, the centers of the negative and positive electromagnetic dipoles can be identified by determining the center of mass. The center of the negative electromagnetic dipole (blue) is then used to define an X vector that extends horizontally to the right of the magnetic field map, and a Y vector that extends from the center of the negative electromagnetic dipole (blue) through the center of the positive electromagnetic dipole (red).

[0257]

[0276] Next, the peak R depolarization angle is determined, which involves determining the angle from the X vector to the Y vector relative to the R wave. When the Y vector is positioned counterclockwise relative to the X vector, a negative angle relative to the R wave is assigned, and conversely, when the Y vector is positioned clockwise relative to the horizontal X vector, a positive angle relative to the R wave is defined.

[0258]

[0277] Similarly, the peak T repolarization angle is determined, which involves determining the angle from the X vector to the Y vector relative to the T wave. When the Y vector is positioned counterclockwise relative to the X vector, a negative angle relative to the T wave is assigned, and conversely, when the Y vector is positioned clockwise relative to the horizontal X vector, a positive angle relative to the T wave is defined.

[0259]

[0278] Next, the RT peak angle difference is determined, which involves determining the absolute difference between the two angles (peak R depolarization angle and peak T repolarization angle). For example, if the R peak angle is -45 degrees and the T peak angle is -30 degrees, the RT peak angle difference is 15 degrees.

[0260]

[0279] Fourth, an evaluation of the entire T-wave duration is performed to distinguish between a single electromagnetic dipole and multiple electromagnetic dipoles (positive or negative) seen on the magnetic field map during the T-wave.

[0280] Fifth, a diagnostic conclusion is determined using the PBI rule as follows: A non-ischemic result is assigned when the RT peak angle difference is less than 100 degrees, or alternatively, when the RT peak angle difference is between 170 degrees and 190 degrees and a single electromagnetic dipole is present in the magnetic field map. An ischemic result is assigned when the RT peak angle difference is between 100 degrees and 170 degrees (regardless of whether multiple electromagnetic dipoles are present in the magnetic field map), or alternatively, when multiple electromagnetic dipoles are present in the magnetic field map (regardless of the value of the RT peak angle difference).

[0261]

[0281] Statistical analysis consisted of calculations of sensitivity, specificity, positive and negative likelihood ratios, PPV, NPV, and accuracy. Cohen's kappa scores were calculated for the PBI and each of the other two sets of interpretations.

[0262]

[0282] result

[0283] The demographic and original outcome data reported in the Pena study were obtained. Accuracy metrics and kappa scores for the composite ischemia measure of coronary angiography-guided revascularization were calculated for the three reader groups, as shown in Table 2. Results demonstrated that evaluation using the PBI rule generally outperformed evaluations using the other two sets of interpretations in terms of NPV and overall accuracy, which are particularly important when considering a "rule-out" diagnostic test for cardiac ischemia. Kappa scores were 0.82 for PBI vs. over-read and 0.72 for PBI vs. study-read. Both of these scores were highly consistent with high correlation, suggesting that the disclosed overall MCG imaging and analysis device can be used to create high-quality magnetic field maps with consistently identifiable elements that can be used to distinguish ischemic from non-ischemic conditions. However, the gradual improvement in accuracy favoring experienced readers over study-read suggested a steeper learning curve. Better accuracy for individual PBI rules may provide greater consistency and a shallower learning curve.

[0263]

[0284]

[0264] [Table 2]

[0265]

[0285] Discussion

[0286] The data demonstrate that a straightforward set of PBI rules can provide accurate interpretation of cardiac magnetic field maps for the purpose of diagnosing or ruling out myocardial ischemia in individuals. A key element deemed consistent for effective analysis of magnetic field maps is the interrogation of both the depolarization phase and the T-wave-dominated repolarization phase of cardiac function. These data are consistent with studies investigating diagnostic patterns resulting from ischemic fluctuations in the current vector and, therefore, the resulting magnetic field. Other studies may rely on variations in interpretation rules, and many of the rule sets are relatively subjective in nature, making consistent assessments across providers more difficult to implement (as shown in Table 1). This study provides a narrower set of magnetic field maps necessary to diagnose ischemia, most of which can be visually understood but are precisely determined using mathematical algorithms. The rule set presented emphasizes comparing energy-independent depolarization, represented by the peak of the R wave, which is automatically provided to the reader by software analysis and evaluation of the magnetic field waveform. Alternatively, the reader can override this displayed data element (determined using a mathematical algorithm) and manually select their own judgment (determined based on the reader's visual judgment) of the location of the peak R wave, which is then used to define "peak R" and subsequently the "R angle" (described above). The reader then proceeds to the peak T wave, which was automatically provided to the reader by software analysis and evaluation of the magnetic field waveform. Alternatively, the reader can override this displayed data element (determined using a mathematical algorithm) and manually select their own judgment (determined based on the reader's visual judgment) of the location of the peak T wave, which is then used to define "peak T" and subsequently the "T angle" (described above). The difference between these angles is defined as the "RT angle difference." These metrics are important because depolarization of cardiac cells begins at the endocardial surface and proceeds to the epicardial surface, and repolarization proceeds only in the opposite direction. Thus, although theoretically the gap should be zero, the data indicate that physiologically non-ischemic patterns can be between 0 and 100 degrees.Note that left bundle branch block results in a double R-peak phenomenon, and by convention the early peak was chosen to determine the "RT angle difference," as well as to define normal. Alternatively, conduction abnormalities not identified on the ECG were identified by MCG, and MFM assessment demonstrated an "RT angle difference" of 180° ± 10°.

[0266]

[0287] Another important criterion identified in the analysis that clearly correlates with cardiac ischemia is the appearance of multiple electromagnetic dipoles (positive or negative) in the T wave. In fact, this has been observed in association with poorly controlled heart failure and epicardial coronary artery disease, leading to its near-universal association with cellular-level ischemia, regardless of etiology. This phenomenon was also proposed by Hailer et al. Abnormal MCG patterns are thought to persist early in the recovery phase following both ST-segment elevation and non-ST-segment elevation myocardial infarction and are associated with higher morbidity and mortality. This suggests that persistent microvascular ischemia represents a currently unmet need for guiding post-discharge medical management in cardiac patients. Similarly, because diagnostic patterns in ischemic magnetic field maps represent cellular-level ischemia regardless of the device used, this technology potentially expands the patient population beyond those simply at risk for significant epicardial coronary occlusive disease.

[0267]

[0288] Accuracy statistics can be validated in different patient groups at risk for ischemic cardiomyopathy, including STEMI, NSTEMI, microvascular ischemia, and type 2 myocardial infarction. The ability to develop diagnostic pathways that include MCG to inform the initial evaluation of patients with potential acute coronary syndromes due to indeterminate troponin is another useful role for evaluating magnetic current maps. Furthermore, the disclosed systems, devices, and methods can be used to replace other methods of evaluating cardiac stress patients without the need for highly trained technicians or radiopharmaceuticals.

[0268]

[0289] conclusion

[0290] Using the disclosed systems, devices, and methods, we have demonstrated a magnetocardiogram imaging and analysis device capable of producing magnetic field maps that can be evaluated using a structural PBI rule set to efficiently diagnose cardiac ischemia due to multiple mechanisms, without the need for highly trained technicians, radiopharmaceuticals, or exposure to external beam radiation. By using this technology more widely across various patient populations, further validation of specific diagnostic criteria related to the evaluation of both the QRS complex and the T wave can be performed. Thus, the disclosed systems, devices, and methods enable rapid and safe evaluation of cardiac patients without the need for expensive shielded rooms closer to the point of service based on evaluation of cardiac magnetic field maps.

[0269]

[0291] reference

[0292] [Pena ME, Pearson CL, Goulet MP, Kazan VM, DeRita AL, Szpunar SM, Dunne RB. "A 90-second magnetocardiogram using a novel analysis system to assess for coronary artery stenosis in Emergency department observation unit chest pain patients", Int J Cardiol Heart Vasc. 2020 Jan 8;26:100466.doi:10.1016 / j.ijcha.2019.100466.eCollection 2020 Feb.], which is incorporated herein by reference in its entirety.

[0270]

[0293] [Hailer B, Van Leeuwen P. "Detection of coronary artery disease with MCG", Neurol Clin Neurophysiol 2004;2004:82] is incorporated herein by reference in its entirety.

[0271]

[0294] [Park JW, Leithauser B, Vrsansky M, et al., “Dobutamine stress magnetocardiography for "The detection of significant coronary artery stenoses - a prospective study in comparison with simultaneous 12-lead electrocardiography," Clin Hemorheol Microcirc. 2008;39(1-4):21-32.4] is incorporated herein by reference in its entirety.

[0272]

[0295] [Lim HK, Kwon H, Chung N, Ko YG, Kim JM, Kim IS, Park YK, "Usefulness of magnetocardiogram to detect unstable angina pectoris and non-ST elevation myocardial infarction", Am J Cardiol. 2009 Feb 15;103(4):448-54] is incorporated herein by reference in its entirety.

[0273]

[0296] [Gapelyuk A, Schirdewan A, Fischer R, et al., "Cardiac magnetic field mapping quantified by kullback-leibler entropy detects patients with coronary artery disease," PhysiolMeas. 2010;31(10):1345-1354], which is incorporated herein by reference in its entirety.

[0274]

[0297] [Tolstrup K, Madsen BE, Ruiz JA et al., "Non-invasive resting magnetocardiographic imaging for the rapid detection of ischemia in subjects presenting with chest pain," Cardiology. 2006;106(4):270-276] is incorporated herein by reference in its entirety.

[0275]

[0298] [Steinberg BA, Roguin A, Watkins SP 3rd et al., "Magnetocardiogram recordings in a nonshielded environment - reproducibility and ischemia detection," Ann Noninvasive Electrocardiol. 2005;10(2):152-160] is incorporated herein by reference in its entirety.

[0276]

[0299] [Kandori A, Ogata K, Miyashita T, et al., “Subtraction magnetocardiogram for detecting Coronary heart disease”, Ann Noninvasive Electrocardiol. 2010;15(4):360-368], which is incorporated herein by reference in its entirety.

[0277]

[0300] [Baule G, Mcfee R, "Detection of the magnetic field of the heart", Am Heart J. 1963;66:95-96.8] is incorporated herein by reference in its entirety.

[0278]

[0301] [Moshage W, Achenbach S, Weikl A, et al., "Clinical magnetocardiography: Experience with a biomagnetic multichannel system", In J Card Imaging. 1991;7(3-4):217-223], which is incorporated herein by reference in its entirety.

[0279]

[0302] [Hopenfeld B, Stinstra JG, Macleod RS, "Mechanism for ST depression associated with contiguous subendocardial ischemia", J Cardiovasc Electrophysiol. 2004;15(10):1200-1206], which is incorporated herein by reference in its entirety.

[0280]

[0303] [Lim HK, Kwon H, Chung N, Ko YG, Kim JM, Kim IS et al., “Usefulness of magnetocardiogram to detect unstable angina pectoris and non-ST elevation myocardial infarction,” Am J Cardiol 2009;103:448-54], which is incorporated herein by reference in its entirety.

[0281]

[0304] [Kyoon Lim H, Kim K, Lee YH, Chung N, "Detection of non-ST-elevation myocardial infarction using magnetocardiogram: new information from spatiotemporal electrical activation map," Ann Med. 2009;41(7):533-46] is incorporated herein by reference in its entirety.

[0282]

[0305] [Van Leeuwen P, Hailer B, Beck A, Eiling G, Groenemeyer D, "Changes in dipolar structure of cardiac magnetic field maps after ST elevation myocardial infarction", Ann Noninvasive Electrocardiol 2011;16:379-87], which is incorporated herein by reference in its entirety.

[0283]

[0306] Example 7

[0307] A magnetocardiogram (MCG) device (Genetesis, Inc., Mason, Ohio) was used in the evaluation of a population of potential acute coronary syndromes admitted for observational care, followed by normal serial troponin and electrocardiogram (ECG) evaluations using the systems, devices, and methods of the present disclosure. Magnetic field maps were generated using the MCG device and interpreted using PBI rules, as described herein.

[0284]

[0308] Interpretation of the magnetic field map can include pattern recognition of the magnetic field map. For example, the initial focus of the interpretation can be on the duration of the R-peak and T-wave. In some embodiments, interpretation of the magnetic field map includes viewing both the magnetic field map in time series and freezing the image during waveform segments of interest (e.g., corresponding to the R-peak and T-peak periods). This approach provides both global and granular data within the MCG pattern, allowing for static and dynamic observation of magnetic electromagnetic dipoles within the magnetic field map.

[0285]

[0309] Interpretation of the magnetic field map can include identifying positive magnetic poles (e.g., shown in red) and negative magnetic poles (e.g., shown in blue) during the duration of the R peak and T wave. For example, the positive magnetic poles can be determined as the centers (e.g., centers of mass) of positive magnetic field values, and the negative magnetic poles can be determined as the centers (e.g., centers of mass) of negative magnetic field values. A first vector can be defined between the positive and negative magnetic poles for purposes of determining an angle therefrom. Alternatively, the positive magnetic poles can be determined as the centers (e.g., centers of mass) of negative magnetic field values ​​for purposes of determining an angle therefrom. A first line, line segment, or ray can be defined between the negative magnetic pole and the positive x-axis. A second vector can be defined as a horizontal vector (e.g., having the same direction as the positive x-axis) for purposes of determining the angle therefrom. Alternatively, a second line, line segment, or ray can be defined parallel to the horizontal vector (e.g., having the same direction as the positive x-axis) for purposes of determining the angle therefrom. Without loss of generality, the second vector, line, line segment, or ray can pass through the negative magnetic pole (shown in blue). Alternatively, the second vector, line, line segment, or ray can pass through another point (e.g., any point between the positive and negative magnetic poles) without affecting the determination of the angle therefrom. The first and / or second vectors can be represented using any suitable coordinate system, including, but not limited to, 2D Cartesian coordinates, 3D Cartesian coordinate systems, rectangular coordinate systems, parametric coordinate systems, and polar coordinate systems.

[0286]

[0310] After determining the first and second vectors, a vector angle can be defined based on the positive and negative magnetic poles at a given time. The vector angle can represent the angle between the first and second vectors. The vector angle can be determined as the smallest angular change between the first and second vectors. For example, the vector angle can have a value between 0 and 360 degrees, or equivalently, can have a value added or subtracted from any integer multiple of 360 to arrive at a value between 0 and 360 degrees. As an example, the vector angle θ can be determined using the formula cos(θ) = a·b / (|a||b|), where a and b represent the first and second vectors, respectively, "·" represents the dot product of the vectors, and "||" represents the magnitude of the vector.

[0287]

[0311] As one example, the peak R depolarization angle can be determined as the vector angle of the magnetic field map associated with the period during which the R wave (and corresponding R peak) (e.g., which can be measured using an ECG) occurs. As another example, the peak T repolarization angle can be determined as the vector angle of the magnetic field map associated with the period during which the T wave (and corresponding T peak) (e.g., which can be measured using an ECG) occurs.

[0288]

[0312] Such vector angles can be determined at two different time points (e.g., during the R-peak and the T-peak), and the difference, change, or mobility of the vector angles of the two different magnetic field maps (e.g., from the R-peak compared to the T-peak) can be used to perform magnetic field map assessment of coronary artery disease (e.g., a positive or negative result for ischemia). The vector angle difference, change, or mobility can be determined based on the positive clockwise angle between the two vector angles (e.g., from the R-peak compared to the T-peak). Alternatively, the vector angle difference, change, or mobility can be determined based on the positive counterclockwise angle between the two vector angles (e.g., from the R-peak compared to the T-peak).

[0289]

[0313] As one example, the presence of vector angles that shift or rotate by less than 100 degrees indicates that the magnetic field map shows no evidence of ischemia (e.g., a negative or non-ischemic result). Conversely, as another example, the presence of vector angles that shift or rotate by more than 100 degrees indicates that the magnetic field map shows evidence of ischemia (e.g., a positive or ischemic result).

[0290]

[0314] As another example, the presence of a complete 180 degree reversal in the vector angle difference between the positive and negative magnetic poles (e.g., comparing the R-peak magnetic field map with the T-peak magnetic field map) indicates that the magnetic field map indicates a conduction abnormality but not ischemia in the subject's heart, and the subject receives a positive result for the abnormality but a negative result for ischemia. As another example, the presence of multiple electromagnetic dipoles in the magnetic field map seen during any portion of the T-wave indicates that the magnetic field map indicates an abnormal finding.

[0291]

[0315] associated with a normal outcome (e.g., no cardiac abnormalities detected in the subject) The resulting magnetic field map may have one or more of the following characteristics. First, there may be normal QRS duration and morphology without evidence of any waveform deformation that could indicate a potential abnormality. Second, the vector difference between the electromagnetic dipoles of the magnetic field map at the R-peak and T-peak is 100 degrees or less. When viewing the magnetic pole orientation in the magnetic field image during the T-wave phase, the anode is typically located near the top right quadrant (RUQ) of the viewing screen, and the cathode is typically located near the bottom left quadrant (LLQ) of the viewing screen. As an example, a complete 180-degree reversal of the vector angle difference between the R-peak and T-peak indicates no evidence of ischemia (e.g., a negative or non-ischemic result). Third, there may be only one positive and one negative electromagnetic dipole during the T-wave duration.

[0292]

[0316] 35A-35B show an example of R-peak and T-peak magnetic field maps of a subject, respectively, where the R-peak occurs at a time of 400 ms on the waveform representation (FIG. 35A) corresponding to the peak R depolarization and the T-peak occurs at a time of 703 ms on the waveform representation (FIG. 35B) corresponding to the peak T repolarization, which is interpreted as having a normal (e.g., non-ischemic) outcome and where the vectors between the positive and negative electromagnetic dipoles in the R-peak compared to the T-peak are consistent.

[0293]

[0317] 36A-36B show an example of R-peak and T-peak magnetic field maps, respectively, of a subject that are interpreted as having normal (e.g., non-ischemic) results and show a 180 degree reversal of the vectors between the positive and negative electromagnetic dipoles during the R-peak compared to the T-peak, where the R-peak occurs at a time of 400 ms on the waveform representation (FIG. 36A) corresponding to the peak R depolarization, and the T-peak occurs at a time of 717 ms on the waveform representation (FIG. 36B) corresponding to the peak T repolarization.

[0294]

[0318] Furthermore, a magnetic field map associated with an abnormal result (e.g., a cardiac abnormality detected in a subject, such as an ischemic or conduction abnormality) may have one or more of the following characteristics: First, there are multiple magnetic poles in the magnetic field map during the T-wave segment. Second, when comparing the R-peak magnetic field map with the T-peak magnetic field map, the positive and negative magnetic poles of the magnetic field map rotate more than 100 degrees around each other.

[0295]

[0319] 37A-37B show an example of R-peak and T-peak magnetic field maps, respectively, of a subject that is interpreted as having an abnormal (e.g., ischemic) outcome and in which there are multiple electromagnetic dipoles in the T-peak magnetic field map that completely surround a positive electromagnetic dipole, where the R-peak occurs at a time of 399 ms on the waveform representation (FIG. 37A) corresponding to the peak R depolarization, and the T-peak occurs at a time of 609 ms on the waveform representation (FIG. 37B) corresponding to the peak T repolarization.

[0296]

[0320] 38A-38B show an example of R-peak and T-peak magnetic field maps of a subject, respectively, that would be interpreted as having an abnormal (e.g., ischemic) outcome and exhibit electromagnetic dipole movement where the vector between the positive and negative electromagnetic dipoles during the R-peak compared to the T-peak is greater than 100 degrees, where the R-peak occurs at a time of 400 ms on the waveform representation (FIG. 38A) corresponding to the peak R depolarization, and the T-peak occurs at a time of 690 ms on the waveform representation (FIG. 38B) corresponding to the peak T repolarization.

[0297]

[0321] Example 8

[0322] Using the systems, devices, and methods of the present disclosure, a set of one or more of the following parameters and / or plots is determined using an individual's magnetic field map, and the set of parameters and / or plots is analyzed to assess cardiac ischemia in the individual. The parameters can be measured quantitatively for parametric classification (e.g., dipole parameters, integrated MCD parameters, integrated ECD parameters, mean PC (e.g., using D parameters, isointegral parameters, field map correlation parameters, R_peak pegged dipole parameters, pseudocurrent arrow parameters, extremal circle parameters, phase space embedding parameters using delta coordinates, and / or phase space embedding parameters using time delay coordinates). Alternatively, or in combination, plots (e.g., STAG plots, T_peak MFM plots, field map animations, pseudocurrent density arrows, MCD plots, and / or ECD plots) can be qualitatively judged for visual classification (e.g., manually or using computer-based machine vision techniques).

[0298]

[0323] In some embodiments, dipole parameters are determined by measuring angle and magnitude parameters of the magnetic field map at specified time ranges and T-peaks, which may include measurements of Ts / 3, Tp, Te / 3, etc. For example, dipole parameters (e.g., peak angle, maximum angle, minimum angle, angular dynamics, distance dynamics, and minimum-to-maximum ratio) can be measured from the magnetic field map. As another example, dipole parameters (e.g., peak angle, minimum angle, maximum angle, and angular dynamics) can be measured from the current map. Dipole parameters are described, for example, by Lim et al., "Detection of non-ST-elevation myocardial infarction using magnetocardiogram: New information from spatiotemporal electrical activation map," Annals of Medicine, 2009, DOI:10.1080 / 07853890903107883, which is incorporated herein by reference in its entirety.

[0299]

[0324] In some embodiments, the parameters are determined using an integrated maximum current density (MCD) approach, which involves determining an average measurement of the current vector with the largest magnitude at each time point from the start to the end of the T wave, which can include measurements such as PCD, Ts, and Te. For example, integrated MCD parameters (e.g., magnitude, angle, perimeter, and area) can be measured from a magnetic field map (e.g., size 4x4, 6x6, or 50x50). Integrated MCD parameters are described, for example, by Zhao et al., "An Integrated Maximum Current Density Approach for Noninvasive Detection of Myocardial Infarction," IEEE Journal of Biomedical and Health Informatics, 2016, DOI 10.1109 / JBHI.2017.2649570, which is incorporated herein by reference in its entirety.

[0300]

[0325] In some embodiments, the parameters are determined using an equivalent current density (ECD) approach, which includes determining an average measurement of the calculated equivalent current vector at each time point from the start to the end of the T wave, which can include measurements of ECD, Ts, Te, etc. For example, integrated ECD parameters (e.g., magnitude, angle, perimeter, and area) can be measured from a magnetic field map (e.g., size 4x4, 6x6, or 50x50). Integrated ECD parameters are described, for example, by Zhao et al., "An Integrated Maximum Current Density Approach for Noninvasive Detection of Myocardial Infarction," IEEE Journal of Biomedical and Health Informatics, 2016, DOI 10.1109 / JBHI.2017.2649570, which is incorporated herein by reference in its entirety.

[0301]

[0326] In some embodiments, the parameters are calculated using the average pseudo current density (PCD) method. The technique involves determining average measurements of the current vector arrow at each time point from the beginning to the end of the T wave, which can include measurements of PCD, Ts, Te, etc. For example, average PCD parameters (e.g., magnitude, angle, circumference, and area) can be measured from magnetic field maps (e.g., of size 4x4, 6x6, or 50x50). Average PCD parameters are described, for example, by Kandori et al., "A method for detecting myocardial abnormality by using a total current-vector calculated from ST-segment deviation of a magnetocardiogram signal," Med. Biol. Eng. Comput., 2000, 38, 21-28, which is incorporated herein by reference in its entirety.

[0302]

[0327] In some embodiments, the parameters are determined using an isointegral technique, which involves determining integral measurements of the current vector arrow at each spatial point within the QRS complex or T wave, which may include measurements of PCD, Q, S, Te, etc. For example, isointegral parameters (e.g., QS max integral current, ST max integral current, diff integral current, and QS MIC>ST MIC) can be measured from magnetic field maps. Isointegral parameters are described, for example, by Watanabe et al., "Magnetocardiography in Early Detection of Electromagnetic Abnormality in Ischemic Heart Disease," J. Arrhythmia, Vol. 24, No. 1, 2008, which is incorporated herein by reference in its entirety.

[0303]

[0328] In some embodiments, the parameters are determined using a field map correlation technique, which includes determining correlations of the magnetic field map at time points in other time ranges, which may include measurements of T_peak, R_peak, etc. For example, field map correlation parameters (e.g., mean and / or standard deviation values ​​of T-peak to T-wave correlation, T-peak to R-wave correlation, T-peak to T-wave correlation, and / or R-peak to R-wave correlation) may be measured from 100 Hz low-pass and 20 Hz low-pass filtered data. Field map correlation parameters may be determined, for example, as described in Goernig et al., "Magnetocardiography Based Spatiotemporal Correlation Analysis is Superior to MRI," which is incorporated herein by reference in its entirety. to Conventional ECG Analysis for Identifying Myocardial Injury,” Annals of Biomedical Engineering, Vol. 37, No. 1, 2009.

[0304]

[0329] In some embodiments, the parameters are determined using an R_peak pegged dipole parameter approach, which involves determining measurements of magnetic field map angle and / or magnitude parameters over a specified time range, where many angular parameters are calculated relative to the R-peak field map angle, which can include measurements of T_peak, R_peak, etc. For example, R_peak pegged dipole parameters (e.g., R_peak_FMA, T_peak_FMA-R_peak_FMA, TT_CAmax, TT_CAmax-R_peak_FMA, and JT_CMD (representing the maximum current magnitude change within 20 ms from J_point to T_end)) can be measured from 100 Hz low-pass and 20 Hz low-pass filtered data. R_peak pegged dipole parameters can be measured, for example, from Kwon et al., "Non-Invasive Magnetocardiography for the Early Diagnosis of Cardiac Myopathy," in J. Neurophysiology, vol. 1, pp. 111-114, 2002, which is incorporated herein by reference in its entirety. f Coronary Artery Disease in Patients Presenting With Acute Chest Pain,” Circulation Journal, Vol. 74, 2010.

[0305]

[0330] In some embodiments, the parameters are determined using a pseudo-current arrow parameter approach, which involves determining a measure of a parameter for an averaged current arrow map at the T peak of a magnetic field map using either all arrows (global) or four map quadrants (Q1, Q2, Q3, Q4), which may include measures of PCD, T_peak, etc. For example, the pseudo-current arrow parameters may relate to the magnitude of T_peak (e.g., mean, variance, kurtosis, and / or slope) and / or the angle of T_peak (mean, variance, kurtosis, and / or slope). Pseudo-current arrow parameters are described, for example, by Udovychenko et al., "Binary Classification of Heart Failures Using k-NN with Various Distance Metrics," International Journal of Electronics and Telecommunications, Vol. 61, Issue 4, 2015, which is incorporated herein by reference in its entirety.

[0306]

[0331] In some embodiments, the parameters are determined using an extrema circle parameter approach, which involves determining measurements of positive and negative area ratios and zero contour curvature within a circle drawn by the boundaries tangent to the anode and cathode, which may include measurements such as T_end, T_begin, etc. For example, the extrema circle parameters may relate to the area ratio and / or contour curvature of the magnetic field map. Extrema circle parameters are described, for example, by Wu et al., "Noninvasive Diagnosis of Coronary Artery Disease Using Two Parameters Extracted in an Extrema Circle of Magnetocardiogram," 35th Annual International Conference of the IEEE EMBS, 2013, which is incorporated herein by reference in its entirety.

[0307]

[0332] In some embodiments, the parameters are determined using a phase space embedding parameter approach, which involves using delta calculations to determine a reconstruction of a multidimensional phase space approximation of the signal, which may include measurements such as delta coordinates. For example, the phase space embedding parameters may relate to a dimensionality (M) such as 2, 3, or 6, a tied binning parameter with, for example, 10^M bins and even a count per bin, and a Gaussian mixture model with 20 mixtures.

[0308]

[0333] In some embodiments, the parameters are determined using a phase space embedding parameter approach, which involves determining a reconstruction of a multidimensional phase space approximation of the signal using time delays, which may include measurements such as delta coordinates. For example, the phase space embedding parameters may relate to a dimensionality (M) such as 2, 3, or 6, a tied binning parameter with, for example, 10^M bins and even a count per bin, and a Gaussian mixture model with 20 mixtures.

[0309]

[0334] In some embodiments, a STAG plot is generated by plotting the averaged current arrows in the up-down and left-right directions, which can include measurements of PCD, S, Te, etc. For example, one or more of the following visual indicators can be assessed: no separation or discontinuity within the core, no leftward excursion, consistent central location of the red core, smooth shape of the comet head, core tightly aligned with the T wave, condensed excitation shape and area, and / or y-axis compression.

[0310]

[0335] In some embodiments, a T-peak MFM plot is generated by plotting the MFM at the T-peak. For example, one or more of the following visual indicators can be assessed: compressed dipoles, extended dipoles, broken dipoles, and / or rotated magnetic poles.

[0311]

[0336] In some embodiments, the field map animation is generated by evaluating the animation of the MFM at the T-peak based on certain visual indicators, such as one or more of the following visual indicators: dipole drift, dipole rotation, and / or multiple magnetic poles.

[0312]

[0337] In some embodiments, the pseudo current density arrow is generated by evaluating the pseudo current arrow map based on certain visual indicators (e.g., classifying the MFMs into one of five classes). For example, one or more of the following visual indicators may be evaluated: dipole presence, dipole orientation, majority vector direction, and / or vortex uniformity. Pseudo current density arrows are described, for example, by Hailer et al., "The Value of Magnetocardiography in the Course of Coronary Intervention," Annals of Noninvasive Electrocardiology, Vol. 10, No. 2, 2005, which is incorporated herein by reference in its entirety.

[0313]

[0338] In some embodiments, the MCD plot is generated by evaluating the magnetic field map based on a maximum current density vector. In some embodiments, the ECD plot is generated by evaluating the magnetic field map based on an equivalent current density vector. In some embodiments, the magnetic field map is evaluated based on one or more of the following visual indicators: Q, S, Ts, Ts / 3, Tp, Te / 3, Te, and / or Rp.

[0314]

[0339] While preferred embodiments of the present invention have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will occur to those skilled in the art without departing from the invention. It is understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. The following claims define the scope of the invention, and it is intended that methods and structures within the scope of these claims and their equivalents be covered thereby.

Claims

1. 1. A system for determining the presence, absence, or likelihood of coronary artery disease in an individual, comprising: (1) A sensing device configured to sense a magnetic field associated with an individual, comprising: a. a mobile base unit; b. an arm having a proximal end and a distal end, the proximal end coupled to the mobile base unit by a first joint, the first joint configured to allow the arm to move with at least one degree of freedom relative to the mobile base unit; and c. an array of one or more optically excited magnetometers coupled to the distal end of the arm, the sensing device comprising the array of one or more optically excited magnetometers configured to sense the magnetic field associated with the individual; (2) A non-transitory computer-readable medium encoded with a computer program including instructions executable by a processor, the instructions causing the processor to: i. receiving from the sensing device a first magnetic field associated with the individual's heart at a first time; ii. generating a first electromagnetic field map based on the first magnetic field associated with the heart of the individual at the first time; iii. Identifying a first negative electromagnetic dipole and a first positive electromagnetic dipole in the first electromagnetic field map; iv. receiving from the sensing device a second magnetic field associated with the heart of the individual at a second time; v. generating a second electromagnetic field map based on the second magnetic field associated with the heart of the individual at the second time; vi. identifying a second negative electromagnetic dipole and a second positive electromagnetic dipole in the second electromagnetic field map; vii. determining a first angle based on the first negative electromagnetic dipole and the first positive electromagnetic dipole, and determining a second angle based on the second negative electromagnetic dipole and the second positive electromagnetic dipole; and viii. a non-transitory computer-readable medium configured to cause a determination of the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on (i) whether the first angle differs from the second angle by at least 100 degrees, or (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map.

2. The system of claim 1 , wherein the sensing device comprises a shield configured to shield the device from one or more environmental magnetic fields.

3. The system of claim 2 , wherein the shield is configured to at least partially surround a portion of the individual's body associated with the magnetic field.

4. The system of claim 3 , wherein the portion of the individual's body associated with the magnetic field is at least a portion of the individual's chest.

5. The system of claim 2 , wherein the shield comprises two or more layers.

6. The system of claim 5 , wherein each of the two or more layers has a thickness of 0.1 to 10 millimeters.

7. The system of claim 2 , wherein the shield comprises permalloy or mu-metal.

8. 2. The system of claim 1, wherein the arm includes a proximal segment and a distal segment, a second joint positioned between the proximal and distal segments, and the distal segment configured to articulate relative to the proximal segment.

9. 10. The system of claim 1, wherein the array of one or more optically excited magnetometers is movably coupled to the distal end of the arm such that the array of one or more optically excited magnetometers moves with at least one degree of freedom relative to the arm.

10. The system of claim 1 , wherein the array of one or more optically excited magnetometers comprises at least three optically excited magnetometers.

11. The system of claim 10 , wherein the array of one or more optically excited magnetometers is positioned to match a generalized contour of a portion of the individual's body.

12. The system of claim 1 , wherein the computer program comprises instructions configured to cause the processor to further filter the sensed magnetic field.

13. 13. The system of claim 12, further comprising a gradiometer, wherein the computer program comprises instructions configured to cause the processor to filter the sensed magnetic field by canceling the magnetic field sensed by the gradiometer.

14. 13. The system of claim 12, wherein the computer program comprises instructions configured to cause the processor to filter the sensed magnetic field by subtracting a frequency-based measurement from the magnetic field.

15. The system of claim 1 , wherein the computer program comprises instructions configured to cause the processor to further generate a visual representation of the magnetic field including a waveform.

16. The system of claim 1 , wherein the coronary artery disease comprises myocardial ischemia.

17. The system of claim 1 , wherein the coronary artery disease comprises myocardial ischemia associated with epicardial coronary artery disease.

18. The system of claim 1 , wherein the coronary artery disease comprises myocardial ischemia without epicardial coronary artery disease.

19. 2. The system of claim 1, wherein the computer program comprises instructions configured to cause the processor to further determine the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on: (iii) parameters selected from the group consisting of dipole parameters, integrated MCD parameters, integrated ECD parameters, mean PCD parameters, isointegral parameters, field map correlation parameters, R_peak pegged dipole parameters, pseudocurrent arrow parameters, extremal circle parameters, phase space embedded parameters using delta coordinates, and phase space embedded parameters using time delay coordinates; or (iv) visualization selected from the group consisting of a STAG plot, a T_peak MFM plot, a field map animation, a pseudocurrent density arrow, an MCD plot, and an ECD plot.

20. The computer program causes the processor to determine the presence, absence, or likelihood of the coronary artery disease in the individual based at least in part on the parameters.

20. The system of claim 19, further comprising instructions configured to:

21. 20. The system of claim 19, wherein the computer program comprises instructions configured to cause the processor to further determine the presence, the absence, or the likelihood of the coronary artery disease in the individual based at least in part on the visualization.

22. 22. The system of claim 1, wherein the presence of coronary artery disease in the individual is determined based on (i) whether the first angle differs from the second angle by at least 100 degrees, (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map, (iii) the parameters, and (iv) the presence of at least one abnormality in the visualization.

23. 23. The system of any one of claims 1 to 22, wherein the presence of coronary artery disease in the individual is determined based on (i) whether the first angle differs from the second angle by at least 100 degrees, (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map, (iii) the parameters, and (iv) the presence of at least two abnormalities in the visualization.

24. 1. A method for determining the presence, absence, or likelihood of coronary artery disease in an individual, comprising: a. positioning a mobile electromagnetic sensing device in proximity to said individual; b. positioning an arm of the mobile electromagnetic sensing device coupled to an array of one or more optically excited magnetometers in proximity to the individual's heart; c. receiving a first magnetic field associated with the heart of the individual at a first time from the mobile electromagnetic sensing device; d. generating a first electromagnetic field map based on the first magnetic field associated with the heart of the individual at the first time; e. identifying a first negative electromagnetic dipole and a first positive electromagnetic dipole in the first electromagnetic field map; f. receiving a second magnetic field associated with the heart of the individual at a second time from the mobile electromagnetic sensing device; g. generating a second electromagnetic field map based on the second magnetic field associated with the heart of the individual at the second time; h. identifying a second negative electromagnetic dipole and a second positive electromagnetic dipole in the second electromagnetic field map; i. determining a first angle based on the first negative electromagnetic dipole and the first positive electromagnetic dipole, and determining a second angle based on the second negative electromagnetic dipole and the second positive electromagnetic dipole; j. determining the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on (i) whether the first angle differs from the second angle by at least 100 degrees, or (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map.

25. 25. The method of claim 24, further comprising shielding at least a portion of the individual from one or more environmental magnetic fields using a shield.

26. 26. The method of claim 25, wherein the shield is configured to at least partially surround a portion of the individual's body associated with the magnetic field.

27. 27. The method of claim 26, wherein the portion of the body of the individual associated with the magnetic field is at least a portion of the individual's chest.

28. 26. The method of claim 25, wherein the shield comprises two or more layers.

29. 30. The method of claim 28, wherein each of the two or more layers has a thickness of 0.1 to 10 millimeters.

30. 26. The method of claim 25, wherein the shield comprises permalloy or mu-metal.

31. 25. The method of claim 24, wherein the arm includes a proximal segment and a distal segment, a second joint positioned between the proximal and distal segments, and the distal segment configured to articulate relative to the proximal segment.

32. 25. The method of claim 24, wherein the array of one or more optically excited magnetometers is movably coupled to the distal end of the arm such that the array of one or more optically excited magnetometers moves with at least one degree of freedom relative to the arm.

33. 25. The method of claim 24, wherein the array of one or more optically excited magnetometers comprises at least three optically excited magnetometers.

34. 34. The method of claim 33, wherein the array of one or more optically excited magnetometers is positioned to match a generalized contour of a portion of the individual's body.

35. 25. The method of claim 24, further comprising filtering the first magnetic field and / or the second magnetic field.

36. 36. The method of claim 35, wherein the filtering step includes canceling out magnetic fields sensed by a gradiometer.

37. 36. The method of claim 35, wherein the filtering step comprises subtracting a frequency-based measurement from the first magnetic field and / or the second magnetic field.

38. 25. The method of claim 24, wherein the coronary artery disease comprises myocardial ischemia.

39. 25. The method of claim 24, wherein the coronary artery disease comprises myocardial ischemia associated with epicardial coronary artery disease.

40. 25. The method of claim 24, wherein the coronary artery disease comprises myocardial ischemia without epicardial coronary artery disease.

41. 25. The method of claim 24, further comprising determining the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on: (iii) parameters selected from the group consisting of dipole parameters, integrated MCD parameters, integrated ECD parameters, mean PCD parameters, isointegral parameters, field map correlation parameters, R_peak pegged dipole parameters, pseudocurrent arrow parameters, extremal circle parameters, phase space embedded parameters using delta coordinates, and phase space embedded parameters using time delay coordinates; or (iv) visualization selected from the group consisting of a STAG plot, a T_peak MFM plot, a field map animation, a pseudocurrent density arrow, an MCD plot, and an ECD plot.

42. determining a risk of coronary artery disease in the individual based at least in part on the parameters; 42. The method of claim 41, further comprising determining said presence, said absence, or said likelihood.

43. 42. The method of claim 41, further comprising determining the presence, absence, or likelihood of the coronary artery disease in the individual based at least in part on the visualization.

44. 44. The method of any one of claims 24 to 43, further comprising determining the presence of coronary artery disease in the individual based on (i) whether the first angle differs from the second angle by at least 100 degrees, (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map, (iii) the parameters, and (iv) the presence of at least one abnormality in the visualization.

45. 44. The method of any one of claims 24 to 43, further comprising determining the presence of coronary artery disease in the individual based on (i) whether the first angle differs from the second angle by at least 100 degrees, (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map, (iii) the parameters, and (iv) the presence of at least two abnormalities in the visualization.

46. 1. A method for determining the presence, absence, or likelihood of coronary artery disease in an individual, comprising: (a) identifying a first negative electromagnetic dipole and a first positive electromagnetic dipole in a first electromagnetic field map associated with the individual's heart at a first time; (b) identifying a second negative electromagnetic dipole and a second positive electromagnetic dipole in a second electromagnetic field map associated with the heart of the individual at a second time; (c) determining a first angle based on the first negative electromagnetic dipole and the first positive electromagnetic dipole; (d) determining a second angle based on the second negative electromagnetic dipole and the second positive electromagnetic dipole; (e) determining the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on (i) whether the first angle differs from the second angle by at least 100 degrees, or (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map.

47. 47. The method of claim 46, further comprising recording an electrocardiogram of the individual.

48. 48. The method of claim 47, wherein the first angle comprises a peak R depolarization angle at the first time, the first time being the time at which an R wave is recorded on the electrocardiogram.

49. 48. The method of claim 47, wherein the second angle comprises a peak T repolarization angle at the second time, the second time being the time at which a T wave is recorded on the electrocardiogram.

50. 50. The method of claim 49, wherein the third electromagnetic dipole is present in the second electromagnetic field map.

51. 47. The method of claim 46, wherein the coronary artery disease comprises an occlusion of the left anterior descending artery.

52. 47. The method of claim 46, wherein the first angle is determined by determining a first line that passes through both the first negative electromagnetic dipole and the first positive electromagnetic dipole, and determining an angle between the first line and a horizontal axis.

53. 47. The method of claim 46, wherein the second angle is determined by determining a second line that passes through both the second negative electromagnetic dipole and the second positive electromagnetic dipole, and determining an angle between the second line and a horizontal axis.

54. 47. The method of claim 46, wherein the likelihood of the presence of coronary artery disease in the individual is determined if the first angle differs from the second angle by between 100 degrees and 170 degrees.

55. 47. The method of claim 46, wherein the individual has a normal electrocardiogram with chest pain, or a normal troponin level with chest pain.

56. 47. The method of claim 46, wherein the individual has undergone a positive stress test or an abnormal echocardiogram finding.

57. 47. The method of claim 46, further comprising performing a load test if the first angle is different from the second angle or if a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map.

58. 47. The method of claim 46, further comprising sensing a first electromagnetic field associated with the heart of the individual at the first time and sensing a second electromagnetic field associated with the heart of the individual at the second time, wherein the first electromagnetic field map includes a representation of the first electromagnetic field and the second electromagnetic field map includes a representation of the second electromagnetic field.

59. 47. The method of claim 46, further comprising determining a possible presence of a conduction abnormality in the heart of the individual if the first positive electromagnetic dipole and the second negative electromagnetic dipole have the same location or if the first negative electromagnetic dipole and the second positive electromagnetic dipole have the same location.

60. 47. The method of claim 46, further comprising administering to the individual a treatment for coronary artery disease in response to determining the likelihood of the presence of the coronary artery disease in the individual.

61. 61. The method of claim 60, wherein the treatment comprises a daily aspirin prescription.

62. 61. The method of claim 60, wherein the treatment comprises administration of a blood pressure lowering agent.

63. 61. The method of claim 60, wherein the treatment comprises administration of a lipid-lowering agent.

64. 61. The method of claim 60, wherein the treatment comprises cardiac catheterization.

65. 61. The method of claim 60, wherein the treatment comprises surgical intervention.

66. 47. The method of claim 46, further comprising the steps of: (a) through (e) being performed by a computer.

67. 47. The method of claim 46, wherein the coronary artery disease comprises myocardial ischemia.

68. 47. The method of claim 46, wherein the coronary artery disease comprises myocardial ischemia associated with epicardial coronary artery disease.

69. 47. The method of claim 46, wherein the coronary artery disease comprises myocardial ischemia without epicardial coronary artery disease.

70. 47. The method of claim 46, further comprising determining the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on: (iii) parameters selected from the group consisting of dipole parameters, integrated MCD parameters, integrated ECD parameters, mean PCD parameters, isointegral parameters, field map correlation parameters, R_peak pegged dipole parameters, pseudocurrent arrow parameters, extremal circle parameters, phase space embedded parameters using delta coordinates, and phase space embedded parameters using time delay coordinates; or (iv) visualization selected from the group consisting of a STAG plot, a T_peak MFM plot, a field map animation, a pseudocurrent density arrow, an MCD plot, and an ECD plot.

71. 71. The method of claim 70, further comprising determining the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on the parameter.

72. 71. The method of claim 70, further comprising determining the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on the visualization.

73. 73. The method of any one of claims 46 to 72, further comprising determining the presence of coronary artery disease in the individual based on (i) whether the first angle differs from the second angle by at least 100 degrees, (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map, (iii) the parameters, and (iv) the presence of at least one abnormality in the visualization.

74. 73. The method of any one of claims 46 to 72, further comprising determining the presence of coronary artery disease in the individual based on: (i) whether the first angle differs from the second angle by at least 100 degrees; (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map; (iii) the parameters; and (iv) the presence of at least two abnormalities in the visualization.

75. 1. A non-transitory computer-readable medium containing machine-executable code that, when executed by one or more computer processors, implements a method for determining the presence, absence, or likelihood of coronary artery disease in an individual, the method comprising: (a) identifying a first negative electromagnetic dipole and a first positive electromagnetic dipole in a first electromagnetic field map associated with the individual's heart at a first time; (b) identifying a second negative electromagnetic dipole and a second positive electromagnetic dipole in a second electromagnetic field map associated with the heart of the individual at a second time; (c) determining a first angle based on the first negative electromagnetic dipole and the first positive electromagnetic dipole; (d) determining a second angle based on the second negative electromagnetic dipole and the second positive electromagnetic dipole; (e) determining the presence, absence, or likelihood of coronary artery disease in the individual based at least in part on (i) whether the first angle differs from the second angle by at least 100 degrees, or (ii) whether a third electromagnetic dipole is present in the first electromagnetic field map or the second electromagnetic field map.

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