Systems and methods for recording biomagnetic fields of the human heart
A magnetocardiography (MCG) system includes a passively shielded enclosure having walls defining the passively shielded enclosure, each of the walls including passive magnetic shielding material to reduce an ambient background magnetic field within the passively shielded enclosure; an MCG measurement device including optically pumped magnetometers (OPMs); and active shield coils within the passively shielded enclosure and stationary relative to the passively shielded enclosure and the MCG measurement device, wherein the active shield coils are configured to further reduce the ambient background magnetic field within a user area of the passively shielded enclosure.
1. A magnetocardiography (MCG) system, comprising:
a passively shielded enclosure comprising a plurality of walls defining the passively shielded enclosure, each of the plurality of walls comprising passive magnetic shielding material to reduce an ambient background magnetic field within the passively shielded enclosure;
an MCG measurement device comprising a plurality of optically pumped magnetometers (OPMs);
a plurality of active shield coils within the passively shielded enclosure and stationary relative to the passively shielded enclosure and the MCG measurement device, wherein the plurality of active shield coils is configured to further reduce the ambient background magnetic field within a user area of the passively shielded enclosure;
at least one sensing modality disposed in the passively shielded enclosure to monitor a position or orientation of the MCG measurement device; and
an active shield controller coupleable to the active shield coils and to the at least one sensing modality and configured to alter generation of magnetic fields by the active shield coils in response to the monitored position or orientation of the MCG measurement device.
2. The MCG system of claim 1 , wherein the MCG measurement system comprises at least one magnetic field generator disposed adjacent the OPMs to reduce the ambient background magnetic field experienced by the OPMs.
3. The MCG system of claim 1 , wherein the MCG measurement device is wearable by a user.
4. The MCG system of claim 3 , wherein the MCG measurement device is disposed in a vest or harness.
5. The MCG system of claim 1 , wherein the MCG measurement device is mounted so that a user moves next to, or leans against, the MCG measurement device.
6. The MCG system of claim 1 , wherein at least one of the active shield coils is configured for attachment to at least one of the walls of the passively shielded enclosure.
7. The MCG system of claim 1 , wherein all of the active shield coils are configured for attachment to the walls of the passively shielded enclosure.
8. The MCG system of claim 1 , wherein at least one of the active shield coils is configured for free-standing in the passively shielded enclosure.
9. The MCG system of claim 1 , wherein the active shield controller is configured to provide a plurality of independent channels with each of the active shield coils coupled to any one of the independent channels.
10. The MCG system of claim 1 , wherein the plurality of active shield coils comprises at least thirty active shield coils.
11. The MCG system of claim 1 , wherein the plurality of walls comprises a floor, a ceiling, and a first wall having an open doorway without a door for entering or exiting into the passively shielded enclosure, the passively shielded enclosure further comprising a vestibular wall extending from the first wall toward another of the walls to define, and at least partially separate, a vestibular area of the passively shielded enclosure adjacent the doorway and a user area of the passively shielded enclosure.
12. The MCG system of claim 1 , further comprising a mobile platform, wherein the passively shielded enclosure is mounted on the mobile platform.
13. The MCG system of claim 1 , further comprising at least one piece of exercise equipment disposed in the passively shielded enclosure and configured for use by a user during MCG measurement.
14. A shielding arrangement for a magnetocardiography (MCG) system comprising a MCG measurement device, the shielding arrangement comprising:
a passively shielded enclosure comprising a plurality of walls defining the passively shielded enclosure, each of the plurality of walls comprising passive magnetic shielding material to reduce an ambient background magnetic field within the passively shielded enclosure, wherein the plurality of walls comprises a floor, a ceiling, and a first vertical wall having an open doorway without a door for entering or exiting into the passively shielded enclosure;
a vestibular wall extending from the first vertical wall to define, and at least partially separate, a vestibular area of the passively shielded enclosure adjacent the doorway and a user area of the passively shielded enclosure;
a plurality of active shield coils distributed within the passively shielded enclosure and configured to further reduce the ambient background magnetic field within the user area of the passively shielded enclosure;
at least one sensing modality disposed in the passively shielded enclosure to monitor a position or orientation of the MCG measurement device; and
an active shield controller coupleable to the active shield coils and to the at least one sensing modality and configured to alter generation of magnetic fields by the active shield coils in response to the monitored position or orientation of the MCG measurement device.
15. The shielding arrangement of claim 14 , further comprising at least one piece of exercise equipment disposed in the passively shielded enclosure and configured for use by a user during MCG measurement.
16. The shielding arrangement of claim 14 , wherein at least one of the active shield coils is configured for attachment to at least one of the walls of the passively shielded enclosure.
17. The shielding arrangement of claim 14 , wherein the active shield controller is configured to provide a plurality of independent channels with each of the active shield coils coupled to any one of the independent channels.
18. The shielding arrangement of claim 14 , further comprising a mobile platform, wherein the passively shielded enclosure is mounted on the mobile platform.
19. The shielding arrangement of claim 14 , wherein all of the active shield coils are configured for attachment to the walls of the passively shielded enclosure.
20. The shielding arrangement of claim 14 , wherein at least one of the active shield coils is configured for free-standing in the passively shielded enclosure.