Magnetic markers for position sensing
First Claim
1. An imaging system for locating a discrete number of magnets with predetermined magnetic field maps fixed in a medical implant, comprising:
- at least one magnetic field sensor arranged in an array around the implant; and
a computational component configured to calculate the locations of the magnets by iteratively solving for position vector coordinates of the magnets using the pre-determined magnetic field maps of the magnets and the magnetic field measurements observed by each sensor.
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Abstract
An imaging system is provided for locating implants within a patient, and for determining the spatial relationship and orientation between components of an implant within a patient. Magnets are fixed to an implant in pre-determined locations, the magnets having pre-determined quantity, magnetic field map, and moment orientations. An array of sensors is arranged around the implant. The locations of the magnets are estimated by iteratively solving for the position vector coordinates using multi-poles approximating the pre-determined quantity, magnetic field map, and moment orientations of the magnets and the magnetic field measurements for each sensor. The positions and orientations of the implant or components of the implant are inferred from the estimated locations of the magnets.
37 Citations
29 Claims
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1. An imaging system for locating a discrete number of magnets with predetermined magnetic field maps fixed in a medical implant, comprising:
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at least one magnetic field sensor arranged in an array around the implant; and
a computational component configured to calculate the locations of the magnets by iteratively solving for position vector coordinates of the magnets using the pre-determined magnetic field maps of the magnets and the magnetic field measurements observed by each sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A method of imaging an implant, comprising the steps of:
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affixing a pre-determined quantity of magnets with pre-determined field maps to the implant;
disposing an array of magnetic field sensors around the implant; and
iteratively solving for the position vectors of the magnets using the pre-determined field maps for the magnets and the magnetic field measurements observed by each sensor; and
using the determined set of magnet locations to infer the relative position of at least one component in the implant with respect to another component. - View Dependent Claims (15, 16, 17, 18, 19)
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20. An imaging system, comprising:
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an array of magnets fixed in an implant and having pre-determined quantity, magnetic field map, and moment orientations; and
an array of sensors arranged around the implant;
wherein the locations of the magnets are determined by iteratively solving for the position vector coordinates using the pre-determined quantity, magnetic field map, and moment orientations and the magnetic field measurements for each sensor. - View Dependent Claims (21, 22, 23)
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- 24. An implant comprising a pre-determined quantity of magnets fixed thereto for visualization of the implant using static magnetic fields, the magnets having a pre-determined magnetic field map and pre-determined moment orientations.
Specification