Implantable ferromagnetic markers
AssigneeEndomagnetics Ltd
InventorsRobinson Udale, Gabriel Villar
Life of this patent
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Abstract
An implantable susceptometry marker (1001) for use in surgical guidance comprising one or more ferromagnetic elements (1004a, 1004b, 1004c); and at least one diamagnetic element (1003); wherein the one or more ferromagnetic elements are formed of at least one ferromagnetic material having an initial relative permeability of at least about 10,000 and a saturation induction Bs of less than about 1.5 T, and the at least one diamagnetic element is formed of at least one diamagnetic material having a bulk susceptibility of at least about −0.16×10−4; and wherein the total volume of diamagnetic material in the marker is about 100-10,000 times greater than the total volume of ferromagnetic material.
Claims20
An implantable susceptometry marker for use in surgical guidance comprising one or more ferromagnetic elements and at least one diamagnetic element;
- wherein the one or more ferromagnetic elements are formed of at least one ferromagnetic material having an initial relative permeability of at least 10,000 and a saturation induction Bs of less than 1.5 T;
- wherein the at least one diamagnetic element is formed of at least one diamagnetic material having a bulk susceptibility of less than −0.16×10−4, and
- wherein a total volume of diamagnetic material in the marker is 100-10,000 times greater than a total volume of ferromagnetic material in the marker.
A method of manufacturing an implantable susceptometry magnetic marker for use in surgery, the method comprising:
- forming one or more ferromagnetic elements from at least one ferromagnetic material having an initial relative permeability of at least 10,000 and a saturation induction Bs of less than 1.5 T,
- forming at least one diamagnetic element from at least one diamagnetic material, the at least one diamagnetic material having a bulk susceptibility less than −0.16×10−4, a total volume of diamagnetic material in the marker being 100-10,000 times greater than a total volume of ferromagnetic material in the marker, and thereafter
- assembling the one or more ferromagnetic elements and at least one diamagnetic element, such that the at least one diamagnetic element is colocated with the one or more ferromagnetic elements and is configured such that in an MRI field the at least one diamagnetic element produces an artefact having a size and shape that substantially matches an artefact size and shape of an artefact produced by the one or more ferromagnetic elements.
Dependencies are inferred from the claim text.