MRI Compatible Implanted Electronic Medical Device
First Claim
1. An implantable medical device that is compatible with a magnetic resonance imaging scanner, said implantable medical device comprising:
- a housing containing an electronic circuit has a plurality of exterior walls, wherein each exterior wall comprises a substrate of an electrically non-conductive, dielectric material with opposing first and second surfaces, a first layer of electrically conductive material on the first surface, and a second layer of electrically conductive material on the second surface, there being a plurality of first slots in the first layer which expose the dielectric material and divide the first layer into a plurality of first segments, and a plurality of second slots in the second layer which expose the dielectric material and divide the second layer into a plurality of second segments.
1 Assignment
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Accused Products
Abstract
An implantable electronic medical device is compatible with a magnetic resonance imaging (MRI) scanner. The device has a housing with exterior walls, each formed by a dielectric substrate with electrically conductive layers on interior and exterior surfaces. A series of slots divide each layer into segments. Segmenting the layers provides high impedance to eddy currents produced by fields of the MRI scanner, while capacitive coupling of the segments provides radio frequency shielding for components inside the housing. Electrical leads extending from the housing have a pair of coaxially arranged conductors and traps that attenuate currents induced in the conductors by the fields of the MRI scanner.
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Citations
22 Claims
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1. An implantable medical device that is compatible with a magnetic resonance imaging scanner, said implantable medical device comprising:
a housing containing an electronic circuit has a plurality of exterior walls, wherein each exterior wall comprises a substrate of an electrically non-conductive, dielectric material with opposing first and second surfaces, a first layer of electrically conductive material on the first surface, and a second layer of electrically conductive material on the second surface, there being a plurality of first slots in the first layer which expose the dielectric material and divide the first layer into a plurality of first segments, and a plurality of second slots in the second layer which expose the dielectric material and divide the second layer into a plurality of second segments. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. An medical device that is implantable in a patient and compatible with magnetic resonance imaging MRI scanner, said implantable medical device comprising means to substantially mitigate undesirable effects of MRI direct current magnetic fields, MRI gradient magnetic fields and MRI RF fields on a patient, the medical device and the magnetic resonance imaging scanner.
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18. An implantable medical device that is compatible with a magnetic resonance imaging scanner, said implantable medical device comprising:
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a housing containing an electronic circuit and having a plurality of exterior walls with opposing first and second sides, wherein each exterior wall comprises a plurality of electrically non-conductive segments on the first side interleaved with a plurality of electrically conductive segments on the second side, thereby creating two wall surfaces that substantially attenuate eddy currents at frequencies less than 200 KHz which are induced in the wall surfaces by one or more fields of the magnetic resonance imaging scanner, wherein capacitive coupling between the electrically conductive segments renders the wall surfaces conductive to currents at frequencies above 1.0 MHz; and
a cable extending from the housing, wherein the cable comprises a first conductor, a second conductor, and a plurality of traps connected to the second conductor at intervals along the cable, each trap mitigating electrical current induced in the cable due to one or more fields of the magnetic resonance imaging scanner. - View Dependent Claims (19, 20, 21, 22)
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Specification