Implantable medical device

• US 9,393,408 B2
• Filed: 12/24/2014
• Issued: 07/19/2016
• Est. Priority Date: 03/24/2006
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Kast, John, Wahlstrand, Carl D., Conroy, Mark J., Scott, Erik R.
• Primary Examiner(s): Stice, Paula J
• Application Number:
  US14/582,817
• Publication Number:
  US 20150107089A1
• Time in Patent Office: 573 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61N 1/05 for implantation or insertion into the body, e.g. heart electrode A61N1/06 takes precedence
• CPC Class Codes: A61N 1/0529 Electrodes for brain stimulation
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/086 Magnetic resonance imaging [MRI] compatible leads
• CPC Class Codes: A61N 1/3605 Implantable neurostimulators for stimulating central or peripheral nerve system
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents
• CPC Class Codes: A61N 1/37514 Brain implants
• CPC Class Codes: A61N 1/3758 Packaging of the components within the casing
• CPC Class Codes: A61N 1/378 Electrical supply
• CPC Class Codes: G01R 33/3875 using correction coil assemblies, e.g. active shimming
• CPC Class Codes: G01R 33/56572 caused by a distortion of a gradient magnetic field, e.g. non-linearity of a gradient magnetic field G01R33/56509, G01R33/56518, G01R33/56536 take precedence
• CPC Class Codes: H01M 10/0431 Cells with wound or folded electrodes H01M10/045 takes precedence
• CPC Class Codes: H01M 10/052 Li-accumulators
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/0587 of accumulators having only wound construction elements, i.e. wound positive electrodes, wound negative electrodes and wound separators
• CPC Class Codes: H01M 10/4257 Smart batteries, e.g. electronic circuits inside the housing of the cells or batteries
• CPC Class Codes: H01M 2220/30 Batteries in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 50/103 prismatic or rectangular H01M50/109, H01M50/11 take precedence
• CPC Class Codes: H01M 50/119 : Metals
• CPC Class Codes: H01M 50/121 : Organic material
• CPC Class Codes: H01M 50/122 : Composite material consisting of a mixture of organic and inorganic materials
• CPC Class Codes: H01M 50/14 : for protecting against damage caused by external factors
• CPC Class Codes: H01M 50/147 : Lids or covers
• CPC Class Codes: H01M 50/528 : Fixed electrical connections, i.e. not intended for disconnection
• CPC Class Codes: H01M 50/553 : Terminals adapted for prismatic, pouch or rectangular cells
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02P 70/50 : Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49 : Method of mechanical manufacture
• CPC Class Codes: Y10T 29/49002 : Electrical device making

Abstract

A method of manufacturing an implantable medical device having reduced MRI image distortion, includes producing an implantable medical device. The implantable medical device has a configuration that comprises a housing and one or more internal components disposed within the housing. The configuration is based upon a design process that includes creating a first prototype, determining the aggregate relative magnetic permeability of the first prototype, and modifying the design of the first prototype by at least one of (a) selecting and adding a diamagnetic shimming material to the first prototype or (b) repositioning one or more internal components of the first prototype. Modifying the design results in a modified design that is the configuration for the implantable medical device.

Claims

1. A method of manufacturing an implantable medical device having reduced MRI image distortion comprising:

producing an implantable medical device, wherein the implantable medical device has a configuration that comprises a housing and one or more internal components disposed within the housing;

wherein the configuration is based upon a design process that includes;

creating a first prototype;

determining an aggregate relative magnetic permeability of the first prototype; and

modifying the design of the first prototype by at least one of (a) selecting and adding a diamagnetic shimming material to the first prototype or (b) repositioning one or more internal components of the first prototype, wherein said modifying results in a modified design that is the configuration for the implantable medical device.

2. The method of claim 1, wherein the design process further includes:

creating a first electromagnetic model to determine the aggregate relative magnetic permeability of the first prototype; and

creating a second electromagnetic model of the modified design to determine the aggregate relative magnetic permeability of the modified design.

3. The method of claim 1, comprising the step of selecting and adding the diamagnetic shimming material, which includes positioning the diamagnetic shimming material to reduce MM image distortion caused by the housing or the one or more internal components.

4. The method of claim 1 comprising the step of repositioning the internal components of the implantable medical device to reduce MRI image distortion caused by the internal components.

5. The method of claim 4, wherein repositioning the internal components of the implantable medical device includes repositioning a diamagnetic internal component closer to a paramagnetic internal component, or repositioning a paramagnetic internal component further from another paramagnetic internal component.

6. The method of claim 1, wherein the step of determining the aggregate relative magnetic permeability includes viewing field perturbation of the first prototype in a magnetic field.

7. The method of claim 1, wherein the step of modifying the design is performed by selecting the diamagnetic shimming material according to the aggregate relative magnetic permeability of the first prototype.

8. The method of claim 1, wherein the diamagnetic shimming material is added to the first prototype by coating at least a portion of the housing with the diamagnetic shimming material.

9. The method of claim 8, wherein the one or more internal components include a telemetry device, wherein a portion of the housing proximate to the telemetry device is not coated with the diamagnetic shimming material.

10. The method of claim 1, wherein the one or more internal components include a first internal component causing a first image distortion and a second internal component causing a second image distortion greater than the first image distortion, wherein the method further comprises:

providing a first shimming material having a first thickness proximate to the first internal component and a second shimming material having a second thickness proximate to the second internal component.

11. The method of claim 10, wherein first shimming material and the second shimming material have the same composition.

12. The method of claim 11, wherein the second thickness is greater than the first thickness.

13. The method of claim 10, wherein the first shimming material has a different composition than the second shimming material.