Magnetic resonance imaging interference immune device

• US 7,839,146 B2
• Filed: 10/29/2007
• Issued: 11/23/2010
• Est. Priority Date: 06/24/2003
• Status: Expired due to Fees

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Gray, Robert W.
• Primary Examiner(s): Shrivastav; Brij B
• Application Number:
  US11/926,216
• Publication Number:
  US 20080129435A1
• Time in Patent Office: 1,121 Days
• Field of Search: 324300-322, 324/207.17, 600607-445, 327/129
• US Class Current: 324/318
• 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 1/086 Magnetic resonance imaging [MRI] compatible leads
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents
• CPC Class Codes: H01F 5/00 Coils superconducting coils H01F6/06; fixed inductances of the signal type H01F17/00
• CPC Class Codes: H03H 1/0007 of radio frequency interference filters

Abstract

A medical apparatus includes a medical assist device to process signals to relating biological functions. A first lead is operatively connected to the medical assist device, the first lead having a distal end and a proximal end. A second lead is operatively connected to the medical assist device, the second lead having a distal end and a proximal end. The first electrode is operatively connected to the distal end of the first lead, and a second electrode is operatively connected to the distal end of the second lead. A filter circuit is operatively connected near the distal end of the first lead and the distal end of the second lead. A compensation circuit, operatively connected to the first lead, provides a compensation voltage to enable the filter to effectively block changing magnetic fields induced current in the second lead from passing through the second electrode of the distal end of the second lead.

Claims

1. An implantable medical lead comprising:

an electrode configured to contact a heart of a patient; and

a conductor configured to electrically couple the electrode to internal electronics of an implantable medical device when connected to the implantable medical device,

wherein the conductor has a plurality of first sections of coils and a plurality of second sections of coils, each first section of coils having coils coiled along an axis of a length of the medical lead, each second section of coils having coils coiled perpendicular to the coils of said first section,

further wherein the plurality of first sections of coils and the plurality of second sections of coils are interleaved along the length of the medical lead such that at least one of the plurality of second sections of coils is located between two of the plurality of first sections of coils.

2. A implantable medical lead comprising:

an electrode configured to contact a heart of a patient; and

a conductor configured to electrically couple the electrode to internal electronics of an implantable medical device when connected to the implantable medical device,

wherein the conductor has a plurality of first sections of coils and a plurality of second sections of coils, each first section of coils having coils coiled along an axis of a length of the medical lead, each second section of coils having coils coiled perpendicular to the coils of said first section.

3. A medical lead, comprising:

a conductor having a plurality of first sections of coils and a plurality of second sections of coils, each first section of coils having coils coiled along an axis of a length of the medical lead, each second section of coils having coils coiled perpendicular to the coils of said first section.

4. The medical lead as claimed in claim 3, wherein said conductor has a plurality of third sections of coils, each third section of coils having coils coiled perpendicular to the coils of said first section and perpendicular to the coils of said second section.

5. The medical lead as claimed in claim 3, wherein each first section of coils has a predetermined number of coils per unit length, each second section of coils has a predetermined number of coils per unit length, and the predetermined number of coils per unit length of said first sections of coils is different than the predetermined number of coils per unit length of said second sections of coils.

6. The medical lead as claimed in claim 4, wherein each third section of coils has a predetermined number of coils per unit length, the predetermined number of coils per unit length of said first sections of coils is different than the predetermined number of coils per unit length of said third sections of coils, and the predetermined number of coils per unit length of said third sections of coils is different than the predetermined number of coils per unit length of said second sections of coils.

7. The medical lead as claimed in claim 3, further comprising an electrode configured to contact a heart of a patient, wherein the conductor is configured to electrically couple the electrode to internal electronics of an implantable medical device when connected to the implantable medical device.

8. The medical lead as claimed in claim 3, wherein the plurality of first sections of coils and the plurality of second sections of coils are interleaved along the length of the medical lead such that at least one of the plurality of second sections of coils is located between two of the plurality of first sections of coils.