ELECTROPHYSIOLOGY LABORATORY SYSTEM FOR USE WITH MAGNETIC RESONANCE IMAGING SYSTEMS

• US 20150119690A1
• Filed: 03/15/2013
• Published: 04/30/2015
• Est. Priority Date: 04/23/2012
• Status: Active Grant

• Current Assignee: St. Jude Medical (Abbott Laboratories Incorporated)
• Original Assignee: St. Jude Medical (Abbott Laboratories Incorporated)
• Inventors: Deno, D. Curtis, Schweitzer, Jeffrey A.
• Granted Patent: US 10,610,127 B2
• Time in Patent Office: Days
• US Class Current: 600/411
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2018/00577 Ablation
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2090/374 NMR or MRI
• CPC Class Codes: A61B 2562/18 Shielding or protection of sensors from environmental influences, e.g. protection from mechanical damage
• CPC Class Codes: A61B 5/02055 Simultaneously evaluating both cardiovascular condition and temperature
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/063 using impedance measurements
• CPC Class Codes: A61B 5/283 Invasive
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: A61B 5/7203 for noise prevention, reduction or removal
• 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 1/36 for stimulation
• CPC Class Codes: G01R 33/285 Invasive instruments, e.g. catheters or biopsy needles, specially adapted for tracking, guiding or visualization by NMR
• CPC Class Codes: G01R 33/3685 Means for reducing sheath currents, e.g. RF traps, baluns

Abstract

An electrophysiological laboratory system comprises a subsystem configured to perform diagnostic and/or therapeutic functions, a medical device, and an interface module disposed therebetween. The medical device comprises a shaft having proximal and distal portions, high- and low-impedance electrical pathways disposed within the shaft, and an electrode disposed at the distal portion of the shaft and electrically coupled to one or both of the high- and low-impedance electrical pathways. The electrode is configured to perform diagnostic and/or therapy delivery functions. The interface module comprises a high-impedance channel configured to couple the high-impedance pathway of the medical device to the subsystem, and to attenuate magnetic resonance RF and gradient field pulses generated by the MRI system. The interface module further comprises a low-impedance channel configured to couple the low- impedance pathway of the medical device to the subsystem.

Claims

1. A magnetic resonance imaging (MRI) compatible medical device, comprising:

an elongate shaft having a proximal portion and a distal portion;

at least one electrode disposed at said distal portion of said shaft configured to perform at least one of a diagnostic and a therapy delivery function;

a high-impedance electrical pathway disposed within said shaft and extending from said distal portion to said proximal portion of said shaft; and

a low-impedance electrical pathway disposed within said shaft and extending from said distal portion to said proximal portion of said shaft;

wherein at least one of said high-impedance electrical pathway and said low-impedance electrical pathway is electrically coupled to said electrode.

2. The MRI-compatible medical device of claim 1, wherein both of said high-impedance and low-impedance electrical pathways are electrically coupled to said electrode.

3. The MRI-compatible medical device of claim 1, wherein said electrode is a first electrode and is configured to perform a diagnostic function, and said medical device further comprises a second electrode disposed at said distal portion of said shaft and configured to perform at least one of a diagnostic and a therapy delivery function, and further wherein:

said first electrode is electrically coupled to said high-impedance electrical pathway; and

said second electrode is electrically coupled to said low-impedance electrical pathway.

4. The MRI-compatible medical device of claim 1 further comprising a temperature sensor disposed at said distal portion of said shaft and electrically coupled to said low-impedance electrical pathway.

5. The MRI-compatible medical device of claim 1, wherein said high-impedance electrical pathway has an impedance of greater than or equal to 2 kΩ

6. The MRI-compatible medical device of claim 1, wherein said high-impedance electrical pathway comprises a non-ferromagnetic electrical conductor having a high impedance.

7. The MRI-compatible medical device of claim 6, wherein said electrical conductor is constructed of a metal alloy comprising one of:

a nickel-chromium alloy;

a nickel-iron alloy;

a copper-nickel alloy; and

a manganese-nickel-copper alloy.

8. The MRI-compatible medical device of claim 1, wherein said high-impedance electrical pathway comprises an electrical conductor having a plurality of segments and a resistor element electrically connected in series between a pair of said plurality of conductor segments.

9. The MRI-compatible medical device of claim 1, wherein said low-impedance electrical pathway comprises an inductive element configured to attenuate magnetic resonance radio frequency pulses generated by an MRI system, and to limit the magnitude of radio frequency currents induced in said low-impedance electrical pathway.

10. The MRI-compatible medical device of claim 9, wherein said inductive element comprises a choke.

11. The MRI-compatible medical device of claim 9, wherein said low-impedance electrical pathway further comprises a non-ferromagnetic electrical conductor having a plurality of segments and said inductive element is electrically connected in series between a pair of said plurality of conductor segments.

12. The MRI-compatible medical device of claim 1, wherein said high-impedance electrical pathway is a first high-impedance electrical pathway, and said medical device further comprises a second high-impedance electrical pathway electrically coupled to said low-impedance electrical pathway and extending therefrom to said proximal portion of said shaft.

13. The MRI-compatible medical device of claim 12, wherein said second high-impedance electrical pathway comprises a non-ferromagnetic electrical conductor having a plurality of segments and an impedance element electrically connected in series between a pair of said plurality of conductor segments.

14. The MRI-compatible medical device of claim 1, wherein said high-impedance electrical pathway is configured to limit the magnitude of radio frequency currents induced in the high-resistance pathway by magnetic resonance radio frequency pulses generated by an MRI system.

15. An interface module of an electrophysiology laboratory (EP lab) system configured for use with a magnetic resonance imaging (MRI) system, comprising:

a high-impedance channel comprising an electrical pathway configured to electrically couple a high-impedance electrical pathway of a medical device with at least one of a diagnostic and a therapeutic subsystem of the EP lab system, and to attenuate magnetic resonance radio frequency and gradient field pulses generated by the MRI system; and

a low-impedance channel comprising a plurality of electrical pathways configured to electrically couple a low-impedance electrical pathway of the medical device to at least one of a diagnostic and a therapeutic subsystem of the EP lab system.

16. The interface module of claim 15, wherein said high-impedance channel comprises a high input impedance amplifier disposed within said electrical pathway thereof.

17. The interface module of claim 15, wherein said low-impedance channel is a first low-impedance channel, and said interface module further comprises a second low-impedance channel comprising an electrical pathway configured to electrically couple a patch electrode with at least one of a diagnostic and a therapeutic subsystem of the EP lab system.

18. The interface module of claim 15, wherein said electrical pathway of said high-impedance channel comprises a low pass filter configured to be electrically coupled to the high-impedance electrical pathway of the medical device and to attenuate the magnetic resonance radio frequency pulses generated by the MRI system.

19. The interface module of claim 18, wherein said electrical pathway of said high-impedance channel further comprises a limiter circuit electrically coupled to an output of said low-pass filter and configured to attenuate the magnetic resonance gradient field pulses generated by the MRI system.

20. The interface module of claim 19, wherein said electrical pathway of said high-impedance channel further comprises a high input impedance amplifier configured to be electrically coupled between an output of said limiter circuit and the subsystem of the EP lab system to which the high-impedance electrical pathway of the medical device is coupled.

21. The interface module of claim 15, wherein:

a first of said plurality of electrical pathways of said low-impedance channel is configured to provide an uninterruptable connection between the low-impedance electrical pathway of the medical device and the subsystem of the EP lab system to which the low-impedance electrical pathway of the medical device is coupled; and

a second of said plurality of electrical pathways comprises said interrupter circuit, said interrupter circuit configured to be electrically coupled between the low-impedance electrical pathway of the medical device and the subsystem of the EP lab system to which the low-impedance electrical pathway of the medical device is coupled.

22. An electrophysiological laboratory (EP lab) system configured for use with an magnetic resonance imaging (MRI) system, comprising:

a subsystem configured to perform at least one of a diagnostic and therapeutic function;

an MRI-compatible medical device comprising;

an elongate shaft having a proximal portion and a distal portion,

a high-impedance electrical pathway and a low-impedance electrical pathway each disposed within said shaft and extending from said distal portion to said proximal portion thereof,

at least one electrode disposed at said distal portion of said shaft configured to perform at least one of a diagnostic and therapy delivery function, wherein said electrode is electrically coupled to at least one of said high-impedance and low-impedance electrical pathways; and

an interface module disposed between said MRI-compatible medical device and said subsystem, said interface module comprising;

a high-impedance channel comprising an electrical pathway configured to electrically couple said high-impedance electrical pathway of said medical device to said subsystem and to attenuate magnetic resonance radio frequency and gradient field pulses generated by the MRI system; and

a low-impedance channel comprising a plurality of electrical pathways configured to electrically couple said low-impedance electrical pathway of said medical device to said subsystem.

23. The EP lab system of claim 22, wherein said subsystem comprises one of:

a visualization, navigation, and/or mapping system;

an EP monitoring and recording system;

a tissue contact sensing system;

an ablation system; and

a stimulation system.

24. The EP lab system of claim 22, wherein said subsystem further comprises at least one patch electrode, and said low-impedance channel of said interface module is a first low-impedance channel, and further wherein said interface module further comprises a second low-impedance channel comprising an electrical pathway configured to electrically couple said patch electrode to said subsystem.