MRI system having implantable device safety features

• US 7,561,915 B1
• Filed: 12/17/2004
• Issued: 07/14/2009
• Est. Priority Date: 12/17/2004
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Von Arx, Jeffrey A., Cooke, Daniel J.
• Primary Examiner(s): Bockelman; Mark W
• Assistant Examiner(s): Bertram; Eric D
• Application Number:
  US11/016,191
• Time in Patent Office: 1,670 Days
• Field of Search: 607/31, 607/63, 607/59, 607/60, 600/410, 600/411
• US Class Current: 607/31
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents
• CPC Class Codes: A61N 1/37264 Changing the program; Upgrading firmware

Abstract

One embodiment of the present invention relates to a telemetry device which is in communication with an MRI system, and which is operable to communicate with an implantable medical device (IMD). The telemetry device includes a controller and telemetry circuitry. In one embodiment, the telemetry device is operable to automatically detect the presence of an IMD, and determine if the IMD is in an MRI-safe mode. If the IMD is not in an MRI-safe mode, the telemetry device can initiate processing to prevent the MRI system from conducting an MRI scan while the IMD in not in an MRI-safe mode.

Claims

1. A method for causing an implantable medical device (“

IMD”

) to operate in a safe mode during an MRI scan, the method comprising;

detecting the presence of the IMD using an MRI system containing a telemetry device wirelessly communicating with the IMD, the IMD initially programmed to operate according to a first mode of therapy;

determining that the IMD is not operating according to an MRI-safe mode of therapy using the telemetry device;

sending a signal from the telemetry device to the IMD causing the IMD to operate according to the MRI-safe mode of therapy; and

preventing an MRI system from conducting an MRI scan if the IMD is not in the MRI-safe mode,

wherein causing the IMD to operate according to the MRI-safe mode of therapy includes at least one of;

causing the first mode of therapy of the IMD to change from rate-responsive cardiac pacing to fixed-rate cardiac pacing;

causing the first mode of therapy of the IMD to change from demand cardiac pacing to non-demand cardiac pacing;

causing the first mode of therapy of the IMD to change from providing tachycardia therapy to not providing tachycardia therapy; and

causing the first mode of therapy of the IMD to change from tachycardia detection to not detecting tachycardia.

2. The method as recited in claim 1, wherein preventing the MRI system from conducting an MRI scan includes generating an alarm message for alerting an operator that the IMD is not in the MRI-safe mode.

3. The method as recited in claim 1, further comprising:

disabling the MRI system while the IMD is not in the MRI-safe mode.

4. The method as recited in claim 1, further comprising:

conducting an MRI scan after the IMD is switched to the MRI-safe mode.

5. The method as recited in claim 4, further comprising receiving a confirmation from the IMD that the IMD is in the MRI-safe mode prior to conducting the MRI scan.

6. The method as recited in claim 1, further comprising transmitting a command to the IMD instructing the IMD to switch back to the first mode of therapy after the MRI scan is complete.

7. The method as recited in claim 1, wherein the telemetry device is selected from the group consisting of an IMD programmer and an IMD repeater device.

8. The method as recited in claim 1, wherein the IMD is operable to detect a magnetic field produced by an MRI system, the method further comprising determining if the IMD is in the MRI-safe mode by receiving a command from the IMD indicating that an IMD is present and not in the MRI-safe mode.

9. A method for causing an implantable medical device (“

IMD”

) to operate in a safe mode during an MRI scan, the method comprising;

detecting the presence of the IMD using an MRI system containing a telemetry device wirelessly communicating with the IMD, the IMD initially programmed to operate according to a first mode of therapy;

determining that the IMD is not operating according to an MRI-safe mode of therapy using the telemetry device;

sending a signal from the telemetry device to the IMD causing the IMD to operate according to the MRI-safe mode of therapy;

receiving a confirmation from the IMD that the IMD is in the MRI-safe mode prior to conducting the MRI scan;

transmitting a command to the IMD instructing the IMD to switch back to the first mode of therapy after the MRI scan is complete; and

preventing an MRI system from conducting an MRI scan if the IMD is not in the MRI-safe mode;

wherein causing the IMD to operate according to the MRI-safe mode of therapy includes at least one of;

causing the first mode of therapy of the IMD to change from rate-responsive cardiac pacing to fixed-rate cardiac pacing;

causing the first mode of therapy of the IMD to change from demand cardiac pacing to non-demand cardiac pacing;

causing the first mode of therapy of the IMD to change from providing tachycardia therapy to not providing tachycardia therapy;

causing the first mode of therapy of the IMD to change from tachycardia detection to not detecting tachycardia.

10. The method as recited in claim 9, wherein preventing the MRI system from conducting an MRI scan includes generating an alarm message for alerting an operator that the IMD is not in the MRI-safe mode.

11. The method as recited in claim 9, further comprising:

disabling the MRI system while the IMD is not in the MRI-safe mode.

12. The method as recited in claim 9, further comprising:

conducting an MRI scan after the IMD is switched to the MRI-safe mode.

13. The method as recited in claim 9, wherein the telemetry device is selected from the group consisting of an IMD programmer and an IMD repeater device.

14. The method as recited in claim 9, wherein the IMD is operable to detect a magnetic field produced by an MRI system, the method further comprising determining if the IMD is in the MRI-safe mode by receiving a command from the IMD indicating that an IMD is present and not in the MRI-safe mode.