System and method for controlling an implantable medical device subject to magnetic field or radio frequency exposure

• US 20040267233A1
• Filed: 06/30/2003
• Published: 12/30/2004
• Est. Priority Date: 06/30/2003
• Status: Active Grant

• Current Assignee: Medos International Sarl (Johnson & Johnson)
• Original Assignee: Codman Neuro Sciences Sarl
• Inventors: Ginggen, Alec
• Granted Patent: US 7,242,981 B2
• Time in Patent Office: Days
• US Class Current: 604/500
• CPC Class Codes: A61M 2205/3317 Electromagnetic, inductive or dielectric measuring means
• CPC Class Codes: A61M 2205/3523 using telemetric means
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2205/702 automatically during use
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61N 1/37 Monitoring; Protecting
• CPC Class Codes: A61N 1/3718 Monitoring of or protection against external electromagnetic fields or currents

Abstract

A system for controlling an implantable medical device (e.g., a drug delivery device) susceptible to malfunctioning during exposure to a magnetic field and/or Radio Frequency field (e.g., during a magnetic resonance imaging procedure) and a method for operating the same. Exposure of the implantable device to the magnetic field and/or the Radio Frequency field is detected using the sensing device. When the detected magnetic field and/or Radio Frequency field exceeds a corresponding predetermined threshold level, an input signal is generated at the microcontroller. In response to the generated input signal, the microcontroller automatically triggers (i) a safety mode enabling a predetermined safety mode operation that alters some operation, without ceasing all operation, of the implantable medical device and/or (ii) after expiration of a predetermined safety mode time interval when the at least one field being detected falls below its corresponding predetermined threshold level or a predetermined period of time elapses, a self testing mode enabling a predetermined self testing operation to verify proper operation of the implantable medical device. Preferably, both the safety and self testing modes are automatically triggered.

Claims

1. A method for operating a system for controlling an implantable drug delivery device susceptible to malfunctioning during exposure to at least one of a magnetic field or a Radio Frequency field, the method comprising the steps of:

detecting exposure of the implantable device to the at least one of the magnetic field or the Radio Frequency field using a sensing device;

when the at least one field being detected exceeds a corresponding predetermined threshold level, generating an input signal at a microcontroller;

automatically triggering, in response to the generated input signal, at least one of (i) a safety mode enabling a predetermined safety mode operation that alters some operation, without ceasing all operation, of the implantable drug delivery device;

or (ii) after expiration of a predetermined safety mode time interval when the at least one field being detected falls below its corresponding predetermined threshold level or a predetermined period of time elapses, a self testing mode enabling a predetermined self testing operation to verify proper operation of the implantable drug delivery device.

2. The method in accordance with claim 1, wherein only the safety mode is automatically triggered.

3. The method in accordance with claim 1, wherein only the self testing mode is automatically triggered.

4. The method in accordance with claim 1, wherein the safety mode is automatically triggered followed by the self testing mode, the predetermined safety mode operation continuing simultaneously with the predetermined self testing mode operation.

5. The method in accordance with claim 4, wherein the predetermined safety mode operation further comprises at least one of:

(i) duplicating all data, (ii) saving all data to a memory, (iii) short circuiting a transmitter/receiver of the implantable drug delivery device, (iv) reverting to a default operation of the implantable drug delivery device stored in a non-volatile memory at the time of implantation, (v) calculating memory checksums to be verified during the self testing mode, (vi) store data detected by the sensing device, and (vii) ceasing delivery of drugs.

6. The method in accordance with claim 1, wherein the sensing device comprises a plurality of Reed switches or a plurality of Hall Magnetic Sensors.

7. The method in accordance with claim 1, wherein the predetermined self testing mode operation comprises at least one of:

(i) verifying of memory contents, (ii) testing operation of memory device, and (iii) verifying the operation of components of the implantable drug delivery device.

8. The method in accordance with claim 1, further comprising, if no error in operation is detected during the self testing mode, disabling the predetermined safety mode operation.

9. The method in accordance with claim 1, further comprising the steps of:

when an error in operation is detected during the self testing mode, indicating that the error has been detected; and

disabling the predetermined safety mode operation when the error in operation has been corrected.

10. A system for controlling an implantable drug delivery device susceptible to malfunctioning during exposure to at least one of a magnetic field or Radio Frequency field, the system comprising the steps of:

a sensing device for detecting exposure of the implantable drug delivery device to the at least one of the magnetic field or the Radio Frequency field;

a microcontroller electrically connected to the sensing device, the microcontroller receiving an input signal when the at least one field being detected exceeds a corresponding predetermined threshold level;

the microcontroller automatically triggering, in response to the input signal, at least one of (i) a safety mode enabling a predetermined safety mode operation that alters some operation, without ceasing all operation, of the implantable drug delivery device, or (ii) after expiration of a predetermined safety mode time interval when the at least one field being detected falls below its corresponding predetermined threshold level or a predetermined period of time elapses, a self testing mode enabling a predetermined self testing operation to verify proper operation of the implantable drug delivery device.

11. The system in accordance with claim 10, wherein the microcontroller automatically triggers only the safety mode.

12. The system in accordance with claim 10, wherein the microcontroller automatically triggers only the self testing mode.

13. The system in accordance with claim 10, wherein the microcontroller automatically triggers the safety mode followed by the self testing mode, the predetermined safety mode operation continuing simultaneously with the predetermined self testing mode operation.

14. The system in accordance with claim 10, wherein the microcontroller is programmed with the predetermined safety mode operation comprising at least one of:

(i) duplicating all data, (ii) saving all data to a memory, (iii) short circuiting a transmitter/receiver of the electronic implantable drug delivery device, (iv) reverting to a default operation of the implantable drug delivery device stored in a non-volatile memory at the time of implantation, (v) calculating memory checksums to be verified during the self testing mode, (vi) store data detected by the sensing device, and (vii) ceasing delivery of drugs.

15. The system in accordance with claim 10, wherein the sensing device comprises a plurality of Reed switches or a plurality of Hall Magnetic Sensors.

16. The system in accordance with claim 10, wherein the predetermined self testing mode operation programmed in the microcontroller comprises at least one of:

(i) verifying of memory contents, (ii) testing operation of memory device, and (iii) verifying the operation of components of the implantable drug delivery device.

17. The system in accordance with claim 10, wherein if no error in operation is detected during the self testing mode, the microcontroller disables the predetermined safety mode operation.

18. The system in accordance with claim 10, the microcontroller is programmed to indicate during the self testing mode the detection of an error in operation and disable the predetermined safety mode operation when the error in operation has been corrected.

19. A method for operating a system for controlling an implantable medical device susceptible to malfunctioning during exposure to at least one of a magnetic field or a Radio Frequency field, the method comprising the steps of:

detecting exposure of the implantable device to the at least one of the magnetic field or the Radio Frequency field using a sensing device;

when the at least one field being detected exceeds a corresponding predetermined threshold level, generating an input signal at a microcontroller;

automatically triggering, in response to the generated input signal, (i) a safety mode enabling a predetermined safety mode operation that alters some operation, without ceasing all operation, of the implantable medical device, and (ii) after expiration of a predetermined safety mode time interval when the at least one field being detected falls below its corresponding predetermined threshold level or a predetermined period of time elapses, a self testing mode enabling a predetermined self testing operation to verify proper operation of the implantable medical device.

20. A system for controlling an implantable medical device susceptible to malfunctioning during exposure to at least one of a magnetic filed or Radio Frequency field, the system comprising the steps of:

a sensing device for detecting exposure of the implantable device to the at least one of the magnetic field or the Radio Frequency field;

a microcontroller electrically connected to the sensing device, the microcontroller receiving an input signal when the at least one field being detected exceeds a corresponding predetermined threshold level;

the microcontroller automatically triggering, in response to the input signal, (i) a safety mode enabling a predetermined safety mode operation that alters some operation, without ceasing all operation, of the implantable medical device, and (ii) after expiration of a predetermined safety mode time interval when the at least one field being detected falls below its corresponding predetermined threshold level or a predetermined period of time elapses, a self testing mode enabling a predetermined self testing operation to verify proper operation of the implantable medical device.