TELEMETRY DUTY CYCLE MANAGEMENT SYSTEM FOR AN IMPLANTABLE MEDICAL DEVICE

• US 20100152816A1
• Filed: 02/26/2010
• Published: 06/17/2010
• Est. Priority Date: 12/19/2001
• Status: Active Grant

• Current Assignee: Jeffrey A Von Arx, Ron Balczewski, Scott T. Mazar, William J. Linder, William R. Mass
• Original Assignee: Jeffrey A Von Arx, Ron Balczewski, Scott T. Mazar, William J. Linder, William R. Mass
• Inventors: Von Arx, Jeffrey A., Linder, William J., Mazar, Scott T., Mass, William R., Balczewski, Ron
• Granted Patent: US 8,046,080 B2
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61N 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/37276 characterised by means for reducing power consumption during telemetry
• CPC Class Codes: A61N 1/3956 Implantable devices for applying electric shocks to the heart, e.g. for cardioversion

Abstract

An implantable medical device comprising a far field RF transmitter and receiver, a controller circuit communicatively coupled to the RF transmitter and receiver, and a wakeup timer circuit integral to, or communicatively coupled to, the controller. The controller is configured to initiate power up of the RF transmitter and receiver during a wakeup interval defined by the wakeup timer circuit, detect a digital key received from a second device during the wakeup interval, transmit a response using the RF transmitter when the digital key is received, and receive a communication from the second device and resynchronize the wake-up timer according to a time of the communication.

Claims

1. An implantable medical device (IMD) comprising:

a far field RF transmitter and receiver;

a controller circuit communicatively coupled to the RF transmitter and receiver; and

a wakeup timer circuit integral to, or communicatively coupled to, the controller, wherein the controller circuit is configured to;

initiate power up of the RF transmitter and receiver during a wakeup interval defined by the wakeup timer circuit;

detect a digital key received from a second device during the wakeup interval;

transmit a response using the RF transmitter when the digital key is received; and

receive a communication from the second device and resynchronize the wake-up timer according to a time of the communication.

2. The IMD of claim 1, wherein the controller circuit is configured to:

calculate an average of the amount the wakeup timer circuit is adjusted for resynchronization; and

adjust the wakeup timer circuit using the calculated average.

3. The IMD of claim 1, wherein the controller circuit is configured to:

determine an amount of time since the previous communication with the second device; and

adjust the wakeup timer circuit using the determined time.

4. The IMD of claim 1, wherein the controller circuit is configured to resynchronize the wakeup timer circuit by aligning the wakeup interval to the start of the communication.

5. The IMD of claim 1, wherein the controller circuit is configured to resynchronize the wakeup timer circuit by setting the wakeup timer ahead or behind the start of the communication.

6. The IMD of claim 1, wherein the wakeup interval timed by the wakeup circuit is different from the wakeup interval of the second device.

7. The IMD of claim 6, wherein the wakeup interval is long enough to receive a plurality of digital keys.

8. The IMD of claim 1, wherein the controller circuit is configured to:

detect a different digital key received from a second device during the wakeup interval; and

resynchronize the wake-up timer according to a time the different digital key was received.

9. The IMD of claim 1, wherein the controller circuit is configured to change the wakeup interval according to the communication from the second device.

10. The IMD of claim 1, wherein the controller circuit is configured to shorten the wakeup interval when a low battery condition is detected.

11. The IMD of claim 1, wherein the controller circuit is configured to initiate transmitting data in the response before receiving a message indicating that the second device is ready.

12. The IMD of claim 1, wherein the controller circuit is configured to receive data from the second device without receiving an acknowledge of the response.

13. The IMD of claim 1, wherein, upon detection of a specified event, the controller circuit is configured to communicate as a master device according to a specified master/slave communication protocol during the wakeup interval.

14. The IMD of claim 13, wherein the controller circuit is configured to:

transmit a digital key to the second device;

establish a communications session with the second device when a response to the digital key is received from the second device; and

initiate transmission of a terminate command to end the communications session.

15. The IMD of claim 1, wherein the controller circuit is configured to enable the far field transmitter and receiver for an interval of time indicated in the communication from the second device.

16. A method comprising:

supplying power to a far field RF transmitter and receiver of an IMD according to a wakeup interval determined by a device wakeup timer;

detecting a digital key received from a second device during the wakeup interval;

transmitting a response using the RF transmitter when the digital key is received;

receiving a communication from the second device; and

re-synchronizing the device wake-up timer according to a time of the communication.

17. The method of claim 16, wherein re-synchronizing the device wake-up timer includes aligning the wakeup interval to the start of the communication.

18. The method of claim 16, wherein re-synchronizing the device wake-up timer includes setting the wakeup timer ahead or behind the start of the communication.

19. The method of claim 16, including communicating with the IMD as a master device according to a specified master/slave communication protocol during the wakeup interval upon an IMD detection of a specified event.

20. The method of claim 19, wherein communicating with the IMD as a master device includes:

initiating communications with the second device;

establishing a communications session with the second device when a response is received from the second device; and

transmitting a terminate command to end the communications session.