Systems and methods for timing-based communication between implantable medical devices

• US 20060122667A1
• Filed: 07/21/2005
• Published: 06/08/2006
• Est. Priority Date: 12/03/2004
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Von Arx, Jeffrey A., Chavan, Abhijeet V., Mazar, Scott T.
• Granted Patent: US 8,374,693 B2
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61M 2205/3523 using telemetric means
• CPC Class Codes: A61M 2205/3569 sublocal, e.g. between console and disposable
• CPC Class Codes: A61M 2205/8212 with means or measures taken for minimising energy consumption
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61N 1/37276 characterised by means for reducing power consumption during telemetry
• CPC Class Codes: A61N 1/378 Electrical supply
• CPC Class Codes: A61N 1/3962 in combination with another heart therapy
• CPC Class Codes: A61N 1/39622 Pacing therapy
• CPC Class Codes: A61N 1/3975 Power supply A61N1/378 takes precedence

Abstract

A method carried out by an implantable medical device (IMD) for coordinating performance of one or more designated functions includes waiting in a low-power state for a predetermined event, detecting the predetermined event, and, responsive to detecting the predetermined event, searching for a wake-up command from a coordinating device implanted in the human body. The method further includes, receiving the wake-up command, and responsive to receiving the wake-up command, performing the one or more designated functions, and returning to the low-power state. A system includes a network of one or more implantable medical devices (IMDs) implanted in a human body. The system includes a satellite IMD operable to change between a plurality of power states, search for a wake-up command, and transmit an identification signal. The system may include a primary unit operable to receive the signal and coordinate a wake-up time based on the signal.

Claims

1. A method carried out by an implantable medical device (IMD) for coordinating performance of one or more designated functions, the IMD being implantable in a human body, the method comprising:

waiting in a low-power state for a predetermined event;

detecting the predetermined event;

responsive to detecting the predetermined event, searching for a wake-up command from a coordinating device implanted in the human body;

receiving the wake-up command;

responsive to receiving the wake-up command, performing the one or more designated functions; and

returning to the low-power state.

2. The method as recited in claim 1, further comprising transmitting a signal to the coordinating device, the signal identifying the IMD.

3. The method as recited in claim 1, wherein the predetermined event is passage of a scheduled time.

4. The method as recited in claim 1, wherein receiving the wake-up command comprises receiving a carrier signal modulated with on-off shift keying.

5. The method as recited in claim 1, wherein receiving the wake-up command comprises receiving an ultrasonic signal.

6. The method as recited in claim 3, wherein the scheduled time is retrieved from a look up table.

7. The method as recited in claim 3, wherein the scheduled time is set in a programmable timer.

8. The method as recited in claim 1, wherein at least one of the one or more designated functions includes measuring a physiologic parameter.

9. The method as recited in claim 1, wherein at least one of the one or more designated functions includes administering a therapy.

10. The method as recited in claim 1, wherein the coordinating device is operable to perform a therapeutic function.

11. The method as recited in claim 3 further comprising:

receiving time interval data from the coordinating device, the time interval data designating the scheduled time; and

setting a timer in the IMD based at least in part on the time interval data.

12. The method as recited in claim 3 further comprising:

receiving time correction data from the coordinating device; and

setting a timer based on the time correction data.

13. The method as recited in claim 12, wherein setting the timer comprises adjusting an oscillator frequency, adjusting an oscillator divider, or setting a count value in a register.

14. A method for coordinating communication of physiologic data from each of a plurality of implantable medical devices (IMDs) implanted in a human body and forming a network of IMDs, the method comprising:

determining a wake-up time associated with each of the IMDs;

transmitting a wake-up signal at a selected time prior to a selected one of the wake-up times, the wake-up signal causing the IMD associated with the selected wake-up time to generate physiologic data;

receiving the physiologic data from the IMD associated with the selected wake-up time

15. The method as recited in claim 14 further comprising:

determining a correction factor for the IMD associated with the selected wake-up time; and

transmitting the correction factor to the IMD associated with the selected wake-up time.

16. The method as recited in claim 14 wherein the determined scheduled wake-up times are staggered.

17. The method as recited in claim 14 further comprising discovering a new IMD introduced into the network of IMDs.

18. The method as recited in claim 17 wherein discovering the new IMD comprises:

detecting a request from the new IMD to integrate into the network; and

acknowledging receipt of the request.

19. The method as recited in claim 18 further comprising:

activating the new IMD;

determining a new wake-up time associated with the new IMD; and

communicating the new wake-up time to the new IMD.

20. The method as recited in claim 19, wherein activating the new IMD comprises using an external device to passively activate the new IMD.

21. The method as recited in claim 14, wherein the network of IMDs is a wireless network.

22. The method as recited in claim 14 wherein the wake-up signal causes the associated IMD to perform a therapeutic function.

23. The method as recited in claim 15, wherein the transmitted correction factor causes the associated IMD to adjust an internal timer.

24. A system for coordinating communication between implantable medical devices (IMDs) in a network of one or more IMDs implanted in a human body, the system comprising:

a satellite IMD having a timing component configured to track time, the IMD operable to change between a plurality of power states, search for a wake-up command, and transmit a signal identifying the satellite IMD; and

a primary unit implantable in a human body and operable to receive the signal identifying the satellite IMD and coordinate a wake-up time based on the signal identifying the satellite IMD, the wake-up time designating when the satellite IMD is to search for the wake-up command.

25. The system of claim 24, wherein the primary unit is further operable to determine a correction factor usable by the satellite IMD to adjust timing parameters associated with the timing component.

26. The system of claim 24, wherein the plurality of power states includes one or more of the following:

a sleep state in which all components of the satellite IMD are powered off, except for the timing component;

a search state in which the satellite IMD searches for the wake-up command; and

a fully active state in which the satellite IMD performs a designated function.

27. The system of claim 24, wherein the satellite IMD is further operable to:

perform a designated function including one or more of a therapeutic function and a sensing function; and

communicate data generated from the performance of the designated function to the primary unit.

28. A satellite implantable medical device (IMD) comprising:

a timing component configured to track time;

a battery configured to power components in the satellite IMD;

communication circuitry configured to transmit and receive information;

a memory component;

a functional component operable to perform at least a sensing function; and

a processor configured to cause the satellite IMD to detect a wake-up command from another IMD using the communication circuitry, and transmit data in response to detecting the wake-up command.

29. A system for coordinating communications between a plurality of medical devices implanted in a human body, the system comprising:

a receiver operable to receive timing data from the medical devices;

a transmitter operable to transmit an activation signal to each of the medical devices at associated scheduled times;

means for determining the associated scheduled times, each scheduled time being a time at which the associated medical device is to search for the activation signal; and

means for determining a time correction factor for one or more of the plurality of medical devices.

30. The system of claim 29, wherein the time correction factor is usable by an IMD to correct time drift associated with a timing component in the IMD.

31. The system of claim 29, wherein the transmitter and the receiver communicate via an ultra sonic communications link.