Implantable medical device communication system with macro and micro sampling intervals

• US 20070060977A1
• Filed: 09/12/2005
• Published: 03/15/2007
• Est. Priority Date: 09/12/2005
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Spital, Glenn
• Granted Patent: US 8,380,320 B2
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61N 1/37276 characterised by means for reducing power consumption during telemetry
• CPC Class Codes: H04W 52/0229 where the received signal is a wanted signal
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A communication signal is communicated between an implantable medical device including an implant transceiver and an external unit including an external unit transceiver. At least one of the transceivers includes a receiver capable of sampling a communication channel for the communication signal at times based on a macro sampling interval and a micro sampling interval. The sampling includes a series of micro samples. The duration of the series of micro samples is less than the macro sampling interval.

Claims

1. A medical device comprising:

device circuitry for controlling the operation of the device and for processing data; and

a receiver for sampling energy on a communication channel based on a macro sampling interval and a micro sampling interval, a duration of a series of samples, spaced by the micro sampling interval, being less than the macro sampling interval, the receiver sampling to detect presence of a transmission signal on the communication channel, and to thereafter receive data contained in the transmission signal.

2. The medical device of claim 1, wherein the receiver first samples to detect the presence of a preamble segment of the transmission signal, and subsequently samples to detect presence of an attention segment of the transmission signal.

3. The medical device of claim 2, wherein the receiver remains on after detecting presence of the attention segment to receive a frame sync segment and the data.

4. The medical device of claim 2, wherein a duration of the preamble segment is greater than the macro sampling interval.

5. The medical device of claim 2, wherein a duration of the attention segment is greater than the micro sampling interval.

6. The medical device of claim 1, wherein the receiver samples to detect the transmission signal, and once the transmission signal has been detected the receiver remains on to receive the data.

7. The medical device of claim 6, wherein the receiver samples within a drift window of a scheduled time slot.

8. The medical device of claim 7, wherein the time between the scheduled time slot and a next scheduled time slot is equal to the macro sampling interval.

9. The medical device of claim 6, wherein the receiver samples to detect the attention segment of the transmission signal.

10. The medical device of claim 9, wherein the micro sampling interval of the receiver exceeds a duration of the attention segment.

11. The medical device of claim 9, wherein the receiver remains on after detecting an attention segment until a frame sync segment and the data have been received.

12. The medical device of claim 1, wherein the medical device is an implantable medical device.

13. A method of operating a receiver of a medical device, the method comprising:

sampling at a first time to determine whether energy is present on a communication channel, the first time based on a macro sampling interval;

sampling at periodic times after the first time with a series of samples to determine if data is about to be transmitted, the periodic times based on a micro sampling interval, wherein a duration of the series of samples is less than the macro sampling interval; and

turning on to receive the data after determining that data is about to be transmitted.

14. The method of claim 13, wherein the first time is a scheduled time slot.

15. The method of claim 13, wherein the receiver samples with the series of samples only if energy is detected at the first time.

16. The method of claim 13, wherein sampling at the first time comprises sampling for a preamble segment of a transmission signal.

17. The method of claim 16, wherein a duration of the preamble segment is greater than the macro sampling interval.

18. The method of claim 13, wherein sampling with a series of samples comprises sampling for an attention segment.

19. The method of claim 18, wherein a duration of the attention segment is greater than the micro sampling interval.

20. The method of claim 13, wherein the receiver samples with the series of samples, even if energy is not detected at the first time, and wherein the duration of the series of samples being greater than a drift window of a scheduled time slot.

21. The method of claim 20, wherein the receiver calculates the beginning of the drift window by calculating a duration of the drift window based upon a length of time since a previous communication and subtracting one half of the duration of the drift window from a scheduled time slot.

22. The method of claim 13, wherein the medical device is an external medical device.

23. The method of claim 13, wherein the medical device is an implantable medical device.

24. A communication system comprising:

an implantable medical device including an implant transceiver;

an external unit including an external unit transceiver;

wherein at least one of the transceivers includes a receiver that samples for a communication at times based upon a macro sampling interval and a micro sampling interval, wherein a duration of a series of samples, spaced by the micro sampling interval, is less than the macro sampling interval.

25. The communication system of claim 24, wherein the receiver is part of the implant transceiver.

26. The communication system of claim 25, wherein the external unit transceiver includes a transmitter capable of transmitting the communication signal including a preamble segment, an attention segment, a frame sync segment, and data;

a duration of the preamble segment being at least as long as the macro sampling interval of the receiver;

a duration of the attention segment being at least as long as the micro sampling interval; and

wherein the data follows the frame sync segment.

27. The communication system of claim 24, wherein the receiver is part of the external unit transceiver.

28. The communication system of claim 27, wherein the implant transceiver includes a transmitter for transmitting the communication signal including an attention segment, a frame sync segment, and data, a duration of the attention segment being at least as long as the micro sampling interval of the receiver, and wherein the data follows the frame sync segment.