Method and apparatus for the staged detection of RF energy

• US 8,108,044 B2
• Filed: 09/30/2008
• Issued: 01/31/2012
• Est. Priority Date: 03/27/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Le Reverend, Remi, Delight, Guy A.
• Primary Examiner(s): Getzow, Scott
• Assistant Examiner(s): Patton, Amanda
• Application Number:
  US12/242,782
• Publication Number:
  US 20090248116A1
• Time in Patent Office: 1,218 Days
• Field of Search: 607 30- 32, 607 59- 60
• US Class Current: 607/32
• CPC Class Codes: A61N 1/37276 characterised by means for reducing power consumption during telemetry
• CPC Class Codes: H04Q 9/00 Arrangements in telecontrol or telemetry systems for selectively calling a substation from a main station, in which substation desired apparatus is selected for applying a control signal thereto or for obtaining measured values therefrom

Abstract

A low power method and apparatus for detecting wake-up signals in sniff processing performed in an implantable medical device (IMD) using a staged detection of RF energy in signals received in order to conserve current consumption. Incoming signals are monitored in a plurality of detection stages which each incrementally increase the accuracy of detecting whether the received signal is a wake-up communication signal. A desired number of stages of signal quantity measurements are performed such that a combined signal quantity is calculated by updating the signal quantity measurements performed in prior stages with signal quantity measurements performed at each stage. The combined signal quantity of the received communication signal is compared at each detection stage against a corresponding threshold value for that stage. The staged detection process aborts sniff processing if the combined signal quantity fails to meet the corresponding threshold value for that stage.

Claims

1. A method comprising:

operating an implanted medical device capable of receiving wireless communication signals; and

monitoring a communication signal received in a receiver in the implanted medical device using a staged detection process to detect characteristics of the received communication signal, the staged detection process further comprising;

performing a desired number of stages of measurements of a signal quantity of the received communication signal, wherein a combined signal quantity of the received communication signal is calculated by updating the signal quantity measurements performed in prior stages with signal quantity measurements performed at each stage,

comparing the combined signal quantity of the received communication signal at each measurement stage against a corresponding threshold value for that stage, and

aborting the staged detection process if the combined signal quantity fails to meet the corresponding threshold value for that stage.

2. The method of claim 1, further comprising selecting the desired number of stages of measurements to achieve a desired standard deviation of the signal quantity measurements.

3. The method of claim 1, further comprising selecting the desired number of stages of measurements to achieve a desired level of certainty in the comparison between the combined signal quantity of the received communication signal and its corresponding threshold value.

4. The method of claim 1, wherein the measured signal quantity is a frequency deviation.

5. The method of claim 1, wherein the measured signal quantity is a strength of the received communication signal.

6. The method of claim 5, further comprising:

calculating the combined signal quantity by adding the signal quantity measurement for a current stage of the staged detection process to the signal quantity measurements from prior stages;

scaling the corresponding threshold value for the current stage of the staged detection process;

comparing the combined signal quantity of the received communication signal at the current stage of the staged detection process against the scaled threshold value for that stage; and

aborting the staged detection process if the combined signal quantity fails to meeting the scaled threshold value for that stage.

7. The method of claim 1, further comprising indicating a passing state of the staged detection process of the received communication signal if the staged detection process is not aborted.

8. A low power, wake-up communication signal detector in an implantable medical device comprising:

a receiver configured to detect a communication signal being received from a remote device; and

a signal detector configured to monitor the communication signal received using a staged detection process to detect whether the received communication signal is a wake-up communication signal intended for the implanted medical device, wherein the signal detector is further configured perform the staged detection process by;

performing a desired number of stages of measurements of a signal quantity of the received communication signal, wherein a combined signal quantity of the received communication signal is calculated by updating the signal quantity measurements performed in prior stages with signal quantity measurements performed at each stage,

comparing the combined signal quantity of the received communication signal at each measurement stage against a corresponding threshold value for that stage, and

aborting the staged detection process if the combined signal quantity fails to meeting the corresponding threshold value for that stage.

9. The wake-up communication signal detector of claim 8, wherein the desired number of stages of measurements are selected to achieve a desired standard deviation of the signal quantity measurements.

10. The wake-up communication signal detector of claim 8, wherein the desired number of stages of measurements are selected to achieve a desired level of certainty in the comparison between the combined signal quantity of the received communication signal and its corresponding threshold value.

11. The wake-up communication signal detector of claim 8, wherein the measured signal quantity is a frequency deviation.

12. The wake-up communication signal detector of claim 8, wherein the measured signal quantity is a strength of the received communication signal.

13. The wake-up communication signal detector of claim 12, wherein the signal detector is further configured perform the staged detection process by:

calculating the combined signal quantity by adding the signal quantity measurement for a current stage of the staged detection process to the signal quantity measurements from prior stages;

scaling the corresponding threshold value for the current stage of the staged detection process;

comparing the combined signal quantity of the received communication signal at the current stage of the staged detection process against the scaled threshold value for that stage; and

aborting the staged detection process if the combined signal quantity fails to meeting the scaled threshold value for that stage.

14. A telemetry module in an implantable medical device comprising:

wake-up receiver means configured to perform sniff operations for detecting whether a wake-up communication signal is being received by the implantable medical device; and

signal detector means for monitoring a communication signal received in a receiver in the implanted medical device using a staged detection process to detect characteristics of the received communication signal, the staged detection process further comprising;

performing a desired number of stages of measurements of a signal quantity of the received communication signal, wherein a combined signal quantity of the received communication signal is calculated by updating the signal quantity measurements performed in prior stages with signal quantity measurements performed at each stage,

comparing the combined signal quantity of the received communication signal at each measurement stage against a corresponding threshold value for that stage, and

aborting the staged detection process if the combined signal quantity fails to meet the corresponding threshold value for that stage.

15. The telemetry module of claim 14, wherein the desired number of stages of measurements is selected to achieve a desired standard deviation of the signal quantity measurements.

16. The telemetry module of claim 14, wherein the desired number of stages of measurements is selected to achieve a desired level of certainty in the comparison between the combined signal quantity of the received communication signal and its corresponding threshold value.

17. The telemetry module of claim 14, wherein the measured signal quantity is a frequency deviation.

18. The telemetry module of claim 14, wherein the measured signal quantity is a strength of the received communication signal.

19. The telemetry module of claim 14, wherein the staged detection process performed by the signal detector means further comprises:

calculating the combined signal quantity by adding the signal quantity measurement for a current stage of the staged detection process to the signal quantity measurements from prior stages;

scaling the corresponding threshold value for the current stage of the staged detection process;

comparing the combined signal quantity of the received communication signal at the current stage of the staged detection process against the scaled threshold value for that stage; and

aborting the staged detection process if the combined signal quantity fails to meet the scaled threshold value for that stage.