Implantable medical device telemetry with adaptive frequency hopping

• US 8,386,043 B2
• Filed: 04/23/2012
• Issued: 02/26/2013
• Est. Priority Date: 07/12/2006
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Bange, Joseph E., Vallapureddy, Vineel
• Primary Examiner(s): Lavert, Nicole F
• Application Number:
  US13/453,806
• Publication Number:
  US 20120209353A1
• Time in Patent Office: 309 Days
• Field of Search: 607/30, 607/32, 607/60
• US Class Current: 607/32
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61N 1/37252 Details of algorithms or data aspects of communication system, e.g. handshaking, transmitting specific data or segmenting data
• CPC Class Codes: A61N 1/37254 Pacemaker or defibrillator security, e.g. to prevent or inhibit programming alterations by hackers or unauthorised individuals
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: H04B 1/7093 Matched filter type
• CPC Class Codes: H04B 17/318 Received signal strength

Abstract

A far-field radio-frequency (RF) telemetry system transmits data between an implantable medical device and an external system using an active channel selected from a plurality of channels each representing a frequency band within a predetermined frequency range. One or more preferred channels are identified from the plurality of channels based on channel quality indicators produced for each of the channels. When channel hopping is needed, a hop channel is selected from the one or more preferred channels and becomes the active channel.

Claims

1. A method for transmitting data between an implantable medical device and an external system via radio-frequency telemetry, the method comprising:

receiving a channel selection signal;

selecting a hop channel from one or more preferred channels in response to the channel selection signal;

making the hop channel an active channel;

transmitting data between the implantable medical device and the external system using the active channel;

producing, by the external system, channel quality indicators each associated with one channel of a plurality of channels, wherein each channel quality indicator includes at least a received signal strength indicator indicative of a strength of signal received through the one channel, each channel of the plurality of channels representing a channel frequency band;

receiving, by the external system, an RF channel quality indicator produced by the implantable medical device; and

identifying the one or more preferred channels from the plurality of channels based on the channel quality indicators.

2. The method of claim 1, comprising:

selecting a first hop channel from one or more first preferred channels in response to the channel selection signal;

making the first hop channel a first active channel;

transmitting the data from the implantable medical device to the external system using the first active channel;

selecting a second hop channel from one or more second preferred channels in response to the channel selection signal;

making the second hop channel a second active channel; and

transmitting the data from the external system to the implantable medical device using the second active channel,

wherein the one or more preferred channels comprise the one or more first preferred channels and the one or more second preferred channels.

3. The method of claim 1, wherein identifying the one or more preferred channels comprises identifying the one or more preferred channels from the plurality of channels by identifying one or more of the channel quality indicators that meet one or more predetermined requirements.

4. The method of claim 1, wherein identifying the one or more preferred channels comprises producing a sequence of prioritized preferred channels by prioritizing channels according to their associated channel quality indicators.

5. The method of claim 1, wherein the channel quality indicators comprise noise floor indicators each associated with one channel of the plurality of channels and indicative of a noise floor of that channel, and identifying the one or more preferred channels comprises identifying the one or more preferred channels from the plurality of channels based on the received signal strength indicators and the noise floor indicators.

6. The method of claim 5, wherein producing the channel quality indicators comprises producing the noise floor indicators by measuring a noise level associated with each channel of the plurality of channels when no data is transmitted between the external system and the implantable medical device using the each channel.

7. The method of claim 1, wherein the channel quality indicators comprise frame exchange metrics each associated with one channel of the plurality of channels, and identifying the one or more preferred channels comprises identifying the one or more preferred channels from the plurality of channels based on the received signal strength indicators and the frame exchange metrics.

8. The method of claim 7, wherein the frame exchange metrics comprise success ratios each associated with one channel of the plurality of channels and being a ratio of a number of successful frame exchanges to a total number of frame exchanges, and producing the channel quality indicators comprises calculating the success ratios.

9. The method of claim 1, wherein the channel quality indicators comprise performance history indicators each associated with one channel of the plurality of channels and indicative of a history of the channel quality indicator of that channel, and identifying the one or more preferred channels comprises identifying the one or more preferred channels from the plurality of channels based on the received signal strength indicators and the performance history indicators.

10. The method of claim 1, wherein producing the channel quality indicators comprises producing at least one quality parameter of each of the channel quality indicators using the implantable medical device.

11. The method of claim 1, wherein producing the channel quality indicators includes producing a signal-to-noise ratio associated with one channel of the plurality of channels, the signal-to-noise ratio being a ratio of the received signal strength indicator to the noise floor indicator for the one channel.

12. The method of claim 1, wherein producing the channel quality indicators includes producing at least one channel quality indicator for a channel using the external device and producing a channel quality indicator for the channel using the implantable medical device.

13. The method of claim 1, wherein making a hop channel an active channel includes making the hop channel an active channel that includes an active transmission channel selected from the plurality of channels and an active receiving channel selected from the plurality of channels.

14. The method of claim 1, wherein producing the channel quality indicators includes:

producing one or more of;

a noise floor indicator associated with one channel of the plurality of channels and indicative of a noise floor of that channel;

a frame exchange metric associated with one channel of the plurality of channels and indicative of a ratio of a number of successful frame exchanges to a total number of frame exchanges for that channel; and

a performance history indicator associated with one channel of the plurality of channels and indicative of a history of the channel quality indicator of that channel; and

applying a weighting factor to one or more of the noise floor indicator, the frame exchange metric, and the performance history indicator.

15. The method of claim 1, wherein producing the channel quality indicators includes:

producing a first channel quality indicator that includes a received signal strength indicator using the implantable medical device; and

producing a second channel quality indicator that includes one or more of a signal strength indicator, a noise floor indicator, a frame exchange metric, and a performance history indicator using the external system.

16. The method of claim 1, including producing the channel selection signal when quality of data transmission fails to satisfy one or more quality criteria.

17. The method of claim 1, including producing the channel selection signal according to a predetermined schedule.

18. The method of claim 1, including producing the channel selection signal when a telemetry session begins.

19. The method of claim 1, wherein transmitting data between the implantable medical device and the external system includes:

transmitting data between the implantable medical device and an external device that is local to the implantable medical device; and

communicating with the external device using a device that is remote from the implantable medical device.

20. The method of claim 1, wherein a channel of the plurality of channels representing a channel frequency band is included within the Medical Implant Communication Service (MICS) band.