RANKING AND SWITCHING OF WIRELESS CHANNELS IN A BODY AREA NETWORK OF MEDICAL DEVICES

• US 20110149759A1
• Filed: 12/23/2009
• Published: 06/23/2011
• Est. Priority Date: 12/23/2009
• Status: Active Grant

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: JOLLOTA, James
• Granted Patent: US 8,755,269 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/0024 for multiple sensor units attached to the patient, e.g. using a body or personal area network
• CPC Class Codes: A61B 5/1112 Global tracking of patients, e.g. by using GPS
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 84/10 Small scale networks; Flat hierarchical networks

Abstract

Operating techniques and methodologies for a body area network of medical devices are provided. One technique relates to an intelligent channel hopping scheme that detects loss of wireless synchronization on an initial wireless channel, thereafter obtains a measure of quality for the initial wireless channel, and then selects a new wireless channel when the obtained measure of quality fails to satisfy a threshold criteria. Another operating technique dynamically adapts an ordered list of available wireless channels in accordance with a quality measure of the available wireless channels. Thus, when quality degradation associated with a first wireless channel is detected, the ordered list can be updated to indicate a lower preference for the first wireless channel and to indicate a higher preference for a second wireless channel that does not suffer from quality degradation. Another channel hopping or switching technique selects wireless channels in a manner that is influenced by the current geographic position of the medical device.

Claims

1. A method of operating a wireless coordinator device in a body area network of wireless medical devices, the method comprising:

detecting loss of wireless synchronization, for a current wireless data communication channel, between the wireless coordinator device and a wireless end node device of the body area network of medical devices;

in response to detecting loss of wireless synchronization, obtaining a measure of quality for the current wireless data communication channel;

when the obtained measure of quality fails to satisfy a threshold criteria, selecting a new wireless data communication channel for the wireless coordinator device; and

thereafter, transmitting wireless beacons with the wireless coordinator device, using the new wireless data communication channel.

2. The method of claim 1, further comprising obtaining, for a plurality of available wireless data communication channels, a respective measure of wireless channel quality, wherein the new wireless data communication channel is selected from the plurality of available wireless data communication channels based upon its respective measure of wireless channel quality.

3. The method of claim 2, wherein the respective measure of wireless channel quality for the new wireless data communication channel indicates highest quality among the plurality of available wireless data communication channels.

4. The method of claim 1, further comprising:

prior to detecting loss of wireless synchronization, sending initial wireless beacons from the wireless coordinator device, using the current wireless data communication channel; and

prior to obtaining the measure of quality for the current wireless data communication channel, ceasing the sending of the initial wireless beacons.

5. The method of claim 1, further comprising:

saving, at the wireless coordinator device, ping timing information corresponding to the wireless end node device; and

synchronizing the wireless coordinator device for receipt of wireless pings from the wireless end node device in accordance with the saved ping timing information, wherein detecting loss of wireless synchronization utilizes the saved ping timing information.

6. The method of claim 5, wherein detecting loss of wireless synchronization comprises determining that the wireless coordinator device missed at least a threshold number of wireless pings in sequence, as defined by the ping timing information.

7. The method of claim 5, further comprising receiving the ping timing information from the wireless end node device.

8. A method of operating a wireless coordinator device in a wireless network that includes a wireless end node device, the method comprising:

obtaining, at the wireless coordinator device, a ping schedule for the wireless end node device, the ping schedule indicating time slots during which the wireless coordinator device should expect to receive pings from the wireless end node device;

configuring the wireless coordinator device to monitor for pings sent by the wireless end node device in accordance with the ping schedule;

the wireless coordinator device performing wireless data communication with the wireless end node device, using a current wireless data communication channel;

detecting that the wireless coordinator device missed a number of expected pings as indicated by the ping schedule;

in response to the detecting step, testing quality of the current wireless data communication channel;

when the quality of the current wireless data communication channel is below a threshold quality measure, selecting a new wireless data communication channel; and

thereafter, the wireless coordinator device using the new wireless data communication channel to transmit wireless beacons.

9. The method of claim 8, further comprising obtaining, for a plurality of available wireless data communication channels including the new wireless data communication channel, a respective measure of wireless channel quality, wherein the new wireless data communication channel is selected from the plurality of available wireless data communication channels based upon its respective measure of wireless channel quality.

10. The method of claim 8, further comprising:

obtaining, at the wireless coordinator device, a second ping schedule for a second wireless end node device, the second ping schedule indicating time slots during which the wireless coordinator device should expect to receive pings from the second wireless end node device;

configuring the wireless coordinator device to monitor for pings sent by the second wireless end node device in accordance with the second ping schedule; and

the wireless coordinator device performing wireless data communication with the second wireless end node device, using the current wireless data communication channel.

11. A wireless medical device for a body area network of medical devices, the wireless medical device comprising:

a processor;

a memory element coupled to the processor and configured to store a ping schedule for a wireless end node device; and

a wireless communication module coupled to the processor and configured to receive ping messages from the wireless end node device using a current wireless data communication channel;

wherein the processor is configured to;

detect when the wireless communication module has missed a number of expected pings from the wireless end node device, as indicated by the ping schedule;

test a quality characteristic of the current wireless data communication channel when the wireless communication module has missed the number of expected pings; and

switch from the current wireless data communication channel to a new wireless data communication channel when the quality characteristic fails to satisfy predetermined quality criteria.

12. The wireless medical device of claim 11, wherein the wireless communication module is configured to transmit wireless beacons using the new wireless data communication channel.

13. The wireless medical device of claim 11, wherein the processor is configured to obtain, for a plurality of available wireless data communication channels including the new wireless data communication channel, a respective measure of wireless channel quality, and is further configured to select the new wireless data communication channel from the plurality of available wireless data communication channels based upon its respective measure of wireless channel quality.

14. The wireless medical device of claim 11, wherein the wireless communication module is configured to receive the ping schedule from the wireless end node device.

15. The wireless medical device of claim 11, wherein the body area network of medical devices comprises an insulin infusion system.

16. A method of operating a wireless coordinator device in a wireless network that includes at least one wireless end node device, the method comprising:

maintaining, at the wireless coordinator device, an ordered list of available wireless channels for wireless data communication between the wireless coordinator device and the at least one wireless end node device, wherein the ordered list is arranged in accordance with a quality measure of the available wireless channels, and wherein the ordered list includes an entry for a first wireless channel utilized by the wireless coordinator device;

detecting quality degradation associated with the first wireless channel;

in response to detecting the quality degradation, testing a quality characteristic of a second wireless channel in the ordered list; and

when the quality characteristic satisfies a quality criteria for the wireless coordinator device, updating the ordered list of available wireless channels to indicate a higher preference for the second wireless channel and a lower preference for the first wireless channel.

17. The method of claim 16, wherein updating the ordered list results in an updated list of available wireless channels, and wherein the method further comprises sending the updated list of available wireless channels to the at least one wireless end node device.

18. The method of claim 16, further comprising switching from the first wireless channel to the second wireless channel when the quality characteristic satisfies the quality criteria.

19. The method of claim 16, wherein:

updating the ordered list results in an updated list of available wireless channels; and

the first wireless channel has the lowest preference in the updated list.

20. The method of claim 16, further comprising:

testing, with the wireless coordinator device, a respective measure of wireless channel quality for each of the available wireless channels; and

generating the ordered list of available wireless channels such that each of the available wireless channels is ordered based upon its respective measure of wireless channel quality.

21. The method of claim 20, further comprising sending the ordered list of available wireless channels to the at least one wireless end node device.

22. A method of operating a wireless device in a wireless network having a wireless coordinator device, the method comprising:

receiving, from the wireless coordinator device in the wireless network, an initial ordered list of available wireless channels for wireless data communication between the wireless device and the wireless coordinator device, wherein the ordered list is arranged in accordance with a quality measure of the available wireless channels, and wherein the ordered list includes an entry for a first wireless channel;

wirelessly communicating with the wireless coordinator device, using the first wireless channel;

determining that wireless connectivity with the wireless coordinator device has been lost; and

in response to the determining step, searching for wireless beacons sent by the wireless coordinator device using the available wireless channels, other than the first wireless channel, wherein the searching step traverses the available wireless channels sequentially in accordance with the ordered list.

23. The method of claim 22, further comprising:

receiving a beacon sent by the wireless coordinator device using a second wireless channel;

thereafter, wirelessly communicating with the wireless coordinator device, using the second wireless channel; and

receiving, from the wireless coordinator device and using the second wireless channel, an updated ordered list of available wireless channels, wherein the updated ordered list indicates a higher preference for the second wireless channel and a lower preference for the first wireless channel.

24. The method of claim 22, further comprising updating the ordered list resident at the wireless device to indicate a higher preference for the second wireless channel and a lower preference for the first wireless channel.

25. The method of claim 24, wherein:

updating the ordered list results in an updated list of available wireless channels; and

the first wireless channel has the lowest preference in the updated list.

26. A wireless coordinator device for a network of wireless devices, the wireless coordinator device comprising:

a processor;

a memory element coupled to the processor and configured to store a list of available wireless channels, wherein the list is ordered in accordance with interference or noise associated with the available wireless channels; and

a wireless communication module coupled to the processor and configured to send the list of available wireless channels to a wireless end node device in the network, using a first wireless channel;

wherein the processor is configured to detect quality degradation associated with the first wireless channel and, in response thereto, reorder the list of available wireless channels; and

wherein the wireless communication module is configured to send the reordered list of available wireless channels to the wireless end node device.

27. The wireless coordinator device of claim 26, wherein the first wireless channel appears last in the reordered list.

28. The wireless coordinator device of claim 26, wherein the network of wireless devices comprises an insulin infusion system.