Systems and methods for communication between medical devices

• US 9,853,743 B2
• Filed: 08/17/2016
• Issued: 12/26/2017
• Est. Priority Date: 08/20/2015
• Status: Active Grant

• Current Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Original Assignee: Cardiac Pacemakers Incorporated (Boston Scientific Corporation)
• Inventors: Schmidt, Brian L., Juffer, Lance Eric, Maile, Keith R., Kane, Michael J., Koop, Brendan Early
• Primary Examiner(s): Tran, Tuan A
• Application Number:
  US15/239,484
• Publication Number:
  US 20170054516A1
• Time in Patent Office: 496 Days
• Field of Search: None
• CPC Class Codes: A61B 5/0028 Body tissue as transmission medium, i.e. transmission systems where the medium is the human body
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61N 1/37205 Microstimulators, e.g. implantable through a cannula
• CPC Class Codes: A61N 1/37211 Means for communicating with stimulators
• CPC Class Codes: A61N 1/37217 characterised by the communication link, e.g. acoustic or tactile
• CPC Class Codes: A61N 1/37223 Circuits for electromagnetic coupling
• 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: A61N 1/3756 Casings with electrodes thereon, e.g. leadless stimulators
• CPC Class Codes: H04B 13/005 Transmission systems in which the medium consists of the human body
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04W 76/25 Maintenance of established connections

Abstract

Systems and methods for conducted communication are described. In one embodiment, a method of communicating with a medical device implanted within a patient comprises receiving, at a medical device via electrodes connected to the patient, a conducted communication signal, wherein the conducted communication signal comprises a signal component and a noise component. The method may further comprise adjusting, by the medical device, a receive threshold based at least in part on an amplitude of the received conducted communication signal so as to reduce an amplitude of the noise component of the conducted communication signal.

Claims

1. A method of communicating with a medical device implanted within a patient comprising:

receiving, at a medical device via electrodes connected to the patient, a conducted communication signal, wherein the conducted communication signal comprises;

a signal component that includes a plurality of communication pulses generated by a remote medical device; and

a noise component;

adjusting, by the medical device, a receive threshold based at least in part on an amplitude of the received conducted communication signal; and

wherein adjusting the receive threshold at least partially reduces an amplitude of the noise component of the conducted communication signal.

2. The method of claim 1, wherein adjusting the receive threshold based at least in part on the amplitude of the received conducted communication signal comprises:

counting, by the medical device, a number of pulses in the conducted communication signal that have an amplitude greater than the receive threshold during a communication window;

determining, by the medical device, whether the counted number of pulses exceeds a pulse count threshold, wherein the pulse count threshold is based at least in part on a number of communication pulses that could occur in the signal component of the conducted communication signal during the communication window; and

after determining the counted number of pulses exceeds the pulse count threshold, increasing, by the medical device, the receive threshold.

3. The method of claim 2, further comprising increasing the receive threshold by a predetermined amount.

4. The method of claim 2, wherein the pulse count threshold represents a maximum number of communication pulses that could occur in the signal component of the conducted communication signal during the communication window.

5. The method of claim 2, further comprising, after determining the counted number of pulses exceeds the pulse count threshold, beginning, by the medical device, a new communication window.

6. The method of claim 2, further comprising, by the medical device:

tracking a communication session timer; and

after determining the communication session timer has reached a threshold value, setting, by the medical device, the receive threshold to a lower predetermined value.

7. The method of claim 6, further comprising resetting, by the medical device, the communication session timer after successfully receiving a message.

8. The method of claim 1, wherein adjusting the receive threshold based at least in part on an amplitude of the received conducted communication signal comprises:

after a communication window timer reaches a threshold value, determining, by the medical device, whether a message was received before the communication window timer reached the threshold value, wherein the message represents a predefined sequence of pulses in the conducted communication signal having an amplitude above the receive threshold; and

after determining that no message was received before the communication window timer reached the threshold value, increasing, by the medical device, the receive threshold.

9. The method of claim 8, wherein increasing the receive threshold comprises increasing the receive threshold by a predetermined amount.

10. The method of claim 8, further comprising:

before the communication window timer has reached the threshold value, determining, by the medical device, whether a message has been received; and

after determining that a message has been received before the communication window timer has reached the threshold value, resetting, by the medical device, the communication window timer threshold value.

11. The method of claim 10, further comprising:

tracking, by the medical device, a communication session timer; and

after determining that the communication session timer has reached a threshold value, setting, by the medical device, the receive threshold to a lower predetermined value.

12. The method of claim 11, further comprising resetting, by the medical device, the communication session timer after determining that a message has been received.

13. The method of claim 1, wherein adjusting the receive threshold based at least in part on an amplitude of the received conducted communication signal comprises setting, by the medical device, the receive threshold to a value proportional to a maximum amplitude of a pulse of the conducted communication signal having an amplitude above the receive threshold.

14. The method of claim 13, wherein setting the receive threshold to a value proportional to the maximum amplitude of a pulse of the conducted communication signal having an amplitude above the receive threshold comprises setting the receive threshold to the maximum value of the amplitude of the pulse of the conducted communication signal having an amplitude above the receive threshold.

15. The method of claim 13, further comprising setting, by the medical device, the receive threshold to a value proportional to a maximum amplitude of each pulse of the conducted communication signal having an amplitude above the receive threshold.

16. The method of claim 13, wherein the receive threshold decays according to a predetermined function.

17. A medical device comprising:

one or more electrodes; and

a controller connected to the one or more electrodes, the controller configured to;

receive a conducted communication signal via the one or more electrodes, the conducted communication signal comprises;

a signal component that includes a plurality of communication pulses in a pulse pattern communicated from an external medical device; and

a noise component that includes noise signals; and

determine if the received conducted communication signal comprises one or more pulses that do not match the pulse pattern of the communication pulses, and when so, adjust a receive threshold to further filter out the noise signals from the received conducted communication signal.

18. The medical device of claim 17, wherein the controller is further configured to adjust the receive threshold by setting the receive threshold to a value proportional to a maximum amplitude of a pulse of the received conducted communication signal that exceeds the receive threshold.

19. The medical device of claim 17, wherein the receive threshold is configured to decay according to a predetermined decay function.