Method and apparatus for communicating between an ambulatory medical device and a control device via telemetry using randomized data

• US 7,171,274 B2
• Filed: 05/12/2003
• Issued: 01/30/2007
• Est. Priority Date: 01/21/2000
• Status: Expired due to Term

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Inventors: Weiss, Philip T., Starkweather, Timothy J., Villegas, Daniel H., Lebel, Ronald J., Armstrong, John T., Richert, John D.
• Primary Examiner(s): Schaetzle; Kennedy
• Application Number:
  US10/437,366
• Publication Number:
  US 20030212441A1
• Time in Patent Office: 1,359 Days
• Field of Search: 607/60, 607/32, 607/31, 607/30, 607/3, 607/2, 607/72, 607/68, 128/903, 128/904, 600/300, 600/301, 600/302, 600/347, 600/365
• US Class Current: 607/60
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/6847 mounted on an invasive device
• CPC Class Codes: A61M 2005/14208 with a programmable infusion control system, characterised by the infusion program
• CPC Class Codes: A61M 2205/18 with alarm
• CPC Class Codes: A61M 2205/3507 with implanted devices, e.g. external control
• CPC Class Codes: A61M 2205/3523 using telemetric means
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/582 by tactile feedback
• CPC Class Codes: A61M 2205/6018 providing set-up signals for the apparatus configuration
• CPC Class Codes: A61M 2205/8206 battery-operated
• CPC Class Codes: A61M 2207/00 Methods of manufacture, assembly or production
• CPC Class Codes: A61M 5/14244 adapted to be carried by the patient, e.g. portable on the body
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: A61M 5/168 Means for controlling media flow to the body or for metering media to the body, e.g. drip meters, counters ; Monitoring media flow to the body flow control in general G05D7/00
• CPC Class Codes: A61M 5/16831 Monitoring, detecting, signalling or eliminating infusion flow anomalies low-level float-valves causing cut-off A61M5/40; indicating or recording presence, absence or direction of flow in general G01P13/0066
• CPC Class Codes: A61M 5/172 electrical or electronic A61M5/16804, A61M5/16831 take precedence
• CPC Class Codes: A61N 1/37211 Means for communicating with stimulators
• CPC Class Codes: A61N 1/37247 : User interfaces, e.g. input or presentation means
• 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 1/37258 : Alerting the patient
• CPC Class Codes: A61N 1/37264 : Changing the program; Upgrading firmware
• CPC Class Codes: A61N 1/3727 : characterised by the modulation technique
• CPC Class Codes: A61N 1/37276 : characterised by means for reducing power consumption during telemetry
• CPC Class Codes: A61N 1/37512 : Pacemakers
• CPC Class Codes: G06F 3/0619 : in relation to data integrity, e.g. data losses, bit errors
• CPC Class Codes: G06F 3/065 : Replication mechanisms
• CPC Class Codes: G06F 3/0673 : Single storage device
• CPC Class Codes: G06F 8/60 : Software deployment
• CPC Class Codes: G06F 8/65 : Updates security arrangements therefor G06F21/57
• CPC Class Codes: G16H 20/17 : delivered via infusion or injection
• CPC Class Codes: G16H 40/40 : for the management of medical equipment or devices, e.g. scheduling maintenance or upgrades
• CPC Class Codes: Y02D 10/00 : Energy efficient computing, e.g. low power processors, power management or thermal management
• CPC Class Codes: Y10S 128/13 : Infusion monitoring
• CPC Class Codes: Y10S 128/903 : Radio telemetry
• CPC Class Codes: Y10T 29/49117 : Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49826 : Assembling or joining

Abstract

An implanted medical device (e.g. infusion pump) and handheld communication device communicate with one another via telemetry wherein transmitted messages have enhanced numbers of and/or regularity of bit transitions to minimize the risk of synchronization loss between transmitted bits of data and received bits of data. Bit transitions for portions of messages may be enhanced by applying a pseudo-randomization scheme to those portions of messages that are transmitted in a way that allows the receiver to extract the original data from the received randomized data. Preferred randomization techniques modify (i.e. randomize) the data using a CRC value that is being accumulated while simultaneously causing the modified data to modify subsequent accumulation of the CRC itself. Upon reception, the reversal of data randomization occurs so that the intended message is appropriately received.

Claims

1. A method of communicating between medical system components, comprising:

providing an ambulatory medical device (MD) for treating or monitoring a selective state of a body of a patient, the ambulatory medical device having an MD electronic control circuitry with at least one MD telemetry system and at least one MD processor;

controlling, with the MD processor, at least part of the operation of the MD telemetry system and of the ambulatory medical device;

providing a communication device (CD) for sending messages to or receiving messages from the MD telemetry system, the communications device having CD electronic control circuitry with at least one CD telemetry system and at least one CD processor;

controlling, with the CD processor, at least part of the operation of the CD telemetry system and of the communication device; and

modifying at least one portion, but not all, of at least one message with at least one of the MD processor and the CD processor, in preparation for transmission by the medical device or the communication device such that a higher number of bit transitions occur in the at least one modified portion than were found in corresponding at least one portions prior to being modified.

2. The method of claim 1 wherein a first portion of the MD telemetry system is incorporated into the MD processor and a second portion of the MD telemetry system is external to the MD processor, or wherein a first portion of the CD telemetry system is incorporated into the CD processor and a second portion of the CD telemetry system is external to the CD processor.

3. The method of claim 1 wherein the at least one modified portion of the at least one message includes no more bits than found in the corresponding at least one portions prior to being modified.

4. The method of claim 3, wherein modifying the at least one portion comprises providing a pseudo-randomization of the at least portion.

5. The method of claim 4 wherein the pseudo-randomization occurs in a single pass as the message is being prepared for transmission by one of the medical device or the external communication device.

6. The method of claim 5 wherein a de-randomization occurs in a single pass as the message is being received by the other of the external communication device or the medical device.

7. The method of claim 6 wherein the pseudo-randomization is obtained by use of a CRC table.

8. The method of claim 7, further comprising

preparing an error checking code using the CRC table;

and

transmitting the error checking code with the message.

9. The method of claim 7 wherein the at least one message comprises an identifier of the receiver or the transmitter, an op-code, and data, wherein the identifier and op-code are not randomized but the data is randomized.

10. The method of claim 3 wherein the medical device comprises an implantable medical device.

11. The method of claim 10 wherein the medical device comprises at least one of (1) an implantable infusion pump for selectively dispensing a selected drug, (2) an implantable infusion pump for selectively dispensing insulin, (3) an implantable sensor for sensing a selected state of the body, (4) an implantable sensor for sensing glucose level, or (5) an implantable electrode for selectively stimulating a portion of the body of the patient.

12. The method of claim 1 wherein:

the at least one message comprises a plurality of elements; and

the modifying at least one portion, but not all, of at least one message comprises modifying at least one element of the at least one message, but not all elements of the at least one message.

13. The method of claim 12 wherein:

the at least one message comprises at least one data element, and at least one of a preamble element, a frame sync element, and an identifier element of the transmitter or the receiver; and

the modifying at least one portion, but not all, of at least one message comprises modifying at least one data element of at least one message.

14. A method of communicating between medical system components, comprising:

providing an ambulatory medical device (MD) for treating or monitoring a selective state of a body of a patient, the ambulatory medical device having an MD electronic control circuitry with at least one MD telemetry system and at least one MD processor;

controlling, with the MD processor, at least part of the operation of the MD telemetry system and of the ambulatory medical device;

providing a communication device (CD) for sending messages to or receiving messages from the MD telemetry system, the communications device having CD electronic control circuitry with at least one CD telemetry system and at least one CD processor;

controlling, with the CD processor, at least part of the operation of the CD telemetry system and of the communication device; and

modifying at least one portion, but not all, of at least one message with at least one of the MD processor and the CD processor, in preparation for transmission by the medical device or the communication device such that a more uniform spacing of bit transitions exist in the at least one modified portion than were found in corresponding at least one portion prior to being modified.

15. The method of claim 14 wherein a first portion of the MD telemetry system is incorporated into the MD processor and a second portion of the MD telemetry system is external to the MD processor, or wherein a first portion of the CD telemetry system is incorporated into the CD processor and a second portion of the CD telemetry system is external to the CD processor.

16. The method of claim 14 wherein the medical device comprises an implantable medical device.

17. The method of claim 14 wherein the medical device comprises at least one of (1) an implantable infusion pump for selectively dispensing a selected drug, (2) an implantable infusion pump for selectively dispensing insulin, (3) an implantable sensor for sensing a selected state of the body, (4) an implantable sensor for sensing glucose level, or (5) an implantable electrode for selectively stimulating a portion of the body of the patient.

18. The method of claim 14 wherein:

the at least one message comprises a plurality of elements; and

the modifying at least one portion, but not all, of at least one message comprises modifying at least one element of the at least one message, but not all elements of the at least one message.

19. The method of claim 18 wherein:

the at least one message comprises at least one data element, and at least one of a preamble element, a frame sync element, and an identifier element of the transmitter or the receiver; and

the modifying at least one portion, but not all, of at least one message comprises modifying at least one data element of at least one message.

20. The method of claim 19, wherein:

modifying the at least one portion comprises providing a pseudo-randomization of the at least one portion; and

the pseudo-randomization is obtained by use of a CRC table.

21. The method of claim 20, further comprising

preparing an error checking code using the CRC table;

and

transmitting the error checking code with the message.

22. The method of claim 20 wherein the at least one message comprises an identifier of the receiver or the transmitter, an op-code, and data, wherein the identifier and op-code are not randomized but the data is randomized.

23. A method of communicating between medical system components, comprising:

providing an ambulatory medical device (MD) for treating or monitoring a selective state of a body of a patient, the ambulatory medical device having an MD electronic control circuitry with at least one MD telemetry system and at least one MD processor;

controlling, with the MD processor, at least part of the operation of the MD telemetry system and of the ambulatory medical device;

providing a communication device (CD) for sending messages to or receiving messages from the MD telemetry system, the communications device having CD electronic control circuitry with at least one CD telemetry system and at least one CD processor;

controlling, with the CD processor, at least part of the operation of the CD telemetry system and of the communication device; and

modifying at least one portion, but not all, of at least one message with at least one of the MD processor and the CD processor, in preparation for transmission by the medical device or the communication device such that a more uniform distribution of byte patterns occur in the at least one modified transmitted message than in the corresponding at least one portion prior to being modified.

24. The method of claim 23 wherein a first portion of the MD telemetry system is incorporated into the MD processor and a second portion of the MD telemetry system is external to the MD processor, or wherein a first portion of the CD telemetry system is incorporated into the CD processor and a second portion of the CD telemetry system is external to the CD processor.

25. The method of claim 23 wherein the medical device comprises an implantable medical device.

26. The method of claim 23 wherein the medical device comprises at least one of (1) an implantable infusion pump for selectively dispensing a selected drug, (2) an implantable infusion pump for selectively dispensing insulin, (3) an implantable sensor for sensing a selected state of the body, (4) an implantable sensor for sensing glucose level, or (5) an implantable electrode for selectively stimulating a portion of the body of the patient.

27. The method of claim 23 wherein:

the at least one message comprises a plurality of elements; and

the modifying at least one portion, but not all, of at least one message comprises modifying at least one element of the at least one message, but not all elements of the at least one message.

28. The method of claim 27 wherein:

the at least one message comprises at least one data element, and at least one of a preamble element, a frame sync element, and an identifier element of the transmitter or the receiver; and

the modifying at least one portion, but not all, of at least one message comprises modifying at least one data element of at least one message.

29. The method of claim 28, wherein:

modifying the at least one portion comprises providing a pseudo-randomization of the at least one portion; and

the pseudo-randomization is obtained by use of a CRC table.

30. The method of claim 29, further comprising

preparing an error checking code using the CRC table;

and

transmitting the error checking code with the message.

31. The method of claim 29 wherein the at least one message comprises an identifier of the receiver or the transmitter, an op-code, and data, wherein the identifier and op-code are not randomized but the data is randomized.

32. A process of communicating between medical system components, comprising:

providing an ambulatory medical device (MD) for treating or monitoring a selective state of a body of a patient, the ambulatory medical device having an MD electronic control circuitry with at least one MD telemetry system and at least one MD processor;

controlling, with the MD processor, at least part of the operation of the MD telemetry system and of the ambulatory medical device;

providing a communication device (CD) for sending messages to or receiving messages from the MD telemetry system, the communications device having CD electronic control circuitry with at least one CD telemetry system and at least one CD processor;

controlling, with the CD processor, at least part of the operation of the CD telemetry system and of the communication device; and

modifying at least one portion, but not all, of at least one message by a randomization algorithm in preparation for transmission from a first of the medical device or the communication device to a second of the communication device or the medical device, such that a higher number of bit transitions occur in the at least one modified portion than were found in corresponding at least one portion prior to being modified.

33. The method of claim 32 wherein a first portion of the MD telemetry system is incorporated into the MD processor and a second portion of the MD telemetry system is external to the MD processor, or wherein a first portion of the CD telemetry system is incorporated into the CD processor and a second portion of the CD telemetry system is external to the CD processor.

34. The method of claim 32 wherein the medical device comprises an implantable medical device.

35. The method of claim 32 wherein the medical device comprises at least one of (1) an implantable infusion pump for selectively dispensing a selected drug, (2) an implantable infusion pump for selectively dispensing insulin, (3) an implantable sensor for sensing a selected state of the body, (4) an implantable sensor for sensing glucose level, or (5) an implantable electrode for selectively stimulating a portion of the body of the patient.

36. The method of claim 32 wherein the randomization algorithm is a pseudo-randomization algorithm.

37. The method of claim 36 wherein the pseudo-randomization is obtained by use of a CRC table.

38. The method of claim 37, further comprising

preparing an error checking code using the CRC table;

and

transmitting the error checking code with the message.

39. The method of claim 37 wherein the at least one messages comprises an identifier of the receiver or the transmitter, an op-code, and data, wherein the identifier and op-code are not randomized but the data is randomized.

40. A process of communicating between medical system components, comprising:

providing an ambulatory medical device (MD) for treating or monitoring a selective state of a body of a patient, the ambulatory medical device having an MD electronic control circuitry with at least one MD telemetry system and at least one MD processor;

controlling, with the MD processor, at least part of the operation of the MD telemetry system and of the ambulatory medical device;

providing a communication device (CD) for sending messages to or receiving messages from the MD telemetry system, the communications device having CD electronic control circuitry with at least one CD telemetry system and at least one CD processor, wherein messages sent between the communication device and the medical device comprise a transmission preamble, an op-code for identifying the type of message being transmitted, a data portion, and an error checking code;

controlling, with the CD processor, at least part of the operation of the CD telemetry system and of the communication device; and

adding, on a predetermined basis, segments of information to the data portion of the message prior to transmission, by the medical device or the communication device, wherein each segment of information includes at least one bit transition and wherein at least two bits with opposite values are added to the data portion within a number of bits of data to be transmitted.

41. The method of claim 40 wherein a first portion of the MD telemetry system is incorporated into the MD processor and a second portion of the MD telemetry system is external to the MD processor, or wherein a first portion of the CD telemetry system is incorporated into the CD processor and a second portion of the CD telemetry system is external to the CD processor.

42. The method of claim 40 wherein the medical device comprises an implantable medical device.

43. The method of claim 40 wherein the medical device comprises at least one of (1) an implantable infusion pump for selectively dispensing a selected drug, (2) an implantable infusion pump for selectively dispensing insulin, (3) an implantable sensor for sensing a selected state of the body, (4) an implantable sensor for sensing glucose level, or (5) an implantable electrode for selectively stimulating a portion of the body of the patient.