Ambulatory medical apparatus and method using a robust communication protocol

• US 6,813,519 B2
• Filed: 01/22/2001
• Issued: 11/02/2004
• 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: Shahmirian, Varaz, Lebel, Ronald J., Armstrong, John T., Bowman, Sam W. IV, Richert, John D., Dennard, Robert C.
• Primary Examiner(s): ROBINSON, DANIEL LEON
• Application Number:
  US09/768,043
• Publication Number:
  US 20020198513A1
• Time in Patent Office: 1,380 Days
• Field of Search: 607/32, 607/9, 607/2, 607/17, 607/18, 607/19, 607/25, 607/27, 607/28, 607/29, 607/30, 607/31, 600/300, 340/573.1, 340/573.2, 340/573.3, 340/573.4, 434/258, 604/131, 604/132, 128/903, 128/904
• US Class Current: 607/32
• 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 external device communicate with one another via telemetry wherein messages are transmitted under a robust communication protocol. The communication protocol gives enhanced assurance concerning the integrity of messages that impact medical operations of the implantable device. Messages are transmitted using a multipart format that includes a preamble, a frame sync, a telemetry ID, data, and a validation code. The data portion of the message includes an op-code that dictates various other elements that form part of the message. The data portion may also include additional elements such as sequence numbers, bolus numbers, and duplicate data elements. A telemetry ID for the transmitting device may be implicitly embedded in the message as part of the validation code that is sent with the message and that must be pre-known by the receiver to confirm the integrity of the received message.

Claims

1. A medical system, comprising:

a) an ambulatory medical device (MD) comprising MD electronic control circuitry that further comprises at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; and

b) a communication device (CD) comprising CD electronic control circuitry that further comprises at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages from the MD telemetry system,

wherein the MD telemetry system and the CD telemetry system are controlled to use one of a predefined plurality of preambles including a first preamble for messages sent from the communication device to the medical device and a second preamble for messages sent from the medical device to the communication device.

2. The system 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 system of claim 2 wherein (1) the MD electronic control circuitry comprises at least one external MD functional module, other than the second portion of the MD telemetry system, that is external to the MD processor, (2) the CD electronic control circuitry comprises at least one external CD functional module, other than the second portion of the CD telemetry system, that is external to the CD processor, (3) the MD processor comprises an internal MD CPU and at least one other internal MD functional module, or (4) the CD processor comprises an internal CD CPU and at least one other internal CD functional module.

4. The system of claim 1 wherein the medical device comprises and implantable infusion pump for selectively dispensing a drug.

5. The system of claim 4 wherein the drug comprises insulin.

6. The system of claim 1 wherein the medical device comprises an implantable sensor for sensing a selected state of the body.

7. The system of claim 6 wherein the sensor comprises a glucose sensor.

8. The system of claim 1 wherein the medical device comprises an implantable electrode for selectively stimulating a portion of the body of the patient.

9. The system of claim 1 wherein at least a portion of the plurality of preambles comprise different bit patterns.

10. The system of claim 9 wherein at least one bit pattern comprises a sequence that includes repeated use of a pattern of 10 or 01 and at least one other bit pattern comprises a sequence that includes repeat use of a pattern of 110, 011, 001, or 100.

11. The system of claim 1 wherein at least a portion of the plurality of preambles comprise bit patterns of different lengths.

12. The system of claim 1 wherein the first preamble comprises a sequence that includes repeated use of a pattern of 110 and wherein the second preamble comprises a sequence that includes repeated use of a pattern of 10.

13. The system of claim 1 wherein at least a portion of the preambles of messages sent to the medical device from the communication device have preambles of varying length.

14. The system of claim 1 wherein the preambles of messages sent to the communication device by the medical device have fixed lengths.

15. The system of claim 14 wherein at least some of the plurality of preambles comprise both different bit patterns and different lengths.

16. The system of claim 1 wherein a first preamble is used to send at least some messages from the communication device to the medical device and a second preamble, which is different from the first preamble, is used to send at least some messages from the medical device to the communication device.

17. The system of claim 1 wherein messages are sent from the communication device to the medical device using at least two different preamble lengths.

20. A system of claim 1, wherein the first and second preambles each comprises a first bit pattern and wherein the first bit pattern in one of the first or second preambles is repeated an extended number of times relative to the first bit pattern in the other of the first or second preambles.

21. A system of claim 1, wherein the first and second preambles each comprises a first bit pattern and wherein the first bit pattern in the first preamble is repeated an extended number of times relative to the first bit pattern in the second preamble.

22. A system of claim 1 wherein the CD telemetry system is controlled to send messages from the communication device to the medical device using at least two different first preambles, including an attention preamble for some messages and a standard preamble for other messages, the attention preamble comprising a preamble that captures and holds the attention of the MD telemetry system as long as it continues to be received, and the standard preamble comprising a preamble that does not hold the attention of the MD telemetry system beyond a prescribed inbound listening period.

18. A medical system comprising:

a) an ambulatory medical device (MD) comprising MD electronic control circuitry that further comprises at least one MD telemetry system and at least one MD processor that controls, at least in part, operation of the MD telemetry system and operation of the medical device, wherein the medical device is configured to provide a treatment to a body of a patient or to monitor a selected state of the body; and

b) a communication device (CD) comprising CD electronic control circuitry that further comprises at least one CD telemetry system and at least one CD processor that controls, at least in part, operation of the CD telemetry system and operation of the communication device, wherein the CD telemetry system sends messages to or receives messages form the MD telemetry system,

wherein the CD telemetry system is controlled to send messages from the communication device to the medical device using at least two different preambles, including an attention preamble for some messages and a standard preamble far other messages, the attention preamble comprising a preamble that captures and holds the attention of the MD telemetry system as long as it continues to be received, and the standard preamble comprising a preamble that does not hold the attention of the MD telemetry system beyond a prescribed inbound listening period.

19. The system of claim 18 wherein the attention preamble is of a different pattern than the standard preamble.