Medical telemetry system with cellular reception of patient data

• US 6,589,170 B1
• Filed: 05/25/2000
• Issued: 07/08/2003
• Est. Priority Date: 11/13/1995
• Status: Expired due to Term

• Current Assignee: GE Medical Systems Information Technologies Incorporated (General Electric Company)
• Original Assignee: GE Medical Systems Information Technologies Incorporated (General Electric Company)
• Inventors: Flach, Terry E., Stoop, Michael D.
• Primary Examiner(s): Nasser, Robert L.
• Application Number:
  US09/578,986
• Time in Patent Office: 1,139 Days
• Field of Search: 600/300, 128/903
• US Class Current: 600/300
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• 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 5/1113 Local tracking of patients, e.g. in a hospital or private home
• CPC Class Codes: H03L 3/00 Starting of generators
• CPC Class Codes: H03L 7/10 for assuring initial synchronisation or for broadening the capture range
• CPC Class Codes: H03L 7/14 for assuring constant frequency when supply or correction voltages fail or are interrupted
• CPC Class Codes: H04B 1/1615 Switching on; Switching off, e.g. remotely battery saving circuits associated with selective call operation H04W52/00; details of power consumption reduction in a PLL, H03L7/0802, H03L7/14, H03L2207/08, H03L2207/18; muting amplifiers by gain control see H03G3/34
• CPC Class Codes: H04W 52/028 switching on or off only a part of the equipment circuit blocks
• CPC Class Codes: Y02D 30/70 in wireless communication networks
• CPC Class Codes: Y10S 128/903 Radio telemetry
• CPC Class Codes: Y10S 128/904 Telephone telemetry

Abstract

A medical telemetry system is provided for collecting the real-time physiologic data of patients (including ambulatory patients) of a medical facility, and for transferring the data via RF to a real-time data distribution network for monitoring and display. The system includes battery-powered remote telemeters which attach to respective patients, and which collect and transmit (in data packets) the physiologic data of the patients. The remote telemeters communicate bi-directionally with a number of ceiling-mounted RF transceivers, referred to as “VCELLs,” using a wireless TDMA protocol. The VCELLs, which are hardwire-connected to a LAN, forward the data packets received from the telemeters to patient monitoring stations on the LAN. The VCELLs are distributed throughout the medical facility such that different VCELLs provide coverage for different patient areas. As part of the wireless TDMA protocol, the remote telemeters continuously assess the quality of the RF links offered by different nearby VCELLs (by scanning the frequencies on which different VCELLs operate), and connect to those VCELLs which offer the best link conditions. To provide a high degree of protection against multi-path interference, each remote telemeter maintains connections with two different VCELLs at-a-time, and transmits all data packets (on different frequencies and during different timeslots) to both VCELLs; the system thereby provides space, time and frequency diversity on wireless data packet transfers from the telemeters. The telemeters and VCELLs also implement a patient location protocol for enabling the monitoring of the locations of individual patients. The architecture can accommodate a large number of patients (e.g., 500 or more) while operating within the transmission power limits of the VHF medical telemetry band.

Claims

1. A medical telemetry system for permitting real-time monitoring of patients within a medical facility, comprising:

a plurality of wireless remote telemeters, the remote telemeters configured to receive and transmit real-time physiologic data of respective patients; and

a plurality of transceivers which communicate bi-directionally with the plurality of remote telemeters using a plurality of wireless channels, the transceivers coupled to a computer network and being distributed throughout the medical facility such that different transceivers provide data-reception coverage for different areas of the medical facility, at least some of the transceivers receiving physiologic data on different wireless channels, the transceivers configured to receive the physiologic data transmitted by the remote telemeters and to forward the physiologic data for monitoring on the computer network;

wherein at least some of the remote telemeters automatically switch between different wireless channels of the plurality of wireless channels in response to patient movement throughout the medical facility to connect to and disconnect from individual transceivers of the plurality of transceivers.

2. The medical telemetry system according to claim 1, wherein the remote telemeters evaluate wireless link conditions offered by different transceivers and establish wireless connections with individual transceivers based at least upon said wireless link conditions.

3. The medical telemetry system according to claim 2, wherein the remote telemeters evaluate the wireless link conditions by at least monitoring bit error rates of signals received from the transceivers.

4. The medical telemetry system according to claim 1, further comprising at least one monitoring station connected to the computer network to monitor the physiologic data in real time.

5. The medical telemetry system according to claim 1, wherein at least two of the transceivers communicate with the remote telemeters on the same wireless channel.

6. The medical telemetry system according to claim 5, wherein the at least two transceivers which communicate on the same wireless channel are sufficiently spaced apart to substantially avoid interference with one another.

7. The medical telemetry system according to claim 1, wherein the transceivers broadcast timeslot availability messages to the remote telemeters, the timeslot availability messages indicating available TDMA timeslots for communicating.

8. The medical telemetry system according to claim 7, wherein each transceiver broadcasts timeslot availability messages on an assigned channel of a plurality of wireless channels, and the remote telemeters switch between the plurality of wireless channels to receive timeslot availability messages from multiple transceivers.

9. The medical telemetry system according to claim 1, wherein at least one of the transceivers is positioned proximate to a known intermittent source of electromagnetic interference.

10. The medical telemetry system according to claim 9, wherein the at least one transceiver is positioned within a patient X-ray room.

11. The medical telemetry system according to claim 1, wherein at least some of the transceivers transmit patient location signals to the remote telemeters.

12. The medical telemetry system according to claim 1, wherein at least some of the remote telemeters are ambulatory telemeters that are adapted to be worn by respective patients.

13. The medical telemetry system according to claim 1, wherein at least some of the remote telemeters are instrument remote telemeters that receive the real-time physiologic data of patients from bedside monitors.

14. A medical telemetry system for permitting real-time monitoring of patients within a medical facility, comprising:

a plurality of wireless remote telemeters, the remote telemeters configured to receive and transmit real-time physiologic data of respective patients; and

a plurality of transceivers which communicate bi-directionally with the plurality of remote telemeters using a plurality of wireless channels, the transceivers coupled to a computer network and being distributed throughout the medical facility such that different transceivers provide data-reception coverage for different areas of the medical facility, at least some of the transceivers receiving physiologic date on different wireless channels, the transceivers configured to receive the physiologic data transmitted by the remote telemeters and to forward the physiologic data for monitoring on the computer network;

wherein at least some of the remote telemeters automatically switch between different wireless channels of the plurality of wireless channels in response to patient movement throughout the medical facility to connect to and disconnect from individual transceivers of the plurality of transceivers; and

wherein at least one remote telemeter of the plurality of remote telemeters maintains wireless connections with at least two different transceivers at-a-time, and transmits the physiologic data of a respective patient to the at least two different transceivers during different timeslots to provide redundant transmission paths that benefit from at least time and space diversity.

15. The medical telemetry system according to claim 14, wherein the remote telemeter transmits the physiologic data to the at least two different transceivers on different frequencies.

16. A medical telemetry system for permitting real-time monitoring of patients within a medical facility, comprising:

a plurality of wireless remote telemeters, the remote telemeters configured to receive and transmit real-time physiologic data of respective patients; and

a plurality of transceivers which communicate bi-directionally with the plurality of remote telemeters using a,plurality of wireless channels, the transceivers coupled to a computer network and being distributed throughout the medical facility such that different transceivers provide data-reception coverage for different areas of the medical facility, at least some of the transceivers receiving physiologic data on different wireless channels, the transceivers configured to receive the physiologic data transmitted by the remote telemeters and to forward the physiologic data for monitoring on the computer network;

wherein at least some of the remote telemeters automatically switch between different wireless channels of the plurality of wireless channels in response to patient movement throughout the medical facility to connect to and disconnect from individual transceivers of the plurality of transceivers; and

wherein at least some of the transceivers of the plurality of transceivers are synchronized with one another.

17. A medical telemetry system for permitting real-time monitoring of patients within a medical facility, comprising:

a plurality of wireless remote telemeters, the remote telemeters configured to receive and transmit real-time physiologic data of respective patients; and

a plurality of transceivers which communicate bi-directionally with the plurality of remote telemeters using a plurality of wireless channels, the transceivers coupled to a computer network and being distributed throughout the medical facility such that different transceivers provide data-reception coverage for different areas of the medical facility, at least some of the transceivers receiving physiologic data on different wireless channels, the transceivers configured to receive the physiologic data transmitted by the remote telemeters and to forward the physiologic data for monitoring on the computer network;

wherein at least some of the remote telemeters automatically switch between different wireless channels of the plurality of wireless channels in response to patient movement throughout the medical facility to connect to and disconnect from individual transceivers of the plurality of transceivers; and

further comprising a plurality of concentrator computers interconnected by the computer network, wherein different subsets of the plurality of transceivers are connected to respective concentrator computers, and each concentrator computer receives physiologic data from a respective subset of the transceivers for transmission on the computer network.

18. The medical telemetry system according to claim 17, further comprising a plurality of monitoring stations connected to the computer network to display the real-time physiologic data of the patients.

19. A medical telemetry system for permitting real-time monitoring of patients within a medical facility, comprising:

a plurality of wireless remote telemeters, the remote telemeters configured to receive and transmit real-time physiologic data of respective patients; and

a plurality of transceivers which communicate bi-directionally with the plurality of remote telemeters using a plurality of wireless channels, the transceivers coupled to a computer network and being distributed throughout the medical facility such that different transceivers provide data-reception coverage for different areas of the medical facility, at least some of the transceivers receiving physiologic data on different wireless channels, the transceivers configured to receive the physiologic data transmitted by the remote telemeters and to forward the physiologic data for monitoring on the computer network;

wherein at least some of the remote telemeters automatically switch between different wireless channels of the plurality of wireless channels in response to patient movement throughout the medical facility to connect to and disconnect from individual transceivers of the plurality of transceivers; and

wherein at least one of the transceivers maintains wireless connections with multiple remote telemeters at-a-time.

20. A medical telemetry system for permitting real-time monitoring of patients within a medical facility, comprising:

a plurality of wireless remote telemeters, the remote telemeters configured to receive and transmit real-time physiologic data of respective patients; and

a plurality of transceivers which communicate bi-directionally with the plurality of remote telemeters using a plurality of wireless channels, the transceivers coupled to a computer network and being distributed throughout the medical facility such that different transceivers provide data-reception coverage for different areas of the medical facility, at least some of the transceivers receiving physiologic data on different wireless channels, the transceivers configured to receive the physiologic data transmitted by the remote telemeters and to forward the physiologic data for monitoring on the computer network;

wherein at least some of the remote telemeters automatically switch between different wireless channels of the plurality of wireless channels in response to patient movement throughout the medical facility to connect to and disconnect from individual transceivers of the plurality of transceivers; and

wherein at least one remote telemeter of the plurality of remote telemeters includes a processor which executes a control program to implement a wireless communications protocol in which the remote telemeter transmits data packets to different transceivers during different timeslots, the control program configured to maintain wireless connections with at least two different transceivers at-a-time on at least two different wireless channels, and to transmit data packets that contain like physiologic data to the at least two different transceivers to provide multiple simultaneous transmission paths for the transfer of the physiologic data between the remote Telemeter and the computer network.

21. A medical telemetry system for monitoring patients of a medical facility, the system comprising:

a plurality of transceivers distributed throughout at least a portion of the medical facility such that different transceivers provide data reception coverage for different areas of the medical facility, the plurality of transceivers coupled to at least one common data receiving node, at least some of the transceivers assigned to different channels of a plurality of wireless channels to receive physiologic data of patients; and

a plurality of remote telemeters, each remote telemeter configured to connect to a respective patient to receive physiologic data of that patient, and including a transmission circuit that transmits the physiologic data on at least one of the wireless channels for reception by at least one of the transceivers;

wherein the transceivers and the remote telemeters include control circuitry which implements a switchover protocol in which connections are established and terminated between individual transceivers and remote telemeters for the transmission of physiologic data based at least upon assessments of wireless link conditions therebetween.

22. The medical telemetry system as in claim 21, wherein at least two of the plurality of transceivers are assigned to the same wireless channel to provide frequency re-use.

23. The medical telemetry system as in claim 22, wherein the at least two transceivers are spaced apart by at least a pre-selected distance to substantially avoid interference.

24. The medical telemetry system as in claim 21, wherein the assessments of wireless link conditions include bit error rates of transmissions between the transceivers and the remote telemeters.

25. The medical telemetry system as in claim 24, wherein the assessments of wireless link conditions further include signal strength measurements.

26. The medical telemetry system according to claim 21, wherein at least one of the transceivers is positioned proximate to a known intermittent source of electromagnetic interference.

27. The medical telemetry system according to claim 26, wherein the at least one transceiver is positioned within a patient X-ray room.

28. The method as in claim 21, wherein the physiologic data includes real-time ECG waveform data.

29. The medical telemetry system according to claim 21, wherein at least some of the remote telemeters are ambulatory telemeters that are adapted to be worn by respective patients.

30. The medical telemetry system according to claim 21, wherein at least one of the remote telemeters is an instrument remote telemeter that connects to a respective patient by way of a connection to a bedside monitor connected to the patient.

31. A medical telemetry system for monitoring patients of a medical facility, the system comprising:

a plurality of transceivers distributed throughout at least a portion of the medical facility such that different transceivers provide data reception coverage for different areas of the medical facility, the plurality of transceivers coupled to at least one common data receiving node, at least some of the transceivers assigned to different channels of a plurality of wireless channels to receive physiologic data of patients; and

a plurality of remote telemeters, each remote telemeter configured to connect to a respective patient to receive physiologic data of that patient, and including a transmission circuit that transmits the physiologic data on at least one of the wireless channels for reception by at least one of the transceivers;

wherein the transceivers and the remote telemeters include control circuitry which implements a switchover protocol in which connections are established and terminated between individual transceivers and remote telemeters for the transmission of physiologic data based at least upon assessments of wireless link conditions therebetween; and

wherein at least one of the remote telemeters is configured to maintain connections with multiple transceivers at a time to provide redundant data transmission paths to the data receiving node.

32. The medical telemetry system as in claim 31, wherein the at least one remote telemeter is configured to transmit a block of physiologic data to a first transceiver during a first timeslot of a TDMA frame, and to transmit the block of physiologic data to a second transceiver during a second timeslot of the TDMA frame.

33. The medical telemetry system as in claim 32, wherein the at least one remote telemeter is configured to transmit the block of physiologic data to the first transceiver on a first frequency, and to transmit the block of physiologic data to the second transceiver on a second frequency.

34. A medical telemetry system for monitoring patients of a medical facility, the system comprising:

a plurality of transceivers distributed throughout at least a portion of the medical facility such that different transceivers provide data reception coverage for different areas of the medical facility, the plurality of transceivers coupled to at least one common data receiving node, at least some of the transceivers assigned to different channels of a plurality of wireless channels to receive physiologic data of patients; and

a plurality of remote telemeters, each remote telemeter configured to connect to a respective patient to receive physiologic date of that patient, and including a transmission circuit that transmits the physiologic data on at least one of the wireless channels for reception by at least one of the transceivers;

wherein the transceivers and the remote telemeters include control circuitry which implements a switchover protocol in which connections are established and terminated between individual transceivers and remote telemeters for the transmission of physiologic data based at least upon assessments of wireless link conditions therebetween; and

wherein the remote telemeters and the transceivers implement a TDMA protocol in which each transceiver is capable of maintaining data connections with multiple remote telemeters at a time.