Portable remote patient telemonitoring system

• US 6,416,471 B1
• Filed: 04/15/1999
• Issued: 07/09/2002
• Est. Priority Date: 04/15/1999
• Status: Expired due to Fees

• Current Assignee: Clearpath Partners, LLC
• Original Assignee: Nexan Limited
• Inventors: Johnson, Paul, OʼBrien, William G., Nicolson, Laurence J., Mullarkey, William J., Relph, Peter M., Llewellyn, Michael D., New, William Jr., Kumar, Harpal S., Place, John D.
• Primary Examiner(s): Winakur, Eric F.
• Assistant Examiner(s): ASTORINO, MICHAEL C
• Application Number:
  US09/292,405
• Time in Patent Office: 1,181 Days
• Field of Search: 600/300-301, 600/481-486, 600/500-508, 600/529-538, 600/544-545, 128/903, 128/904, 128/900, 128/920-925
• 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 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/7232 involving compression of the physiological signal, e.g. to extend the signal recording period
• CPC Class Codes: G16H 10/65 stored on portable record carriers, e.g. on smartcards, RFID tags or CD
• CPC Class Codes: G16H 40/67 for remote operation
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation
• CPC Class Codes: Y10S 128/903 Radio telemetry
• CPC Class Codes: Y10S 128/904 Telephone telemetry

Abstract

A system and method for monitoring vital signs and capturing data from a patient remotely using radiotelemetry techniques. The system is characterized by a cordless, disposable sensor band with sensors form measuring full waveform ECG, full waveform respiration, skin temperature, and motion, and transmission circuitry for the detection and transmission of vital signs data of the patient. A small signal transfer unit that can either be worn by the patient, e.g., on his or her belt, or positioned nearby receives data from the sensor band, which it then forwards by e.g., radio transmission to a base station that can be located up to 60 meters away. The base station receives data transmissions from the signal transfer unit and is designed to connect to conventional phone lines for transferring the collected data to a remote monitoring station. The base station may also capture additional clinical data, such as blood pressure data, and to perform data checks. Patient safety is enhanced by the ability of the base station to compare clinical data, e.g., ECG, against given profiles and to mark events when appropriate or when the base station is programmed to do so. Such events are indicated to the physician and could be indicated to the patient by reverse transmission to the signal transfer unit. A remote monitoring station allows the presentation and review of data (including events) forwarded by the sensor band. ECG analysis software and a user-friendly graphical user interface are provided to remotely analyze the transmitted data and to permit system maintenance and upkeep. The system of the invention has useful application to the collection of patient clinical data during drug trials and medical testing for regulatory approvals as well as management of patients with chronic diseases.

Claims

1. A health parameter data collection and monitoring system, comprising:

a sensor band having a sensor assembly for application to a subject, said sensor assembly producing a data signal including health parameter data indicative of values of at least one health parameter of the subject, said sensor band further comprising a transmitter which transmits said data signal over a first communications link;

a transceiver coupled to said first communications link so as to receive said data signal for retransmission over a second, wireless communications link;

a base station unit disposed so as to receive said retransmitted data signal from said transceiver via said second communications link, said base station unit storing received health parameter data for retransmission over a third communications link; and

a remote monitoring station disposed so as to receive said retransmitted data signal from said base station unit via said third communications link, said remote monitoring station storing and displaying said health parameter data.

2. A system as in claim 1, wherein said sensor band is adapted for attachment to a chest of the subject and said sensor assembly produces health parameter data indicative of at least one of ECG, respiration, skin temperature, and subject motion.

3. A system as in claim 1, wherein said sensor band includes a circuit which multiplexes health parameter data signals from at least two different sensors in said sensor assembly for transmission over said first communications link by said transmitter.

4. A system as in claim 1, wherein said transceiver comprises a buffer which stores health parameter data received from said sensor band at least during times when said second communications link is disconnected, lost, or unreliable.

5. A system as in claim 1, wherein said remote monitoring station requests retransmission of said data signal to said remote monitoring station at predetermined times or conditions or on demand.

6. A system as in claim 5, wherein said remote monitoring station includes an interface which allows a user to set said predetermined times or conditions for said retransmission of said data signal to said remote monitoring station.

7. A system as in claim 6, wherein said interface allows the user of the remote monitoring station to select a subject for review of at least that subject'"'"'s health parameter data.

8. A system as in claim 6, wherein said interface allows the user to simultaneously review and compare time synchronized health parameter data for a plurality of health parameters for a particular subject.

9. A system as in claim 6, wherein said interface permits the user to select at least one of unprocessed health parameter data and summary data for display to the user of the remote monitoring station.

10. A system as in claim 1, further comprising a database accessible by said remote monitoring station to store health parameter data for a plurality of subjects.

11. A system as in claim 10, wherein said remote monitoring station includes software which generates case record forms from at least the health parameter data stored for a subject in said database.

12. A system as in claim 1, wherein said transceiver is adapted to receive health parameter data transmitted by at least two sensor bands for retransmission to said remote monitoring station.

13. A system as in claim 1, wherein said base station unit includes a processor which calculates physiological parameter data including at least one of a subject'"'"'s heart rate and a subject'"'"'s respiration rate from said health parameter data and stores said physiological parameter data in a memory for transmission to said remote monitoring station.

14. A system as in claim 13, wherein said memory of said base station unit is a rolling first-in-first-out (FIFO) memory which stores said health parameter data irrespective of whether said health parameter data has been transmitted to said remote monitoring station.

15. A system as in claim 1, wherein said base station unit comprises at least one input connection for accepting auxiliary data input parameters from an auxiliary health parameter sensor and a memory which stores said auxiliary data input for transmission to said remote monitoring station.

16. A system as in claim 15, wherein said base station unit time stamps said health parameter data and said auxiliary data synchronously and ages independently said auxiliary data and said health parameter data while stored in said memory of said base station unit.

17. A system as in claim 15, wherein said auxiliary health parameter sensor is at least one of a blood pressure sensor, a spirometer, a weigh scale, and a blood glucose meter.

18. A system as in claim 15, wherein said base station unit detects abnormal physiological conditions in said auxiliary data and indicates an event condition and stores event data indicating a significant physiological event in said memory when an abnormal physiological condition is detected.

19. A system as in claim 18, wherein said base station unit time stamps said health parameter data and said auxiliary data synchronously and ages independently said auxiliary data and said health parameter data while stored in said memory of said base station unit.

20. A system as in claim 15, wherein said base station unit includes a processor which calculates physiological parameter data including at least one of a subject'"'"'s heart rate and a subject'"'"'s respiration rate from said health parameter data and stores said physiological parameter data in said memory at said base station unit for transmission to said remote monitoring station.

21. A system as in claim 20, wherein said processor further performs ECG analysis of said health parameter data and stores ECG analysis data in said memory.

22. A system as in claim 20, wherein said memory separately stores said health parameter data and said calculated physiological parameter data.

23. A system as in claim 15, wherein said remote monitoring station includes an interface which allows a user to schedule auxiliary health parameter sensor measurements at said base station unit if such measurements are required.

24. A system as in claim 1, wherein said base station unit comprises a memory and compares received health parameter data with predetermined ranges for detected physiological variables and detects abnormal physiological conditions in said health parameter data, said base station unit indicating an event condition and storing event data indicating a significant physiological event in said memory when said received health parameter data is outside said predetermined ranges or when an abnormal physiological condition is detected.

25. A system as in claim 23, wherein said memory of said base station unit is a rolling first-in-first-out (FIFO) memory which stores at least said health parameter data irrespective of whether said health parameter data has been transmitted to said remote monitoring station.

26. A system as in claim 24, wherein said remote monitoring station includes an interface which allows a user to set at least one of said predetermined ranges of said base station unit.

27. A system as in claim 23, wherein said remote monitoring station includes means for checking received data for event data and an interface which allows a user to view such event data, whereby if event data is detected, said interface allows the user of said remote monitoring station to view a desired amount of health parameter data before, during, and after an occurrence of an event condition indicated by said event data.

28. A system as in claim 1, wherein said second communications link is a bidirectional asynchronous radio link.

29. A system as in claim 28, wherein said transceiver initiates all communications dialogs with said base station unit.

30. A system as in claim 28, wherein said health parameter data is transmitted from said transceiver to said base station unit over said second communications link in data packets including CRC error detection code and ARQ code for the retransmission of erroneous data packets.

31. A system as in claim 30, wherein said data packets are scrambled for transmission in a data packet stream so as to minimize a DC component in said data packet stream.

32. A system as in claim 30, wherein if said base station unit or said transceiver receives two consecutive erroneous data packets over said second communications link, said second communications link will be determined to be disconnected, lost, or unreliable, and said transceiver will wait a predetermined period of time before attempting to re-establish the second communications link with said base station unit.

33. A system as in claim 30, wherein each data packet is one of the following types of data packets:

a dialog request packet for initiating a dialog between said transceiver and said base station unit, an acknowledgment packet for informing the sender of the success of a transmitted data packet, a health parameter data packet which includes health parameter data for transfer from said transceiver to said base station unit, and a control data packet for transferring configuration data from said base station unit to said transceiver.

34. A system as in claim 28, wherein said base station unit sends an alarm signal or an indication to a subject to do something to said transceiver via said second communications link when at least one of the following occurs:

a physiological event is detected in said health parameter data, it is time for the subject to take a physiological parameter reading or a medication, and the base station unit cannot accept more health parameter data.

35. A system as in claim 1, wherein said third communications link is a telecommunications link.

36. A system as in claim 35, wherein said remote monitoring station initiates a connection with said base station unit, and once the connection is established, said remote monitoring station and base station unit listen for commands.

37. A system as in claim 30, wherein said commands include a data request command from said remote monitoring station requesting at least one of real-time health parameter data and health parameter data in a designated time range from said base station unit.

38. A system as in claim 1, wherein an ID of said base station unit is checked by said remote monitoring station before data is transmitted via said third communications link.

39. A system as in claim 1, further comprising a database accessible by said remote monitoring station to capture and store health parameter data for a plurality of subjects and said remote monitoring station further includes an interface through which a user of the remote monitoring station may select a subject for review of at least that subject'"'"'s health parameter data.

40. A system as in claim 1, wherein said base station unit is adapted to receive health parameter data transmitted by at least two transceivers for retransmission to said remote monitoring station.

41. A system as in claim 1, wherein said remote monitoring station is adapted to receive health parameter data transmitted by at least two base station units.

42. A system as in claim 41, wherein said remote monitoring station includes a server which controls the receipt and storage of health parameter data from said at least two base station units.

43. A health parameter data collection and monitoring system, comprising:

a sensor band having a sensor assembly for application to a subject, said sensor assembly producing a data signal including health parameter data indicative of values of at least one health parameter of the subject, said sensor band further comprising a transmitter which transmits said data signal over a first communications link;

a transceiver coupled to said first communications link so as to receive said health parameter data for retransmission of said data signal over a second, wireless communications link, said transceiver including a buffer which stores health parameter data received from said sensor band at least during times when said second communications link is disconnected, lost, or unreliable, said transceiver stopping data transmission when said second communications link becomes disconnected, lost, or becomes unreliable, and said transceiver retransmitting said data signal over said second communications link from said transceiver at an increased transmission rate after said second communications link is restored as compared to a transmission rate before said second communications link is disconnected, lost, or becomes unreliable; and

a remote monitoring station disposed so as to receive said retransmitted data signal from said transmitter via said second communication link.

44. A system as in claim 43, wherein said transceiver includes an alarm indicator which warns the subject that said second communications link has been disconnected, lost, or has become unreliable so that the subject may take steps to restore said second communications link.

45. A system as in claim 43, wherein said transceiver includes at least one event button, wherein depression of said event button indicates an event condition and corresponding event data is transmitted to said remote monitoring station.

46. A system as in claim 45, wherein said remote monitoring station includes means for checking received data for said event data and an interface which allows a user to view such that event data, whereby if event data is detected, said interfcae allows the user of said remote monitoring station to view health parameter data before, during, and after an occurrence of the event condition indicated by said event data.

47. A health parameter data collection and monitoring system, comprising:

a sensor band having a sensor assembly for application to a subject, said sensor assembly producing a data signal including health parameter data indicative of values at least one health parameter of the subject, said sensor band further comprising a transmitter having a first antenna which transmits said data signal over a first wireless communications link;

a transceiver having a second antenns inductively coupled to said first communiations link so as to form a wireless inductive loop with said first antenna for reception of said health parameter data, said transceiver further retransmitting said data signal over a second wireless communications link; and

a remote monitoring station disposed so as to receive said retransmitted data signal from said transmitter via said second wireless communications link.

48. A system as in claim 47, wherein said data signal is transmitted over said first wireless communications link by said transmitter in QPSK formatted coded data packets.

49. A system as in claim 48, wherein said data packets are transmitted in at least one frequency channel of a plurality of frequency division multiplexed channels spaced at predetermined intervals in a selected frequency range.

50. A system as in claim 49, wherein coded data packets in each of said frequency channels comprise a clock signal, a framing pulse, and said health parameter data.

51. A system as in claim 48, wherein said transmitter includes a controller which codes said coded data packets from template waveforms representative of each possible transition of symbols corresponding to a different phase offset of the transmitted signal relative to a fixed carrier phase locked to symbol transitions.

52. A system as in claim 51, wherein said controller converts each of said template waveforms into respective digital data streams which are, in turn, converted into controller instructions.

53. A system as in claim 52, wherein said controller converts zero-to-one state changes of said template waveforms into controller instructions which set an output port bit of said transmitter, converts one-to-zero state changes of said template waveforms into controller instructions which clear said output port bit of said transmitter, and converts idle periods between state changes into a sequence of no-operation instructions so as to introduce correct time delays between state changes.

54. A system as in claim 53, wherein said controller replaces certain no-operation instructions in said template waveforms by jump instructions which jump into a template waveform to a point which ensures continuity of the coded data packets, said controller further deleting instructions in each template waveform rendered unnecessary by said jump instructions.

55. A system as in claim 54, wherein said controller applies an optimization algorithm to said template waveforms to reduce the length each.

56. A health parameter data collection and monitoring system, comprising:

a sensor band having a sensor assembly for application to a subject, said sensor assembly producing a data signal including health parameter data indicative of values of at least one health parameter of the subject, said sensor band further comprising a transmitter which transmits said data signal over a first communications link;

a transceiver coupled to said first communications link so as to receive said health parameter data for retransmission of said data signal over a second, wireless communications link; and

a remote monitoring station disposed so as to receive said retransmitted data signal from said transceiver via said second communications link, said remote monitoring station capturing said health parameter data and storing said health parameter data in a database with health parameter data from a plurality of other subjects, said remote monitoring station including a user interface which provides access to health parameter data in said database and processing of said health parameter data.

57. A system as in claim 56, wherein said remote monitoring station requests retransmission of said data signal to said remote monitoring station at predetermined times, in response to certain conditions, or on demand.

58. A system as in claim 57, wherein said interface allows the user to set said predetermined times and conditions for said retransmission of said data signal to said remote monitoring station.

59. A system as in claim 56, wherein said interface allows the user of the remote monitoring station to select a subject for review of at least that subject'"'"'s health parameter data.

60. A system as in claim 56, wherein said interface allows the user to simultaneously review and compare time synchronized health parameter data for a plurality of health parameters for a particular subject.

61. A system as in claim 56, wherein said interface permits the user to select at least one of unprocessed health parameter data and summary data for display to the user of the remote monitoring station.

62. A system as in claim 56, wherein said remote monitoring station further includes means for performing ECG analysis of said health parameter data.

63. A system as in claim 56, wherein said interface requests a password from a user before permitting the user to access said database.

64. A system as in claim 56, wherein said interface keeps an audit record of actions performs by the user when using said interface and of actions performed by said remote monitoring station.

65. A system as in claim 56, wherein said interface formats at least a portion of said health parameter data into a histogram of R—

R intervals of ECG data, presents said data to a display upon user request, and permits the user to navigate and select said ECG data for detailed viewing.

66. A system as in claim 56, wherein said interface formats received physiological parameter data into trend data, presents said trend data to a display upon user request, and permits the user to navigate and select said trend data for detailed viewing.

71. A method as in claim 62, wherein said retransmitting step comprises the step of transmitting said data signal over a cellular communications link to said base station unit.

72. A method as in claim 62, wherein said retransmitting step comprises the step of retransmitting said data signal to said remote monitoring station at said designated time, in response to a certain condition, or on demand.

73. A method as in claim 72, wherein said retransmitting step comprises the step of allowing a user to set said designated time and certain condition for said retransmission of said data signal to said remote monitoring station.

74. A method as in claim 72, wherein said step of retransmitting said data signal to said remote monitoring station includes the step of real-time transmission of said data signal to said remote monitoring station on receipt of a demand from said remote monitoring station.

75. A method as in claim 62, comprising the further step of storing said health parameter data received from said sensor band in a buffer of said transceiver at least during times when said second communications link is disconnected, lost, or unreliable.

76. A method as in claim 62, comprising the further step of accessing said health parameter data stored in said database for medical diagnosis or analysis.

77. A method as in claim 76, wherein said step of accessing said health parameter data comprises the step of using the remote monitoring station to select a subject for review of at least that subject'"'"'s health parameter data.

78. A method as in claim 77, wherein said step of accessing said health parameter data comprises the step of simultaneously reviewing and comparing time synchronized health parameter data for a plurality of health parameters for the selected subject.

79. A method as in claim 76, wherein said step of accessing said health parameter data step comprises the step of permitting the user to select at least one of unprocessed health parameter data and summary data for display.

67. A method of collecting health parameter data, comprising the steps of:

applying a sensor band having a sensor assembly to a subject whereby said sensor assembly produces a data signal including health parameter data indicative of values of at least one health parameter of the subject;

said sensor band transmitting said data signal over a first communications link to a transceiver which is disposed so as to receive said health parameter data;

said transceiver retransmitting said data signal over a second, wireless communications link to a base station unit;

said base station unit storing said health parameter data until a designated time for transmission of said health parameter data to a remote monitoring station; and

said remote monitoring station receiving said retransmitted data signal from said base station unit via a third communications link and capturing said health parameter data for storage in a database as a continuous record of the subject'"'"'s health parameters.

68. A method as in claim 67, wherein said sensor band applying step comprises the step of attaching said sensor band to a chest of the subject whereby said sensor assembly produces health parameter data indicative of at least one of ECG, respiration, skin temperature, and subject motion.

69. A method as in claim 67, wherein said sensor band transmitting step comprises the step of multiplexing health parameter data signals from at least two different sensors in said sensor assembly for transmission over said first communications link.

70. A method as in claim 67, wherein said retransmitting step comprises the step of transmitting said data signal over a cellular communications link to said remote monitoring station.

80. A method as in claim 67, comprising the further step of generating case record forms from at least the health parameter data stored for a subject in said database.

81. A method as in claim 67, comprising the further step of receiving at said transceiver health parameter data transmitted by at least two sensor bands for retransmission to said remote monitoring station.

82. A method as in claim 67, comprising the further steps of determining whether the subject moved during a measurement of said health parameter data and deleting or ignoring health parameter data collected during a time the subject moved if such movement may have corrupted the health parameter data.

83. A method as in claim 82, wherein corruption of the health parameter data is determined by comparing motion data to at least one of an ECG waveform and a respiration waveform.

84. A method of collecting health parameter data, comprising the steps of:

applying a sensor band having a sensor assembly to a subject whereby said sensor assembly produces a data signal including health parameter data indicative of values of at least one health parameter of the subject;

said sensor band transmitting said data signal over a first communications link to a transceiver which is disposed so as to receive said health parameter data;

said transceiver retransmitting said data signal over a second, wireless communications link unless said second communications link becomes disconnected, lost, or becomes unreliable;

said transceiver storing health parameter data received from said sensor band at least during times when said second communications link is disconnected, lost, or unreliable and retransmitting said data signal over said second communications link from said transceiver at an increased transmission rate after said second communications link is restored as compared to a transmission rate before said second communications link is disconnected, lost, or becomes unreliable; and

a remote monitoring station receiving said retransmitted data signal from said transceiver and capturing said health parameter data for storage in a database as a continuous record of the subject'"'"'s health parameters.

85. A method as in claim 84, comprising the additional step of warning the subject that said second communications link has been disconnected, lost, or has become unreliable so that the subject may take steps to restore said second communications link.

86. A method of remotely collecting health parameter data continuously for at least a day, comprising the steps of:

applying a sensor band having a sensor assembly to a subject whereby said sensor assembly produces a data signal including health parameter data indicative of values of at least one health parameter of the subject;

said sensor band transmitting said data signal over a first communications link to a transceiver which is disposed so as to receive said health parameter data;

said transceiver retransmitting said data signal over a second, wireless communications link;

a remote monitoring station receiving said retransmitted data signal from said transceiver and capturing said health parameter data for storage in a database as a continuous record of the subject'"'"'s health parameters; and

temporarily buffering said health parameter data so as to prevent data loss in the event of transmission error over said first or second communications links.

87. A method as in claim 86, comprising the further step of providing real-time access to said health parameter data from said remote monitoring station to said transceiver by bypassing said buffering step when real-time data is requested by said remote monitoring station.

88. A method of continuously monitoring a subject'"'"'s health parameters during a drug/therapy trial, comprising the steps of:

applying a sensor band having a sensor assembly to a subject whereby said sensor assembly produces a data signal including health parameter data indicative of values of at least one health parameter of the subject;

said sensor band transmitting said data signal over a first communications link to a transceiver which is disposed so as to receive said health parameter data;

providing a drug/therapy to the subject and electronically providing event data indicating that such an event has occurred and when;

said transceiver retransmitting said data signal and event data over a second, wireless communications link; and

a remote monitoring station receiving said retransmitted data signal and event data from said transceiver and capturing said health parameter data and event data for storage in a database as a continuous record of the subject'"'"'s health parameters during a trial period of said drug/therapy, whereby said subject'"'"'s physiological condition during said trial period may be monitored remotely.

89. A method a s in claim 88, comprising the further step of electronically providing event data marking (1) that the subject feels ill and (2) when the subject feels ill.

90. A method as in claim 89, comprising the further step of collecting vital signs data at times before, during, and after the timing of an event marked by said event data and providing a display of any changes in said health parameter data as a result of said drug/therapy or of the subject feeling ill.