External defibrillator with automatic self-testing prior to use

• US 5,879,374 A
• Filed: 05/10/1994
• Issued: 03/09/1999
• Est. Priority Date: 05/18/1993
• Status: Expired due to Term

• Current Assignee: Philips Electronics North America Corporation (Koninklijke Philips N.V.)
• Original Assignee: Heartstream, Inc. (HP Inc.)
• Inventors: Cameron, David, Mydynski, Steven T., Cole, Clinton S., Powers, Daniel J., Morgan, Carlton B., Lyster, Thomas D.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US08/240,272
• Time in Patent Office: 1,764 Days
• Field of Search: 607/4, 607/5, 607/3, 607/6-8, 324/403, 324/415, 324/500, 324/512, 324/519, 324/523, 324/525, 324/527, 330/2
• US Class Current: 607/5
• CPC Class Codes: A61N 1/046 Specially adapted for shock therapy, e.g. defibrillation
• CPC Class Codes: A61N 1/048 Electrodes characterised by a specific connection between lead and electrode
• CPC Class Codes: A61N 1/0492 Patch electrodes A61N1/0412, A61N1/0428 take precedence
• CPC Class Codes: A61N 1/3925 Monitoring; Protecting
• CPC Class Codes: A61N 1/3931 Protecting, e.g. back-up systems

Abstract

A defibrillator with an automatic self-test system that includes a test signal generator and a defibrillator status indicator. The test system preferably performs functional tests and calibration verification tests automatically in response to test signals generated periodically and/or in response to predetermined conditions or events and indicates the test results visually and audibly. The invention also relates to a method for automatically determining and indicating a defibrillator'"'"'s status without human intervention.

Claims

1. An external defibrillator comprising:

a high voltage delivery system comprising an energy source, an electrode interface and a switch connecting the energy source to the electrode interface;

a controller operably connected to the high voltage delivery system; and

a self-test system comprising a defibrillator status indicator, a test signal generator, and means for operating the defibrillator status indicator and the test signal generator prior to any attempted use of the defibrillator.

2. The defibrillator of claim 1 wherein the self-test system further comprises a functionality tester and communication channels between the functionality tester and the test signal generator and between the functionality tester and the status indicator.

3. The defibrillator of claim 2 wherein the self-test system further comprises a communication channel between the functionality tester and the switch.

4. The defibrillator of claim 2 wherein the self-test system further comprising a communication channel between the functionality tester and the controller.

5. The defibrillator of claim 2 wherein the self-test system further comprises a relay having an operational position and a test position, the self-test system further comprising a communication channel between the functionality tester and the relay.

6. The defibrillator of claim 1 wherein the self-test system further comprises a calibration verifier and communication channels between the calibration verifier and the test signal generator and between the calibration verifier and the status indicator.

7. The defibrillator of claim 6 further comprising an overcurrent detector, the self-test system further comprising a communication channel between the calibration verifier and the overcurrent detector.

8. The defibrillator of claim 6 further comprising an undercurrent detector, the self-test system further comprising a communication channel between the calibration verifier and the undercurrent detector.

9. The defibrillator of claim 6 further comprising an overvoltage detector, the self-test system further comprising a communication channel between the calibration verifier and the overvoltage detector.

10. The defibrillator of claim 6 further comprising an ECG front end, the self-test system further comprising a communication channel between the calibration verifier and the ECG front end.

11. The defibrillator of claim 6 wherein the high voltage delivery system comprises a resistor, the self-test system further comprising a communication channel between the calibration verifier and the resistor.

12. The defibrillator of claim 11 wherein the controller comprises means for using the high voltage delivery system resistor as a reference standard for the defibrillator.

13. The defibrillator of claim 11 further comprising a second resistor in communication with the controller, wherein the controller comprises means for using the high voltage delivery system resistor and the second resistor together as reference standards for the defibrillator.

14. The defibrillator of claim 6 wherein the high voltage delivery system comprises a capacitor, the self-test system further comprising a communication channel between the calibration verifier and the capacitor.

15. The defibrillator of claim 6 wherein the controller comprises a clock, the self-test system further comprising a communication channel between the calibration verifier and the clock.

16. The defibrillator of claim 15 wherein the controller comprises means for using the controller clock as a reference standard for the defibrillator.

17. The defibrillator of claim 16 further comprising a second clock in communication with the controller, wherein the controller comprises means for using the controller clock and the second clock together as reference standards for the defibrillator.

18. The defibrillator of claim 6 further comprising a reference voltage source, the self-test system further comprising a communication channel between the calibration verifier and the voltage source.

19. The defibrillator of claim 18 wherein the controller comprises means for using the reference voltage source as a reference standard for the defibrillator.

20. The defibrillator of claim 19 further comprising a second voltage source in communication with the controller, wherein the controller comprises means for using the first and second voltage sources together as reference standards for the defibrillator.

21. The defibrillator of claim 1 further comprising a battery, the self-test system further comprising a battery condition tester and communication channels between the battery condition tester and the battery, between the battery condition tester and the status indicator, and between the battery condition tester and the test signal generator.

22. The defibrillator of claim 1 wherein the test signal generator comprises a system monitor.

23. The defibrillator of claim 22 wherein the system monitor comprises an application specific integrated circuit.

24. The defibrillator of claim 22 further comprising a controller power supply, wherein the system monitor comprises a system monitor power supply separate from the controller power supply.

25. The defibrillator of claim 22 wherein the system monitor further comprises means for generating periodic test signals.

26. The defibrillator of claim 22 wherein the system monitor further comprises means for generating test signals in response to specified events or conditions.

27. The defibrillator of claim 26 further comprising means for receiving a removable battery and for connecting a battery to the high voltage delivery system, in which the event or condition is the insertion of a battery into the defibrillator.

28. The defibrillator of claim 22 in which the event or condition is environmental.

29. The defibrillator of claim 28 in which the environmental event or condition is temperature.

30. The defibrillator of claim 28 in which the environmental event or condition is moisture.

31. The defibrillator of claim 28 in which the environmental event or condition is mechanical shock.

32. The defibrillator of claim 28 which the environmental event or condition is vibration.

33. The defibrillator of claim 22 wherein the system monitor comprises a watchdog timer.

34. The defibrillator of claim 1 wherein the status indicator comprises a sound generator.

35. The defibrillator of claim 1 further comprising memory and a communication channel between the self-test system and the memory.

36. The defibrillator of claim 1 wherein the status indicator comprises a visual display.

37. The defibrillator of claim 36 in which the visual display comprises means for providing fail-safe operation.

38. A defibrillator comprising:

a high voltage delivery system comprising an energy source and a switch connecting the energy source to the exterior of the defibrillator;

a controller operably connected to the high voltage delivery system; and

a self-test system comprising a defibrillator status indicator, a test signal generator, and a recalibrator.

39. The defibrillator of claim 38 further comprising a current sensor, the self-test system further comprising a communication channel between the recalibrator and the current sensor.

40. The defibrillator of claim 38 further comprising a waveform shape controller, the self-test system further comprising a communication channel between the recalibrator and the waveform shape controller.

41. An external defibrillator comprising:

a high voltage delivery system comprising an energy source, an electrode interface and a switch connecting the energy source to the electrode interface;

a controller operably connected to the high voltage delivery system; and

a self-test system comprising a defibrillator status indicator, a periodic test signal generator, and means for operating the defibrillator status indicator and the periodic test signal generator prior to any attempted use of the defibrillator.

42. A method for automatically determining and indicating an operational status of an external defibrillator, the method comprising the following steps:

generating a test signal within the external defibrillator automatically and periodically;

performing a self-test in response to the test signal; and

indicating the operational status of the defibrillator based on a result of the self-test;

the generating, performing and indicating steps being performed prior to any attempted use of the defibrillator.

43. An external defibrillator comprising:

a high-voltage delivery system; and

a self-test system, the self-test system comprising a test signal generator and a fail-safe visual display.

44. A method for automatically determining and indicating an operational status of an external defibrillator, the method comprising the following steps:

generating a test signal within the external defibrillator automatically in response to a predetermined event or condition;

performing a self-test in response to the test signal; and

indicating the operational status of the defibrillator based on a result of the self-test;

the generating, performing and indicating steps being performed prior to any attempted use of the defibrillator.

45. The method of claim 44 wherein the step of generating a test signal within the defibrillator automatically in response to a predetermined event or condition comprises generating a test signal within the defibrillator automatically in response to insertion of a battery into the defibrillator.

46. The defibrillator of claim 44 in which the step of generating a test signal within the defibrillator automatically in response to a predetermined event or condition comprises generating a test signal within the defibrillator automatically in response to an environmental event or condition.

47. The method of claim 46 in which the step of generating a test signal within the defibrillator automatically in response to an environmental event or condition comprises generating a test signal within the defibrillator automatically in response to temperature.

48. The method of claim 46 in which the step of generating a test signal within the defibrillator automatically in response to an environmental event or condition comprises generating a test signal within the defibrillator automatically in response to moisture.

49. The method of claim 46 in which the step of generating a test signal within the defibrillator automatically in response to an environmental event or condition comprises generating a test signal within the defibrillator automatically in response to mechanical shock.

50. The method of claim 46 in which the step of generating a test signal within the defibrillator automatically in response to an environmental event or condition comprises generating a test signal within the defibrillator automatically in response to vibration.

51. The method of claim 44 wherein the step of performing a self-test comprises determining functionality of a defibrillator component or system.

52. The method of claim 44 wherein the step of performing a self-test comprises verifying calibration of a defibrillator component or system.

53. The method of claim 52 wherein the step of performing a self-test comprises performing a calibration verification self-test, the method further comprising the step of recalibrating a defibrillator component or system in response to the calibration verification self-test.

54. The method of claim 52 wherein the step of performing a self-test comprises discharging a capacitor and measuring electrical and time values associated with the capacitor'"'"'s discharge.

55. The method of claim 52 wherein the step of performing a self-test comprises using a resistance within the defibrillator as a reference value.

56. The method of claim 52 wherein the step of performing a self-test comprises using two resistances within the defibrillator as reference values through a comparison of two resistance values.

57. The method of claim 52 wherein the step of performing a self-test comprises using a voltage source within the defibrillator as a reference value.

58. The method of claim 52 wherein the step of performing a self-test comprises using two voltage sources within the defibrillator as reference values through a comparison of two voltage source values.

59. The method of claim 52 wherein the step of performing a self-test comprises using a clock within the defibrillator as a reference value.

60. The method of claim 52 wherein the step of performing a self-test comprises using two clocks within the defibrillator as reference values through a comparison of two clocks.

61. The method of claim 44 wherein the indicating step comprises displaying status information on a visual display.

62. The method of claim 61 wherein the displaying step comprises providing an active display signal to the visual display, the visual display having a first state when provided with the active display signal and a second state when not provided with the active display signal, the second state indicating a nonoperational state of the defibrillator.

63. The method of claim 62 wherein the step of providing an active display signal comprises providing an AC signal.

64. The method of claim 44 wherein the indicating step comprises providing audible status information.

65. The method of claim 44 wherein the step of generating a test signal within the defibrillator automatically in response to a predetermined event or condition comprises generating a test signal within the defibrillator automatically in response to the passage of time.

66. The method of claim 44 wherein the step of performing a self-test comprises recalibrating a defibrillator component or system.

67. A method for testing and indicating an operational status of an external defibrillator comprising the following steps:

generating a test signal within the external defibrillator automatically and periodically;

performing a plurality of self-tests in response to the test signal to determine the operational status of a plurality of components of the defibrillator, the tests being performed without human intervention prior to any attempted use of the defibrillator; and

indicating the operational status of the defibrillator in response to at least one of the self-tests.

68. The method of claim 67 wherein the generating step comprises generating a test signal within the defibrillator automatically on a predetermined schedule.

69. The method of claim 67 further comprising the step of generating a test signal within the defibrillator automatically in response to a predetermined event.

70. The method of claim 69 further comprising the step of generating a test signal within the defibrillator automatically in response to an environmental condition or event.

71. The method of claim 67 wherein the step of performing a plurality of self-tests comprises determining functionality of a defibrillator component or system.

72. The method of claim 71 wherein the step of performing a plurality of self-tests comprises verifying calibration of a defibrillator component or system.

73. The method of claim 72 further comprising the step of automatically recalibrating a defibrillator component or system in response to a self-test.