Determining initial treatments from spectral data

• US 10,039,925 B2
• Filed: 06/10/2015
• Issued: 08/07/2018
• Est. Priority Date: 06/10/2014
• Status: Active Grant

• Current Assignee: Zoll Medical Corporation (Asahi Kasei Corporation)
• Original Assignee: Zoll Medical Corporation (Asahi Kasei Corporation)
• Inventors: Quan, Weilun, Kaufman, Christopher Luke, Freeman, Gary A.
• Primary Examiner(s): Layno, Carl H
• Assistant Examiner(s): Piateski, Erin M
• Application Number:
  US14/736,079
• Publication Number:
  US 20150352367A1
• Time in Patent Office: 1,154 Days
• Field of Search: 600 59
• CPC Class Codes: A61B 5/316 Modalities, i.e. specific diagnostic methods
• CPC Class Codes: A61B 5/347 Detecting the frequency distribution of signals
• CPC Class Codes: A61B 5/7253 characterised by using transforms
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61B 5/726 using Wavelet transforms
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61H 2201/501 connected to external computer devices or networks
• CPC Class Codes: A61H 2201/5015 using specific interfaces or standards, e.g. USB, serial, parallel
• CPC Class Codes: A61H 2201/5043 Displays
• CPC Class Codes: A61H 2201/5046 Touch screens
• CPC Class Codes: A61H 2201/5058 Sensors or detectors
• CPC Class Codes: A61H 2201/5084 Acceleration sensors
• CPC Class Codes: A61H 2201/5097 wireless
• CPC Class Codes: A61H 2230/105 used as a control parameter for the apparatus
• CPC Class Codes: A61H 31/004 Heart stimulation
• CPC Class Codes: A61H 31/005 with feedback for the user
• CPC Class Codes: A61H 31/006 Power driven
• CPC Class Codes: A61H 31/007 Manual driven
• CPC Class Codes: A61N 1/3925 Monitoring; Protecting
• CPC Class Codes: A61N 1/3987 characterised by the timing or triggering of the shock
• CPC Class Codes: A61N 1/3993 : User interfaces for automatic external defibrillators
• CPC Class Codes: G16H 50/30 : for calculating health indices; for individual health risk assessment

Abstract

This document presents a system for managing treatment for an emergency cardiac event. The system includes memory, one or more electronic ports for receiving ECG signals, and a treatment module executable on one or more processing devices. The module is configured to generate transform values for a time segment of ECG, obtain one or more previous values derived from one or more earlier time segments of the ECG, and determine, based on the generated transform values, and the one or more previous values, at least one of: a) a future therapeutic action for treating the emergency cardiac event, or b) a phase of the cardiac event. The module is further configured to cause one or more output devices to present an indication of at least one of the therapeutic action or the phase of the cardiac event.

Claims

1. A system for managing treatment for an emergency cardiac event, the system comprising:

a memory;

one or more electronic ports for receiving signals from sensors for obtaining a time domain electrocardiogram (ECG) of a patient;

a patient treatment module executable on one or more processing devices, the patient treatment module being configured to;

receive signals representing the time domain ECG of the patient from the one or more electronic ports,

generate a first frequency domain transform value from a first time segment of the time domain ECG,

generate a second frequency domain transform value from a second time segment of the time domain ECG, wherein the first time segment occurs prior to the second time segment,

calculate a change between the second frequency domain transform value and the first frequency domain transform value,

selectively determine a suggested treatment for the patient based on a magnitude of the change between the second frequency domain transform value and the first frequency domain transform value relative to a threshold, and

cause one or more output devices to present an indication of the suggested treatment for the patient; and

a patient treatment device configured to selectively deliver a defibrillating shock to the patient based on the indication.

2. The system of claim 1, wherein the patient treatment module comprises an ECG analyzer for generating an amplitude spectrum area (AMSA) value using the transform values.

3. The system of claim 1, wherein at least one of the first frequency domain transform value derived from the first time segment of the time domain ECG and the second frequency domain transform value derived from the second time segment of the time domain ECG is an AMSA value.

4. The system of claim 1, wherein at least one of the first frequency domain transform value and the second frequency domain transform value is updated at a rate of 0.1-10 Hz.

5. The system of claim 1, wherein the length of at least one of the first time segment and the second time segment is in the range between about 1 and 4 seconds.

6. The system of claim 1, wherein the patient treatment module is configured to generate at least one of the first frequency domain transform value for the first time segment of ECG and the second frequency domain value for the second time segment of ECG using a tapered window.

7. The system of claim 6, wherein the tapered window is one of:

a Tukey window, a Hann window, a Blackman-Harris window, or a Flat Top window.

8. The system of claim 1, wherein the suggested treatment is determined based at least in part on comparing a value obtained from the generated frequency domain transform values to a threshold.

9. The system of claim 1, wherein the transform comprises at least one of:

Fourier, fast Fourier, discrete Fourier, Hilbert, discrete Hilbert, wavelet, and discrete wavelet methods.

10. The system of claim 1, wherein determining the suggested treatment for the patient comprises computing an average based on at least one of the first frequency domain transform value and the second frequency domain transform value.

11. The system of claim 10, wherein the average is also based on a value obtained from the time domain ECG.

12. The system of claim 1, wherein at least one of the first frequency domain transform value and the second frequency domain transform value is generated via processing of multiple earlier time segments of the ECG.

13. The system of claim 12, wherein the processing is performed two or more times during the cardiac event.

14. The system of claim 1, wherein the output device is configured to present an audible or visual feedback of at least one of the indication of the suggested treatment for the patient.

15. The system of claim 1, wherein the suggested treatment for the patient comprises delivering the defibrillating shock to the patient.

16. The system of claim 1, wherein the suggested treatment for the patient comprises initiating or continuing cardiopulmonary resuscitation (CPR).

17. The system of claim 1, wherein the suggested treatment for the patient comprises adjusting a cardiopulmonary resuscitation (CPR) technique.

18. The system of claim 1, wherein the output device is configured to present a visual or audible feedback based on the first frequency domain transform value and the second frequency domain transform value.

19. The system of claim 18, wherein the feedback comprises an indication of a likelihood of success from delivering the defibrillating shock.

20. The system of claim 1, wherein the suggested treatment for the patient is generated based on one or more additional parameters.

21. The system of claim 20, wherein the one or more additional parameters comprise at least one of:

trans-thoracic impedance (TTI), levels of prior successful defibrillations, and a trend in AMSA values over time.

22. A system for treating a patient in cardiac arrest, the system comprising:

a memory;

one or more electronic ports for receiving signals from sensors for obtaining a time domain electrocardiogram (ECG) of a patient;

a patient treatment module executable on one or more processing devices, the patient treatment module being configured to;

receive signals representing the time domain ECG of the patient from the one or more electronic ports,

generate frequency domain transforms that represent magnitudes of two or more frequency components of the time domain ECG,

generate a time series from a plurality of the frequency domain transforms,

selectively determine, based on a magnitude of a change of the time series relative to a threshold, a suggested treatment for treating the cardiac arrest, and

cause one or more output devices to present an indication of the suggested treatment for the patient; and

a patient treatment device configured to selectively deliver a defibrillating shock to the patient based on the indication.

23. The system of claim 22, wherein the suggested treatment comprises delivering the defibrillating shock to the patient.

24. The system of claim 22, wherein the suggested treatment comprises continuing CPR.

25. The system of claim 22, wherein the suggested treatment comprises adjusting a CPR technique.

26. The system of claim 22, wherein the frequency domain transforms comprise amplitude spectrum area (AMSA) values.

27. The system of claim 22, wherein the suggested treatment is determined based on determining a trending of the frequency domain transforms in the time series.

28. The system of claim 22, wherein the frequency domain transforms comprise normalized transform values.

29. The system of claim 22, wherein the frequency domain transforms comprise a Fast Fourier Transform.

30. The system of claim 22, wherein the frequency domain transforms comprise one or more of:

Fourier, discrete Fourier, Hilbert, discrete Hilbert, wavelet, and discrete wavelet methods.

31. The system of claim 22, wherein the frequency domain transforms are a transform that uses zero crossing analysis.

32. One or more machine-readable storage devices having encoded thereon machine readable instructions for causing one or more processors to perform operations comprising:

receiving, a time domain electrocardiogram (ECG) of a patient;

generating frequency domain transforms from a first time segment of the time domain ECG;

generating a second frequency domain transform value from a second time segment of the time domain ECG, wherein the first time segment occurs prior to the second time segment;

calculating a change between the second frequency domain transform value and the first frequency domain transform value;

selectively determining a suggested treatment for the patient based on a magnitude of the change between the second frequency domain transform value and the first frequency domain transform value relative to a threshold;

causing one or more output devices to present an indication of the suggested treatment and

causing a patient treatment device to selectively deliver a defibrillating shock to the patient based on the indication.

33. The one or more machine readable storage devices of claim 32, further comprising instructions for generating an amplitude spectrum area (AMSA) value using the frequency domain transforms.

34. The one or more machine readable storage devices of claim 32, wherein the previous values derived from one or more earlier time segments of the ECG are AMSA values.

35. The one or more machine readable storage devices of claim 32, wherein the frequency domain transforms are updated at a rate of 0.1-10 Hz.

36. The one or more machine readable storage devices of claim 32, wherein the length of the time segment is in the range between about 1 and 4 seconds.

37. The one or more machine readable storage devices of claim 32, wherein the frequency domain transforms for the time segment of ECG are generated using a tapered window.

38. The one or more machine readable storage devices of claim 37, wherein the tapered window is one of:

a Tukey window, a Hann window, a Blackman-Harris window, or a Flat Top window.

39. The one or more machine readable storage devices of claim 32, wherein the is determined based at least in part on comparing a value obtained from the generated frequency domain transforms to a threshold.

40. The one or more machine readable storage devices of claim 32, wherein the transform comprises at least one of:

Fourier, fast Fourier, discrete Fourier, Hilbert, discrete Hilbert, wavelet, and discrete wavelet methods.

41. The one or more machine readable storage devices of claim 32, wherein determining the suggested treatment comprises computing an average based on the one or more previous values.

42. The one or more machine readable storage devices of claim 41, wherein the average is also based on a value obtained from the generated frequency domain transforms.

43. The one or more machine readable storage devices of claim 32, wherein the one or more previous values are generated via processing of multiple earlier time segments of the ECG.

44. The one or more machine readable storage devices of claim 32, wherein the suggested treatment comprises at least one of:

delivering the defibrillating shock to the patient, initiating or continuing cardiopulmonary resuscitation (CPR), and adjusting a CPR technique.

45. The one or more machine readable storage devices of claim 32, wherein the phase is one of:

an electrical phase, a circulatory phase, or a metabolic phase.

46. The one or more machine readable storage devices of claim 32, wherein the one or more output devices presents a visual or audible feedback based on the generated frequency domain transforms and the previous values.

47. The one or more machine readable storage devices of claim 46, wherein the feedback comprises an indication of a likelihood of success from delivering the defibrillating shock.

48. The one or more machine readable storage devices of claim 32, wherein the suggested treatment or the phase of the cardiac event is generated based on one or more additional parameters that includes at least one of:

trans-thoracic impedance (TTI), levels of prior successful defibrillations, and a trend in AMSA values over time.

49. One or more machine-readable storage devices having encoded thereon machine-readable instructions for causing one or more processors to perform operations comprising:

receiving signals representing a time domain electrocardiogram (ECG) of a patient;

generating a first frequency domain transform;

generating a second frequency domain transform value from a second time segment of the time domain ECG, wherein the first time segment occurs prior to the second time segment;

generating a time series from a plurality of the first frequency domain transform value and the second frequency domain transform value;

selectively determining, based on a magnitude of a change of the time series relative to a threshold, a suggested treatment for treating a cardiac arrest of the patient; and

causing a patient treatment device to selectively deliver a defibrillating shock to the patient based on the indication.

50. The one or more machine-readable storage devices of claim 49, wherein the suggested treatment comprises at least one of:

delivering the defibrillating shock to the patient, continuing cardiopulmonary resuscitation (CPR), and adjusting a CPR technique.

51. The one or more machine-readable storage devices of claim 49, wherein the frequency domain transform values comprise amplitude spectrum area (AMSA) values.

52. The one or more machine-readable storage devices of claim 49, wherein the suggested treatment is determined based on determining a trending of the frequency domain transform values in the time series.

53. The one or more machine-readable storage devices of claim 49, wherein the frequency domain transform values comprise normalized transform values.

54. The one or more machine-readable storage devices of claim 49, wherein the frequency domain transform values are generated using a transform that comprises at least one of:

Fourier, fast Fourier, discrete Fourier, Hilbert, discrete Hilbert, wavelet, and discrete wavelet methods.

55. The one or more machine-readable storage devices of claim 49, wherein the frequency domain transform values are generated using a transform that uses zero crossing analysis.