Mixed-segment electrocardiogram analysis in coordination with cardiopulmonary resuscitation for efficient defibrillation electrotherapy

41:

• An external defibrillator comprising:
• therapy delivery circuitry configured to discharge electrotherapy to a patient;
• at least one chest compression sensor configured to acquire motion signals during and after administration of cardiopulmonary resuscitation (CPR) to the patient;
• at least one electrocardiogram (ECG) sensor configured to acquire ECG signals from the patient;
• and
• at least one processor coupled to the therapy delivery circuitry, the at least one chest compression sensor, and the at least one ECG sensor and configured to:
• generate first ECG data from ECG signals acquired during a cycle of CPR,
• generate second ECG data from ECG signals acquired after the cycle of CPR,
• determine shock/no-shock guidance based on the first ECG data,
• confirm the shock/no-shock guidance based on the second ECG data, to confirm comprising to
• determine at least one impedance measurement based on an impedance detection signal acquired after the cycle of CPR and/or determine at least one acceleration measurement based on a motion signal acquired after the cycle of CPR, and
• determine, based on the at least one impedance measurement and/or the at least one acceleration measurement, whether the second ECG data comprises noise sufficient to prevent confirmation, and
• control the therapy delivery circuitry to discharge the electrotherapy where the shock/no-shock guidance is confirmed to specify electrotherapy.

42:

• The external defibrillator of claim 41, wherein the at least one impedance measurement comprises a plurality of impedance measurements, the at least one acceleration measurement comprises a plurality of acceleration measurements, and to determine whether the second ECG data comprises noise sufficient to prevent confirmation comprises to:
• derive at least one standard deviation measurement for the plurality of impedance measurements and/or the plurality of acceleration measurements;
• compare the at least one standard deviation measurement to at least one threshold standard deviation value;
• and
• determine that the second ECG data comprises noise sufficient to prevent confirmation where the at least one standard deviation measurement transgresses the at least one threshold standard deviation value and an amplitude specified in the second ECG data transgresses a threshold amplitude value.

43:

• The external defibrillator of claim 41, wherein the at least one impedance measurement comprises a plurality of impedance measurements and/or the at least one acceleration measurement comprises a plurality of acceleration measurements, and to determine whether the second ECG data comprises noise sufficient to prevent confirmation comprises to:
• derive at least one standard deviation measurement for the plurality of impedance measurements and/or the plurality of acceleration measurements;
• compare the at least one standard deviation measurement to at least one threshold standard deviation value;
• determine that the at least one standard deviation measurement transgresses the at least one threshold standard deviation value;
• determine whether an amplitude specified within the second ECG data transgresses a threshold amplitude value;
• and
• determine that the second ECG data comprises noise sufficient to prevent confirmation where the at least one standard deviation measurement transgresses the at least one threshold standard deviation value and the amplitude transgresses the threshold amplitude value.

44:

• The external defibrillator of claim 41, wherein to determine whether the second ECG data comprises noise sufficient to prevent confirmation comprises to:
• determine whether the second ECG data indicates saturation;
• and
• determine that the second ECG data comprises noise sufficient to prevent confirmation where the second ECG data indicates saturation.

45:

• The external defibrillator of claim 44, wherein the at least one impedance measurement comprises a plurality of impedance measurements, the at least one acceleration measurement comprises a plurality of acceleration measurements, and to determine whether the second ECG data comprises noise sufficient to prevent confirmation comprises to:
• determine that the second ECG data does not indicate saturation;
• derive at least one standard deviation measurement for the plurality of impedance measurements and/or the plurality of acceleration measurements;
• compare the at least one standard deviation measurement to at least one threshold standard deviation value;
• determine that the at least one standard deviation measurement transgresses the at least one threshold standard deviation value;
• determine whether an amplitude specified within the second ECG data transgresses a threshold amplitude value;
• and
• determine that the second ECG data comprises noise sufficient to prevent confirmation where the at least one standard deviation measurement transgresses the at least one threshold standard deviation value and the amplitude transgresses the threshold amplitude value.

46:

• The external defibrillator of claim 41, wherein to determine whether the second ECG data comprises noise sufficient to prevent confirmation comprises to:
• identify a plurality of temporally overlapping segments in the second ECG data;
• determine a plurality of impedance measurements based on the ECG signals acquired after the cycle of CPR and/or determine a plurality of acceleration measurements based on a motion signal acquired after the cycle of CPR;
• and
• determine, based on the at least one impedance measurement and/or the at least one acceleration measurement, whether at least one segment of the plurality of temporally overlapping segments comprises noise sufficient to prevent confirmation.

47:

• The external defibrillator of claim 46, wherein the at least one impedance measurement comprises a plurality of impedance measurements and/or the at least one acceleration measurement comprises a plurality of acceleration measurements, and to determine whether the at least one segment of the plurality of temporally overlapping segments comprises noise sufficient to prevent confirmation comprises to:
• derive at least one standard deviation measurement for the plurality of impedance measurements and/or the plurality of acceleration measurements;
• compare the at least one standard deviation measurement to at least one threshold standard deviation value;
• determine that the at least one standard deviation measurement transgresses the at least one threshold standard deviation value;
• determine whether an amplitude specified within the at least one segment of the plurality of temporally overlapping segments transgresses a threshold amplitude value;
• and
• determine that the at least one segment of the plurality of temporally overlapping segments comprises noise sufficient to prevent confirmation where the at least one standard deviation measurement transgresses the at least one threshold standard deviation value and the amplitude transgresses the threshold amplitude value.

48:

• The external defibrillator of claim 46, wherein to determine whether at least one segment of the plurality of temporally overlapping segments comprises noise sufficient to prevent confirmation comprises to:
• determine whether the at least one segment of the plurality of temporally overlapping segments indicates saturation;
• and
• determine that the at least one segment of the plurality of temporally overlapping segments comprises noise sufficient to prevent confirmation where the at least one segment of the plurality of temporally overlapping segments indicates saturation.

49:

• The external defibrillator of claim 48, wherein the at least one impedance measurement comprises a plurality of impedance measurements, the at least one acceleration measurement comprises a plurality of acceleration measurements, and to determine whether the at least one segment comprises noise sufficient to prevent confirmation comprises to:
• determine that the at least one segment of the plurality of temporally overlapping segments does not indicate saturation;
• derive at least one standard deviation measurement for the plurality of impedance measurements and/or the plurality of acceleration measurements;
• compare the at least one standard deviation measurement to at least one threshold standard deviation value;
• determine that the at least one standard deviation measurement transgresses the at least one threshold standard deviation value;
• determine whether an amplitude specified within the at least one segment transgresses a threshold amplitude value;
• and
• determine that the at least one segment of the plurality of temporally overlapping segments comprises noise sufficient to prevent confirmation where the at least one standard deviation measurement transgresses the at least one threshold standard deviation value and the amplitude transgresses the threshold amplitude value.

50:

• The external defibrillator of claim 41, wherein to determine the shock/no-shock guidance comprises to:
• identify a plurality of temporally overlapping segments in the first ECG data;
• and
• determine the shock/no-shock guidance based on the plurality of temporally overlapping segments in the first ECG data.

51:

• The external defibrillator of claim 50, wherein to determine the shock/no-shock guidance based on the plurality of temporally overlapping segments comprises to analyze each segment of the plurality of temporally overlapping segments to:
• derive at least one feature from the segment;
• determine whether the at least one feature meets at least one criterion of a plurality of criteria, each criterion of the plurality of criteria specifying one or more constraints on one or more features of one of the ECG signals acquired during the cycle of CPR;
• and
• increment at least one counter associated with the at least one criterion where the at least one feature meets the at least one criterion.

56:

• The external defibrillator of claim 41, wherein to confirm the shock/no-shock guidance comprises to:
• identify a plurality of temporally overlapping segments in the second ECG data;
• and
• confirm the shock/no-shock guidance based on the plurality of temporally overlapping segments in the second ECG data.

57:

• The external defibrillator of claim 56, wherein to confirm the shock/no-shock guidance based on the plurality of temporally overlapping segments comprises to analyze each segment of the plurality of temporally overlapping segments to:
• derive at least one feature from the segment;
• determine whether the at least one feature meets at least one criterion specifying one or more constraints on one or more features of one of the ECG signals acquired after the cycle of CPR;
• and
• confirm the shock/no-shock guidance where the at least one feature meets the at least one criterion.