Apparatus for monitoring a cardiac rhythm during cpr
AssigneeKoninklijke Philips N.V.
InventorsSTACY EARL GEHMAN, JAMES KNOX RUSSELL, CHRISTOPHER WILLIAM FLEMING, DAWN BLILIE JORGENSON, DAVID ROY AXNESS
Life of this patent
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Abstract
A defibrillator and method for using a defibrillator which adopts an ECG analysis algorithm that can detect a cardiac arrhythmia in the presence of noise artifact induced by cardio pulmonary resuscitation (CPR) compressions. The apparatus and method offers guidance throughout a cardiac rescue protocol involving both defibrillation shocks and CPR that improves the effectiveness of the rescue, resulting in more CPR “hands-on” time, better treatment of refibrillation, and reduced transition times between CPR and electrotherapy.
Claims12
An automated external defibrillator (AED) for use during cardiopulmonary resuscitation (CPR) comprising:
- an input of an ECG signal;
- a user interface having at least one of an aural instruction output and a visual display;
- an ECG analyzer in communication with the input and operable to determine a shockable cardiac rhythm in the presence of CPR-related signal noise artifact from the input;
- a memory for storing instructions related to a CPR rescue protocol that includes a period for providing CPR compressions;
- and
- a processor in communication with the ECG analyzer and the user interface, the processor operable to issue instructions via the user interface responsive to the determined shockable cardiac rhythm,
- wherein the ECG analyzer is operable to determine the shockable cardiac rhythm in the presence of CPR-related signal noise artifact from the input with a sensitivity of greater than about 70% and a specificity of greater than about 95%,
- wherein the input comprises a stream of digitized ECG signal data, and further wherein the ECG analyzer segments the ECG signal data corresponding to a predetermined time segment,
- wherein the ECG analyzer further comprises a set of fixed-frequency band pass filters which operate to filter the CPR-related signal noise artifact from the ECG signal data,
- wherein the ECG analyzer further comprises an algorithm which determines the shockable cardiac rhythm from both a measure of a filtered ECG signal data centered on one frequency at about 25 Hz and of a second filtered ECG signal data centered on a second frequency of about 35 Hz, and
- wherein the ECG analyzer further determines that the cardiac rhythm is shockable if both the filtered ECG signal data and the second filtered ECG signal data are below respective predetermined thresholds.
-8. (canceled)
A method for controlling an electrotherapy output from a defibrillator during the application of CPR, comprising the steps of:
- receiving an ECG signal data stream from two or more external electrodes in electrical contact with a patient, the ECG signal data comprising a cardiac signal characterized by corruption from a CPR compressions noise artifact;
- filtering the stream of ECG signal data through a set of frequency band pass filters disposed to separate the cardiac signal from the CPR compressions noise signal;
- obtaining a stream of signal data corresponding to a predetermined time segment;
- analyzing the separated cardiac signal to determine whether a shockable cardiac rhythm exists with a sensitivity of greater than about 70% and a specificity of greater than about 95%;
- deciding that a shock is to be delivered by an electrotherapy delivery circuit based on the analyzing step;
- arming an electrotherapy delivery circuit responsive to the deciding step;
- and
- automatically issuing a user prompt to stop CPR and to deliver the electrotherapy at the completion of the arming step.
Dependencies are inferred from the claim text.