Abstract: Examples described herein include defibrillators or other medical equipment that may employ hidden Markov models to classify cardiac rhythms in ECG signals. Hidden Markov models may additionally or instead be used to determine presence of a chest compression from the thoracic impedance signal. Classification of cardiac rhythms may be used to determine when to deliver a shock to a patient. Other applications are also described.

Abstract: Examples of systems, apparatuses, and methods for classification of electrocardiogram signals during cardiopulmonary resuscitation are described. An example system may include a defibrillator comprising an electrocardiogram analyzer. The electrocardiogram analyzer may be configured to apply a prediction modeling technique to an electrocardiogram signal to generate a predicted signal. The electrocardiogram signal may be captured from a patient undergoing cardiopulmonary resuscitation. The electrocardiogram analyzer may be further configured to subtract the predicted signal from the electrocardiogram signal to generate an error signal and to classify a rhythm of the electrocardiogram signal as one of a shockable rhythm or non-shockable based on the error signal. Decision parameters derived from the signals may be used in conjunction with a machine learning technique to classify the electrocardiogram signal.

Abstract: The present technology describes various embodiments of systems and methods for analyzing electrocardiograms to detect ventricular fibrillation. In several embodiments, systems for detecting ventricular fibrillation can be implemented without interrupting cardiopulmonary resuscitation. In one embodiment, a method of identifying a cardiac rhythm in a person includes recording an electrocardiogram signal of the person and stratifying the signal. A signal having a parameter value within a pre-determined range is categorized as a shockable ventricular fibrillation signal while a signal having a parameter value outside the pre-determined range is categorized as a non-shockable signal.