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 determining whether CPR is being conducted based on an impedance signal are described. An example system may include a defibrillator including a cardiopulmonary resuscitation (CPR) analyzer configured to detect an impedance signal between electrodes applied to a chest of a patient. The CPR analyzer may be further configured to transform the impedance signal to a frequency domain representation to provide transformed frequency data, and to detect peaks within the transformed frequency data. The CPR analyzer may be further configured to classify the impedance signal as one of CPR or no CPR based on the detected peaks. The CPR analyzer may be further configured to determine a chest compression rate based on the detected peaks.

Abstract: The present technology is generally directed to schemas for using dynamic color and pattern backgrounds for electrocardiogram display and associated systems and methods. In a particular embodiment, a method of displaying an electrocardiogram rhythm can include receiving an electrocardiogram signal and applying an algorithm to the signal to determine a rhythm diagnosis or recommended therapy. The method can further include displaying a color and/or a pattern corresponding to the rhythm diagnosis or recommended therapy. In various embodiments, the method can be performed in real time or on a pre-recorded signal for post-event analysis.

Abstract: A defibrillation system for use in treatment of ventricular fibrillation includes at least one sensor to measure heart rhythm; at least one applicator to apply a defibrillation pulse to a patient; and at least one processor in communication with the sensor and the applicator to determine a first value related to the rate of change of a leading edge of a lagged phase space reconstruction of ventricular fibrillation heart rhythm measured over a period of time.

Abstract: A defibrillation system for use in treatment of ventricular fibrillation includes at least one sensor to measure heart rhythm; at least one applicator to apply a defibrillation pulse to a patient; and at least one processor in communication with the sensor and the applicator to determine a first value related to the rate of change of a leading edge of a lagged phase space reconstruction of ventricular fibrillation heart rhythm measured over a period of time.

Abstract: A method of determining a state of ventricular fibrillation, includes: measuring the rhythm of the heart during ventricular fibrillation for a period of time; creating a lagged phase space reconstruction of the measured rhythm; determining a first value related to the rate of change of the leading edge of the phase space reconstruction over the period of time; and determining the state of ventricular fibrillation by relating the first value to the state of ventricular fibrillation. A defibrillation system includes at least one processor in communication with a sensor to measure heart rhythm and an applicator to apply a defibrillation pulse. The processor is adapted to create a lagged phase space reconstruction of ventricular fibrillation heart rhythm and to determine a first value related to the rate of change of the leading edge of the phase space reconstruction over a period of time.

Abstract: A method of determining a state of ventricular fibrillation, includes: measuring the rhythm of the heart during ventricular fibrillation for a period of time; creating a phase space reconstruction of the measured ventricular fibrillation heart rhythm; determining a first value related to the rate of change of the leading edge of the phase space reconstruction over the period of time; and determining the state of ventricular fibrillation by relating the first value to the state of ventricular fibrillation. A defibrillation system for use in treatment of ventricular fibrillation includes at least one sensor to measure heart rhythm and at least one applicator to apply a defibrillation pulse to a patient (either a human or another member of the animal kingdom). The system further includes at least one processor in communication with the sensor and the applicator.

Abstract: A defibrillator, which selectively delivers a defibrillation pulse to a patient, includes electrodes adapted for placement on the patient, a monitoring circuit for providing an electrocardiogram (ECG) of the patient, and a defibrillation pulse generator having an energy store for delivering a defibrillation pulse. A switch in electrical communication with the ECG monitoring circuit and the defibrillation pulse generator selectively electrically connects the monitoring circuit and the defibrillation pulse generator to the electrodes. A microprocessor is in electrical communication with the monitoring circuit, the defibrillation pulse generator, and the switch. The microprocessor causes the switch to electrically connect the monitoring circuit to the electrodes in order to provide the ECG of the patient. The microprocessor also determines a scaling exponent for the patient from the ECG thereof.