Processing impedance signals for breath detection

An apparatus for assisting ventilations provided to a patient, the apparatus comprising:

• a plurality of electrodes configured to provide signals representative of airflow activities of the patient, the signals comprising electrical impedance signals measured across the patient's chest and indicative of changes to the patient's chest geometry;
• one or more chest compression sensors configured to provide signals representative of chest displacement due to chest compressions;
• a processor and a memory configured to:
• receive the signals representative of the airflow activities of the patient from the plurality of electrodes,
• receive the signals representative of chest displacement due to chest compressions from the one or more chest compression sensors,
• identify a presence of chest compressions applied to the patient based on the signals representative of chest displacement,
• subsequent to identification of the presence of chest compressions, confirm an absence of chest compressions applied to the patient based on the signals representative of chest displacement,
• for the signals representative of the airflow activities of the patient, adjust one or more signal processing parameters from a first set of threshold values to a second set of threshold values in response to the confirmed absence of chest compressions applied to the patient, the one or more signal processing parameters comprising at least the first set of threshold values which are for use in processing the electrical impedance signals in the presence of chest compressions applied to the patient and the second set of thresholds which are for use in the absence of chest compressions applied to the patient, and
• process the signals representative of the airflow activities of the patient using the adjusted one or more signal processing parameters to determine feedback for providing the ventilations to the patient in the absence of chest compressions;
• and
• an output device coupled to the processor and the memory and configured to provide the feedback for providing the ventilations to the patient.