A medical system comprises at least one sensor configured to be positioned in an airflow path of a conscious patient experiencing dyspnea. The at least one sensor is configured to sense a presence of ventilation airflow, measure a gas flow rate in the airflow path and sense gas pressure in the airflow path of the conscious patient experiencing dyspnea. The medical system further comprises a processor arranged to receive data generated by the at least one sensor and determine one or more ventilation quality parameters requiring gas flow volume, calculated based on the sensed gas flow rate and gas pressure, for their calculation, the one or more ventilation quality parameters comprising spirometric information. The medical system further comprises a feedback unit configured to provide feedback to a rescuer based on the one or more ventilation quality parameters.
