Respiratory rate monitoring for respiratory flow therapy systems

Systems and methods can determine respiratory rates of a patient using a respiratory device by performing one or more frequency analyses of a signal from the gases flow. The signal from the gases flow can be one that varies with the patients breathing. The system can include a non-sealed patient interface, such as a nasal cannula in a nasal high flow therapy, or any other patient interfaces. The respiratory system can also detect whether the patient has taken off the patient interface and/or whether the patient connected to the patient interface is talking or eating. Data of the patients use of the respiratory system and the patients respiratory rates can provide therapy compliance and long-term trend of use information and/or progress in the patients respiratory functions and/or other physiological functions.