The present disclosure provides methods, devices and systems for calculating integrated breath status values comprising: defining breath cycles based on CO2 waveforms； generating transformed signals based on PPG signals； calculating respiratory effort values based on the transformed PPG signals； and calculating integrated breath status values based on the defined breath cycles and the respiratory effort values. The disclosure also provides methods, devices and systems for calculating cardiovascular status values comprising: defining breath cycles based on a CO2 waveforms； generating transformed signals based on a PPG signals； calculating pulse output values based on the transformed PPG signal； calculating pulse output per breath values based on the defined breath cycles and the calculated pulse output values； and determining integrated cardiovascular status values based on a comparison of a change in the pulse output per breath values and in the CO2 waveforms.
