Abstract: A method for recognizing occurrences of breaths in respiratory signals. The method includes receiving digitized respiratory signals that includes tidal volume signals, filtering the received respiratory signals to limit artifacts having a duration less than a selected duration, and recognizing breaths in the filtered respiratory signals. A breath is recognized when amplitude deviations in filtered tidal volume signals exceed a selected fraction of an average of previously determined breaths. This invention also include methods for recognizing breathes from electrocardiogram R-waves; computer methods having code for performing the methods of this invention; monitoring systems that monitor a subject and include local or remote computers or other devices that perform the methods of this invention.