1. A method for producing a single representative CO 2 waveform representing a set of CO 2 waveforms obtained from a subject, the method comprising: obtaining a set of two or more CO 2 waveforms from the subject; identifying a unique pattern in the two or more waveforms, wherein the unique pattern is a recurring pattern that recurs over a predetermined number of consecutive waveforms of the two or more CO 2 waveforms, and wherein the recurring pattern is representative of a physiological condition; removing the unique pattern from the two or more CO 2 waveforms; determining one or more scale factors and one or more shape factors for each of the two or more CO2 waveforms from which the unique pattern has been removed; computing a representative set of shape factors based on the one or more shape factors; computing a representative set of scale factors based on the one or more scale factors; wherein each of the representative set of shape factors and the representative set of scale factors represent the two or more CO 2 waveforms from which the unique pattern has been removed; constructing a single representative CO 2 waveform based on an integration of the representative sets of shape and scale factors; such that the single representative CO 2 waveform is representative of both the shape and scale of the two or more CO 2 waveforms from which the unique pattern has been removed; superimposing the removed unique pattern on the representative CO 2 waveform to obtain a final representative CO 2 waveform.