A comment on 'Comparative analysis of the isovolume calibration method for non-invasive respiratory monitoring techniques based on area transduction versus circumference transduction using the connected cylinders model' (2011 Pysiol. Meas. 32 1265-74)

An analysis introduced by the authors in 2011 examining the robustness of the isovolume method for the calibration of the respiratory inductive plethysmograph based on the connected cylinders particular model of Konno and Mead's generalized two-compartment model of respiration is extended. It is demonstrated that extending this to a more physically realistic geometrical model, termed the connected prismatic elliptical segments model, does not enhance the earlier analysis, and that the analysis can easily be proven to cover all area-based transduction sensors, irrespective of the actual geometry of the compartments.