Comments on 'Flow dependence and repeatability of interrupter resistance in lower airways and nose'

The authors (Eiser et al 2005 Physiol. Meas. 26 143-56) have undertaken a much needed investigation into the extent of the flow dependence of resistance, as measured by the interrupter technique (Rint). The clear explanations of the general principles should prove invaluable to the readers. However, I should like to highlight some small technical errors as well as raising some points of concern regarding the accuracy of the findings due to the relatively slow sampling rate for flow and subjects being asked to breathe 'deeper and faster', if the device was not triggering at higher flows.