Figure 1

A non-invasive respiratory volume monitor (ExSpiron; Respiratory Motion, Inc.) that provides continuous, real-time, non-invasive measurements of minute ventilation, tidal volume and respiratory rate. This photograph shows standard electrode placement on an obese patient (not the patient reported here; body mass index, 36.7kg/m²). One electrode is placed at the sternal notch, another on the xiphoid and the third in the right mid-axillary line at the level of the xiphoid.