The VMax229 could be used as a metabolic measurement cart (VO2, VCO2, Ve etc) or as a standard pulmonary function testing system (spirometry, N2 washout lung volumes and DLCO). From http://www.ebay.com/itm/SENSORMEDICS-VMAX-229-SPIROMETER-PULMONARY-RESPIRATORY-ANALYZER-769200-101-/290931490837