Inspired and end-tidal gas concentration and alveolar ventilation: concurrent breath-by-breath measurement.
A system is described which concurrently measures, breath-by-breath, the inspired and end-tidal concentrations of five gases, and alveolar and total ventilation. Gas concentrations are measured by means of a quadrupole mass spectrometer and mixed-expired carbon-dioxide concentration, required for the computation of alveolar ventilation, is computed as the volume-weighted average of expired carbon dioxide.
D000776:Anesthesiology / Q000295:instrumentation*; D006801:Humans; D013058:Mass Spectrometry / Q000295:instrumentation; D008991:Monitoring, Physiologic / Q000295:instrumentation* / Q000379:methods; D011659:Pulmonary Gas Exchange; D012984:Software