Our method is simple and results are obtained in about 90 seconds. The equipment needed is inexpensive:
An IR CO2 analyzer, a deadspace with precisely known volume - made up of a cylinder, a filter and a mouthpiece and a noseclip to prevent breathing through the nose. Finally a laptop for gathering and evaluating the data.
Present methods of measuring FRC are complicated and the equipment needed are expensive and not suitable for bedside use or out-of-hospital applications
References:
Pre-operative assessment:
Chest Volume 115, Issue 5, Supplement, May 1999, Pages 58S-63S
Preoperative Assessment of Pulmonary Risk
Ferguson M K
https://doi.org/10.1378/chest.115.suppl_2.58S
Out-of-hospital management of lung disease:
NPJ Prim Care Respir Med 7;31:23 2021
Pulmonary function testing in COPD: looking beyond the curtain of FEV1
Kakavas S et al.
doi: 10.1038/s41533-021-00236-w