Factor | Examples |
Equipment related | Analyser rise time Analyser linearity Flow measurement linearity Size of equipment related deadspace volume, including distance between gas and flow measurement points |
Procedure related | Inert gas used (and concentration) Breathing stability Age of subjects tested |
Analysis related | Algorithms used for calculation of indices BTPS correction applied Corrections applied for equipment-related deadspace Drift correction algorithms Synchronisation of flow and gas concentration signals Acceptability criteria applied (e.g. FRC values within 10%) |
BTPS: body temperature, ambient pressure, saturated with water; FRC: functional residual capacity.