This procedure consists of instructing the patient to carry out a maximal inspiration and an 8-10 second breath hold
(during which the expiratory valve is closed), followed by a slow exhalation to the level of Residual Volume. The inhaled
mixture contains a low concentration of CO (0.3%) and a tracer gas which is not metabolized (CH4, Methane).
The expired concentrations of CO and the Tracer gas (CH4) are analyzed and the test results are determined.
The “wash-out volume”, “collected volume”, and “breath hold time” must be within a specific range which has been
established by ATS and ERS standards.
You do have the option to customize the optimal range of “wash-out” and “collected” volumes according to the Vital
Capacity demonstrated by the patient being tested. This function may be useful when patients demonstrate a lower than
normal VC and have difficulty exhaling the typical “collected volume” required to obtain measurements.