Use of a two-way non-rebreathing valve to simplify the measurement of twitch mouth pressure using an inspiratory pressure trigger and the establishment of an optimal trigger threshold for healthy subjects and COPD patients

Highlights • The measurement of Tw Pmo by the use of two way set-up is of clinical value for the investigation the suspected diaphragm contractility. • The controlled trigger-technique using a two-way non-rebreathing valve is superior to previous ones. • −2 cmH2 O is the greatest trigger threshold for clinical applications.