Fig. 1

Illustration of bench test to simulate spontaneous breathing to assess trigger performances. The figure illustrates the bench test used to simulate spontaneous breathing to assess trigger performances. A double chamber Michigan test lung was used to simulate spontaneous breathing. One chamber of the test lung was defined as the driving lung while the other chamber was connected to the ventilator being tested. A lung-coupling clip allowed a connection between the two chambers, so that a positive pressure created in the driving lung (by the driving ventilator) induced a negative pressure in the experimental lung (“exp. Lung” on the figure), leading to trigger the ventilator tested. Of note, only one chamber of the test lung (experimental lung) is used to assess Vte error whereas the two chambers (driving lung and experimental lung) are used to simulate spontaneous breathing to assess trigger performances