Table 1 Upper and lower bounds for inspiratory times (t_insp) and percentages of tidal volumes (V_T) that trigger “bag slower/faster” and “leak detected” audio cues, respectively, at V_T = 300, 500, and 700 mL. Upper and lower bounds represent intervals within which true values lie. The trigger for the “Bag slower” audio cue could not be tested at V_T = 750 mL because the maximum pressure allowed by the mechanical ventilator was exceeded for t_insp ≤ 0.5 s

From: Experimental validation of a portable tidal volume indicator for bag valve mask ventilation