Fig. 1From: The effects of pressure- versus volume-controlled ventilation on ventilator work of breathingResistive MW of the ventilator (cmH2O.L) assuming different flow waveforms (square, sinusoidal, and decelerating) for both normal subjects (left column) and COPD patients (right column) with RR = 15/min and different I:E ratios under different tidal volumes; a, d) VT = 0.5 L, b, e) VT = 1 L, c, f) VT = 2 L; increasing I:E ratio in the same RR would decrease MW for all flow profiles. For a fixed I:E ratio, the square profile has the smallest MW for all VT = 0.5 L (see blue bars) while the largest MW is achieved by sinusoidal or decelerating depending on I:E ratio. Resistive MW in COPD patients is about two times higher than that in normalsBack to article page