Table 1.

Mean values for volumes of expired air and mean for all three ultrasound methods to measure diaphragm movement

	Mean	SD	Minimum	Maximum	n, observation
M-mode, cm	6.6	2.4	1.9	10.8	79
Volume of expired air, l	4.5	2.3	0.8	8.4	79
B-mode, cm	3.0	1.8	0.4	7.4	79
Volume of expired air, l	3.8	2.3	0.4	7.3	79
Area Method, cm2	89.8	51.0	17.0	197.0	72
Volume of expired air, l	3.8	2.2	0.4	7.3	72