Table 1

Resistive loss coefficients (k) and equivalent linear resistances for air and helium/oxygen 78/22 for combinations of parabolic resistors used with the test lung
R [cm H20 L-1s]
k Q[L/min] Air He/O278/22
Rp5 3.3 22.5 1.0 0.4
36.0 1.6 0.6
52.5 2.4 0.8
Rp20 21.5 22.5 6.6 2.3
36.0 10.6 3.7
52.5 15.4 5.4
2xRp5 6.6 22.5 2.0 0.7
36.0 3.2 1.1
52.5 4.7 1.7
Rp5 + Rp20 24.8 22.5 7.6 2.7
36.0 12.2 4.3
52.5 17.8 6.2
2xRp20 43.0 22.5 13.2 4.6
36.0 21.1 7.4
52.5 30.8 10.8

k is defined in the relationship <a onClick="popup('http://www.biomedcentral.com/1471-2466/12/62/mathml/M2','MathML',630,470);return false;" target="_blank" href="http://www.biomedcentral.com/1471-2466/12/62/mathml/M2">View MathML</a>, where ΔP is the pressure loss across the resistor, ρ is the gas density, and Ū is the mean gas velocity entering the resistor.

Martin et al.

Martin et al. BMC Pulmonary Medicine 2012 12:62   doi:10.1186/1471-2466-12-62

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