Reference values of impulse oscillometry (IOS) for healthy Chinese children aged 4–17 years

Respiratory Research

Table 4 Respiratory System Reference Equations Obtained by the Impulse Oscillometry System for Boys and Girls

IOS parameters	Equations	R	R²	SE of the estimate
Boy
R₅, kPa/L/s	1.894 – 0.007 × H-0.028 × A + 0.002 × W	0.620	0.385	0.264
R₂₀, kPa/L/s	1.087 – 0.004 × H-0.010 × A + 0.001 × W	0.608	0.370	0.136
X₅, kPa/L/s	− 0.554 + 0.002 × H + 0.007 × A	0.566	0.321	0.091
Z₅, kPa/L/s	1.934 – 0.008 × H-0.017 × A + 0.002 × W	0.716	0.513	0.189
Fres, Hz	31.885 – 0.094 × H − 0.257 × A + 0.035 × W	0.532	0.283	3.615
R₅–R₂₀, kPa/L/s	0.703–0.003 × H − 0.013 × A + 0.001 × W	0.536	0.287	0.133
Girl
R₅, kPa/L/s	1.834–0.008 × H-0.0190 × A + 0.003 × W	0.677	0.458	0.176
R₂₀, kPa/L/s	0.964 – 0.003 × H-0.009 × A	0.562	0.316	0.123
X₅, kPa/L/s	− 0.563 + 0.002 × H + 0.006 × A	0.542	0.294	0.089
Z₅, kPa/L/s	1.970–0.009 × H-0.020 × A + 0.003 × W	0.696	0.484	0.180
Fres, Hz	33.941 – 0.104 × H-0.303 × A + 0.040 × W	0.494	0.244	4.027
R₅–R₂₀, kPa/L/s	0.787 – 0.004 × H − 0.012 × A + 0.002 × W	0.533	0.284	0.130

R₅ = resistance at 5 Hz, R₂₀ = resistance at 20 Hz, X₅ = reactance at 5 Hz, Fres = resonant frequency, Z₅ = impedance at 5 Hz, R₅–R₂₀ = fall in resistance between R₅ and R₂₀

ISSN: 1465-993X