Table 5.
Selected parameters derived from model fits
| Subject | VD,tot/VA,tot | (VD,tot/VA,tot) | LogSDV̇ | LogSDQ̇ | Shunt /% |
|---|---|---|---|---|---|
| Young #1 | 0.066 ± 0.004 | 0.029 ± 0.001 | 0.35 ± 0.08 | 0.38 ± 0.05 | 0.8 ± 1.5 |
| Young #2 | 0.056 ± 0.002 | 0.028 ± 0.003 | 0.42 ± 0.08 | 0.42 ± 0.05 | 1.2 ± 1.3 |
| Young #3 | 0.051 ± 0.005 | 0.019 ± 0.001 | 0.52 ± 0.09 | 0.49 ± 0.07 | 0.4 ± 1.1 |
| Young #4 | 0.055 ± 0.004 | 0.024 ± 0.002 | 0.41 ± 0.13 | 0.42 ± 0.08 | 4.9 ± 2.9 |
| Young #5 | 0.046 ± 0.003 | 0.017 ± 0.002 | 0.33 ± 0.08 | 0.33 ± 0.07 | 0.9 ± 1.5 |
| Young #6 | 0.050 ± 0.003 | 0.017 ± 0.001 | 0.41 ± 0.07 | 0.39 ± 0.06 | 0.3 ± 0.9 |
| Mean | 0.054 | 0.022 | 0.41 | 0.40 | 1.5 |
| CoV | 7% | 7% | 22% | 16% | |
| Old #1 | 0.069 ± 0.003 | 0.021 ± 0.003 | 0.53 ± 0.07 | 0.52 ± 0.06 | 3.2 ± 2.6 |
| Old #2 | 0.065 ± 0.004 | 0.025 ± 0.003 | 0.42 ± 0.08 | 0.44 ± 0.07 | 1.9 ± 1.8 |
| Old #3 | 0.083 ± 0.007 | 0.021 ± 0.007 | 0.60 ± 0.06 | 0.64 ± 0.03 | 8.2 ± 2.3 |
| Old #4 | 0.058 ± 0.003 | 0.026 ± 0.002 | 0.49 ± 0.09 | 0.53 ± 0.05 | 4.7 ± 3.5 |
| Old #5 | 0.062 ± 0.003 | 0.013 ± 0.003 | 0.58 ± 0.05 | 0.54 ± 0.04 | 5.9 ± 1.7 |
| Old #6 | 0.057 ± 0.004 | 0.019 ± 0.003 | 0.59 ± 0.04 | 0.65 ± 0.05 | 0.9 ± 0.7 |
| Mean | 0.066 | 0.021 | 0.53 | 0.55 | 4.1 |
| CoV | 6% | 17% | 13% | 9% | |
| COPD #1 | 0.105 ± 0.008 | 0.044 ± 0.013 | 0.64 ± 0.07 | 1.26 ± 0.34 | 4.7 ± 3.8 |
| COPD #2 | 0.152 ± 0.011 | 0.064 ± 0.027 | 0.75 ± 0.18 | 1.34 ± 0.20 | 6.8 ± 5.3 |
| COPD #3 | 0.085 ± 0.004 | 0.040 ± 0.003 | 0.85 ± 0.23 | 0.84 ± 0.06 | 2.7 ± 2.3 |
| COPD #4 | 0.086 ± 0.012 | 0.047 ± 0.006 | 0.92 ± 0.24 | 1.10 ± 0.07 | 4.3 ± 2.9 |
| COPD #5 | 0.088 ± 0.004 | 0.033 ± 0.001 | 0.81 ± 0.05 | 0.89 ± 0.03 | 9.7 ± 3.5 |
| COPD #6 | 0.096 ± 0.014 | 0.061 ± 0.006 | 1.02 ± 0.17 | 0.92 ± 0.13 | 1.4 ± 2.7 |
| Mean | 0.102 | 0.048 | 0.83 | 1.06 | 5.0 |
| CoV | 9% | 17% | 19% | 12% | |
| Analysis of variance | |||||
| F ratio (BG:WG) | 17.1*** | 22.8*** | 30.5*** | 42.6*** | 2.9 |
| F ratio (BP:WP) | 30.2*** | 7.5*** | 3.7*** | 7.6*** | 5.5*** |
| ICC | 0.99 | 0.96 | 0.95 | 0.98 | 0.86 |
LogSDV̇ and LogSDQ̇ are estimates for the standard deviation for the natural logarithm of the ventilation–perfusion (V̇A:Q̇) distribution, as estimated from the alveolar ventilation and perfusion distributions within the lung model, respectively. Other parameters are as defined in Table 1. CoV, coefficient of variation; F ratio (BG:WG) is the variance ratio for the between-group to within-group comparison; F ratio (BP:WP) is the variance ratio for the between-participant to within-participant comparison. ICC is the intraclass correlation coefficient. Errors shown are for ± 1SD.
***
P < 0.001.