Table 2 Fitting results for the elasticity parameters, \({c}_{1}\) and \({c}_{2}\), and the collagen thickness fraction \({\chi }_{2}\) in the shell model.

From: Stress–strain curve and elastic behavior of the fibrotic lung with usual interstitial pneumonia pattern during protective mechanical ventilation

Data source

Adj-R2

SSE

Elastin and ground substance

Collagen

\({c}_{1}\)(cmH2O)

\({c}_{2}\)(cmH2O)

\({\chi }_{2}\)(-)

Healthy lung (D’Angelo et al.14)

0.9774

2.458

53.29 [39.71–66.87]

365.0 [246–483.9]

0.05 [− 0.19–0.29]

Healthy lung (Levy et al.15)

0.9754

8.07

74.64 [66.21–83.06]

392.9 [315.7–470.0]

0.04 [− 0.07–0.15]

ARDS

0.7435

135.0

95.0 [70.0–120.0]

212.0 [91.05–333.0]

0.08 [− 0.16–0.32]

EUIP

0.5743

340.9

189.4 [102.1–276.7]

702.3 [370.7–1034]

0.31 [− 0.01–0.63]

  1. The fitting has been obtained using Eq. (18) for human pressure–volume curves for normal, ARDS and EUIP lungs. The thickness fraction of collagen, \({\chi }_{2},\) has been found about 4% in normal lungs and in ARDS patients, and 31% in EUIP patients. The volume fraction of elastin and ground material is simply given by \({1-\chi }_{2}\).The 95% confidence intervals are indicated in square brackets. Data are presented as median and IQR.
  2. EUIP, Acute exacerbation of interstitial lung disease with usual interstitial pneumonia pattern; ARDS, Acute respiratory distress syndrome; IQR, Interquartile range.
Back to article page