Fig. 4

a Correlation between mucosal oxygen saturation and the converted μPO₂ saturation. R² = 0.39, intercept 18.5 slope 0.41. b Blant–Altman plot of the mucosal oxygen saturation and the converted μPO₂ saturation. VLS—μPO₂_saturation: − 16.00974, 2.5% limit: − 52.83358, 97.5% limit: 20.81410, SD (diff): 18.41192