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Fig. 4 | BMC Infectious Diseases

Fig. 4

From: A novel optical biosensor for the early diagnosis of sepsis and severe Covid-19: the PROUD study

Fig. 4

Validation of the diagnostic algorithm in COVID-19. a) Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of an OB algorithm value greater than 18 for the diagnosis of COVID-19. b) Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of an algorithm value greater than 18 for the diagnosis of severe COVID-19. c) Comparative diagnostic performance of an OB algorithm value greater than 18 and of C-reactive protein (CRP) greater or equal to 56 mg/l for the diagnosis of severe COVID-19. The 56 mg/l of CRP was defined after co-ordinate point analysis of the ROC curve. The p-values of the indicated comparisons are provided. CI: confidence interval. d) NO levels in the blood measured by the Griess reaction. Circles denote outliers and asterisks denote extremes. The p-values of the indicated comparisons by the Mann-Whitney U test are shown. Panels E to J are histograms comparing the absorption rates of the PPG optical biosensor between patients with severe COVID-19 (in blue) and non-severe COVID-19 (in dark red). d) Heart Rate. e) R 660/940 nm: absorption of oxygenated versus de-oxygenated hemoglobin. f) sysTimediff (395 to 940 nm): the difference in time between the systolic points in 395 to 940 nm in millisecond providing an approximation of the vessel diameter. g) R 530/940 nm: information on kidney function. h) R 395/940 nm: levels of nitric oxide (NO). i) R 530/660 nm: ratio expressing poor oxygen absorption due to inflammatory interferences

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