Fig 1.
The SCiO (Consumer Physics Ltd., Israel) pocket infrared scanner (Panel A) and schematic diagram of the device in position for scanning a 2.5 cm x 7.5 cm microscope slide with a coverslip and a drop of blood (Panel B).
Fig 2.
Detection of carboxyhemoglobin (COHb) in thin films of 50 μL of human and bovine blood in vitro with spectrograms from the SCiO pocket molecular sensor.
A. Representative spectrograms of human blood with varying fractional content of COHb, produced by adding pure CO gas to heparinized blood. Hemoximeter measured COHb is indicated, expressed as % of total hemoglobin, as are the wavelengths of interest in the analysis (775 nm, 875 nm and 925 nm). The multiple traces of the same color indicate repeat scans of the same sample, to indicate reproducibility. B. Regression analysis of spectrometric model [COHb] = f(850nm spectrogram signal-775 nm spectrogram signal)/925 nm signal and hemoximeter measured COHb levels in human and C. bovine blood, based on creation of an index relating differences in spectrogram signals at 875 and 775 nm relative to an isobestic wavelength of 925 nm (see text). D. Modified Bland-Altman bias plot of errors in SCiO estimates of [COHb] % based on the regression equation relating SCiO index value and hemoximeter measured [COHb]. Dashed lines show 95% confidence limits for the regressions.
Table 1.
Predictive power of a simple linear model* derived from SCiO spectrograms to detect carboxyhemoglobin in single drops of human blood.
Fig 3.
Detection of methemoglobin (MetHb) in 50 μL thin films of human and bovine blood with in vitro with spectrograms from the SCiO pocket molecular sensor.
A. Representative SCiO spectrograms of human blood with increased fractional content of MetHb, produced by adding NaNO3 solution to syringes of heparinized blood. The wavelengths used in the spectrophotometric model (775 nm, 875 nm and the isobestic wavelength of 975 nm) are indicated by the vertical lines). B. Regression analysis comparing the spectrometric model and hemoximeter measured MetHb levels in human blood. C. Regression analysis comparing the spectrometric model and hemoximeter measured MetHb levels in bovine blood. D. Modified Bland-Altman bias plot of errors in SCiO estimates of [MetHb] % based on the regression equations relating SCiO MetHb Index value and hemoximeter measured [MetHb] for human and bovine blood.
Table 2.
Predictive power of a linear model* based on SCiO spectrograms to detect methemoglobin in single drops of human and bovine blood.