Comparison of tissue oximeters on a liquid phantom with adjustable optical properties

The SafeBoosC trial showed that cerebral oximetry combined with a treatment guideline can reduce the the burden of hypoxia in neonates by 50% [Brit. Med. J. 350, g7635 (2015)]. However, guidelines based on oximetry by one oximeter are not directly usable by other oximeters. We made a blood-lipid phantom simulating the neonatal head to determine the relation between oxygenation values obtained by different oximeters. We calculated coefficients for easy conversion from one oximeter to the other. We additionally determined the corresponding SafeBoosC intervention thresholds at which we measured an uncertainty of up to 9.2% when varying hemoglobin content from 25μM to 70μM. In conclusion, this paper makes the comparison of absolute values obtained by different oximeters possible.