In Vitro Comparisons of Near-Infrared Spectroscopy Oximeters: Impact of Slow Changes in Scattering of Liquid Phantoms

摘要

Several cerebral oximeters based on near-infrared spectroscopy (NIRS) are commercially available that determine tissue oxygen saturation (StO(2)). One problem is an inconsistency of StO(2) readings between different brands of instruments. Liquid blood phantoms mimicking optical properties of the neonatal head enable quantitative device comparisons. However, occasionally, the reduced scattering coefficient (mu(s)') of these phantoms decreases over time. Aim: To investigate whether this decrease in mu(s)' affects the validity of comparison of these devices. StO(2) was measured by several NIRS oximeters simultaneously on a phantom, which exhibited a particularly strong decrease in mu(s)'. We found that a decrease in mu(s)' by = 16% from baseline led to deviations in StO(2) of = 3%.