Are saturation values the same over all areas of the fetal face?
A working assumption in pulse oximetry is that arterial oxygen saturation is essentially uniform throughout the arterial tree, assuming there is adequate flow. Some sensor designs, however, can result in saturation readings that are sensitive to the histological environment in the region underneath and near the sensor. The OxiFirst fetal sensor has been designed to minimize this artifact, resulting in FSpO2 readings that are less sensitive to where the sensor is located (within the accuracy specifications of the system).
