From the clinical research perspective, it is a problem that different oximeter devices and sensors give different values in normal individuals. They may also respond differently to hypoxia, as first demonstrated during oxygenation after birth in normal term infants.
The SafeBoosC project therefore has included
a) The design of an oximeter for use in preterm infants. It was named OxyPrem and developed by a spin-off company from Zurich University to obtain CE-marking for clinical use
b) Comparisons of the readings of various oximeters before use in the clinical trials. This was first done during arterial occlusion in the human adult human forearm1, 2, later during spontaneous apnea-induced cerebral desaturation in preterm infant-vitro3. In-vitro comparison using the blood-lipid phantom has also been refined. This allows comparisons at varying levels of scatter (i.e. modelling different tissues) and haemoglobin concentrations over the full range of desaturation4, 5, 6, 7.
Several partners in the SafeBoosC consortium have been members of a working group under the International Standardisation Organisation (ISO) that has prepared a standard for cerebral oximeters.
Issue oximetry: a comparison of mean values of regional tissue saturation, reproducibility and dynamic range of four NIRS-instruments on the human forearm (NCBI)
A comparison between two NIRS oximeters (INVOS, OxyPrem) using measurement on the arm of adults and head of infants after caesarean section (PubMed)
Comparison of INVOS 5100C and Nonin SenSmart X-100 oximeter performance in preterm infants with spontaneous apnea (Nature.com)
Calibration of a prototype NIRS oximeter against two commercial devices on a blood-lipid phantom (NCBI)
Comparison of tissue oximeters on a liquid phantom with adjustable optical properties (NBCI)
Comparison of tissue oximeters on a liquid phantom with adjustable optical properties: an extension (OSA publishing)
- Medical electrical equipment — Part 2-85: Particular requirements for the basic safety and essential performance of cerebral tissue oximeter equipment (ISO.org)