A Neonatal Fiberoptic Probe for Oximetry and Dye Curves

Development of a miniaturized fiberoptic/dye probe is described for intended application with a neonatal 5 French (FR) umbilical artery catheter (UAC). A simplified model of the optical system leads to the choice of 5 mil plastic fibers for which a large numerical aperture compensates for high absorption losses at 930 nm over short distances. Initial dog trials have yielded excellent in situ oximetry measurements and dye curves that clearly show the recirculation component.