Project Abstract: Raydiant Oximetry, Inc. has developed and patented novel optical-sensing technology for noninvasive, trans-abdominal fetal pulse oximetry (ROSS: Raydiant Oximetry Sensing System) with the thesis that, with the additional knowledge of fetal oxygenation, clinicians can be more reliably informed about fetal well-being. Owing to misinterpretation and inherent limitations of electronic fetal heart rate monitoring (EFHRM), there is an intolerably high false positive rate for detecting fetal hypoxemia, which results in a high rate of medically unnecessary cesarean deliveries. Furthermore, the false negative rate of EFHRM results in newborns that suffer from devastating hypoxic injuries such as hypoxic ischemic encephalopathy. Monitoring fetal oxygenation, in conjunction with EFHRM, will provide a more precise modality of fetal surveillance during labor and delivery and reduce the occurrence of newborns suffering the consequences of metabolic acidosis. The proposed Phase 1 SBIR project builds directly on the initial feasibility studies. The goals of the proposed research are to improve the accuracy and reliability of our ROSS technology with the long-term commercial goal of system that can effectively measure fetal arterial hemoglobin oxygen saturation accurately and non-invasively during labor and delivery.