SBIR Phase I:Design and optimization of non-invasive fetal oxygenation sensing hardware and algorithm

Raydiant Oximetry, Inc, San Ramon CA

Investigators

Abstract

This SBIR Phase I project is developing a breakthrough technology to non-invasively monitor fetal oxygen levels in utero, to enable the more accurately detection of fetuses in distress and facilitate safer births for mothers and babies. Currently, obstetricians struggle with a 50-year old monitoring technology, which reports fetal heart rate and maternal contractions, and that is associated with an 89% false positive rate for detecting babies in distress. This is a major contributor to high cesarean section rates worldwide and up to 40% in some US hospitals. Because of the costs, risks for mothers and negative implications for babies' health, C-section rates are coming under scrutiny from insurers and accreditors, however, clinicians lack the means to accurately identify oxygenation starvation and, to date, no non-invasive means of directly measuring fetal oxygenation has been developed. Raydiant's system builds off traditional pulse oximetry and will employ safe levels of light, through the mother's abdomen, to monitor fetal pulse and report oxygen saturation, the crucial, but missing diagnostic. This technology will be applicable to over 2.9 million births per year in the US as an enhancement to traditional monitoring whenever a heart rate signal of concern is observed. Both the absolute oxygenation value and its trend over time will enable more informed decision making throughout the birth process. This project pushes the fundamental boundaries of pulse oximetry and bio-photonics. Unlike traditional finger pulse oximetry, sensing non-invasively through the maternal abdomen presents a body in a body problem, where the fetal pulse signal is orders of magnitude weaker than and intertwined with the maternal. Photons are scattered and absorbed by multiple tissue layers and there are tradeoffs between signal strength, noise and the ratio of fetal to maternal signal. Non-homogeneities from subject to subject makes calibration difficult. Addressing these challenges will require innovation in photonics hardware and signal processing and this proposal has a three specific aims: the development of a specific sensor hardware architecture that will facilitate detection of the fetal signal; development of Raydiant's algorithm to separate fetal from maternal signal, reject noise and report saturation; and validation of the combined system in a pregnant animal model, where fetal oxygenation levels are actively controlled and compared to the device reading. This proposal encompasses developing a second generation prototype system and represents critical technology de-risking aiming towards a commercial system for integration with current monitoring technology and clinical practice. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.