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

SBIR一期项目正在开发一种突破性技术，用于无创监测子宫内胎儿的氧含量，从而能够更准确地检测出胎儿的窘迫，并促进母亲和婴儿更安全的分娩。目前，产科医生正在努力使用一种已有50年历史的监测技术，该技术可以报告胎儿心率和母体收缩，而这种技术在检测婴儿窘迫时的假阳性率为89%。这是全球剖宫产率高的主要原因，在美国一些医院高达40%。由于成本、对母亲的风险和对婴儿健康的负面影响，剖腹产率正受到保险公司和认证机构的严格审查，然而，临床医生缺乏准确识别氧合饥饿的手段，迄今为止，还没有开发出直接测量胎儿氧合的非侵入性手段。Raydiant的系统建立在传统脉搏血氧仪的基础上，并将使用安全水平的光线，通过母亲的腹部，监测胎儿脉搏并报告氧饱和度，这是至关重要的，但缺少的诊断。这项技术将适用于美国每年超过290万的新生儿，作为传统监测的增强，每当观察到值得关注的心率信号时。绝对氧合值及其随时间的变化趋势将使在整个分娩过程中做出更明智的决策。这个项目推动了脉搏血氧仪和生物光子学的基本边界。与传统的手指脉搏血氧仪不同，通过母体腹部进行无创感应会出现身体中的身体问题，胎儿的脉搏信号比母体弱几个数量级，并且与母体交织在一起。光子被多个组织层散射和吸收，在信号强度、噪声和胎儿与母体信号的比例之间存在权衡。受试者之间的非均质性使得校准变得困难。解决这些挑战将需要在光子硬件和信号处理方面进行创新，本提案有三个具体目标：开发一种特定的传感器硬件架构，以促进胎儿信号的检测；Raydiant算法的开发，从母体信号中分离胎儿信号，抑制噪声和报告饱和度；并在怀孕动物模型中验证组合系统，其中胎儿氧合水平被主动控制并与设备读数进行比较。该提案包括开发第二代原型系统，并代表了降低风险的关键技术，旨在与当前监测技术和临床实践相结合的商业系统。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.