Validation of Transabdominal Fetal Pulse Oximetry in Hypoxic Fetal Lamb Models

经腹胎儿脉搏血氧饱和度在缺氧胎儿羔羊模型中的验证

• 批准号: 10214652
• 负责人: Diana Lee Farmer
• 金额: $ 18.67万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-15 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10214652
• 关键词: Abdomen; Address; Amniotic Fluid; Animal Model; Animals; Aorta; Area; Arteries; Back; Blood; Blood gas; Blood specimen; Calibration; Catheters; Cesarean section; Chemicals; Clinical; Conservatism; Data; Detection; Development; Devices; Dimensions; Equipment; Event; Exhibits; Fascia; Fetal Distress; Fetal Heart Rate; Fetal Monitoring; Fetal Sheep; Fetal health; Fetus; Foundations; Gestational Age; Goals; Gold; Head; Health; Heart Rate; Hypoxia; Hysterotomy; IACUC; Infant; Intervention; Joints; Light; Measurable; Measurement; Measures; Modeling; Monitor; Neck; Noise; Optics; Oxygen; Oxygen saturation measurement; Photoplethysmography; Physiologic pulse; Physiological; Pregnancy; Pregnant Women; Process; Property; Protocols documentation; Pulse Oximetry; Respiration; Risk; Saline; Signal Transduction; Skin; Subcutaneous Tissue; Technology; Testing; Thick; Time; Tissues; Ultrasonography; Uterine Contraction; Uterus; Validation; Variant; Vascular blood supply; Vision; Work; base; cost; detector; fetal; fetal blood; fetus hypoxia; hemodynamics; human subject; imager; improved; in vivo; intrapartum; lamb model; light intensity; light scattering; portability; prototype; simulation

Project Summary Despite significant cost and clear evidence of health risks associated with Cesarean deliveries (C-sections), an unnecessarily large number of infants are delivered via C-sections in the US. The high rate of C-sections in the nation, relative to globally accepted norms, is in part attributed to the high false positive rate of fetal distress, associated with the current half-a-century-old intrapartum fetal monitoring technology. The long-term vision of this project is to alleviate this problem, by developing an improved and more specific technology for intrapartum fetal health monitoring. Specifically, we have developed the technology and built a device prototype for non-invasive, transabdominal measurement of fetal arterial blood oxygen saturation (FSpO2). The device works by shining light in the abdominal area at two specific near infrared wavelengths, followed by sensing the weak back scattered light reflections transcutaneously. The sensed signals are subsequently processed to remove various noises, including the unwanted maternal contributions, from the measurements to infer variations in light intensity that are strictly due to pulsation of fetal arteries. The device prototype is successfully validated in several preliminary tests, including simulations, photo-plethysmography (PPG) acquisition in human subjects through a thick optical phantom mimicking optical properties of a pregnant woman's abdominal area, PPG detection and separation of emulated fetal signal through an emulated maternal tissue, and in-vivo validation in a hypoxic fetal lamb model. To further advance the technology, we aim to investigate device's accuracy and reliability in measuring FSpO2 in hypoxic fetal lamb models (n=18). Our animal study protocol, already demonstrated to be effective in our preliminary work, includes hysterotomy to cannulate lamb fetus for fetal hemodynamic monitoring and drawing fetal blood samples, and placement of an inflatable catheter in the maternal aorta through which, we regulate the ewe's blood supply to the uterus, and induce controllable fetal hypoxia. The study will enable us to collect gold standard fetal arterial blood oxygen saturation (FSaO2) data via arterial blood gas (ABG) tests, under a number of hypoxia scenarios, and to compare them against our device's concurrent measurements. The study is organized into two complementary groups, depending on whether the uterus is closed around the fetal neck (n=9) or the fetus is fully returned to the uterus (n=9) before closing ewe's abdominal fascia, which enables us to isolate the impact of different tissue layers, and to characterize the technology's operating range and limitations. The project will provide the foundation for unleashing the potential clinical impact of the technology down the road.

项目概要 尽管成本高昂且有明确证据表明与剖腹产（C-sections）相关的健康风险， 在美国，大量婴儿是通过剖腹产分娩的。剖腹产率很高 相对于全球公认的标准，该国的部分原因是胎儿窘迫的假阳性率较高， 这与目前已有半个世纪历史的产时胎儿监测技术有关。长期愿景 该项目的目的是通过开发一种改进的、更具体的技术来缓解这个问题 产时胎儿健康监测。 具体来说，我们开发了该技术并构建了用于非侵入性经腹手术的设备原型 测量胎儿动脉血氧饱和度（FSpO2）。该设备的工作原理是在光照射下 在两个特定的近红外波长下检测腹部区域，然后感测微弱的背散射光 经皮反射。随后对感测到的信号进行处理以消除各种噪声， 包括不需要的母体贡献，从测量中推断出光强度的变化 这完全是由于胎儿动脉搏动造成的。该设备原型已在多个国家成功验证 初步测试，包括模拟、通过人体受试者进行光电体积描记法 (PPG) 采集 模仿孕妇腹部区域光学特性的厚光学模型，PPG 检测 通过模拟母体组织分离模拟胎儿信号，并在体内验证 缺氧胎羔模型。 为了进一步推进技术，我们的目标是研究设备测量 FspO2 的准确性和可靠性 在缺氧胎羔模型中（n=18）。我们的动物研究方案已被证明在我们的研究中有效 前期工作包括子宫切开术以对羔羊胎儿进行插管以进行胎儿血流动力学监测和 抽取胎儿血液样本，并在母体主动脉中放置一根充气导管，通过该导管，我们 调节母羊子宫的血液供应，诱导胎儿可控缺氧。这项研究将使我们能够 通过动脉血气 (ABG) 测试收集金标准胎儿动脉血氧饱和度 (FSaO2) 数据， 在多种缺氧情况下，并将它们与我们设备的并发测量进行比较。 该研究分为两个互补组，具体取决于子宫周围是否闭合 胎儿颈部（n = 9）或胎儿完全返回子宫（n = 9）之前关闭母羊腹部筋膜，这 使我们能够隔离不同组织层的影响，并描述该技术的工作范围 和限制。该项目将为释放该药物的潜在临床影响奠定基础。 技术在路上。

项目成果

Robust Fetal Heart Rate Tracking through Fetal Electrocardiography (ECG) and Photoplethysmography (PPG) Fusion.

通过胎儿心电图 (ECG) 和光电容积描记法 (PPG) 融合进行稳健的胎儿心率跟踪。

• 发表时间: 2023-07
• 作者: Kasap, Begum;Vali, Kourosh;Qian, Weitai;Saffarpour, Mahya;Fowler, Randall;Ghiasi, Soheil
• 通讯作者: Ghiasi, Soheil

BASS: Safe Deep Tissue Optical Sensing for Wearable Embedded Systems.

BASS：用于可穿戴嵌入式系统的安全深层组织光学传感。

• 发表时间: 2023-09-09
• 作者: Vali, Kourosh;Vafi, Ata;Kasap, Begum;Ghiasi, Soheil
• 通讯作者: Ghiasi, Soheil

Estimation of Fetal Blood Oxygen Saturation from Transabdominally Acquired Photoplethysmogram Waveforms.

从经腹部获得的光电体积描记图波形估计胎儿血氧饱和度。

• 发表时间: 2021-11
• 作者: Vali, Kourosh;Kasap, Begum;Qian, Weitai;Vafi, Ata;Saffarpour, Mahya;Ghiasi, Soheil
• 通讯作者: Ghiasi, Soheil

Short: Prediction of fetal blood oxygen content in response to partial occlusion of maternal aorta.

简短：预测胎儿血氧含量对母体主动脉部分闭塞的反应。

• 发表时间: 2023-06
• 作者: Qian, Weitai;Zhong, Hongtao;Ghiasi, Soheil
• 通讯作者: Ghiasi, Soheil

KUBAI: Sensor Fusion for Non-Invasive Fetal Heart Rate Tracking.

KUBAI：用于无创胎儿心率跟踪的传感器融合。

• 发表时间: 2023-07
• 作者: Kasap, Begum;Vali, Kourosh;Qian, Weitai;Saffarpour, Mahya;Ghiasi, Soheil
• 通讯作者: Ghiasi, Soheil