Transvaginal Probe for Fetal Magnetocardiography

描述（由申请人提供）：目前胎儿心脏磁图（fMCG）的检测在胎龄小于15周时是不可能的，在妊娠期小于20-24周时是不可靠的，在肥胖患者甚至在妊娠晚期也常常是困难的。这提出了一系列的问题，在评估胎儿心脏条件的高危患者的具体情况下，并在产前护理管理一般。经阴道入路胎儿超声心动图增强了胎儿成像，可以更好地近距离观察13周以内的极小胎儿解剖结构，但不能精确测量胎儿心律和传导障碍。为了应对这一挑战，基于squid的胎儿MCG系统的开创性工作已经证明了其独特的功能，包括QRS和QT间期测量、准确的搏动分析、精确的心律失常记录和详细的胎儿心率趋势分析。该提案的目的是开发一种经阴道SQUID fMCG系统，用于直接记录胎龄小于15周的胎儿心脏活动，以及胎儿的大脑电磁活动。这将有助于早期发现危及生命的心律失常、获得性心力衰竭和结构性先天性心脏病胎儿的宫内临床状况。传统的胎儿MCG系统体积庞大，需要安装在一个沉重而昂贵的磁屏蔽室中，而新系统将被设计得紧凑轻便，适合在临床环境中使用。在第二阶段的工作中，我们已经确定了主要的技术挑战，并将系统地解决这些挑战，为顺利过渡到第三阶段的人体试验和未来的临床操作铺平道路。第一阶段的仪器将被修改为包含矢量测量和噪声消除通道。将进行动物试验，以证明改进的第一阶段仪器在活体物体上的可行性。在数据分析中，将集成和测试新的降噪算法。这些研究结果将指导易于适应妇产科诊所的轻质磁屏蔽的设计和建造；可适应不同妊娠阶段胎儿发育的参考阵列矢量传感器探头；安全舒适的病人椅和探头龙门，简化测试程序。将进行一系列测试，以获得模拟探测器机械和低温故障的风险水平。该计划的成功完成将导致有史以来第一个胎儿心脏病学诊断工具，能够从怀孕早期提供准确的记录。它提供了识别胎儿心律失常和其他心脏疾病的重要能力。此外，它将极大地推进关于胎儿心脏和大脑发育的科学知识，这可以导致更好的产前护理和遗传疾病的潜在治疗。1

DESCRIPTION (provided by applicant): Currently the detection of fetal magnetocardiogram (fMCG) is not possible at gestational ages earlier than 15 weeks, is unreliable at gestations less than 20-24 weeks, and is often difficult in obese patients even in the last trimester. This presents a series problem in the assessment of fetal heart conditions in patients with high- risk cardiac conditions in specific, and in prenatal care management in general. Transvaginal approach for fetal echocardiography has enhanced fetal imaging by allowing better resolution of extremely small fetal anatomy at close range down to about 13 weeks, but cannot precisely measure fetal heart rhythm and conduction disorders. To answer this challenge, pioneering work on fMCG has demonstrated the unique capabilities of SQUID-based fetal MCG system, including QRS and QT interval measurements, accurate beat- to-beat analysis, precise arrhythmia recording, and detailed fetal heart rate trend analysis. The objective of proposal is to develop a transvaginal SQUID fMCG system for direct recording of fetal cardiac activities at gestational ages younger 15 weeks, and in addition fetal brain electromagnetic activity. This will facilitate early detections of intrauterine clinical condition of fetuses with life-threatening arrhythmias, acquired heart failure, and structural congenital heart disease. Unlike the conventional fetal MCG system, which is bulky and requires to be installed in a heavy and costly magnetic shielded room, the new system will be designed to be compact and light, suitable for use in clinical settings. In this Phase II work we have identified major technical challenges, and will address them systematically to pave way for smooth transition to human testing in Phase III and to future clinical operations. The Phase I instrument will be modified to incorporate vector measurement and noise cancellation channels. The animal tests will be conducted to demonstrate the feasibility of the improved Phase I instrument in live objects. In data analysis new noise reduction algorithm will be integrated and tested. Results of these studies will guide the design and construction of light weight magnetic shielding that is easily adaptive to OBGYN clinics; vector sensor probe with reference array that can accommodate development of fetus at different pregnancy stages; safe and comfortable patient chair and probe gantry to streamline test procedures. A series of tests will be carried out to access risk level in simulated mechanical and cryogenic failures of the probe. Successful completion of this program will lead to the first-ever diagnostic tool for fetal cardiology that is capable of providing accurate recording from early pregnancy stages. It offers the significant ability to identify fetal arrhythmias and other cardiac disorders. In addition, it will greatly advance scientific knowledge on both fetal heart and brain development, which can lead to better prenatal care and potential treatments for genetic disorders. 1 PUBLIC HEALTH RELEVANCE: This proposal aims to develop a compact, noninvasive transvaginal SQUID-based magnetocardiography (fMCG) system for unique early monitoring of fetal heart rhythm conditions. The transvaginal placement is the most effective minimally invasive method for optimizing the signal-to-noise ratio in obese patients and in early pregnancy, as has been demonstrated with transvaginal ultrasound. The new instrument will be a world's first in its capability to reliably characterize the conduction patterns and intrauterine clinical condition of fetuses with life-threatening arrhythmias, acquired heart failure, and structural congenital heart disease. In addition, its impact on the field of fetal Magnetoencephalography (fMEG) could be even greater since intrauterine evaluation of human fetal brain function has so far been impossible. 1