A scalable superconducting dual-shielded fetal magnetocardiography system

项目摘要 美国每年有26，000例不明原因的胎儿死亡，全球每年有400多万例。胎儿心脏 心律失常是胎儿死亡的重要原因，在1-3%的妊娠中被诊断出。虽然大多数事件 是良性的，严重的心律失常，如果不诊断或治疗，可导致危及生命的并发症。 超声心动图和心脏分娩描记术已被广泛用于评估胎儿心脏功能;然而， 使用并没有减少胎儿猝死的发生率。胎儿心磁图（fMCG）记录了 由心脏电活动产生的磁场，能够直接评估胎儿心脏 电生理学然而，唯一获得FDA批准的fMCG系统使用昂贵的SQUID传感器，并且需要 一个专用的磁屏蔽室（MSR），以实现必要的灵敏度，以检测胎儿磁 信号高于环境磁干扰。因此，高昂的费用和不切实际限制了本发明的实施。 使用潜在的救生设备，并且仍然非常需要负担得起的敏感设备 并且可用于改善胎儿心律失常的结果。 应用物理系统（APS）的解决方案是一个集成的快速消费品系统，使用更实惠， 光泵磁强计传感器（OPM），现在与SQUID传感器一样灵敏， 创新的超导双屏蔽基于OPM的快速消费品的实验室原型， 铁磁屏蔽已经被开发出来，一项人体研究证明了铁磁屏蔽的可行性。 基于OPM的fMCG系统与基于SQUID的fMCG一样灵敏和准确，但成本仅为其一小部分。 然而，与SQUID相比，实验室原型中的屏蔽允许fMCG记录中的噪声更高 在MSR中。这种屏蔽是实现商业化的剩余技术障碍。超导屏蔽 与铁磁屏蔽相比，具有上级屏蔽，APS在商业化方面有40年的成功 超导双屏蔽在岩石磁力仪系统。我们的初步数据显示 在这种屏蔽系统内的改进的OPM灵敏度的概念。因此，APS将以这些研究为基础 建立超导双屏蔽系统，以降低环境噪声，从而提高信号灵敏度 和可用性的系统通过3个目标。在目标1中，我们将扩大我们的超导双屏蔽系统， 设计OPM传感器阵列及其相关软件。我们将展示 我们的系统的性能匹配或超过标准的MSR和热性能的 超导系统在目标2中，我们将完全组装fMCG系统与患者输送系统 并确认其符合电气安全标准。在目标3中，我们将进行人类受试者研究，首先在非 在妊娠受试者中确认安全性，然后在妊娠受试者中确认我们的fMCG的灵敏度和准确性 与FDA批准的基于SQUID的fMCG系统相比。

PROJECT SUMMARY There are 26,000 unexplained fetal deaths in the US and over 4 million worldwide annually. Fetal cardiac arrythmia is a significant cause of fetal demise and is diagnosed in 1-3% pregnancies. While most occurrences are benign, serious arrhythmia can lead to life-threatening complications if undiagnosed or untreated. Echocardiography and cardiotocography have been widely used to assess fetal cardiac function; however, their use has not reduced the incidence of fetal sudden death. Fetal magnetocardiography (fMCG) records the magnetic fields generated by the electrical activity of the heart, enabling direct assessment of fetal heart electrophysiology. However, the only FDA-approved fMCG system uses expensive SQUID sensors and requires a dedicated magnetically shielded room (MSR) to achieve the necessary sensitivity to detect the fetal magnetic signal above environmental magnetic interference. Thus, the prohibitive expense and impracticality limits the use of a potentially life-saving device and there remains significant need for a sensitive device that is affordable and accessible to improve outcomes for fetal cardiac arrhythmias. Applied Physics Systems’ (APS) solution is an integrated fMCG system that uses the more affordable, optically pumped magnetometer sensors (OPMs), which are now as sensitive as SQUID sensors, with an innovative superconducting dual-shield. A laboratory prototype of an OPM-based fMCG with a person-sized ferromagnetic shield has already been developed and a human subject study demonstrated feasibility of an OPM-based fMCG system as sensitive and accurate as SQUID-based fMCG, but at a fraction of the cost. However, the shield in the laboratory prototype allowed higher noise in the fMCG recordings compared to SQUID in an MSR. This shielding is the remaining technical hurdle to reach commercialization. Superconducting shields have superior shielding compared to ferromagnetic shields and APS has 40 years of success in commercializing superconducting dual-shielding in rock magnetometer systems. Our preliminary data demonstrates proof of concept of improved OPM sensitivity within such a shielding system. Therefore, APS will build upon these studies to create a superconducting dual-shield system to reduce environmental noise, thus improving signal sensitivity and usability of the system through 3 aims. In Aim 1, we will scale up our superconducting dual-shield system to be person-sized and design the OPM sensor array and its associated software. We will demonstrate the shielding performance of our system matches or exceed that of a standard MSR and thermal performance of the superconducting system. In Aim 2, we will fully assemble the fMCG system with a patient conveyance system and confirm it meets electrical safety standards. In Aim 3, we will conduct human subject studies, first in non- pregnant subjects to confirm safety, then in pregnant subjects to confirm sensitivity and accuracy of our fMCG system compared to the FDA-approved SQUID-based fMCG system.