Development of low-cost optically pumped magnetometer system for fetal applications

摘要 目前，我们可以用磁传感器记录非侵入性的胎儿心磁图（FMCG）信号- 基于SARA（SQUID阵列生殖评估）的系统安装在阿肯色州大学， 医学科学。胎儿心脏的研究，特别是发育中的心脏传导系统， 在过去的二十年里，通过引入快速消费品，我们得到了很大的帮助。美国心脏协会 最近承认了这种新模式的学术和临床实用性。几项研究表明 FMCG可以为评估胎儿心脏活动提供新的相关临床参数， 补充目前可用的参数。尽管有这些好处， SQUID技术包括系统和维护成本，低温氦冷却，刚性的一刀切的阵列， 而母亲只能选择一个姿势我们已经证明了使用非制冷生物磁力计的可行性 用于基于微制造光泵磁力计（OPM）的潜在产前评估。的 OPM具有许多类似于基于低温SQUID的系统的功能，因为它们测量相同的场 组件，并与标准的磁屏蔽室兼容。这项建议是为了回应 NIBIB的PAR-19 - 158生物工程研究赠款，在那里我们申请了一个多学科的综合团队 我们计划设计，测试和验证一个24通道的OPM传感器系统，适合在产妇 腹部将根据数据评估OPM在三层屏蔽室中的性能 FMCG信号的质量将与从基于金标准SQUID的系统获得的信号进行比较。 总体目标是证明，使用OPM系统，我们可以（a）设计独立的灵活阵列， 母胎应用（B）记录与SQUID传感器等效的期望生物磁信号;（c）能够 将信号分离为其成分以提取FMCG和（d）量化胎儿心脏信号和相关信号 指标.我们相信，随着潜在的较低成本和维护要求，使用胎儿的好处， 生物磁测量可以从研究转化为可能广泛的临床应用。 具体目标如下： 目标1：设计和配置一个基于床的独立式OPM阵列， 以获得具有足够信噪比的信号用于胎儿应用。 目的2：提取和量化FMCG波形分量以计算a）PQRS和T波检测 心率和心脏时间间隔（CTI）。 目的3：记录和表征心脏异常胎儿的快速消费品 通过常规超声检查发现。

Abstract Currently, we can record non-invasive fetal magnetocardiographic (FMCG) signals with a magnetic sensor- based system called SARA (SQUID Array for Reproductive Assessment) installed at University of Arkansas for Medical Sciences. The study of the fetal heart, and in particular, the developing cardiac conduction system, has been significantly aided in the last two decades by the introduction of FMCG. The American Heart Association recently acknowledged the academic and clinic usefulness of this new modality. Several studies have shown that FMCG can provide new relevant clinical parameters for assessment of fetal cardiac activity and also supplement the parameters that are currently available. Despite all these benefits, the major hurdles facing SQUID technology include system and maintenance cost, cryogenic helium cooling, a rigid one-size-fits-all array, and a single position option for the mother. We have shown the feasibility of using uncooled biomagnetometer for potential prenatal assessments based on microfabricated optically-pumped magnetometers (OPM). The OPMs have many features similar to cryogenic SQUID-based systems as they measure the same field components, and are compatible with standard magnetically-shielded rooms. This proposal is in response to NIBIB’s PAR-19-158 Bioengineering Research Grants, where we apply a multidisciplinary integrative team approach to we plan to design, test and validate a 24-channel OPM sensor system that fits over the maternal abdomen. Performance of the OPM in a three-layered shielded room will be evaluated with respect to the data quality of FMCG signals which will be compared to those obtained from a gold standard SQUID based system. The overall goal is to demonstrate that with OPM systems (a) we can design a stand-alone flexible array for maternal-fetal application (b) record the desired biomagnetic signals equivalent to SQUID sensors; (c) be able to separate the signal into their constituents to extract FMCG and (d) quantify fetal heart signals and the relevant metrics. We believe that with potential lower costs and maintenance requirements, the benefits of using fetal biomagnetometery could be translated from the research to possible widespread clinical applications. The specific aims are as follows: Aim 1: Design and configure a bed-based stand-alone array of OPMs that conforms to the shape of the maternal abdomen in order to obtain signals with sufficient signal-to-noise ratio for fetal applications. Aim 2: Extract and quantify the FMCG waveform components to compute a) PQRS and T wave detection rates and cardiac time intervals (CTI). Aim 3: Record and characterize FMCG of fetuses that have been referred with abnormal heart conditions detected through routine ultrasound examination.