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

摘要 目前，我们可以用磁性传感器记录无创胎儿心磁图(FMCG)信号- 基于系统SARA(Squid阵列生殖评估)安装在阿肯色大学 医学系。对胎儿心脏，特别是发育中的心脏传导系统的研究， 在过去的二十年里，快速消费品的引入大大地帮助了我们。美国心脏协会 最近承认了这一新模式的学术和临床用途。多项研究表明 FMCG可为胎儿心脏活动的评估提供新的相关临床参数 补充当前可用的参数。尽管有这些好处，但面临的主要障碍 SQUID技术包括系统和维护成本、低温氦冷却、刚性一刀切阵列 母亲有一个单一的职位选择。我们已经证明了使用非制冷生物磁强计的可行性。 用于基于微型制造的光泵磁力仪(OPM)的潜在产前评估。这个 OPM具有许多类似于基于低温SQUID的系统的特征，因为它们测量相同的场 组件，并与标准磁屏蔽室兼容。这项提议是对以下问题的回应 NIBIB的PAR-19-158生物工程研究补助金，在那里我们应用了一个多学科综合团队 我们计划设计、测试和验证24通道OPM传感器系统，该系统适用于母体 腹部。OPM在三层屏蔽室中的性能将根据数据进行评估 FMCG信号的质量将与基于黄金标准的SQUID系统获得的信号质量进行比较。 总体目标是演示使用OPM系统(A)我们可以设计独立的灵活阵列，以 母婴应用(B)记录所需的相当于鱿鱼传感器的生物磁信号；(C)能够 将信号分离成其成分以提取FMCG和(D)量化胎儿心脏信号和相关的 指标。我们相信，由于潜在的较低成本和维护要求，使用胎儿 生物磁学可以从这项研究转化为可能广泛的临床应用。 具体目标如下： 目标1：设计和配置基于床的独立OPM阵列，符合OPM的形状 为了获得具有足够信噪比的信号以用于胎儿应用，需要对产妇的腹部进行检测。 目的2：提取并量化FMCG波形分量，计算a)PQRS和T波检测 心率和心脏时间间期(CTI)。 目标3：记录和描述被转介为异常心脏疾病的胎儿的FMCG 通过常规超声检查检测。

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.