Modeling, measurement and prediction of cardiac magneto-stimulation thresholds

心脏磁刺激阈值的建模、测量和预测

• 批准号: 10734438
• 负责人: Bastien Guerin
• 金额: $ 65.65万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-08 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10734438
• 关键词: Accounting; Address; Animal Model; Animals; Arrhythmia; Biomedical Engineering; Canis familiaris; Cardiac; Cardiac Volume; Cardiovascular system; Cells; Chest; Collaborations; Computer Models; Confidence Intervals; Coupled; Data; Devices; Diffusion Magnetic Resonance Imaging; Electrodes; Electromagnetic Fields; Electromagnetics; Electrophysiology (science); Evaluation; Event; Family suidae; Fatty acid glycerol esters; Fiber; Frequencies; Generations; Geometry; Goals; Heart; Heart Abnormalities; Heart Arrest; Human; Image; Individual; Ion Channel; MRI Scans; Magnetic Resonance Imaging; Measurement; Measures; Methodology; Methods; Modeling; Myocardium; Nerve; Pacemakers; Patients; Peripheral Nerve Stimulation; Peripheral Nerves; Pharmaceutical Preparations; Positioning Attribute; Process; Publishing; Recommendation; Research Project Grants; Resolution; Safety; Speed; Structure of purkinje fibers; System; Techniques; Technology; Time; Update; Validation; Variant; Ventricular; Water; Work; cardiac magnetic resonance imaging; connectome; design and construction; electric field; experimental study; improved; magnetic field; multidisciplinary; operation; physiologic model; porcine model; programs; response; simulation; tool

Project Summary/Abstract In MRI, cardiac stimulation (CS) is the direct stimulation of the heart by rapid switching of the gradient coils, a phenomenon referred to as magneto-stimulation. The Federal Drug Administration (FDA) imposes limits on the speed and amplitude of gradient switching in MRI, however there is an almost complete lack of data on magneto-stimulation, which has resulted in a necessarily restrictive safety limit. Instead, the IEC 60601-2-33 limit for CS in MRI, which is the limit that the FDA relies on, is based on simplified electric field calculations in uniform cylinders that mimic the human torso, and open-chest CS experiments performed in animals using electrodes. Because of the known limitations of this methodology, the IEC built in large safety factors in their choice of the CS limit, thus resulting in a conservative safety recommendation. For example, for the four Siemens Connectome scanners in use, the CS safety limit is more restrictive than the peripheral nerve stimulation limit at long rise times, which is unlikely since conducting cells in the myocardium are harder to stimulate than large peripheral nerves and the heart is deep inside the body, and therefore more shielded from electric fields than shallow nerves. As the IEC MRI cardiac stimulation safety limit becomes more and more restrictive for improving gradient systems, it is essential to study the magneto-stimulation phenomenon in a more detailed manner using direct animal measurements and state-of-the-art simulation methods. To our knowledge, only two groups have published direct measurements of cardiac magneto- stimulation performed, in dogs, in the early 1990s. We propose a multidisciplinary bioengineering research project that aims to measure, for the first time, cardiac magneto-stimulation thresholds in pigs, a widely used animal model for the human cardiovascular system. In addition, we develop a detailed simulation pipeline of cardiac magneto-stimulation using state-of-the-art modeling techniques in order to shed light on the mechanisms of action of CS in MRI and estimate stimulation thresholds in humans for a variety of coils and gradient waveforms. We will work closely with the MT40 sub-committee of the IEC throughout the duration of the project in order to ensure that our work maximally informs the setting of the IEC limit in the next update of the IEC 60601-2-33 standard.

项目概要/摘要 在 MRI 中，心脏刺激 (CS) 是通过快速切换梯度对心脏进行直接刺激 线圈，这种现象被称为磁刺激。美国联邦药物管理局 (FDA) 对 MRI 中梯度切换的速度和幅度施加了限制，但是几乎有一个 完全缺乏磁刺激数据，这导致了必然的安全限制 限制。相反，FDA 所依赖的 IEC 60601-2-33 对 MRI 中 CS 的限制是 基于模仿人体躯干的均匀圆柱体的简化电场计算，以及 使用电极在动物身上进行开胸 CS 实验。由于已知的限制 根据这种方法，IEC 在选择 CS 限值时内置了很大的安全系数，从而导致 保守的安全建议。例如，对于 4 个西门子 Connectome 扫描仪 使用时，CS 安全限值比长上升时间的周围神经刺激限值更具限制性， 这是不可能的，因为心肌中的传导细胞比大的传导细胞更难刺激 周围神经和心脏位于身体深处，因此更能屏蔽电 领域比浅神经。随着IEC MRI心脏刺激的安全极限变得越来越大 由于限制了改进梯度系统，因此有必要研究磁刺激 使用直接的动物测量和最先进的技术以更详细的方式研究现象 模拟方法。 据我们所知，只有两个小组发表了心脏磁力的直接测量结果 20 世纪 90 年代初，对狗进行了刺激。我们提出多学科生物工程 旨在首次测量心脏磁刺激的研究项目 猪是一种广泛使用的人类心血管系统动物模型。在 此外，我们开发了一个详细的心脏磁刺激模拟流程 最先进的建模技术，以阐明 CS 的作用机制 在 MRI 中估计各种线圈和梯度对人体的刺激阈值 波形。我们将在整个期间与 IEC MT40 分委会密切合作 该项目，以确保我们的工作最大限度地为下一步 IEC 限值的设置提供信息 IEC 60601-2-33 标准的更新。