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.

项目总结/摘要 在MRI中，心脏刺激（CS）是通过梯度的快速切换对心脏的直接刺激 线圈，一种被称为磁刺激的现象。联邦药品管理局（FDA） 对MRI中梯度切换的速度和幅度施加了限制，然而， 完全缺乏关于磁刺激的数据，这导致了必然的限制性安全性 极限相反，IEC 60601-2-33对MRI中CS的限值（FDA所依赖的限值）是 基于模拟人体躯干的均匀圆柱体中的简化电场计算，以及 使用电极在动物中进行的开胸CS实验。由于已知的局限性， 在这种方法中，IEC在选择CS限值时采用了较大的安全系数，因此， 保守的安全建议。例如，对于中的四台Siemens Connectome扫描仪， 使用时，CS安全限值比长上升时间的外周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。 周围神经和心脏都在身体深处，因此更容易受到电的屏蔽。 而不是肤浅的神经。随着IEC MRI心脏刺激安全限值越来越多， 为了改善梯度系统的性能，有必要对磁刺激进行研究 使用直接动物测量和最新技术，以更详细的方式对这一现象进行了研究。 模拟方法 据我们所知，只有两个小组发表了直接测量心脏磁- 在20世纪90年代早期，在狗身上进行了刺激。我们提出了一个多学科的生物工程 该研究项目旨在首次测量心脏磁刺激 阈值，这是一种广泛用于人类心血管系统的动物模型。在 此外，我们开发了一个详细的模拟管道的心脏磁刺激使用 最先进的建模技术，以阐明CS的作用机制 并估计各种线圈和梯度人体刺激阈值 波形我们将在整个期间与IEC的MT40小组委员会密切合作。 项目，以确保我们的工作最大限度地通知IEC限制的设置， 更新IEC 60601-2-33标准。