Magnetic Resonance Systems Development

我们正在解决的问题很容易理解：许多人需要永久或半永久植入医疗设备（例如起搏器），其中许多人在生命中的某个时候需要进行MR扫描。由于大多数标准医疗器械在MRI系统内停止运行或在MR环境中对受试者构成危险，因此这些人没有资格接受MRI。联邦政府和各省已经在医学成像基础设施方面进行了大量投资，特别是在MRI方面。但是，过去超过1.5亿美元的MRI投资并没有转化为医疗器械行业的明显优势。这是因为MR兼容医疗器械的开发是一个高度复杂的问题，其解决方案需要获得专门的设施和适当的专业知识，而这在加拿大目前尚不存在。该项目的最终目标是通过促进更安全、更先进的医疗设备的开发，以改善加拿大人的生活，这些设备可用于更安全、更先进的MRI系统。由于以下几个原因，MR环境对医疗设备来说尤其具有挑战性。电磁环境是高度复杂和极端的。静磁场比地球磁场强数千倍。静磁场的空间梯度导致即使是轻微磁性的材料和物体上也会产生巨大的力和扭矩。强时变（kHz或“音频”）梯度场会导致导电器械发热、电磁干扰以及kHz机械振动和扭矩。最后，射频（RF）电场和磁场比人类或设备通常暴露的任何东西都要强烈得多。暴露于射频场主要导致器械显著发热。射频电磁干扰也可能是控制和通信电路中的一个问题。我们建议建立一个全面的计划，用于研究和开发MR兼容的医疗设备和MR技术。我们已经在所有相关场强（从占主导地位的临床场强1.5T和3 T，到新兴的人类使用的7 T系统，我们在该国拥有唯一的安装）中安装了无与伦比的MR扫描仪。为了使我们成为开发和测试MR兼容医疗器械和技术的综合性“一站式商店”，我们需要额外的专业能力：（1）在实验室的受控、可再现条件下，重新创建假设会影响任何给定医疗器械的MR系统的那些方面;（2）对器械操作和对实验室暴露环境的反应进行仔细、可再现的测量;（3）在实际MR系统中验证结果的重要性。在本申请中，我们建议在磁共振成像的一般领域，更具体地在MR系统开发和MR兼容医疗设备开发领域，培养6名研究生和10名本科生。

The problem we are addressing is easy enough to understand: many people need permanently or semi-permanently implanted medical devices (e.g. pacemakers), and many of these people will need an MR scan at some point in their lives. Because most standard medical devices either cease to operate within an MRI system or present a danger to the subject when within the MR environment, these people will not be eligible to receive an MRI. This effectively results in a lower standard of care for subjects with implanted medical devices.The federal government and the provinces have made massive investments in medical imaging infrastructure, particularly in MRI. But these past MRI investments, exceeding $150 million, have not translated into a clear advantage for the medical device industry. This is due to the fact that MR-compatible medical device development is a highly complex problem whose solution requires access to a dedicated facility and appropriate expertise, which is currently absent in Canada. This project ultimately aims to improve the lives of Canadians by facilitating the development of safer, more advanced medical devices for use within safer, more advanced MRI systems.The MR environment is especially challenging for medical devices for several reasons. The electromagnetic environment is both highly complex and extreme. Static magnetic fields thousands of times stronger than Earth’s magnetic field are present. Spatial gradients of the static magnetic fields result in massive forces and torques on even slightly magnetic materials and objects. Strong time-varying (kHz, or “audio frequency”) gradient fields result in heating of conductive devices, electromagnetic interference, and kHz mechanical vibrations and torques. Finally, the radiofrequency (RF) electric and magnetic fields are much more intense than anything humans or devices are normally exposed to. Exposure to RF fields primarily results in significant device heating. RF electromagnetic interference can also be a problem in control and communication circuits.We are proposing to establish a comprehensive program for the research and developmentof MR-compatible medical devices and MR technology more generally. We already have an unrivaled installation of MR scanners, across all relevant field strengths (from the dominant clinical field strengths of 1.5T and 3T, to the emerging 7T systems for human use, of which we have the only installation in the country). In order for us to be a comprehensive “one-stop-shop” for development and testing of MR-compatible medical devices and technology, we need the additional specialized capacity to:(1) recreate those aspects of the MR system that are hypothesized to affect any givenmedical device, but under the controlled, reproducible conditions of the laboratory;(2) make careful, reproducible measurements of device operation and reaction to theselaboratory exposure environments;(3) validate the results in the actual MR systems of importance.In this application we are proposing to train 6 graduate students and 10 undergraduates in the general area of magnetic resonance imaging, and more specifically in the areas of MR systems development and MR compatible medical device development.