Minimally invasive medical procedures under magnetic resonance imaging (MRI) guidance have significant clinical promise. However, this potential has not been fully realized yet due to challenges regarding MRI compatibility and miniaturization of active and precise positioning systems inside MRI scanners, i.e., restrictions on ferromagnetic materials and long conductive cables and limited space around the patient for additional instrumentation. Lorentz force‐based electromagnetic actuators can overcome these challenges with the help of very high, axial, and uniform magnetic fields (3–7 Tesla) of the scanners. Here, a miniature, MRI‐compatible, and optically powered wireless Lorentz force actuator module consisting of a solar cell and a coil with a small volume of 2.5 × 2.5 × 3.0 mm³ is proposed. Many of such actuator modules can be used to create various wireless active structures for future interventional MRI applications, such as positioning needles, markers, or other medical tools on the skin of a patient. As proof‐of‐concept prototypes toward such applications, a single actuator module that bends a flexible beam, four modules that rotate around an axis, and six modules that roll as a sphere are demonstrated inside a 7 Tesla preclinical MRI scanner.

中文翻译：

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磁共振成像兼容的光动力微型无线模块化洛伦兹力作动器

在磁共振成像（MRI）指导下的微创医疗程序具有重大的临床前景。但是，由于有关MRI兼容性以及MRI扫描仪内部有源和精确定位系统小型化的挑战，即铁磁材料和长导电电缆的限制以及患者周围用于附加仪器的空间有限，因此尚未完全实现这种潜力。基于洛伦兹力的电磁执行器可以借助扫描仪的极高，轴向且均匀的磁场（3-7特斯拉）来克服这些挑战。此处是一个微型，与MRI兼容且由光驱动的无线洛伦兹力执行器模块，该模块由一个太阳能电池和一个体积为2.5×2.5×3.0 mm ³的线圈组成被提议。许多这样的致动器模块可用于创建各种无线有源结构，以用于将来的介入MRI应用，例如在患者皮肤上定位针，标记或其他医疗工具。作为针对此类应用的概念验证原型，在7台Tesla临床前MRI扫描仪中演示了一个弯曲柔性梁的致动器模块，四个绕轴旋转的模块以及六个球体滚动的模块。