Actuation and visualization of a magnetically coated swimmer with magnetic particle imaging
Actuation and visualization of a magnetically coated swimmer with magnetic particle imaging
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DOI：
10.1016/j.jmmm.2018.10.056
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发表时间：
2019-03-01
影响因子：
2.7
通讯作者：
Buzug, Thorsten M.
中科院分区：
文献类型：
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作者：
Bakenecker, Anna C.;von Gladiss, Anselm;Buzug, Thorsten M.
无系绳驱动的毫米和微型设备是非常感兴趣的各种医疗应用。展示了一个毫米大小的游泳者，它是3d打印的，并涂有磁性纳米颗粒。涂层必须满足两个要求：首先，它必须具有高磁矩，以便对磁场表现出强烈的反应，从而获得良好的驱动性能。其次，它必须适合于磁颗粒成像（MPI）。MPI是一种新兴的医学成像技术，基于超顺磁性纳米颗粒对振荡磁场的非线性响应。它的目的是双重使用的MPI扫描仪：为驱动和可视化。当施加旋转均匀磁场时，游泳者由于其形状和周围介质的粘度而进行轴向运动。这些字段可以用MPI扫描器生成。对游泳者的动力学进行了观察，发现在磁场旋转频率为10 Hz时，最大游泳速度为6 mm/s。实验是用市售的临床前MPI扫描仪进行的。结果表明，游泳者适合MPI成像。此外，显示了运动游泳者的顺序获取图像。为此，MPI扫描仪在成像和驱动模式下交替驱动。
The untethered actuation of milli-and microdevices is of great interest for a variety of medical applications. A millimeter sized swimmer is shown, which is 3D-printed and coated with magnetic nanoparticles. The coating has to fulfill two requirements: First, it must have a high magnetic moment in order to show a strong reaction to a magnetic field for good actuation performance. Second, it has to be suitable for magnetic particle imaging (MPI). MPI is an emerging medical imaging technique, based on the nonlinear response of superparamagnetic nanoparticles to oscillating magnetic fields. It is aimed at dual use of an MPI scanner: for both actuation and visualization. When applying rotating homogeneous magnetic fields, the swimmer performs an axial movement due to its shape and the viscosity of the surrounding medium. These fields can be generated with an MPI scanner. The swimmer dynamics have been observed and a maximum swimming velocity of 6 mm/s at a rotation frequency of the magnetic field of 10 Hz was found. The experiments are performed with a commercially available preclinical MPI scanner. It is shown, that the swimmer is suitable to be imaged with MPI. Furthermore, sequentially acquired images of a moving swimmer are shown. For this, the MPI scanner was alternately driven in imaging and actuation mode.