N. Nothnagel, J. Rahmer, B. Gleich, A. Halkola, T.M. Buzug, J. Borgert, University of Lübeck, Philips Technologie GmbH, Germany.
Magnetic manipulation is a promising approach that enables contact-free manipulation of devices inside a patient. By controlling magnetic forces, new medical applications become possible, such as magnetically guided catheters or magnetic steering of camera pills. A newly developed magnetic particle imaging (MPI) system combines fast imaging with a flexible and powerful field applicator. This work demonstrates that it is therefore well suited for controlled steering of small magnetic devices.
To this end, the MPI imaging sequence is adapted to magnetic steering by implementing a closed feedback loop for 3D device localization and force actuation. The high field gradients of up to 2.5 T/m/μ0 and the high imaging rate of more than 40 volumes/second render the MPI system a powerful tool for the controlled application of translational forces on magnetic material. Several types of magnetic materials are evaluated with respect to their MPI signal performance, leading to a first prototype design of an MPI steering device. Experimental evidence is presented, demonstrating that small magnetic devices can be steered in arbitrary direction and with variable force. Due to the strong forces that can be achieved, the prototype device can be easily steered against the gravitational force, but also against flow.
Keywords: Magnetic Particle Imaging, Magnetic Steering, Magnetic Devices, Magnetic Actuation