Method to rotate an endovascular device around the axis of a vessel using an external magnetic field

A magnetic guidance methodology to rotate a device around the catheter axis is proposed. The specific medical application is to intracranial aneurysms. An endovascular device, the asymmetric stent, has a low porosity region that is rotated to cover the aneurysm neck so as to reduce the blood flow into and hence obliterate the aneurysm. The magnetic guidance system consists of a magnetic device attached to the asymmetric stent and an external homogeneous magnetic field of 0.1 T. This magnetic field puts a torque on the magnetic moment of the magnetic device, thereby rotating the stent for proper orientation. For the magnetic device with the required magnetic moment of 2 0.001 A m, a cylindrical neodymium permanent magnet is proposed due to its favorable material characteristics while a coil electromagnet with iron core appears impractical due to demagnetizing effects. (c) 2007 American Association of Physicists in Medicine.