A variable
magnet system for manipulating a magnetic
catheter is described. In one embodiment, a cluster of electromagnets is configured to generate a desired
magnetic field. In one embodiment, one or more poles of the cluster are moveable with respect to other poles in the cluster to allow shaping of the
magnetic field. In one embodiment, one or more
magnetic poles can be extended or retracted to shape the
magnetic field. In one embodiment, the electromagnets can be positioned to generate magnetic fields that exert a desired torque and / or movement force on the
catheter. In one embodiment, the
catheter guidance system includes a closed-loop
servo feedback
system. In one embodiment, a
radar system is used to determine the location of the distal end of the catheter inside the body, thus, minimizing or eliminating the use of
ionizing radiation such as X-rays. The catheter
guidance system can also be used in combination with an X-
ray system (or other imaging systems) to provide additional imagery to the operator. The magnetic system used in the magnetic catheter
guidance system can also be used to locate the catheter tip to provide location feedback to the operator and the
control system. In one embodiment, a magnetic field source is used to create a magnetic field of sufficient strength and orientation to move a magnetically-responsive catheter tip in a desired direction by a desired amount.