Method and apparatus for magnetic waveguide forming a shaped field employing a magnetic aperture for guiding and controlling a medical device

An apparatus for controlling the movement of a catheter-like tool to be inserted into the body of a patient, comprising:

• a controllable magnetic field source having a first cluster of poles and a second cluster of poles, wherein at least one pole in said first cluster of poles comprises an anisotropic pole piece, said anisotropic pole piece comprising a core member and a poleface member, said core member and said poleface member comprising different compositions of magnetic material, said first cluster of poles and said second cluster of poles disposed to direct a shaped magnetic field in a region between said first cluster of poles and said second cluster of poles;
• a first group of electromagnet coils provided to said first cluster of poles and a second group of electromagnet coils provided to said second cluster of poles;
• and
• a controller to control electric currents in said first group of electromagnet coils and said second group of electromagnet coils to produce said shaped magnetic field.

A method for controlling movement of a tool having a distal end to be inserted in a body, comprising:

• calculating a desired direction of movement for said distal end;
• computing a magnetic field needed to produce said movement, said magnetic field computed according to a first bending mode of said distal end and a second bending mode of said distal end;
• controlling a plurality of electric currents and pole positions to produce said magnetic field;
• and
• measuring a location of said distal end.

An apparatus for controlling the movement of a catheter-like tool having a distal end responsive to a magnetic field and configured to be inserted into the body of patient, comprising:

• a magnetic field source for generating a magnetic field, said magnetic source comprising an electromagnet, said electromagnet comprising:
• an electromagnet coil;
• a pole piece core;
• and
• a poleface insert, said poleface insert having a different permeability than said pole piece core;
• a sensor system to measure a location of said distal end;
• a sensor system to measure positions of a plurality of fiduciary markers;
• a user input device for inputting commands to move said distal end;
• and
• a system controller for controlling said magnetic field source in response to inputs from said user input device, said radar system, and said magnetic sensors.