Apparatus and method for shaped magnetic field control for catheter, guidance, control, and imaging

• US 20070016006A1
• Filed: 05/27/2005
• Published: 01/18/2007
• Est. Priority Date: 05/27/2005
• Status: Active Grant

• Current Assignee: Neuro-Kinesis Corporation
• Original Assignee: Magnetecs Incorporated
• Inventors: Shachar, Yehoshua
• Granted Patent: US 8,027,714 B2
• Time in Patent Office: Days
• US Class Current: 600/424
• CPC Class Codes: A61B 1/00158 using magnetic field
• CPC Class Codes: A61B 2017/00703 correcting for movement of heart, e.g. ECG-triggered
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/2063 Acoustic tracking systems, e.g. using ultrasound
• CPC Class Codes: A61B 2034/732 arranged around the patient, e.g. in a gantry
• CPC Class Codes: A61B 2090/376 using X-rays, e.g. fluoroscopy
• CPC Class Codes: A61B 34/25 User interfaces for surgical systems
• CPC Class Codes: A61B 34/70 Manipulators specially adapted for use in surgery
• CPC Class Codes: A61B 34/73 Manipulators for magnetic surgery
• CPC Class Codes: A61B 34/77 Manipulators with motion or force scaling
• CPC Class Codes: A61B 5/0507 using microwaves or terahertz waves
• CPC Class Codes: A61B 5/06 Devices, other than using radiation, for detecting or locating foreign bodies for removing same A61B17/50 ; determining position of probes within or on the body of the patient
• CPC Class Codes: A61B 5/062 using magnetic field
• CPC Class Codes: A61M 2025/0166 Sensors, electrodes or the like for guiding the catheter to a target zone, e.g. image guided or magnetically guided
• CPC Class Codes: A61M 25/0127 Magnetic means; Magnetic markers

Abstract

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.

Claims

1. An apparatus for controlling the movement of a catheter-type tool inside a body of a patient, comprising:

a magnetic field source for generating a magnetic field, said magnetic field source comprising a first coil corresponding to a first magnetic pole and a second coil corresponding to a second magnetic pole, wherein said first magnetic pole is moveable with respect to said second magnetic pole; and

a system controller for controlling said magnetic field source to control a movement of a distal end of a catheter, said distal end responsive to said magnetic field, said controller configured to control a current in said first coil, a current in said second coil, and a position of said first pole with respect to said second pole.

2. The apparatus of claim 1, said system controller comprises a closed-loop feedback servo system.

3. The apparatus of claim 1, said distal end comprising one or more magnetic field sensors.

4. The apparatus of claim 1, said distal end comprising one or more magnetic field sensors for providing sensor data to said system controller.

5. The apparatus of claim 1, further comprising an operator interface unit.

6. The apparatus of claim 1, wherein said servo system comprises a correction factor that compensates for a dynamic position of an organ, thereby offsetting a response of said distal end to said magnetic field such that said distal end moves in substantial unison with said organ.

7. The apparatus of claim 6, wherein said correction factor is generated from an auxiliary device that provides correction data concerning said dynamic position of said organ, and wherein when said correction data are combined with measurement data derived from said sensory apparatus to offset a response of said servo system so that said distal end moves substantially in unison with said organ.

8. The apparatus of claim 7, wherein said auxiliary device is at least one of an X-ray device, an ultrasound device, and a radar device.

9. The apparatus of claim 1, wherein said system controller includes a Virtual Tip control device to-allow user control inputs.

10. The apparatus of claim 1, wherein said first magnetic pole is extended and retracted by a hydraulic piston.

11. The apparatus of claim 1, further comprising:

first controller to control said first coil; and

a second controller to control said second coil.

12. The apparatus of claim 11, wherein said first controller receives feedback from a magnetic field sensor.

13. The apparatus of claim 12, wherein said magnetic field sensor comprises a Hall effect sensor.

14. The apparatus of claim 1, wherein said system controller coordinates flow of current through said first and second coils according to inputs from a Virtual tip.

15. The apparatus of claim 14, wherein said Virtual Tip provides tactile feedback to an operator.

16. The apparatus of claim 14, wherein said Virtual Tip provides tactile feedback to an operator according to a position error between an actual position of said distal end and a desired position of said distal end.

17. The apparatus of claim 14, wherein said system controller causes said distal end to follow movements of said Virtual Tip.

18. The apparatus of claim 14, further comprising:

a mode switch to allow a user to select a force mode and a torque mode.

35. The apparatus of claim 1, wherein a correction input is generated by an auxiliary device that provides correction data concerning a dynamic position of an organ, and wherein said correction data are combined with measurement data from said radar system to offset a response of said control system so that said distal end moves substantially in unison with said organ.

36. The apparatus of claim 35, wherein said auxiliary device comprises at least one of an X-ray device, an ultrasound device, and a radar device.

19. 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 is extendable;

a radar system configured to produce a radar image of organs of said body; and

one or more magnetic sensors to sense a magnetic field.

20. The apparatus of claim 19, said distal end comprising one or more magnetic field sensors.

21. The apparatus of claim 19, said distal end comprising one or more magnetic field sensors for providing sensor data to a system controller.

22. The apparatus of claim 19, further comprising an operator interface unit.

23. The apparatus of claim 19, wherein said first cluster of poles is coupled to said second cluster of poles by a magnetic material.

24. 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;

controlling a plurality of electric currents and pole positions to produce said magnetic field; and

measuring a location of said distal end.

25. The method of claim 24, further comprising controlling one or more electromagnets to produce said magnetic field.

26. The method of claim 24, further comprising simulating a magnetic field before creating said magnetic field.

27. 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 outside the body;

a hydraulic system to extend and retract a magnetic core relating to a coil provided to said magnetic core said magnetic field source with respect to the body;

a radar 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.

28. The apparatus of claim 27, said system controller comprising a closed-loop feedback servo system.

29. The apparatus of claim 27, said radar system comprising an impulse radar.

30. The apparatus of claim 27, said distal end comprising one or more magnets.

31. The apparatus of claim 27, where said system controller calculates a position error and controls said magnetic field source to move said distal end in a direction to reduce said position error.

32. The apparatus of claim 27, where said system controller integrates a position data of said distal end with a set of fiduciary markers.

33. The apparatus of claim 27, where said system controller synchronizes a location of said distal end with a fluoroscopic image.

34. The apparatus of claim 27, further comprising an operator interface unit.

37. The apparatus of claim 27, wherein said user input device comprises a virtual tip control device to allow user control inputs.

38. The apparatus of claim 27, further comprising a virtual tip with force feedback.

39. The apparatus of claim 27 wherein a first coil cluster is fitted with shield for flux return.

40. The apparatus of claim 27, further comprising a boundary condition controller, and where computing the fields in the surroundings of the catheter based on the fields on 2D planes.

41. The apparatus of claim 27, wherein a button allows the controller to switch from torque control to force control.

42. The apparatus of claim 27, wherein said system controller is configured to produce coil current polarities and magnitudes are generated to produce desired field directions for torque and force field is established.

43. The apparatus of claim 27, a low level logic simulation of action is provided.