Apparatus for magnetically deployable catheter with MOSFET sensor and method for mapping and ablation

• US 20070197891A1
• Filed: 02/23/2006
• Published: 08/23/2007
• Est. Priority Date: 02/23/2006
• Status: Active Grant

• Current Assignee: Neuro-Kinesis Corporation
• Original Assignee: Magnetecs Incorporated
• Inventors: Gang, Eli, Shachar, Yehoshua, Farkas, Laszlo
• Granted Patent: US 7,869,854 B2
• Time in Patent Office: Days
• US Class Current: 600/374
• CPC Class Codes: A61B 18/1492 having a flexible, catheter-like structure, e.g. for heart ablation A61B18/1477 takes precedence
• CPC Class Codes: A61B 2017/00026 Conductivity or impedance, e.g. of tissue
• CPC Class Codes: A61B 2017/0011 piezoelectric
• CPC Class Codes: A61B 2018/00214 Expandable means emitting energy, e.g. by elements carried thereon
• CPC Class Codes: A61B 2018/00839 Bioelectrical parameters, e.g. ECG, EEG
• CPC Class Codes: A61B 2018/1467 using more than two electrodes on a single probe
• CPC Class Codes: A61B 2018/183 characterised by the type of antenna
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/301 for introducing or steering flexible instruments inserted into the body, e.g. catheters or endoscopes
• CPC Class Codes: A61B 2034/742 Joysticks
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 34/73 Manipulators for magnetic surgery
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/33 specially adapted for cooperation with other devices
• CPC Class Codes: A61B 5/7285 for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence
• CPC Class Codes: A61B 6/541 involving acquisition triggered by a physiological signal
• CPC Class Codes: A61B 8/543 involving acquisition triggered by a physiological signal

Abstract

A mapping and ablation catheter is described. In one embodiment, the catheter includes a MOSFET sensor array that provides better fidelity of the signal measurements as well as data collection and reduces the error generated by spatial distribution of the isotropic and anisotropic wavefronts. In one embodiment, the system maps the change in potential in the vicinity of an activation wavefront. In one embodiment, the mapping system tracks the spread of excitation in the heart, with properties such as propagation velocity changes. In one embodiment, during measurement, the manifold carrying the sensor array expands from a closed position state to a deployable open state. Spatial variation of the electrical potential is captured by the system'"'"'s ability to occupy the same three-dimensional coordinate set for repeated measurements of the desired site. In one embodiment, an interpolation algorithm tracks the electrogram data points to produce a map relative to the electrocardiogram data.

Claims

1. A catheterization system, comprising:

a catheter having a catheter distal end for insertion into a patient, said distal end configured with a first deployable member and a second deployable member;

a first MOSFET sensor provided to a distal end of said first deployable member;

a second MOSFET sensor provided to a distal end of said second deployable member;

a first electrical contact provided to said first deployable member, said first electrical contact configured to make electrical contact with tissue;

a second electrical contact provided to said second deployable member, said second electrical contact configured to make electrical contact with tissue; and

a deployment mechanism configured to increase a separation between said distal end of said first deployable member and said distal end of said second deployable member.

2. The catheterization system of claim 1, said catheter distal end further comprising a magnet.

3. The catheterization system of claim 2, wherein said deployment mechanism comprises a coil provided to said first deployable member and to said second deployable member.

4. The catheterization system of claim 2, wherein said coil is configured to increase a separation between said distal end of said first deployable member and said distal end of said second deployable member when current is provided to said coil.

5. The catheterization system of claim 1, wherein said first electrical contact comprises a PN junction.

6. The catheterization system of claim 1, wherein said first electrical contact comprises a first PN junction oriented such that P material of said first PN junction is provided to said tissue and said second electrical contact comprises a second PN junction oriented such that N material of said second PN junction is provided to said tissue.

7. The catheterization system of claim 1, wherein said first electrical contact comprises a first and said second electrical contact comprises a second PN junction, wherein an said first and second PN junctions are configured with opposite polarity.

8. The catheterization system of claim 1, wherein said first electrical contact comprises an antenna.

9. The catheterization system of claim 1, wherein said catheter comprises a lumen.

10. The catheter system of claim 1, further 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 said catheter distal end, 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.

11. The catheterization system of claim 10, said system controller comprises a closed-loop feedback servo system.

12. The catheterization system of claim 10, wherein one or more magnetic field sensors are used to measure said magnetic field.

13. The catheterization system of claim 10, said distal end comprising one or more magnetic field sensors.

14. The catheterization system of claim 10, said distal end comprising one or more magnetic field sensors for providing sensor data to said system controller.

15. The catheterization system of claim 1, further comprising an operator interface unit.

16. The catheterization system of claim 10, wherein said servo system comprises a correction factor that compensates for a dynamic position of an organ, thereby offsetting a response of said catheter distal end to said magnetic field such that said distal end moves in substantial unison with said organ.

17. The catheterization system of claim 16, 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 catheterization system to offset a response of said servo system so that said distal end moves substantially in unison with said organ.

18. The catheterization system of claim 17, wherein said auxiliary device is at least one of an X-ray device, an ultrasound device, and a radar device.

19. The catheterization system of claim 10, wherein said system controller includes a Virtual Tip control device to allow user control inputs.

20. The catheterization system of claim 10, wherein said first magnetic pole is extended and retracted by a hydraulic piston.

21. The catheterization system of claim 10, further comprising:

first controller to control said first coil; and

a second controller to control said second coil.

22. The catheterization system of claim 21, wherein said first controller receives feedback from a magnetic field sensor.

23. The catheterization system of claim 22, wherein said magnetic field sensor comprises a Hall effect sensor.

24. The catheterization system of claim 10, wherein said system controller coordinates flow of current through said first and second coils according to inputs from a Virtual tip.

25. The catheterization system of claim 24, wherein said Virtual Tip provides tactile feedback to an operator.

26. The catheterization system of claim 24, 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.

27. The catheterization system of claim 24, wherein said system controller causes said distal end to follow movements of said Virtual Tip.

28. The catheterization system of claim 24, further comprising:

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

29. The catheterization system of claim 10, further 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.

30. The catheterization system of claim 29, said distal end comprising one or more magnetic field sensors.

31. The catheterization system of claim 29, said distal end comprising one or more magnetic field sensors for providing sensor data to a system controller.

32. The catheterization system of claim 29, further comprising an operator interface unit.

33. The catheterization system of claim 29, wherein said first cluster of poles is coupled to said second cluster of poles by a magnetic material.

34. A catheterization method, comprising:

guiding a distal end of a catheter to a desired region of tissue;

spreading sensor arms of said catheter;

establishing contact between said sensor arms and the region of tissue;

sensing a position of said sensor arms;

measuring activation potential data using sensors provided to said sensor arms;

measuring impedance data of tissue between said sensor arms using contacts provided to said sensor arms; and

displaying a map of activation potential and impedance of said region of tissue.

35. The method of claim 34, further comprising using said activation potential data and said impedance data in a calculation to predict an RF ablation lesion.

36. The method of claim 35, further comprising creating an RF ablation lesion.

37. The method of claim 34, wherein said sensors comprise MOSFET sensors.

38. The method of claim 34, wherein said contacts comprise PN junctions.

39. The method of claim 34, wherein said contacts comprise alternating PN junctions.

40. The method of claim 34, further comprising calculating an angle between an E vector and an energy vector in said region of tissue.

41. The method of claim 40, further comprising identifying anomalies in activation vector spreads where an angle between said E vector and said energy vector exceeds a threshold.

42. The method of claim 34, wherein said position of said sensor arms is measured using radar.

43. The method of claim 34, wherein said position of said sensor arms is measured using X-rays.

44. The method of claim 34, further 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.

45. The method of claim 34, further comprising controlling one or more electromagnets to produce said magnetic field.

46. The method of claim 34, further comprising simulating a magnetic field before creating said magnetic field.