Remote control of medical devices using a virtual device interface

• US 20040068173A1
• Filed: 05/29/2003
• Published: 04/08/2004
• Est. Priority Date: 08/06/2002
• Status: Active Grant

• Current Assignee: Stereotaxis, Inc.
• Original Assignee: Stereotaxis, Inc.
• Inventors: Viswanathan, Raju R.
• Granted Patent: US 7,630,752 B2
• Time in Patent Office: Days
• US Class Current: 600/407
• CPC Class Codes: A61B 1/005 Flexible endoscopes
• 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 2034/732 arranged around the patient, e.g. in a gantry
• CPC Class Codes: A61B 2034/742 Joysticks
• CPC Class Codes: A61B 2090/376 using X-rays, e.g. fluoroscopy
• CPC Class Codes: A61B 34/70 Manipulators specially adapted for use in surgery
• CPC Class Codes: A61B 34/73 Manipulators for magnetic surgery

Abstract

An interface system and method for controlling a magnetic surgery system by displaying a virtual image of the device, adjusting the configuration of the device or the actuation controls to be applied to the device until the configuration of the displayed device assumes the configuration desired by the user, or selecting a desired target location for the tip, and causing a set of actuation controls to be applied to the actual device to cause the actual device to assume the configuration of the virtual device or to steer the device tip to the desired location.

Claims

1. A method of operating a navigation system that remotely configures the distal end portion of a medical device inside a subject'"'"'s body, the method comprising:

displaying a virtual representation of at least a portion of the medical device, based upon a computational model of the medical device;

accepting inputs made by a user to change the configuration of the portion of the medical device represented by the displayed virtual representation, and updating the virtual representation of the portion of the medical device;

operating the navigation system using the computational model of the medical device to cause the portion of the medical device to conform to the desired configuration represented by the updated virtual representation.

2. The method according to claim 1 wherein the user makes inputs remotely from the subject.

3. The method according to claim 1 wherein the medical device is an elongate medical device having a proximal end outside the subject'"'"'s body, and a distal end inside the subject'"'"'s body, wherein the virtual representation is of at least the distal end portion of the medical device, and wherein the navigation system changes the configuration of at least the distal end portion of the medical device.

4. The method according to claim 3 wherein the step of displaying a virtual representation of the distal end portion of the elongate medical device includes superposing the representation of the end portion of the elongate medical device over a representation of the operating region in the subject.

5. The method according to claim 4 wherein the representation of the operating region in the patient is derived from an x-ray image.

6. The method according to claim 4 wherein the representation of the operating region in the subject is derived from an CT image.

7. The method according to claim 4 wherein the representation of the operating region in the subject is derived from an MR image.

8. The method according to claim 4 wherein the representation of the operating region in the subject is derived from an ultrasound image.

9. The method according to claim 4 wherein the representation of the operating region in the subject is derived from a map of points on surfaces in the operating region.

10. The method according to claim 3 wherein the navigation system operates in response to control variables, and wherein the step of accepting inputs made by a user to change the configuration of the distal end portion of the elongate medical device represented by the displayed virtual representation, comprises accepting desired changes to the control variables of the navigation system, corresponding to desired changes in the operating state of the navigation system, and updating the virtual representation of the distal end portion of the elongate medical device to show the medical device as if the control variables of the navigation system were actually changed.

11. The method according to claim 10 wherein the navigation system comprises at least one external magnet for applying a magnetic field to a magnetically responsive element on the medical device, and wherein the system accepts inputs of desired changes in the magnetic field direction.

12. The method according to claim 3 wherein the step of accepting inputs made by a user to change the configuration of the distal end portion of the elongate medical device represented by the displayed virtual representation, includes accepting input of a new direction for the distal end portion of the elongate medical device.

13. The method according to claim 3 wherein the step of accepting inputs made by a user to change the configuration of the distal end portion of the elongate medical device represented by the displayed virtual representation, includes accepting input of a deflection for the distal end portion of the elongate medical device from its current configuration.

14. The method according to claim 3 wherein accepting inputs made by a user to change the configuration of the distal end portion of the elongate medical device represented by the displayed virtual representation, includes accepting input of a new position for the distal end portion of the elongate medical device.

15. The method according to claim 3 wherein the navigation system comprises elements in the medical device which, when operated, change the configuration of the distal end portion of the medical device.

16. The method according to claim 15 wherein at least some of the elements which change the configuration of the distal end portion of the medical device are electrostrictive elements.

17. The method according to claim 15 wherein at least some of the elements which change the configuration of the distal end portion of the medical device are magnetostrictive elements.

18. The method according to claim 17 further comprising applying a magnetic field from an external source magnet to the magnetostrictive elements change the configuration of the distal end portion of the medical device.

19. The method according to claim 3 wherein the navigation system comprises mechanical links in the medical device which, when translated, change the configuration of the distal end portion of the medical device.

20. The method according to claim 3 wherein the step of operating the navigation system occurs automatically after the inputs by the user are accepted.

21. The method according to claim 3 wherein the step of operating the navigation system only occurs after an input by the user.

22. The method according to claim 3 wherein the computational model is based at least in part on the physical characteristics of the medical device.

23. The method according to claim 22 wherein the computational model is based at least in part on a mathematical representation of at least one physical characteristic of the medical device.

24. The method according to claim 22 wherein the computational model is based at least in part on measurements of at least one physical characteristic of the medical device.

25. The method according to claim 3 wherein the position of the distal end portion of the medical device is controlled by an advancing and retracting mechanism, and wherein the method further comprises accepting inputs made by the user to change the position of the distal end portion of the medical device, and updating the virtual representation of the distal end portion of the elongate medical device;

and operating the advancing and retracting mechanism to cause the distal end portion of the elongate medical device to conform to the desired position represented by the updated virtual representation.

26. The method according to claim 3 further comprising determining the actual position and configuration of the distal end portion of the medical device, comparing the actual position and configuration of the distal end portion of the medical device, with the position and configuration given by a computational model to determine the force of contact between the medical device and tissue in the operating region by computational means.

27. A method of operating a navigation system that remotely configures the distal end portion of a flexible medical device inside a subject'"'"'s body to reach a target, the method comprising;

displaying a representation of the operating region;

accepting an input of the configuration of a portion of the device and displaying a representation of the configuration of said portion;

accepting an input of a target on the display of the operation region;

determining the inputs necessary to the navigation system to cause the medical device to reach the target based upon a computational model of the medical device and the navigation system;

applying the determined inputs to the navigational system to cause the medical device to reach the target.

28. The method according to claim 27 wherein the medical device is an elongate medical device having a proximal end outside the subject'"'"'s body, and a distal end inside the subject'"'"'s body.

29. The method according to claim 28 wherein the navigation system can both change the configuration of the distal end portion of the medical device and advance or retract the distal end of the elongate medical device.

30. The method according to claim 28 wherein the navigation system comprises at least one magnet that applies a magnetic field of selected direction to a magnetically responsive element on the medical device, and wherein determining the inputs necessary to the navigation system to cause the elongate medical device to reach the target based upon a computational model of the elongate medical device and the navigation system includes determining the magnetic field direction needed to cause the medical device to reach the target based upon the computational model.

31. The method according to claim 30 herein determining the inputs necessary to the navigation system to cause the elongate medical device to reach the target based upon a computational model of the elongate medical device and the navigation system includes determining the magnetic field strength needed to cause the medical device to reach the target based upon the computational model.

32. The method according to claim 30 wherein the user makes inputs remotely from the subject.

33. The method according to claim 30 wherein the step of displaying a virtual representation of the distal end portion of the elongate medical device includes superposing the representation of the end portion of the elongate medical device over a representation of the operating region in the subject.

34. The method according to claim 33 wherein the representation of the operating region in the subject is derived from an x-ray image.

35. The method according to claim 33 wherein the representation of the operating region in the subject is derived from an CT image.

36. The method according to claim 33 wherein the representation of the operating region in the subject is derived from an MR image.

37. The method according to claim 33 wherein the representation of the operating region in the subject is derived from an ultrasound image.

38. The method according to claim 33 wherein the representation of the operating region in the subject is derived from a map of points on surfaces in the operating region.

39. The method according to claim 27 wherein the navigation system comprises at least one external magnet for applying a magnetic field to a magnetically responsive element on the elongate medical device, and wherein the control inputs include changes in the magnetic field direction.

40. The method according to claim 27 wherein the navigation system comprises elements in the medical device which, when operated by the navigation system, change the configuration of the distal end portion of the medical device.

41. The method according to claim 40 wherein at least some of the elements which change the configuration of the distal end portion of the medical device are electrostrictive elements.

42. The method according to claim 40 wherein at least some of the elements which change the configuration of the distal end portion of the medical device are magnetostrictive elements.

43. The method according to claim 40 wherein the navigation system comprises mechanical links in the medical device which, when translated, change the configuration of the distal end portion of the medical device.

44. The method according to claim 27 wherein the step of operating the navigation system occurs automatically after the inputs by the user are accepted.

45. The method according to claim 27 wherein the step of operating the navigation system only occurs after an input by the user.

46. The method according to claim 27 wherein the computational model is based at least in part on the physical characteristics of the medical device.

47. The method according to claim 46 wherein the computational model is based at least in part on a mathematical representation of at least one physical characteristic of the medical device.

48. The method according to claim 46 wherein the computational model is based at least in part on measurements of at least one physical characteristic of the medical device.

49. A method of navigating the distal end of a medical device having a magnetically responsive element through the application of a magnetic field from an external source magnet, the method comprising:

accepting inputs from the user of a desired magnetic field;

displaying a virtual representation of the configuration of the distal end of the medical device as if the desired magnetic field were applied;

accepting an instruction from the user to apply the desired magnetic field.

50. A method of navigating the distal end of a medical device having a magnetically responsive element through the application of a magnetic field from an external source magnet, the method comprising:

identifying a plurality of points on an image of the distal end portion of the medical device while a known magnetic field is applied to the distal end portion of the medical device;

processing the identified points to determine at least one geometrical characteristic of the distal end of the medical device;

allowing the user to input a desired magnetic field;

displaying a virtual representation of the distal end of the medical device as if the desired magnetic field were applied;

allow the user to input an instruction to apply the desired magnetic field and reorient the medical device.

51. A method of navigating the distal end of a flexible medical device having actuation elements controlled by applying a set of actuation controls, the method comprising:

displaying a virtual representation of the distal end portion of the medical device;

in response to inputs of desired changes in the shape and orientation of the distal end of the medical device that can be effected by changing the applied actuation controls, updating the displayed virtual representation of the distal end portion of the medical device by using a computational physics-based model for device deformation together with device properties;

in response to an input by the user, applying a set of actuation controls which is based upon the properties of the distal end portion of the medical device that will configure the distal end in the desired shape and orientation.

52. A method of specifying a set of actuation controls to apply to a set of remotely actuated elements at the distal end of a flexible medical device in an operating region in a patient, the method comprising:

identifying points on the distal end of the medical device on an image of the operating region;

based upon information about the distal end of the medical device from the identified points, displaying a reconstructed virtual image of the medical device that can be computationally manipulated as if a new magnetic field were applied to the device;

accepting inputs from the user to change the configuration of the virtual image of the medical device.;

applying actuation controls to actuate the actual medical device in the operating region as computed from a combination of user-specified inputs and a computational model of device physics, corresponding to the user-manipulated virtual image.

53. A method of specifying a set of actuation controls to apply to a set of remotely actuated elements at the distal end of a flexible medical device in an operating region in a patient, the method comprising:

identifying points on the distal end of the medical device on an image of the operating region;

based upon information about the distal end of the medical device from the identified points, displaying a reconstructed virtual image of the medical device that can be computationally manipulated as if a new magnetic field were applied to the device;

accepting inputs from the user identifying a target location on the image of the operating region that the user desires the device tip to reach;

applying actuation controls to actuate the actual medical device in the operating region as computed from a combination of user-specified inputs and a computational model of device physics, corresponding to the user-specified tip location.

54. A method of specifying a set of actuation controls to apply to a set of remotely actuated elements at the distal end of a flexible medical device in an operating region in a patient, the method comprising:

use of device localization data at one or more points on the device to reconstruct the current device configuration;

displaying a reconstructed virtual image of the medical device that can be computationally manipulated as if a new set of actuation controls were applied to the device;

accepting inputs from the user to change the configuration of the virtual image of the medical device;

applying actuation controls to actuate the actual medical device in the operating region as computed from a combination of user-specified inputs and a computational model of device physics, corresponding to the user-manipulated virtual image.

55. A method of specifying a set of actuation controls to apply to a set of remotely actuated elements at the distal end of a flexible medical device, the method comprising:

use of device localization data at one or more points on the device to reconstruct the current device configuration;

displaying a reconstructed virtual image of the medical device that can be computationally manipulated as if a new set of actuation controls were applied to the device;

accepting inputs from the user to identify a target location on the display that the user desires the device tip to reach;

applying actuation controls to actuate the actual medical device in the operating region as computed form a combination of user-specified inputs and a computational model of device physics, corresponding to the user-specified tip location.

56. A method of navigating the distal end of a flexible medical device having a set of remotely actuated elements through the application of a remote set of actuation controls, the method comprising:

identifying a plurality of points on two projected images of the distal end portion of the medical device while a known (or zero) set of actuation controls is applied to the distal end portion of the medical device;

identifying a desired location for the tip of the device on one or both planes of projected images of the device and its operating environment, or on a three-dimensional regional electrical map or its projections;

computer calculation based upon the elastic and magnetic properties of the device and automatic drawing of one or more of;

(a) a locus of possible locations of the medial device tip within the plane of the distal device tip, shown on one or both planes of the projected images(s);

(b) an accessible surface of possible locations that can be accessed by the device tip by a combination of deflection and axial rotation, shown on one or both planes of the projected image(s);

(c) said locus or accessible surface rendered together with device tip in a three-dimensional graphical view;

identifying a desired location for the tip of the device as a point on said locus or on said accessible surface in either image plane, three dimensional graphical view, or regional electrical activity map;

computation of a set of actuation controls and device advancement/retraction that will enable the device to closely reach the desired tip location;

use of a computer-controlled device advancer to control advancement and retraction of said device;

instructing the computer to automatically advance the device to the selected point by application of appropriate actuation controls and device advancer movements; and

displaying one or more of (a) a new set of projected images of the device and its operating environment, or (b) a new three-dimensional regional electrical map or its projections.

57. A method of navigating the distal end of a flexible medical device having a set of remotely actuated elements through the application of a set of actuation controls, the method comprising:

identifying a plurality of points on two projected images of the distal end portion of the medical device while a known (or zero) set of actuation controls is applied to the distal end portion of the medical device;

identifying a desired location for the tip of the device on one or both planes of projected images of the device and its operating environment, or on a three-dimensional region electrical map or its projections;

computer calculation based upon the elastic and magnetic properties of the device and automatic drawing of one or more of;

(a) a locus of possible locations of the medical device tip within the plan of the distal device tip, shown on one or both planes of the bi-plane image;

(b) an accessible surface of possible locations that can be accessed by the device tip by a combination of deflection and axial rotation, shown on one or both planes of the projected image(s);

(c) said locus or accessible surface rendered together with device tip in a three-dimensional graphical view;

identifying a desired location for the tip of the device as a point that is beyond said locus or said accessible surface in either image plane, three-dimensional graphical view, or regional electrical activity map;

computation of a set of actuation controls and device advancement/retraction that will enable the device to closely reach the desired tip location;

use of a computer-controlled device advancer to control advancement and retraction of said device;

instructing the computer to automatically advance the device to the selected point by application of appropriate magnetic fields and device advancer movements; and

displaying one or more of (a) a new set of projected images of the device and its operating environment, or (b) a new three-dimensional regional electrical map or its projections.

58. A method of navigating the distal end of a magnetically guideable catheter, whose distal tip is orientable with an applied magnetic field, and whose free length from the distal end of a guide sheath is telescopingly adjustable, to a selected target point in an operating region in a subject, the method comprising:

using a computational model of the catheter and information about the position and orientation of the distal end of the guide sheath to determine the magnetic field to apply and to determine the free length to extend the catheter from the guide sheath to cause the distlal tip to reach the target point.

59. The method according to claim 58 further comprising displaying a virtual image of the catheter as if the determined magnetic field was applied to the distal tip and the catheter was extended to the determined free length.

60. The method according to claim 59 further comprising applying the determined magnetic field to the distal tip and extending the catheter from the guide sheath to the determined free length.

61. A method of navigating the distal end of an orientable catheter, whose distal tip is orientable with an applied control variable, and whose free length from the distal end of a guide sheath is telescopingly adjustable, to a selected target point in an operating region in a subject, the method comprising:

using a computational model of the catheter and information about the position and orientation of the distal end of the guide sheath to determine the control variable to apply and to determine the free length to extend the catheter from the guide sheath to cause the distlal tip to reach the target point.