Method and apparatus for determining tracking a virtual point defined relative to a tracked member

• US 8,340,751 B2
• Filed: 04/13/2009
• Issued: 12/25/2012
• Est. Priority Date: 04/18/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Markowitz, H. Toby, Karamanoglu, Mustafa, Mehta, Pooja, Fleming, Ioana, Scanlon, David A., Kryger, Michael, Campbell-Massa, Sean, Giese, Chad, Waldhauser, Steven L., Zhang, Shangqian Peter, Jannicke, Jeff, Falkner, Phillip, Hefner, Don, Warman, Eduardo N., Steeves, James, Receveur, Rogier, Michels, Koen, Eick, Olaf, Larik, Vincent
• Primary Examiner(s): Layno, Carl H
• Assistant Examiner(s): KIMBALL, JEREMIAH T
• Application Number:
  US12/422,689
• Publication Number:
  US 20090262980A1
• Time in Patent Office: 1,352 Days
• Field of Search: 600/523
• US Class Current: 600/523
• CPC Class Codes: A61B 2034/2046 Tracking techniques
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• 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 5/0215 by means inserted into the body catheters A61M25/00
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• 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: A61B 5/066 Superposing sensor position on an image of the patient, e.g. obtained by ultrasound or x-ray imaging
• CPC Class Codes: A61B 5/068 using impedance sensors
• CPC Class Codes: A61B 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• CPC Class Codes: G06F 18/00 Pattern recognition
• CPC Class Codes: G06V 20/64 Three-dimensional objects
• CPC Class Codes: G06V 2201/03 Recognition of patterns in medical or anatomical images
• CPC Class Codes: G06V 2201/034 of medical instruments

Abstract

An volume of a patient can be mapped with a system operable to identify a plurality of locations and save a plurality of locations of a mapping instrument. The mapping instrument can include one or more electrodes that can sense a voltage that can be correlated to a three dimensional location of the electrode at the time of the sensing or measurement. Therefore, a map of a volume can be determined based upon the sensing of the plurality of points without the use of other imaging devices. An implantable medical device can then be navigated relative to the mapping data.

Claims

1. A method of determining map data of a surface of a cavity within a patient with an instrument, comprising:

positioning the instrument within the cavity;

expanding a portion of the instrument to form an expanded surface having a substantially non-compressible contour;

determining a position of a first position element and a second position element, both spaced apart from the expanded surface;

determining a geometry of the expanded surface relative to the first position element;

identifying at least one virtual position element relative to the first position element based on the geometry of the expanded surface;

moving the instrument within the cavity so as to engage a wall of the cavity with the at least one virtual position element, wherein the contour of the expanded surface is maintained as the instrument is moved to a plurality of wall locations;

determining a position within the cavity of the at least one virtual position element based on only the determined positions of the first and second position elements and the geometry of the expanded surface;

and collecting the determined positions of the first and second position elements and the determined positions of the at least one virtual position element.

2. The method of claim 1, wherein determining a position within the cavity of the at least one virtual position element includes:

identifying a plurality of virtual position elements relative to the first position element;

determining a position within the cavity of all the plurality of virtual position elements;

generating map data based on changes in position of the determined position within the cavity of all of the plurality of virtual position elements; and

displaying the generated map data.

3. The method of claim 2, wherein identifying at least one virtual position element includes:

determining a line extending from the first position element; and

determining a position at a longitudinal distance from the first position element along the determined line and a radial distance from the determined line based on of the; and

identifying the at least one virtual position element as the determined position.

4. The method of claim 1, wherein the position of the at least one virtual position element within the cavity is determined based on sensing an electrical property with the first and second position elements.

5. The method of claim 4, wherein the expanded surface is on an inflatable balloon;

and wherein the determined geometry is the geometry of the balloon relative to the first position element.

6. The method of claim 2, wherein determining a position within the cavity of a plurality of position elements includes:

determining area on the expanded surface defined by the plurality of the virtual position elements;

collecting the area at a plurality of positions within the cavity; and

wherein displaying the generated map includes displaying the collected area at the plurality of positions.

7. The method of claim 6, wherein the area on the expanded surface is substantially defined by an inflatable member;

wherein the area of the inflatable member is operable to contact a wall of the cavity to define the map data.

8. The method of claim 7, further comprising:

positioning the instrument in a heart of the patient;

wherein'"'"' the wall of the cavity is defined by an internal heart wall of the patient.

9. The method of claim 1, wherein identifying at least one virtual position element includes:

determining an area on the expanded surface relative to the first position element.

10. The method according to claim 1, comprising:

tracking a position of the first position element in the patient;

collecting positions of the first position element;

determining a validity of the collected positions;

generating a map based on the collected positions;

displaying the map on a display device;

measuring a rhythmic feature of the patient;

wherein tracking the first position element, includes at least one of;

selecting between a uni-polar and bi-polar collection of positions;

determining whether an interfering frequency is present during or prior to collecting the positions;

fixing a location of a first position element relative to a second position element;

moving a flexible member with the first position element relative to a second position element at a fixed position and measuring the position of the first position element relative to the second position element;

measuring a temperature within the patient at at least one of the first position element and the second position element; and

displaying on a display device at least one of;

a corrected map data generated by reducing distortion of a measured position of an instrument by determining a scaling factor between two position elements of the instrument;

a pseudo location of an axis patch electrode relative to the map;

a location of a reference electrode relative to the map;

a location of a feature determined by generating a filled volume and determining curvilinear portions to be displayed relative to the filled volume with the instrument;

a map point determined by generating a virtual point based on a known position of a physical portion of the instrument relative to a position element of the instrument;

a map based on locations categorized relative to the measured rhythmic feature;

a virtual map data point determined based on a geometry of the instrument relative to a position element; and

a location of an introducer though which the instrument or the procedure instrument is passed.

11. A method of generating a map of an internal surface of a cavity of a patient, comprising:

inserting an instrument into the cavity;

expanding a portion of the instrument to form a substantially non-compressible surface having a contour;

determining a position of a first position element and a second position element relative to the substantially non-compressible surface;

determining a geometry of the instrument;

identifying at least one virtual position element on the substantially non-compressible surface based on the determined geometry;

moving the instrument with respect to the cavity so as to engage a wall of the cavity with the substantially non-compressible surface while maintaining the contour;

contacting the at least one virtual position element with a plurality of cavity wall locations while maintaining the contour;

determining a position within the cavity of the at least one virtual position element based on only a determined position within the cavity of the first and second position elements and the determined geometry;

collecting a plurality of determined positions within the cavity of the first and second position elements and the at least one virtual position element at the plurality of wall locations;

and generating a map of the internal surface of the cavity based on incidences of engagements of the at least one virtual position element with the plurality of walls locations and at least one of;

the determined positions within the cavity of the first and second position elements and the at least one virtual position element.

12. The method of claim 11, further comprising;

positioning the instrument in a heart of the patient;

wherein the generated map includes a graphical representation of an internal wall of the heart of the patient.

13. The method of claim 11, further comprising:

storing the plurality of collected determined positions; and

illustrating a representation of the internal surface of the cavity based on the stored plurality of the collected determined positions.

14. The method of claim 11, wherein identifying at least one virtual position element relative to the geometry of the instrument includes:

determining a geometry of the instrument relative to the first position element;

defining an area on the substantially non-compressible surface based on the determined geometry; and

determining a position of the area on the substantially non-compressible surface based on the position of the first position element.

15. The method of claim 11, wherein determining a position within the cavity of the at least one virtual position element based on a determined position of the first and second position elements, includes:

injecting a current into the patient between at least a set of axis generation electrodes;

sensing a voltage at both the first and second position elements within the cavity based on the injected current; and

determining a position within the cavity of the first and second position elements based on the sensed voltage.

16. The method of claim 13, further comprising:

defining the at least one virtual position element by the substantially non-compressible surface of the instrument with a known geometry relative to the first position element; and

wherein illustrating a representation of the internal surface of the cavity includes only contacting the internal surface of the cavity with the substantially non-compressible surface of the instrument.

17. A system to determine a position of an instrument in a heart of a patient, comprising:

an instrument having an expandable member with a substantially non-compressible surface operable to be positioned in a heart of the patient;

a position element carried by the instrument;

a virtual position element defined by the substantially non-compressible surface of the instrument a distance from the position element;

a processor operable to determine the position of the virtual position element relative to the position element based on a geometry of the substantially non-compressible surface; and

a display device to display a map based on a determined position of the position element and the virtual position element within the heart, wherein said determined position within the heart is based on only the determined position of the position element and the geometry of the substantially non-compressible surface.

18. The system of claim 17, further comprising:

a set of axis patch electrodes contacting the patient;

a driver to inject a current between the set of axis patch electrodes; and

wherein an additional processor is operable to determine a position of the position element within the heart based on a sensed voltage in the patient in response to the injected current.

19. The system of claim 18, wherein the substantially non-compressible surface is on an inflatable member of the instrument;

wherein the virtual position element is on an exterior surface of the inflatable member; and

wherein only the position element is operable to sense the voltage.

20. The system of claim 17, further comprising:

a navigational system; and

wherein only the position element is operable to be physically affected by the navigational system.

21. The system of claim 17, wherein the processor is operable to generate the map based on the determined position of the position element and the virtual position element within the heart, the geometry of the substantially non-compressible surface, and the virtual position element contacting an internal surface of the heart and impeding progress of the substantially non-compressible surface.

22. The system of claim 21, wherein the map displayed on the display device includes positions of the virtual position element determined by the processor.

23. The system according to claim 17, wherein the instrument includes at least one of:

a guidewire operable to be positioned through a cannula;

a plurality of additional position elements along a length of the instrument;

a temperature sensor;

a position determination processor operable to determine a position of the instrument;

a display device operable to display a map based at least on the determined position of the instrument;

a display processor operable to augment the map on the display device, wherein the display processor is operable to at least one of;

determine a position of the position elements that are positioned to sense a voltage formed in the patient;

determine a position of an input impedance reference electrode and display it on the display device relative to the map; and

determine a pseudo position of the axis patch electrodes on the display device relative to the map;

a physiological measuring device;

an introducer operable to be located with the position determination processor;

a reference electrode at a fixed position on a surface of the patient, wherein a location of the reference electrode is operable to be determined with the position determination processor; and

a procedure instrument with an additional position element operable to be located relative to the map, wherein a map of the heart is displayed on the display device for visualization by a user based solely on determined positions of one or more of the position elements.