Method And Apparatus For Mapping A Structure

• US 20090264752A1
• Filed: 05/08/2008
• Published: 10/22/2009
• Est. Priority Date: 04/18/2008
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Waldhauser, Steven, Kryger, Michael, Campbell-Massa, Sean, Fleming, Ioana, Scanlon, David, Hefner, Don, Mehta, Pooja, Zhang, Peter, Markowitz, H. Toby, Falkner, Phillip, Karamanoglu, Mustafa, Giese, Chad, Jannicke, Jeff
• Granted Patent: US 8,260,395 B2
• Time in Patent Office: Days
• US Class Current: 600/425
• 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 5/0536 Impedance imaging, e.g. by tomography
• 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 5/063 using impedance measurements
• 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 5/287 Holders for multiple electrodes, e.g. electrode catheters for electrophysiological study [EPS]
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 6/12 Arrangements for detecting or locating foreign bodies
• 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 area 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 an area or volume can be determined based upon the sensing of the plurality of points without the use of an imaging device. An implantable medical device can then be navigated relative to the mapping data.

Claims

1. A system for mapping data and positioning an instrument in a three dimensional volume, comprising:

a first drive patch and a second drive patch;

a driving unit interconnected with the first and the second drive patches operable to generate a voltage between the first and the second drive patches;

an instrument having an inflatable member and an electrode positioned adjacent the inflatable member, wherein the electrode is operable to both move relative to the first drive patch and the second drive patch and sense the voltage generated by the driving unit;

a processor operable to execute instructions to determine a relative position of the electrode as the electrode is moved relative to the first drive patch and the second drive patch; and

a display device operable to display an icon representing a virtual representation of the position.

2. The system of claim 1, further comprising:

a memory system operable to store at least two relative positions of the electrode;

wherein the display device is operable to display both of the two relative positions.

3. The system of claim 1, further comprising:

a second electrode;

wherein the inflatable member is operable to provide a stop such that the electrode does not penetrate a selected portion of an anatomy.

4. The system of claim 1, wherein the instrument is deflectable such that a drag can be formed on the inflatable member to move the inflatable member through an anatomy.

5. The system of claim 2, wherein the display device is operable to display a first position icon and a second position icon representing the two relative positions of electrode stored in the memory system.

6. The system of claim 5, further comprising:

a pressure sensor operable to measure a pressure exerted on the inflatable member;

wherein the pressure exerted on the inflatable member is measured with the pressure sensor.

7. The system of claim 6, wherein the stored positions and the pressure information is operable to identify an anatomical portion in a patient.

8. The system of claim 1, wherein the first patch and the second patch are positioned in contact with a patient.

9. A system for mapping data and positioning an instrument in a three dimensional volume, comprising:

a first drive patch and a second drive patch;

a driving unit interconnected with the first and the second drive patches operable to generate a parameter between the first and the second drive patches;

an instrument having a body covering and an electrode extendable from a retracted position to an extended position through an exit opening of the body covering, wherein the electrode is operable to both move relative to the first drive patch and the second drive patch and sense the parameter generated by the driving unit;

a memory system operable to store a data point representing a position in space relative to the first and the second drive patches;

a processor operable to execute instructions to determine a position of the electrode relative to the stored data point; and

a display device operable to display an icon representing a virtual representation of the position;

wherein the body covering includes a portal positioned a distance from the exit opening;

wherein the portal is operable to allow an electrolyte to contact the electrode when the electrode is in the retracted position.

10. The system of claim 9, wherein the first drive patch and the second drive patch are positioned in contact with a patient.

11. The system of claim 10, wherein the body covering is an insulator to electrical current such that substantially only a high impedance path to the electrode is provided to measure a voltage when covered with the body covering.

14. The system of claim 9, further comprising:

at least a third drive patch, a fourth drive patch, a fifth drive patch, and a sixth drive patch operable with the first drive patch and the second drive patch to form three substantially orthogonal axes in a patient;

wherein the parameter is operable to be sensed or measure via the electrode and includes at least one of a voltage or an impedance.

12. The system of Clam 11, further comprising:

a cover operably associated with the electrode;

wherein the cover is operable to move with the electrode to cover the portal in the body covering to substantially eliminate access to the electrode of the body covering through the portal once the electrode is in the extended position through said exit opening.

13. The system of claim 12, wherein the electrode is formed as a helical coil operable to be screwed into a surface;

wherein the instrument includes a conductor operable to transmit an electrical signal to the electrode.

15. A method for mapping data and positioning an instrument in a three dimensional volume, comprising:

positioning a first drive patch and a second drive patch on a patient;

interconnecting a driving unit with the first drive patch and the second drive patch operable to generate a voltage between the first drive patch and the second drive patch;

positioning a first reference patch and a second reference patch on the patient;

positioning a mapping instrument in the patient;

expanding an expandable portion of the mapping instrument;

moving the mapping instrument from a first position to a second position within the patient;

sensing the voltage at the first position and the second position; and

displaying on a display device the relative location of the first position and the second position with mapping icons.

16. The method of claim 15, wherein positioning a first reference patch includes contacting the first reference patch with a skin surface of the patient substantially adjacent to a xiphoid process of the patient.

17. The method of claim 16, wherein positioning the second reference patch on the patient includes positioning the second reference patch in contact with a skin surface of the patient on a dorsal surface of the patient substantially on a horizontal plane relative to the patient defined by the first reference patch.

18. The method of claim 15, wherein expanding the expandable portion includes injecting a fluid or a gas into the expandable portion to generate a substantially spherical surface;

and

stopping the penetration of the mapping instrument through a selected portion of the patient with the expandable portion.

19. The method of claim 15, further comprising:

determining a impedance at the first position and at the second position;

determining the relative position of the first position and the second position based upon the determined impedances relative to at least one of the first reference patch and the second reference patch;

saving the relative positions of the first position and the second position.

20. The method of claim 19, further comprising:

moving an implantable electrode within the patient;

sensing a voltage on the implantable electrode at an implantable electrode position;

determining a relative position of the implantable electrode relative to the first saved position and the second saved position; and

displaying on a display device the determined position of the implantable electrode relative to the first saved position and the second saved position.

21. A method for mapping data and positioning an instrument in a three dimensional volume comprising:

moving an electrode from a first retracted position to a second extended position;

providing a body covering operable to substantially cover the electrode when the electrode is in the first retracted position;

providing a portal through the body covering; and

moving a cover to cover the portal in the body covering when moving the electrode from the first retracted position to the second extended position;

whereby when the electrode is in the first retracted position the voltage is sensed through the portal;

whereby when the electrode is in the second extended position the portal is closed by the cover.

22. The method of claim 21, wherein a voltage between the first and second drive patches is operable to be sensed when the electrode is in the extended or retracted position.

23. The method of claim 21, further comprising:

implanting the electrode in an extended position.

24. The method of claim 23, further comprising:

contacting a skin surface of a patient with a first patch and a second patch;

generating a current through the patient between the first patch and the second patch; and

determining a location of the electrode by sensing a voltage gradient between the first patch and the second patch with the electrode.

25. The method of claim 24, further comprising:

providing a second electrode with the instrument;

determining a location of the second electrode by sensing a voltage gradient between the first patch and the second patch with the second electrode;

determining a direction between the location of the electrode and the location of the second electrode; and

illustrating the direction on a display device.