Identifying a structure for cannulation
A 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.
1. A method of determining a structure in a volume for cannulation, comprising:
moving an instrument having a position element in the volume;
determining a plurality of positions of the position element;
rendering a map of a surface of the volume using at least a sub-plurality of the plurality of positions of the position element;
moving a portion of the position element into a bore in the surface of the volume; and
illustrating a rendered bore relative to the rendered map.
2. The method of claim 1 , wherein the instrument includes a position element that is moveable relative to a catheter.
3. The method of claim 2 , further comprising;
providing the catheter with a cross-sectional diameter greater than that of a cross-sectional diameter of the position element.
4. The method of claim 3 , further comprising;
providing a guide wire as the position element;
moving the guide wire into a coronary sinus ostium;
determining a plurality of positions of the position element in the coronary sinus ostium;
wherein illustrating a rendered bore relative to the rendered map includes rendering only the determined plurality of positions of the position element in the coronary sinus ostium.
5. The method of claim 1 , further comprising:
generating a navigation field relative to the volume;
forming the position element to include a coil of wire;
inducing a current in the coil of wire due to the generated navigation field;
wherein determining a plurality of positions of the position element includes determining a plurality of induced currents in the coil of wire at a plurality of locations.
6. The method of claim 1 , further comprising;
positioning three pairs of axis electrodes on a surface of the volume;
injecting a current into the volume between each of the pairs of axis electrodes to form three axes of current in the volume;
evaluating an electrical property based on the injected current and information received from the position element;
wherein determining the plurality of positions of the position element includes evaluating the electrical property at a plurality of positions when moving the position element within the volume.
7. The method of claim 6 , wherein rendering the map of the surface of the volume occurs without additional image data of the volume.
8. A method of determining a structure in a volume for cannulation, comprising:
moving an instrument having at least a first position element and a catheter in the volume, wherein the first position element includes a cross-sectional dimension less than a cross-sectional dimension of the catheter;
determining a plurality of positions of the first position element;
rendering a map of a surface of the volume using at least a sub-plurality of the determined plurality of positions of the position element;
moving a portion of the first position element into a bore in the surface of the volume; and
illustrating a rendered bore relative to the rendered map.
9. The method of claim 8 , wherein the first position element is moveable relative to the catheter;
wherein moving the portion of the first position element into the bore includes:
positioning the catheter near the bore in the surface;
substantially holding the catheter near the bore;
moving substantially only the first position element into the bore; and
determining a position of the first position element within the bore.
10. The method of claim 9 , further comprising;
determining a plurality of positions of the position element in the bore;
wherein illustrating a rendered bore relative to the rendered map includes rendering only the determined plurality of positions of the position element in the bore.
11. The method of claim 10 , further comprising:
moving the instrument into a heart of a human;
wherein determining a plurality of positions of the position element in the bore includes determining a plurality of positions within a coronary sinus ostium;
wherein illustrating a rendered bore relative to the rendered map includes rendering only the determined plurality of positions of the position element in the coronary sinus ostium.
12. The method of claim 11 , further comprising identifying the coronary sinus as the rendered bore.
13. The method of claim 12 , further comprising;
positioning three pairs of axis electrodes on a surface of the volume;
injecting a current into the volume between each of the pairs of axis electrodes to form three axes of current in the volume;
evaluating an electrical property based on the injected current and information received from the position element;
wherein determining the plurality of positions of the position element includes evaluating the electrical property at a plurality of positions when moving the position element within the heart.
14. The method of claim 13 , wherein rendering the map of the surface of the volume occurs without additional image data of the volume.
15. A system to determine a structure in a volume for cannulation, comprising:
an instrument having at least a first position element moveable relative to a catheter in the volume, wherein the first position element has a cross-sectional dimension less than a cross-sectional dimension of the catheter;
a position sensing unit, including:
a set of axis electrodes positionable on a surface of the volume;
a driver operable to inject a current into the volume between the set of axis electrodes;
wherein the injected current defines an axis within the volume;
a processor operable to evaluate an electrical property with the first position element and execute instruments to determine a position of the position element within the volume;
a storage device operable to store a plurality of determined positions of the first position element; and
a display device operable to display a rendered map of a surface of the volume using at least a sub-plurality of the stored determined plurality of positions of the position element;
wherein the display device is further operable to display a rendered bore relative to the rendered map.
16. The system of claim 15 , wherein the instrument includes a catheter and the first position element includes a guidewire moveable within the catheter.
17. The system of claim 16 , further comprising:
a second position element positioned at a distal terminal end of the catheter;
wherein the guide wire is operable to protrude from the distal terminal end.
18. The system of claim 16 , further comprising;
a procedure instrument operable to move with the guidewire relative to the guidewire.
19. The system of claim 18 , further comprising;
a second position element moveable with the procedure instrument;
wherein the processor is further operable to determine a position of the second position element;
wherein the display device is further operable to display a rendered bore and in representing the position of the second position element relative to the rendered map.