Locating an Introducer
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.
1 . A method of determining a position of an instrument introducer in a patient relative to a heart, comprising:
moving the instrument introducer into a volume of the patient outside of the heart;
evaluating an electrical property with a position element mounted on the instrument introducer;
determining a position of the position element within the volume based on the evaluated electrical property;
displaying a graphical representation of the determined position of the position element; and
passing an instrument through a throughbore defined by the instrument introducer into the volume and into the heart.
2 . The method of claim 1 , further comprising:
providing an axial bore defined by an outer wall of the instrument introducer as the throughbore of the instrument introducer; and
placing the position element on an exterior of the outer wall in contact with a conductive medium in the volume;
wherein passing the instrument through the instrument introducer includes passing the instrument through the axial bore of the instrument introducer.
3 . The method of claim 2 , wherein evaluating the electrical property includes determining an impedance at the position element at least by sensing a voltage at the position element and determining a current injected into the volume when the voltage was sensed.
4 . The method of claim 2 , wherein evaluating the electrical property includes sensing a voltage at the position element.
5 . The method of claim 2 , further comprising:
guiding the instrument introducer in the volume based on the graphical representation of the determined position;
wherein passing the instrument through the instrument introducer includes passing a lead through the throughbore of the instrument introducer into the heart of the patient;
placing a lead electrode into contact with a wall of the heart; and
implanting the lead electrode into the wall of the heart.
6 . The method of claim 5 , further comprising:
illustrating map data of an interior of the volume; and
wherein guiding the instrument introducer in the volume includes illustrating an icon representing a location of the instrument introducer relative to the map data of the volume.
7 . The method of claim 6 , further comprising guiding the instrument introducer in the volume relative to a predetermined position based on the map data.
8 . The method of claim 6 , further comprising: determining a position of the position element only with a position sensing system, including:
providing a set of axis generation electrodes on an exterior surface of the volume establishing an axis and a conductive path therebetween; and
injecting a current into the volume between the set of electrodes and generating a voltage gradient between the set of electrodes;
wherein evaluating the electrical property includes sensing voltage at the position element between the set of electrodes, and
wherein determining the position of the position element includes determining a position of the sensed voltage along the voltage gradient between the set of electrodes.
9 . The method of claim 8 , further comprising:
providing an additional two sets of axis generation electrodes on the exterior surface of the volume, each set of the additional two sets establishing an axis and a conductive path therebetween, each axis of the three sets of electrodes being substantially orthogonal to each other and intersecting at a common point;
wherein injecting current into the volume includes injecting current into the volume between each of the three sets of electrodes and generating a voltage gradient between each of the three sets of electrodes;
wherein evaluation of the electrical property includes sensing voltage at the position element between each of the three sets of electrodes; and
wherein determining the position of the position element includes determining a position of the sensed voltage along the voltage gradient between each of the three sets of electrodes so as to provide a determined three dimensional position of the position element.
10 . The method of claim 9 , further comprising guiding the instrument introducer in the volume based on the determined position of the position element relative to the first, second and third axes;
wherein the map data is generated based only on an evaluation of a voltage sensed along the first, second and third axes.
11 . A method of determining a position of an instrument introducer in a volume of a patient, comprising:
providing an axial bore defined by an outer wall of the instrument introducer;
placing a position element on an exterior of the outer wall of the instrument introducer;
moving a portion of the instrument introducer into the volume of the patient and placing the position element in contact with a conductive medium in the volume;
providing three sets of axis generation electrodes on an exterior surface of the volume, each set of electrodes spaced apart and arranged to establish an axis and a conductive path therebetween, each axis of the three sets of electrodes being substantially orthogonal to each other and intersecting at a common point;
injecting a current into the volume between each set of electrodes and generating a voltage gradient between each set of electrodes;
sensing voltage at the position element between each set of the three sets of electrodes;
determining a position of the position element based at least on the sensed voltage along the voltage gradients of each of the three sets of electrodes so as to provide a determined three dimensional position of the position element;
displaying a graphical representation of the determined position of the position element; and
guiding the instrument introducer in the volume based on the determined position of the position element.
12 . The method of claim 11 , further comprising passing an instrument through the instrument introducer into the volume and into a heart of the patient.
13 . The method of claim 11 , wherein guiding the instrument introducer in the volume includes providing map data of an interior of the volume and guiding the instrument introducer in the volume based on the determined position and the provided map data.
14 . A system for determining a position of a device in a patient, comprising:
an instrument introducer including an elongated body member having an outer wall, first and second ends, and a bore extending through the elongated body member between the first and second ends, the first end adapted to be inserted into a volume of the patient with the second end remaining outside of the volume; and
a position element affixed to an exterior surface of the outer wall and adapted to contact a conductive medium in the volume upon insertion of the first end into the volume, the position element arranged to sense an electrical property and provide data indicative of a position of the instrument introducer, wherein the position element comprises an electrode arranged to sense a voltage in the volume;
a position sensing unit having at least one set of axis generation electrodes for injecting current into the volume, the at least one set of electrodes adapted to be positioned on an outer surface of the volume and establish an axis via a conductive path therebetween, the injected current generating a voltage gradient in the volume between the at least one set of electrodes; and
a processor coupled to the position sensing unit, the electrode and a display device, wherein the processor is operable to execute instructions to determine the position of the electrode and display a graphical representation of the determined position of the electrode on the display device;
wherein the instrument introducer is adapted to receive an instrument through the second end and guide the instrument through the bore and out of the first end into the volume.
15 . The system of claim 14 , wherein the processor is operable to determine a position of the position element based at least on the sensed voltage along the voltage gradient to determine the position of the electrode.
16 . The system of claim 14 , wherein the processor is operable to determine an impedance based on the sensed voltage and the injected current to determine the position of the position element.
17 . The system of claim 14 , wherein the at least one set of axis generation electrodes includes three sets of axis generation electrodes, each set of axis generation electrodes establishing an axis and a conductive path therebetween, each axis of the three sets of electrodes positioned substantially orthogonal to each other and intersecting at a common point, and wherein the processor is operable to execute instructions to determine a three dimensional position of the electrode relative to the three axes.
18 . The system of claim 14 , further comprising:
a lead electrode operable to be implanted into a heart of a patient, wherein the lead electrode is connected to the instrument and passed through the instrument introducer into the heart of the patient;
wherein the lead electrode is operable to sense the voltage in the patient and the processor is operable to determine a position of the lead electrode.
19 . The system of claim 14 , wherein the instrument is a connector of the lead electrode operable to be implanted and connected with an implantable medical device.
20 . The system of claim 18 , further comprising:
a display device;
a mapping instrument:
wherein the mapping instrument is operable to be passed through the throughbore of the instrument introducer into the patient;
wherein the processor is operable to determine a plurality of positions within the patient and the display device is operable to display the plurality of displayed positions;
wherein the processor is operable to determine a location of the lead electrode relative to the determined plurality of positions and display an icon of the determine position of the lead electrode and the determined plurality of positions on the display device.