Methods for generating luminal organ profiles using impedance
Methods to generate luminal organ profiles using impedance. One embodiment of such a method comprises the steps of introducing an impedance device having at least two detection electrodes positioned in between at least two excitation electrodes into a treatment site of a luminal organ at a first position, measuring a first treatment site conductance at the first position using the impedance device and at least two injections of solutions having different conductivities, moving the impedance device to a second position in the luminal organ, measuring a second treatment site conductance at the second position using the impedance device and the at least two injections of solutions having different conductivities, calculating a first position cross-sectional area using the first treatment site conductance and a second position cross-sectional area using the second treatment site conductance, and constructing a profile of the treatment site.
1. A method for measuring a cross-sectional area of a lumen, comprising:
introducing an impedance device into a treatment site of the lumen, the impedance device having at least two detection electrodes positioned between at least two excitation electrodes;
flowing a first solution having a first concentration through a proximal end of a segment of the lumen and simultaneously measuring a first conductance at the proximal end of the segment of the lumen in a presence of the first solution using the impedance device;
flowing a second solution having a second concentration through a distal end of the segment of the lumen and simultaneously measuring a second conductance at the distal end of the segment of the lumen in a presence of the second solution using the impedance device;
calculating a first cross-sectional area using the first conductance and a second cross-sectional area using the second conductance;
calculating a first total conductance of the proximal end of the segment of the lumen based upon the first cross-sectional area and a second total conductance of the distal end of the segment of the lumen based upon the second cross-sectional area;
calculating a first coefficient ratio based upon the first total conductance and the first cross-sectional area and a second coefficient ratio based upon the second total conductance and the second cross-sectional area;
linearly interpolating along a length between the proximal end of the segment of the lumen and the distal end of the segment of the lumen to determine a third coefficient ratio for an intermediary point between the proximal end of the segment of the lumen and the distal end of the segment of the lumen; and
determining a third cross-sectional area of the intermediary point based on the third coefficient ratio, the first total conductance, and the second total conductance.
2. The method according to claim 1 , wherein calculating the first total conductance is further based upon at least blood conductivity at the proximal end of the segment of the lumen and a distance between the at least two detection electrodes.
3. The method according to claim 2 , wherein calculating the second total conductance is further based upon at least the blood conductivity at the distal end of the segment of the lumen and a distance between the at least two detection electrodes.
4. The method according to claim 1 , further comprising measuring blood conductivity at the proximal end of the segment of the lumen, and measuring blood conductivity at the distal end of the segment of the lumen.
5. The method according to claim 1 , further comprising providing an electrical current flow to the at least two excitation electrodes.
6. The method according to claim 1 , wherein the impedance device includes an inflatable balloon positioned along a longitudinal axis thereof, the method further comprising inflating the balloon to breakup materials causing stenosis at the treatment site of the lumen.
7. The method according to claim 6 , wherein the impedance device includes a stent distendable to a desired size and implantable into the treatment site, the stent positioned over the inflatable balloon, the method further comprising distending the stent.
8. The method according to claim 1 , wherein the impedance device includes a pressure transducer, the method further comprising measuring a first pressure gradient with the pressure transducer near the treatment site of the lumen.
9. The method according to claim 1 , wherein the impedance device includes a first channel for insertion of a guide wire, the method further comprising inserting the first channel of the impedance device over the guide wire.
10. The method according to claim 1 , wherein the impedance device includes a sensor to measure a flow of fluid within the lumen, the method further comprising measuring the flow of fluid within the lumen.
11. The method according to claim 1 , wherein the impedance device includes a port for suctioning of contents or infusion of fluid, the method further comprising suctioning contents from the lumen through the port.
12. The method according to claim 1 , wherein the impedance device includes one or more imaging devices for ultrasound or wall thickness measurements, the method further comprising measuring a thickness of a wall of the lumen with a first image device of the one or more imaging devices.
13. The method according to claim 1 , wherein a distance between the at least two detection electrodes and the at least two excitation electrodes is based on a vessel diameter.
14. The method according to claim 1 , wherein a first detection electrode of the at least two detection electrodes is spaced 1 mm apart from a second detection electrode of the at least two detection electrodes.
15. The method according to claim 1 , wherein a flow rate of flowing each solution of the first solution and the second solution through the segment of the lumen is commensurate with a flow rate of an organ including the segment of the lumen.
16. The method according to claim 15 , further comprising measuring the flow rate of the organ using a sensor on the impedance device.
17. The method according to claim 1 , further comprising flowing the first solution having the first concentration through the distal end of the segment of the lumen and simultaneously measuring a third conductance at the distal end of the segment of the lumen in the presence of the first solution using the impedance device.
18. The method according to claim 17 , further comprising flowing the second solution having the second concentration through the proximal end of the segment of the lumen and simultaneously measuring a fourth conductance at the proximal end of the segment of the lumen in the presence of the second solution using the impedance device.