Patent ID: 8114143

Claim:
An impedance catheter for measuring luminal cross-sectional area of blood vessels, heart valves, and other hollow visceral organs, for enabling selection of an appropriately sized stent or other medical device and for avoiding under or over deployment and under or over sizing of the stent or other medical device, comprising: an elongated tubular body extending from a proximal body end to a distal body end, said body having an exterior surface and defining a first lumen along the longitudinal axis of the body, whereby enabling introduction of the catheter into a treatment site; a first excitation impedance electrode and a second excitation impedance electrode along the longitudinal axis of the body, both located near the distal body end, said first excitation electrode comprising a first excitation impedance lead extending from said first excitation electrode configured for connection to a data acquisition system near the proximal body end, said second excitation electrode comprising a second excitation impedance lead extending from said second excitation electrode configured for connection to the data acquisition system; a first detection impedance electrode and a second detection impedance electrode along the longitudinal axis of the body, both located in between the first and second excitation electrodes, said first detection electrode comprising a first detection impedance lead extending from said first detection electrode configured for connection to the data acquisition system, said second detection electrode comprising a second detection impedance lead extending from said second detection electrode configured for connection to the data acquisition system; and a first suction/infusion port located near the distal end, wherein said first suction/infusion port is in communication with said first lumen, the suction/infusion port configured to allow injection of two or more solutions into the treatment site; the impedance catheter configured so that the first detection impedance electrode and the second detection impedance electrode can obtain one or more conductance values within an electric field generated by the first excitation impedance electrode and the second excitation impedance electrode, and wherein a cross-sectional area of the treatment site can be calculated based in part upon the one or more obtained conductance values and a known distance between said first detection impedance electrode and said second detection impedance electrode; wherein the known distance between said first detection impedance electrode and said second detection impedance electrode is between 0.5 mm and 1 mm, inclusive.