Impedance devices and methods of using the same in connection with a mammalian vasculature

A method for determining vessel compliance, the method comprising the steps of:

• introducing at least part of an impedance device into a site within a vessel, the impedance device comprising:
• an elongated body having a distal body end, and
• a first electrode located along the elongated body at or near the distal body end, the first electrode configured to obtain conductance values within the vessel within an electric field;
• providing electrical current to the first electrode and a first external electrode not coupled to the elongated body to generate the electric field, the first external electrode positioned upon or within a mammalian body having the vessel therein;
• operating the impedance device to obtain two or more conductance values;
• calculating a change in cross-sectional area based in part upon the two or more conductance values;
• calculating vessel compliance based upon the relationship between the change in cross-sectional area and a change in pressure during a cardiac cycle;
• and
• calculating an index of compliance based in part upon a difference between the first vessel parameter and the second vessel parameter divided by the first vessel parameter.

An impedance device for determining vessel compliance, the impedance device comprising:

• an elongated body having a distal body end, and
• a first electrode located along the elongated body at or near the distal body end, the first electrode configured to obtain conductance values within a mammalian luminal organ within an electric field;
• wherein when electrical current is provided to the first electrode and a first external electrode not coupled to the elongated body to generate the electric field, the first external electrode positioned upon or within a mammalian body having the vessel therein, the first electrode is operable, in connection with two or more fluid injections in the vessel at or near the site, to obtain two or more conductance values within the electric field;
• wherein a first vessel parameter of the site and a second vessel parameter of the cite can be calculated based upon at least two of the two or more conductance values and known conductivities of at least two of the two or more fluid injections, wherein a change in vessel parameter can be calculated based upon the calculated first vessel parameter and the calculated second vessel parameter, and wherein a vessel compliance can be calculated based upon a relationship between the change in vessel parameter and a change in pressure during a cardiac cycle.