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

Abstract

Impedance devices and methods of using the same in connection with a mammalian vasculature. In an embodiment of a method for determining vessel compliance, the method comprises 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, 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 within the electric field, and calculating vessel compliance based upon the relationship between a change in vessel parameter and a change in pressure during a cardiac cycle.

Description

PRIORITY[0001]The present patent application is related to, and claims the priority benefit of, U.S. Provisional Patent Application Ser. No. 61 / 800,407, filed on Mar. 15, 2013, the contents of which are hereby incorporated by reference in their entirety into this disclosure.BACKGROUND[0002]The disclosure of the present application relates generally to medical diagnostics and treatment equipment, and in particular, to devices, systems, and methods for measuring luminal cross-sectional area of blood vessels, heart valves and other hollow visceral organs.Coronary Heart Disease[0003]Coronary heart disease is caused by atherosclerotic narrowing of the coronary arteries. It is likely to produce angina pectoris, heart attack or both. Coronary heart disease caused 466,101 deaths in USA in 1997 and is the single leading cause of death in America today. Approximately, 12 million people alive today have a history of heart attack, angina pectoris or both. The break down for males and females is...

AI Technical Summary

Benefits of technology

The present invention relates to devices and methods for removing contrast from a luminal organ of a mammal, such as a heart, to prevent contrast-induced nephropathy. The device has an elongated body with a detector for detecting contrast, and can be introduced into the luminal organ through an aperture. The device can also include a data acquisition and processing system for receiving conductance data from the detector, and can remove contrast using suction or other means. The method involves inflating a balloon and detecting contrast using the detector, with subsequent conductance measurements obtained to monitor any decrease in contrast levels. The invention is useful for reducing the risk of nephropathy and other complications associated with the use of contrast in medical procedures.

Problems solved by technology

It is likely to produce angina pectoris, heart attack or both.

However, using intravascular ultrasound as mentioned above requires a first step of advancement of an ultrasound catheter and then withdrawal of the ultrasound catheter before coronary angioplasty thereby adding additional time to the stent procedure.

Furthermore, it requires an ultrasound machine.

This adds significant cost and time and more risk to the procedure.

Although it appears that progression of AS can be more rapid in patients with degenerative calcific disease than in those with congenital or rheumatic disease, it is not possible to predict the rate of progression in an individual patient.

Problems with Current Aortic Valve Area Measurements

Such patients can be difficult to distinguish from those with low cardiac output and only mild to moderate AS.

Although valve resistance is less sensitive to flow than valve area, resistance calculations have not been proved to be substantially better than valve area calculations.

There are many other limitations in estimating aortic valve area in patients with aortic stenosis using echocardiography and cardiac catheterization.

Accurate measurement of the aortic valve area in patients with aortic stenosis can be difficult in the setting of low cardiac output or concomitant aortic or mitral regurgitations.

Furthermore, because of the dependence of aortic valve area calculation on cardiac output, any under or overestimation of cardiac output will cause inaccurate measurement of valve area.

Falsely measured aortic valve area could cause inappropriate aortic valve surgery in patients who do not need it.

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