Method and system for determining cardiac performance

Abstract

Methods and associated algorithms for determining cardiac and / or cardiovascular performance that are based on at least one cardiac function determinant associated with or at least in part, reflective of preload, contractility and afterload.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Application No. 61 / 133,876, filed Jul. 2, 2008.FIELD OF THE PRESENT INVENTION[0002]The present invention relates generally to methods and systems for determining cardiac function. More particularly, the invention relates to a method for determining cardiac performance as a function of multiple cardiac parameters.BACKGROUND OF THE INVENTION[0003]A clinical and scientific goal for many years has been to accurately and non-invasively determine myocardial or cardiac output of a patient or subject. Indeed, there is a vast array of methods for determining cardiac output in the prior art. While each of the prior art methods can be employed to provide an estimate of cardiac output, as discussed in detail below, the accuracy of the estimated cardiac output is limited by virtue of various methodological constraints, including the limited number of cardiac hemodynamic variables (or cardiac perf...

AI Technical Summary

Benefits of technology

[0019]In accordance with the above objects and those that will be mentioned and will become apparent below, the present invention provides improved methods for determining stroke volume and, hence, cardiac output that substantially reduces or eliminates the disadvantages and drawbacks associated with conventional methods and associated algorithms for determining cardiac output. As discussed in detail below, a key feature and, hence, advantage of the invention is that the methods and associated algorithms disclosed herein employ multiple cardiac function determinants that represent (or account for) the three seminal cardiac parameters or factors, i.e. preload, afterload and contractility. The cardiac stroke volume and, hence, cardiac output determined therefrom is thus highly accurate and clinically useful.

[0020]According to one embodiment of the invention, the methods and associated algorithms for determining cardiac and / or cardiovascular performance (CP) are based on at least one cardiac function determinant that is associated with or at least in part, reflective of preload, contractility and afterload.

[0021]In one embodiment of the invention, cardiac performance is accordingly determined and, hence, represented by the following equationCP=f(CFDx;CFDy;CFDz)where:CFDx=a cardiac function determinant associated with preload;CFDy=a cardiac function determinant associated with contractility;CFDz=a cardiac function determinant associated with afterload; andf(CFDx; CFRy; CFDz)=an empirical relationship between CFDx, CFDy, and CFDz.

[0022]In accordance with another embodiment of the invention, the methods and associated algorithms for determining cardiac performance are based on multiple cardiac function determinants associated with or at least in part, reflective of each cardiac parameter, i.e. preload, contractility and afterload.

[0023]In one embodiment of the invention, cardiac performance, i.e. cardiac stroke volume, is accordingly determined and, hence, represented by the following equationSV=fco(CFD(c)x;CFD(c)y;CFD(c)z)where:

Problems solved by technology

While each of the prior art methods can be employed to provide an estimate of cardiac output, as discussed in detail below, the accuracy of the estimated cardiac output is limited by virtue of various methodological constraints, including the limited number of cardiac hemodynamic variables (or cardiac performance determinants) employed in the methodology.

While each of the prior art methods can be employed to provide an estimate of cardiac output, the accuracy of the estimated cardiac output is typically limited by virtue of various methodological constraints; particularly, the limited number of cardiac function determinants (or hemodynamic variables) employed in the methodology.

Images