Patent ID: 7233821
Filing Date: 2007-06-19
Classification: A61B,A61N

Abstract:
1. A method of evaluating the ventricular performance of a heart comprising: positioning a first sensor at a first location of the heart, and a second sensor at a second location of the heart, the first and second locations spanning a portion of a ventricle; measuring a distance between the first and second sensors over a cardiac cycle of the heart to produce a ventricular dimension signal as a function of time, the cardiac cycle comprising a ventricular filling phase and a ventricular ejection phase; measuring at least one of the following values: a) premature shortening (PS) of the ventricular dimension signal, the value of PS being equal to the decrease in the ventricular dimension signal from a first local maximum value that occurs at or near an end of the ventricular filling phase of the cardiac cycle, to a relative minimum value or inflection point that occurs during a transition from the ventricular filling phase to the ventricular ejection phase of the cardiac cycle; and b) isovolumic lengthening (IL) of the ventricular dimension signal, the value of IL being equal to the increase in the ventricular dimension signal from the relative minimum value or inflection point that occurs during the transition from the ventricular filling phase to the ventricular ejection phase of the cardiac cycle, to a second local maximum value that occurs at or near a beginning of the ventricular ejection phase of the cardiac cycle; and comparing the at least one measured value of PS or IL with at least one reference value or at least one previously measured value of PS or IL.