John Gorcsan III
= John Gorcsan III
{c}
\b[<John Gorcsan III>] is first author of the 1994 experimental study comparing automated <echocardiography> with known ventricular volume and measured <pressure> to estimate <ventricular compliance>. The publisher explicitly supplies his full name. The experiment used six perfused dog hearts, an intraventricular balloon, a micromanometer catheter and computer-linked short-axis border measurements.<Estimation of left ventricular compliance using on-line echocardiographic automated border detection and pressure data by John Gorcsan III and others>[Publisher byline; abstract, isolated-heart apparatus and study objective]{ref}
The methodological question is how a two-dimensional image can track a three-dimensional chamber. The balloon supplies a volume reference, while the ultrasound boundary supplies an <area>; agreement must be tested rather than assumed from visual resemblance.
An original geometry example makes the distinction quantitative. Under uniform scaling of an unchanged shape, area scales as $\lambda^2$ and volume as $\lambda^3$, so $V=KA^{3/2}$ for a shape-dependent constant $K$. A ten-percent area increase then predicts a volume factor $1.1^{3/2}\simeq1.1537$, rather than 1.10. This is a homothetic model, not the study's asserted ventricular shape or an independent volume measurement.
The paper reports strong correspondence between its pressure-area and pressure-volume relationships but explicitly leaves clinical application to further validation.<Estimation of left ventricular compliance using on-line echocardiographic automated border detection and pressure data by John Gorcsan III and others>[Abstract, comparison results and final clinical-validation qualification]{ref} Gorcsan's verified contribution here is leadership of that measurement study, not a claim that every image-area change is already a calibrated volume change.