= Bartley P. Griffith
{c}
{tag=Physiology and neuroscience author}
\b[<Bartley P. Griffith>] coauthored the 1994 experiment comparing image-derived ventricular <area> with a balloon-based pressure-volume reference. The publisher's full byline directly verifies the identity. The study used perfused dog hearts, a micromanometer catheter and automated <echocardiography> to investigate estimates of <ventricular compliance>.<Estimation of left ventricular compliance using on-line echocardiographic automated border detection and pressure data by John Gorcsan III and others>[Publisher full byline; abstract, isolated-heart experiment]{ref}
His university profile identifies his professional field as <surgery>, including heart and lung transplantation and the development of circulatory-support devices.<Bartley P. Griffith faculty profile by University of Maryland School of Medicine>[Primary Appointment and Biosketch, Personal Statement]{ref}
A central issue is the conversion between a geometric surrogate and the mechanical quantity of interest. If volume and area are linked by a differentiable relation $A(V)$, the <chain rule> gives
$$
\frac{dp}{dV}=\frac{dp}{dA}\frac{dA}{dV}.
$$
The reciprocal slope $dA/dp$ has area-per-pressure units, whereas <ventricular compliance> $dV/dp$ has volume-per-pressure units. They require a geometric conversion before being interpreted as the same physical quantity.
For an original local example, suppose $dA/dV=0.10\,\mathrm{cm^2/mL}$ and $dp/dA=2\,\mathrm{mmHg/cm^2}$. Then $dp/dV=0.20$ mmHg/mL and $dV/dp=5$ mL/mmHg. Simply copying the area-pressure inverse slope would give 0.5 square centimetres per mmHg, a different observable.
This illustrates why an experimental reference is valuable even when the surrogate and reference curves have similar shapes. The paper's abstract explicitly confines its conclusion by noting that clinical application remains to be validated.<Estimation of left ventricular compliance using on-line echocardiographic automated border detection and pressure data by John Gorcsan III and others>[Abstract, fitted-curve comparisons and final qualification]{ref}
\Image[https://sompaweb.z13.web.core.windows.net/Faculty/Griffith_Bartley-hero.jpg]
{title=Bartley P. Griffith, identified portrait linked from his University of Maryland faculty profile}
{height=300}
Back to article page
