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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.^[ref]

His university profile identifies his professional field as surgery, including heart and lung transplantation and the development of circulatory-support devices.^[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 givesThe 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 $dA/dV=0.10\mathrm{c}{\mathrm{m}}^2/mL$ and $dp/dA=2mmHg/c{\mathrm{m}}^2$. 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.^[ref]

By John Gorcsan III, William A. Mandarino, Lee G. Deneault, Shigeki Morita, Akihiko Kawai, Bartley P. Griffith, Robert L. Kormos. The International Journal of Cardiac Imaging 10, 103–111, June 1994. Publisher title, full byline, author affiliations and abstract verified at link.springer.com/article/10.1007/BF01137705 . Abstract: six excised dog hearts were perfused ex vivo; an intraventricular balloon supplied volume and a micromanometer catheter supplied pressure. Automated echocardiographic borders measured mid-ventricular short-axis area. Three volume runs in 1 mL increments per heart yielded 1,080 simultaneous observations. The experiment compared pressure-area with pressure-volume relationships; it did not establish clinical validation. Full article not inspected.