Bioprosthetic heart valve leaflet motion monitored by dual camera stereo photogrammetry

Dual camera stereo photogrammetry (DCSP) was applied to investigate the lea flet motion of bioprosthetic heart valves (BHVs) in a physiologic pulse flo w loop (PFL). A 25-mm bovine pericardial valve was installed in the aortic valve position of the PFL, which was operated at a pulse rate of 70 beats/m in and a cardiac output of 51/min. The systolic/diastolic aortic pressure w as maintained at 120/80 mmHg to mimic the physiologic load experienced by t he aortic valve. The leaflet of the test valve was marked with 80 India ink dots to form a fan-shaped matrix. From the acquired image sequences, 3-D c oordinates of the marker matrix were derived and hence the surface contour, local mean and Gaussian curvatures at each opening and closing phase durin g one cardiac cycle were reconstructed. It is generally believed that the l ong-term failure rate of BHV is related to the uneven distribution of mecha nical stresses occurring in the leaflet material during opening and closing . Unfortunately, a quantitative analysis of the leaflet motion under physio logical conditions has not been reported. The newly developed technique per mits frame-by-frame mapping of the leaflet surface, which is essential for dynamic analysis of stress-strain behavior in BHV. (C) 2000 Elsevier Scienc e Ltd. All rights reserved.