ISSN:
1573-9686
Keywords:
Heart valves
;
Artificial heart
;
Laser Doppler velocimetry
;
Velocity
;
Reynolds stress
;
Regurgitant jets
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
,
Technology
Notes:
Abstract Laser Doppler velocimetry, with a high temporal resolution (1 ms time windows), was used to measure the flow field in two regions (major and minor orifices) near the aortic and mitral valves (Bjork Shiley™ monostrut Nos. 25 and 27, respectively) of the Penn State artificial heart. The motion of each valve was also investigated using a 1000 frame/s video camera in order to estimate the valve's closing velocity. Fluid velocities in excess of and opposite to valve closing velocity were detected near the valve, providing evidence of “squeeze flow.” Maximum Reynolds shear stresses of approximately 20,000 dyn/cm2 and time-averaged Reynolds shear stresses of approximately 2000 dyn/cm2 were observed during the regurgitant flow phase. These elevated Reynolds shear stresses suggest that regurgitant jets play a role in the hemolysis and thrombosis associated with tilting disk heart valves in an artificial heart environment. © 1998 Biomedical Engineering Society. PAC98: 8745Hw, 4727Wg, 4279Qx
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1114/1.86
