title: Characteristics of cavitation intensity in a mechanical heart valve using a pulsatile device: synchronized analysis between visual images and pressure signals.
abstract: To investigate the characteristics of cavitation intensity, we performed a synchronized analysis of the visual images of cavitation and the pressure signals using a pulsatile device. The pulsatile device employed was a pneumatic ventricular assist device (PVAD) that is currently being developed by our group. A 23-mm Medtronic Hall valve (M-H valve) and a 23-mm Sorin Bicarbon bileaflet valve (S-B valve) were mounted in the inlet port of the PVAD after the sewing ring had been removed. A function generator provided a square signal, which was used as the trigger signal, via Electrocardiogram R wave (ECG-R) mode, of the control - drive console for circulatory support. The square signal was also used, after a suitable delay, to synchronize operation of a pressure sensor and a high-speed video camera. The data were stored using a digital oscilloscope at a 1-MHz sampling rate, and then the pressure signal was band-pass filtered between 35 and 200 kHz using a digital filter. The valve-closing velocity, visual cavitation time, and root mean square (RMS) pressure of the M-H valve were greater than those of the S-B valve. Both the visual cavitation time and RMS pressure represent the cavitation intensity, and this is a very important factor when estimating mechanical heart valve cavitation intensity in an artificial heart.
authors.affiliation: Department of Artificial Organs, Research Institute, National Cardiovascular Center, 5-7-1 Fujishiro-dai, Suita, 565-8565, Japan. hslee@ri.ncvc.go.jp
authors.forename: Hwansung
authors.initials: H
authors.lastname: Lee
authors.forename: Eiki
authors.initials: E
authors.lastname: Akagawa
authors.forename: Eisuke
authors.initials: E
authors.lastname: Tatsumi
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Taenaka
mesh_terms: D004562:Electrocardiography; D006350:Heart Valve Prosthesis; D006353:Heart-Assist Devices; D011312:Pressure; D014741:Video Recording