{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/31262"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/31262","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Hemodynamic Flow Characterization of St. Jude Medical Bileaflet Mechanical and Bioprosthetic Heart Valve Prostheses in a Left Ventricular Model via Digital Particle Image Velocimetry","abstract":"The performance of the heart after a valve replacement operation will greatly depend on the flow character downstream the mitral valve thus a better understanding of the flow character is essential. Most in vitro studies of the flow downstream of a MHV have been conducted with the valve in the aortic position. Researchers reported detailed measurements most of which were obtained by Laser Doppler Velocimetry (LDV) in rigid models of the aorta. Digital Particle Image Velocimetry (DPIV) has also been utilized to reveal intricate patterns of interacting shed vortices downstream of the aortic valve. The orientation of the valves may considerably affect the flow development and slight difference may produce significant differences in the ventricular flow fields. Two orientations, respectively anatomical and anti-anatomical, of the St. Jude Medical (SJM) bileaflet valve are presented and compared with the SJM Biocor porcine valve, which served to more closely represent the natural valve. In this effort, we employ a powerful tool to monitor the velocity field in a flexible, transparent LV and study the evolution of large eddies and turbulence through a complete cardiovascular cycle. Both time average and instantaneous results of velocity, vorticity, and turbulent kinetic energy distributions are presented. The presence and location of vortical structures were deduced as well as the level of coherence of these structures. The presence of three distinct flow patterns were identified, by the location of vortical structures and level of coherence, for the three configurations corresponding to significant differences in the turbulence level distribution inside the LV.","abstract_html":"The performance of the heart after a valve replacement operation will greatly depend on the flow character downstream the mitral valve thus a better understanding of the flow character is essential. Most in vitro studies of the flow downstream of a MHV have been conducted with the valve in the aortic position. Researchers reported detailed measurements most of which were obtained by Laser Doppler Velocimetry (LDV) in rigid models of the aorta. Digital Particle Image Velocimetry (DPIV) has also been utilized to reveal intricate patterns of interacting shed vortices downstream of the aortic valve. The orientation of the valves may considerably affect the flow development and slight difference may produce significant differences in the ventricular flow fields. Two orientations, respectively anatomical and anti-anatomical, of the St. Jude Medical (SJM) bileaflet valve are presented and compared with the SJM Biocor porcine valve, which served to more closely represent the natural valve. In this effort, we employ a powerful tool to monitor the velocity field in a flexible, transparent LV and study the evolution of large eddies and turbulence through a complete cardiovascular cycle. Both time average and instantaneous results of velocity, vorticity, and turbulent kinetic energy distributions are presented. The presence and location of vortical structures were deduced as well as the level of coherence of these structures. The presence of three distinct flow patterns were identified, by the location of vortical structures and level of coherence, for the three configurations corresponding to significant differences in the turbulence level distribution inside the LV.","abstract_has_math":false,"creators":["Pierrakos, Olga"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Engineering Science and Mechanics","degree_department":"Engineering Science and Mechanics","school":null,"contributors":[],"advisors":[],"committee_chairs":["Telionis, Demetri P.","Vlachos, Pavlos P."],"committee_members":["Pyle, Robert Lee","Berry, Joel"],"year":2002,"date_issued":"2002-11-15","date_published":"2002-11-15","updated_at":"2026-07-22T22:18:49Z","subjects":["St. Jude Medical","orientation","Mechanical heart valves","vorticity","Turbulence","DPIV"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-02182003-143111"],"render_values":[{"text":"etd-02182003-143111","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/31262","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Telionis, Demetri P.","Vlachos, Pavlos P."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Pyle, Robert Lee","Berry, Joel"]},{"key":"dc:contributor.department","label":"Department","values":["Engineering Science and Mechanics"]},{"key":"dc:creator","label":"Author","values":["Pierrakos, Olga"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:31:52Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:31:52Z","2004-03-18"]},{"key":"dc:date.issued","label":"Date","values":["2002-11-15"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Engineering Science and Mechanics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["St. Jude Medical","orientation","Mechanical heart valves","vorticity","Turbulence","DPIV"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-02182003-143111"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/31262"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["The performance of the heart after a valve replacement operation will greatly depend on the flow character downstream the mitral valve thus a better understanding of the flow character is essential. Most in vitro studies of the flow downstream of a MHV have been conducted with the valve in the aortic position. Researchers reported detailed measurements most of which were obtained by Laser Doppler Velocimetry (LDV) in rigid models of the aorta. Digital Particle Image Velocimetry (DPIV) has also been utilized to reveal intricate patterns of interacting shed vortices downstream of the aortic valve. The orientation of the valves may considerably affect the flow development and slight difference may produce significant differences in the ventricular flow fields. Two orientations, respectively anatomical and anti-anatomical, of the St. Jude Medical (SJM) bileaflet valve are presented and compared with the SJM Biocor porcine valve, which served to more closely represent the natural valve. In this effort, we employ a powerful tool to monitor the velocity field in a flexible, transparent LV and study the evolution of large eddies and turbulence through a complete cardiovascular cycle. Both time average and instantaneous results of velocity, vorticity, and turbulent kinetic energy distributions are presented. The presence and location of vortical structures were deduced as well as the level of coherence of these structures. The presence of three distinct flow patterns were identified, by the location of vortical structures and level of coherence, for the three configurations corresponding to significant differences in the turbulence level distribution inside the LV."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Hemodynamic Flow Characterization of St. Jude Medical Bileaflet Mechanical and Bioprosthetic Heart Valve Prostheses in a Left Ventricular Model via Digital Particle Image Velocimetry"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Telionis, Demetri P.","Vlachos, Pavlos P."],"dc:contributor.committeemember":["Pyle, Robert Lee","Berry, Joel"],"dc:contributor.department":["Engineering Science and Mechanics"],"dc:creator":["Pierrakos, Olga"],"dc:date.accessioned":["2014-03-14T20:31:52Z"],"dc:date.available":["2014-03-14T20:31:52Z","2004-03-18"],"dc:date.issued":["2002-11-15"],"dc:description.abstract":["The performance of the heart after a valve replacement operation will greatly depend on the flow character downstream the mitral valve thus a better understanding of the flow character is essential. Most in vitro studies of the flow downstream of a MHV have been conducted with the valve in the aortic position. Researchers reported detailed measurements most of which were obtained by Laser Doppler Velocimetry (LDV) in rigid models of the aorta. Digital Particle Image Velocimetry (DPIV) has also been utilized to reveal intricate patterns of interacting shed vortices downstream of the aortic valve. The orientation of the valves may considerably affect the flow development and slight difference may produce significant differences in the ventricular flow fields. Two orientations, respectively anatomical and anti-anatomical, of the St. Jude Medical (SJM) bileaflet valve are presented and compared with the SJM Biocor porcine valve, which served to more closely represent the natural valve. In this effort, we employ a powerful tool to monitor the velocity field in a flexible, transparent LV and study the evolution of large eddies and turbulence through a complete cardiovascular cycle. Both time average and instantaneous results of velocity, vorticity, and turbulent kinetic energy distributions are presented. The presence and location of vortical structures were deduced as well as the level of coherence of these structures. The presence of three distinct flow patterns were identified, by the location of vortical structures and level of coherence, for the three configurations corresponding to significant differences in the turbulence level distribution inside the LV."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-02182003-143111"],"dc:identifier.uri":["http://hdl.handle.net/10919/31262"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["St. Jude Medical","orientation","Mechanical heart valves","vorticity","Turbulence","DPIV"],"dc:title":["Hemodynamic Flow Characterization of St. Jude Medical Bileaflet Mechanical and Bioprosthetic Heart Valve Prostheses in a Left Ventricular Model via Digital Particle Image Velocimetry"],"dc:type":["Thesis"],"thesis:degree_discipline":["Engineering Science and Mechanics"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:18:49Z"}