The closing velocity of mechanical heart valve leaflets

✍ Scribed by George X. Guo; Tien-Hon Chiang; Rodolfo C. Quijano; Ned H.C. Hwang

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 745 KB
• Volume: 16
• Category: Article
• ISSN: 1350-4533
• DOI: 10.1016/1350-4533(94)90069-8

✦ Synopsis

The closing motion of the occluder leaflets in bileajlet type mechanical heart valves (MHV) was monitored with a laser sweeping technique. The angular displacements of the leaflets were registered with precision of 0.2 t_~s steps. l~x@rimental measurements were made using five 29 mm Edwards-Duromedics 'rM including three original specifycation (EDOS) and two modified specification (ELMS), and two 29 mm St Jude Medical MHVs. The testing valve was installed in the mitral position of a physiologic pulsatile mock circulatory flow loop using water-glycerine solution as the testing fluid. Each value was tested by: (1) direct mounting the ualue on metal washers, and (2) mounting the value with its sewing ring. Experiments were carried out at pulse rates of 70, 90, and 120 beats mini', with the corresponding cardiac output of 5, 6, and 7.5 1itre.s mini', and maximum left ventricular pressure gradients (dp/dt) of 1,800, 3,000 and 5,600 mm Hg 6', respectively. The maximum leaflet closing velocity of each of the tested valve types are presented. The diff erence in leaflet closing movements between the direct rigid mounting and the sewing ring mounting are discussed. The details of the laser sweeping terhnique are presented.