VALVULAR HEART DISEASE Estimation e ur itant Flow Volume Based on Centerline Velocity/Distance roles Using Digital Color M-Q Doppler: Application to Orifices of Different Shapes

Objectives. In this study we Investigated the centerline velocity profile method for low computation applied to noncircular, as well as circular, orifices using digital color Row data . Ractlgroaud. Recently it been fed that low volume thrmo an orifice can be estimated more accurately by computing the axial "centerline" low velocityldistance profile proximal to the orifice. etha'. A total of seven different orifices were mounted in a t.Row model: four circular orifices, two rectangular orfl with a major/mhror axis ratio of 4:1 and 8:1 and an ovoid orifice having a major/minor axis ratio of 2 :1 . Three different low rates were examined (1 .68, 3.48 and 6.48 llierstmin) . Digital measurements of low velocity at discrete positions along the centerline progressing toward the orifice were analyzed to yield complete flow velocity profiles for each orifice at each flow rate .