| Budget Amount *help |
¥1,300,000 (Direct Cost: ¥1,300,000)
Fiscal Year 1996: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1995: ¥900,000 (Direct Cost: ¥900,000)
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| Research Abstract |
[PART 1]
Analysis of Doppler waveform was performed using a flow phantom model. This model is consisted of Cobe-Stockert circulation pump, silicone tubes, water tank, and blood substitute (707G ; ATS Lab). Pulsatile wave can be produced by the circulation pump. For simulating hepatic blood flow system, another silicone tube with constant flow was parallelly placed to a tube of pulsatile flow in the water tank. Stenoses withvarious degree or shunt with various size were made and evaluated by duplex ultrasound systems. Through this study, high velocity pulsatile flows were obtained at atenotic and shunt sites. In shunt case, high velocity and low impedance (low PI or RI) flows were ontained, while on significant change in PI or RI was seen in stenosis model. Maximal velocities and pulsatility index can be changed according to the degree of peripheral stenosis or peripheral pressure.
[PART 2]
Blood flow measurement by a Doppler ultrasound equipment was perfomed using a same phantom. Measured data were compared with the free flow volume at the end of the system. Measurement by manual tracing was by far larger than the true flow volume due to ignoring spectrum of FFT signals.
Though "% window", "mode", and "mean"are the methods for obtaining mean flow velocity, "mean"method could produce most reliable data even for turbulent flow model. Measured data were proportional to the width of sample width, and the sample width should be wide enough for vessel diameter.
Such informtions are very helpful for the evaluation of Doppler study in clinical work.
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