| Summary: | 碩士 === 國立臺灣大學 === 應用力學研究所 === 91 === In this study, we set up a device that can produce regular pulse of different frequency on the elastic tube and vascular graft, and discuss the change of the pressure and flow waveforms in both time domain and frequency domain. We also discuss the change of mechanical properties by measuring the pressure and diameter waveforms simultaneously.
From waveform analysis we found the pulsation of waveform is independent of the pulse frequency but the systemic frequency. Besides, the upstream buffer charmber result in amplitude decrease when pulse frequency is about 2 Hz.
For the elastic tube the viscoelastic effect increases when pulse frequency is over 3Hz. In general , the dynamic Young’s modulus of elastic tube is close to the static Young’s modulus. However, the upstream buffer charmber dissipates more energy and affect the subsequent phase delay . The Young’s modulus of the vascular graft is about 3800 cmH2O/cm is bigger than the elastic tube (542 cmH2O/cm). And the phase delay between the pressure and flow wave also increase with the operated pulse frequency.
For this systemic angle, we also found the phase has zero crossing operated frequency as the input impedance reached the first minimum at the relatively frequency which is about 9 Hz.
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