本研究將傳統之連續流醫用水刀，加裝一電磁閥及其控制電路，使其產生脈衝射出的切割水柱。並使用動態壓力計量測水刀噴嘴出口之脈衝壓力波形，以數位天平量測其平均質量流率，並計算其出口功率。利用凝膠體以模擬相同強度的器官組織，並測試此假體組織在受到脈衝水刀切割時之情況。實驗結果顯示，噴嘴口徑0.30mm時，噴嘴出口處之流場接近層流，其壓力損失較小，上游壓力至噴嘴處約損失五成左右，且壓力損失之比例與上游壓力無關。噴嘴口徑0.20mm時，噴嘴出口處之流場則接近紊流，壓力損失則近八成。另外在壓力波形圖中顯示，脈衝流運用在比較小口徑的噴嘴時時壓力衰減嚴重，並容易誘發流場內部震盪。而在切割實驗時，由於本電磁閥的可用頻率過低，容易造成非連續的切割剖面，因此噴嘴之移動速度速度不宜過大。

A solenoid valve and its controller was modified to provide a pulsed water column for an ordinary continuous flow water-jet cutter. A dynamic pressure sensor was used to measure the pressure waveform of jet from the nozzle outlet. A digital balance was used to measure the averaged mass flux of jet. The phantom of liver tissue made from jelly has been used to simulate the jet cutting patterns in human tissue. The experimental results indicate that the flow field inside a nozzle of 0.30 mm diameter would be laminar flow. And the pressure recovery at the nozzle outlet is about 50% of the upstream pressure. On the other hand, the flow field inside a nozzle of 0.20 mm diameter would be turbulent flow. The pressure loses would close to 80% of the upstream pressure. Pressure waveforms show serious pressure attenuation in nozzle of small diameter, accompanied by an unexpected oscillation. In the phantom cutting experiments, interrupted cutting profiles were observed because of the low operating pulsed frequency, so a slower cutter moving speed is recommended in this case.

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