Effects of ureteric stent holes on urine reflux

• Main Authors: cheng-Ham Chung, 鍾承翰
• Other Authors: Tian-Shiang Yang
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/93673101735745727421

碩士 === 國立成功大學 === 機械工程學系碩博士班 === 93 === Abstract 　Clinically, when the ureter is blocked by ureteric stone, we can insert a double-J stent (having side holes) to release the pressure in kidney. When a stent is inserted, however, the valva (bladder-ureter junction) cannot be tightly closed, and urine can then reflow from the bladder to the kidney, which may result in renal infection. 　In this thesis, the ureter is assumed to be an elastic tube, while the stent is treated as a rigid tube with side holes. A model for the straight ureter-stent system is then set up using fluid mechanics and elasticity theories. In particular, the resulting mathematical equations are solved numerically, in order to evaluate the effects of the location and flow resistance of the side holes, and the rigidity of the ureter, on the total urine reflux. The numerical results indicate that, when the system is in steady state, the total reflux is not affected by the flow resistance of the side holes on the stent. However, increasing the rigidity of the ureter would decrease the total reflux of urine. These results are expected to be useful for improving stent design.