取栓支架屬於魚簍型金屬支架，主要用於治療血管阻塞所造成的缺血性腦中風，其方法為使用金屬支架將堵住動脈之血塊取至引導導管，再隨引導導管取出體外。常用的材料為具有良好生物相容性的鎳鈦合金。
此篇論文研究主要目的為改良支架後製程中的噴砂研磨及電解拋光兩部分，實驗方法為以取栓支架的結構設計為實驗試片的模型，以光纖雷射切割金屬管而成後，再探討其後處理製程並改善優化。首先是為改良金屬支架在傳統機械噴砂上的問題，面對機械噴砂常因手持式的工法導致支架移除不均勻的結果，希望透過新開發的旋轉漿體研磨作為主要改善問題的方法。此方法利用直流馬達作為主要動力源，將支架固定於特製治具並浸入於漿體進行旋轉研磨，觀察在不同砂材粒徑底下，支架模型隨著工作時間增加後的表面形貌變化及融渣移除情況。最後是探討不同電解拋光加工時間及電源輸出形式對於邊緣圓角化的影響。實驗藉由不同電解拋光時間，觀察材料移除量提高後邊緣圓角的變化，另外使用脈衝直流電源供應器比較與一般直流電源供應器之間的差異，觀察其於電解拋光製程上帶來的影響。
實驗結果指出先使用粗粒徑(87.5~73.5μm)再用中粒徑(62~52.5μm)磨料研磨可以完全移除雷射切割後所產生的融渣，且得到較佳的表面形貌品質。在電解拋光的探討中，證實使用脈衝電解拋光能夠改善一般直流電解拋光為達到支架邊緣圓角化而必須提高材料移除量的缺點，而達到相近的圓角值可以省去近3%的材料移除量。
關鍵字:取栓支架、旋轉漿體研磨、脈衝電解拋光、圓角化

The stent retriever is a fish basket type metal stent and mainly used for dealing with ischemic cerebral stroke caused by blood vessel obstruction. The stent can grasp the blood clot that blocks the artery to the catheter, then the clot is taken out of the body with the catheter. The main commonly used material is Nitinol, due to its shape memory property and good biocompatibility.
The main purpose of this thesis is to improve two parts of the post laser cutting process in stent fabrication: sandblasting and electropolishing. The first is to improve the shortcoming of conventional mechanical sandblasting, which often results non-uniform stent material removal due to its hand-held method. Therefore, the newly developed rotary slurry grinding method was performed in this study. In the method, stents were fixed on a special fixture and immersed in the slurry to perform rotary grinding with a controllable DC motor. The surface morphology and slag removal of the stent model were investigated with increasing working time under different particle sizes. Finally, the effect of process time and power source type of electropolishing process on edge rounding was studied. Experiments were carried out by varying time of electropolishing work to observe the relationship between the material removal amount and the change of edge rounding. In addition, a pulsed DC power supply was used, compared with a DC power supply, to study its effect on the material removal rate and edge rounding performance in the stent electropolishing process.
The experimental results indicate that the rotary slurry grinding with the coarse abrasives (size 87.5~73.5μm) firstly and the medium abrasives (size 62~52.5μm) secondly can completely remove the slag generated by laser cutting, and obtain better surface topography quality. In the study of edge rounding, it is observed that the increase in the material removal can improve edge rounding. The study of pulse electropolishing has proved that it can improve the drawback of conventional DC electropolishing, to achieve edge rounding and sacrifice the material usage. The similar edge rounding value can be achieved with pulse electropolishing process and the material removal amount is about 3% less.
Keyword: stent retriever, rotary slurry grinding, pulse electropolishing, edge rounding

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