2018 年 65 巻 6 号 p. 301-306
An evaluation method for the mechanical properties of the catheter shaft under cyclic bending was proposed. Cyclic bending tests were conducted to compare mechanical properties of three kinds of specimens. One was the outer layer of the catheter shaft, and the other two were a steel-ribbon catheter shaft and a W-ribbon catheter shaft. Load difference defined by the maximum load of each cycle was used to decide the buckling displacement. Additionally, finite element analysis (FEA) was performed to analyze the deformation behavior of the catheter shaft during a three-point bending test. The load-displacement curves obtained from the FEA showed a good agreement with the envelope of the load-displacement curves in the experiment. It was also revealed from FEA that the deformation behavior of the catheter shaft at the loading point was different from the material of the wire mesh in the catheter shaft. These results also showed that the W-ribbon catheter shaft demonstrated the highest load resistance and the highest buckling displacement. Thus, it was shown that the proposed experimental procedure based on the cyclic bending tests was effective to compare the mechanical properties of various catheter shafts.