| 摘要 |
PROBLEM TO BE SOLVED: To further improve safety while securing a flow rate by increasing rigidity and tensile strength. SOLUTION: In a catheter which has a coil-shaped spring 3 mounted inside a hollow cylindrical body 2, the coil-shaped spring 3 has a quadrilateral cross section. This coil-shaped spring 3 having the quadrilateral cross section can make its rigidity and strength larger than those of the spring with a circular cross section when the effective inner diameter is equal. By properly altering the winding pitch of the spring, a catheter can be made relatively soft or very high in rigidity to meet the needs of a physician. Easier visual recognition by radiography allows the physician to handle the catheter easily, thereby contributing to reduction in medical accident. |
