| 摘要 |
PROBLEM TO BE SOLVED: To prevent a clogging and a halation from occurring, reduce a a visual burden, and improve safety and certainty by providing a plurality of suction holes by setting the cross sectional area at a specified mm2 or higher, and forming a cap of a material of a color having light-absorbing property. SOLUTION: A suction hole 2 is formed into a circle, an oval shape, a triangle, a square or a hexagon or the like the cross sectional area of which is 0.5 mm2 or higher. When the value is less than 0.5 mm2, there is danger that a clogging with a blood clot, or the like, may occur. One or more suction holes 2 are provided, and even when one suction hole 2 is closed, a suction is made possible continuously by the remaining suction hole 2. The upper limit of the cross sectional area differs depending on the outer diameter of the tip end section of a cap 1, but generally, setting the upper limit at approx. 50% of the outer diameter is preferable in durability. Also, the cap 1 is formed by mixing an X-ray non-transmissible material such as bismuth oxide in a flexible resin such as a vinyl chloride resin, and a searching when residing in body is facilitated. In addition, the cap 1 is made gray or the like which absorbs light. By this constitution, an obstruction to an operation can be prevented from occurring, and the operation can be safely and surely performed. |
