cathetus

例句：

1. 1. The doctor performed a catheterization to remove the blockage in his kidney.
   医生进行了导管插入术，以清除他肾脏中的阻塞。
2. 2. Catheters are used to deliver medications and fluids into the body.
   导管被用来将药物和液体输送到身体中。
3. 3. During labor, the mother's cervix is dilated and the catheter is inserted to monitor fetal heart rate.
   在分娩过程中，母亲的子宫颈会被扩张，导管将被插入以监测胎儿的心率。