A urinary catheter is a tube that is inserted into the bladder through the urethra to drain urine. After the catheter is inserted into the bladder, there is a balloon near the head of the catheter to fix the catheter The tube stays in the bladder and is not easy to come out, and the drainage tube is connected to the urine bag to collect urine. According to dfferent matrial, urinary catheters can be divived into natural rubber catheter, silicone rubber catheter or polyvinyl chloride catheter (PVC catheter) .