Method of preparing urinary catheter having balloon of three cavities at top end of urinary catheter

A method of preparing a urinary catheter having a balloon of three cavities at a top end of the urinary catheter, wherein the method comprises:

• Step 1, preparing a catheter having four cavities, cutting one end of the catheter having four cavities to be flat, wherein a first cavity of the four cavities has a circular center located at a circular center of the catheter having four cavities and serves as a urinary guiding cavity;
• the first cavity has a diameter of 2 mm;
• the other three cavities of the four cavities serve as three water injection cavities;
• a circular center of each of the three second cavities is located at a center of a circular radius of a cross section of the catheter having the four cavities;
• a connection line connecting the circular centers of the three second cavities forms an equilateral triangle;
• a center or a pendant center of the equilateral triangle is the circular center of the first cavity;
• each of the three second cavities has a diameter of 0.5 mm;
• Step 2, cutting 2 cm from the one end of the catheter having the four cavities from the catheter longitudinally, along a length direction of the catheter, to form three catheters separated from each other, wherein each of the three catheters has one respective second cavity of the three second cavities;
• each of the three catheters has a length of 2 cm to 3 cm;
• each of the three catheters has an outer wall;
• and a top end of each of the three catheters, each having the one respective second cavity, is closed;
• Step 3, hot-pressing the three catheters by placing each of the three catheters, each having the one respective second cavity, in a steel plate, wherein a front and a rear of the steel plate supply a pressure and heat;
• a temperature of the hot-pressing is 40° C. to 60° C.;
• a duration of the hot-pressing is 5 minutes to 15 minutes;
• a pressure value applied to each of the three catheters, the one respective second cavity, is 5 kg to 7.5 kg;
• each of the three catheters, each having the one respective second cavity, is pressed to be flat;
• and a redundant portion of the outer wall of each of the three catheters is trimmed to enable each outer wall to have a thickness of 0.5 mm;
• Step 4, connecting each of the top ends of the three catheters, each having the one respective second cavity, to each other by glue or by hot-melting;
• taking a guide thread to pass through the urinary guiding cavity;
• wherein the guide thread enters the urinary guiding cavity from a tail end of the urinary guiding cavity and extends out of the urinary guiding cavity from a top portion of the urinary guiding cavity;
• and after extending out of the urinary guiding cavity, the guide thread is connected to the top ends of the three catheters, each having the one respective second cavity;
• and
• Step 5, pressing a water-soluble polymer to form an outer shell, which is hollow and is disposed at the top end of the urinary catheter;
• coating a tail end of the outer shell with polymer glue;
• collecting the three catheters, each having the one respective second cavity, to an inside of the outer shell;
• glueing the tail end of the outer shell to the top end of the catheter having the four cavities, so as to obtain the urinary catheter having the balloon of three cavities at the top end of the urinary catheter.