One of the ways to prevent CAUIT is unidirectional flow by generating the negative pressure in the drainage system. For this purpose, we develop the drainage sponge and water beads system. Although water beads relatively solve the Drainage sponge's problems, still it is not entirely reliable, and also the generated negative pressure may damage the bladder tissue. For resolving these issues, we design a system which is suitable for in-patient and work with a constant vacuum, but it does not apply any pressure to the bladder. As in every hospital in the USA,  the vacuum unit exists next to the patient's bed; it can provide constant and reliable negative pressure for our system. Our design is an intermediate gadget between the catheter coming from the bladder and a container. It has some windows which prevent the transmission of the negative pressure to the bladder. So we call it "window system". Urine is drained from the bladder through the gravity-driven flow to the intermediate gadget and then removed through the negative pressure to the container.

First, for testing and optimizing, a prototype was made with a Falcon Tube. Then the final 3D version of the prototype was designed by SOLIDWORKS software and finally fabricated by 3D printing. Also, an experiment was developed to verify that the bacterial biofilm can not migrate upstream and infect the bladder, in the presence of the window system.