A Peristaltic Pump to Improve Bladder Emptying and Irrigation in Patients Who Use Clean Intermittent Catheterization

Abstract

Background: Neurogenic bladder patients who intermittently catheterize may have systems that drain slowly and incompletely. These limitations can lead to urinary tract infections and bladder stone formation and be time consuming. We hypothesize that a catheter accessory device could improve drainage, reduce residual bladder volume, and save time. Methods: A yearlong collaboration between an undergraduate biomedical engineering student design team and client mentors from the pediatric urology department led to an evaluation of solutions to enhance emptying of bladders that require intermittent catheterization. Students performed market analysis, identified design requirements, generated design concepts, conducted usability testing, and constructed alpha and beta prototypes verified through benchtop experimentation during the yearlong project. Prototypes were verified using a phantom bladder model built from a compliant stress ball with an attached catheter and placed under an external pressure of 5 cm H 2 O. Tests were conducted to measure the diff erence between passive drainage and device-assisted drainage at various bladder volumes and catheter sizes. Eight student peers compared passive emptying, irrigating, and aspirating a phantom bladder model using the prototype or syringe to assess the usability of the device. Results: We developed a pump that interfaces with commercially available catheters. The pump housing was designed and 3D printed. Fluid can be moved bi-directionally with a battery-powered peristaltic pump and microcontroller. The pump has a built-in current sensing threshold with an automatic shutoff safety mechanism. Testing results showed that for all bladder volumes and catheter sizes, the pump emptied more completely and drained between 1.6 and 6.3 times faster when compared to passive drainage. Usability feedback showed that the pump required less time to irrigate the bladder and was preferred when compared to the manual syringe technique. Conclusions: This portable catheter pump improves phantom bladder emptying by increasing flow rate, decreasing residual volume, and making irrigation easier. Future design improvements will work to implement safety mechanisms and miniaturize the pump. This project demonstrates the feasibility of a catheter accessory device to improve patient quality of life and the ability for understudied clinical problems to be addressed through collaborations between capstone engineering design teams and physicians.