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Early warning of urinary catheter blockage

How the development of a sensor helped enabled prediction of urinary catheter blockages, bringing relief to thousands of patients.

Image of the cross section of a blocked catheter

Urinary catheter blockage occurs following infection by urease-producing bacteria which causes the pH of urine to increase, thereby promoting crystallisation of phosphate salts, and ultimately leads to catheter encrustation. This form of catheter blockage occurs in 50% of long-term catheterised patients and is significant as it can result in serious kidney and bloodstream infections. Until now there have been no effective solutions to managing this problem.

New technologies

The research of Professors Williams and Waters led to the development of a sensor that predicts conditions in the urine amenable to catheter blockage. Bacteria that promote catheter blockage, alter the pH and ammonia content of the urine and the sensor detects this through a visible colour change. This then allows for appropriate management strategies to be promptly applied including changing the catheter or treating the patient with antibiotics to avoid a serious problems occurring.

Development of the background sensor technology was a collaborative effort. Dr David Stickler and Professor Mark Waters, through a MEDLINK project, worked with the Bristol Urology Institute (BUI), Principality Medical and Coloplast, and also received funding by the Department of Health.

Blockages and infection

Every year millions of patients undergo long-term catheterisation to manage urinary incontinence. Half will experience catheter blockage causing painful bladder distension and possible kidney and blood infections. The problem is caused by bacterial infection and is both unpredictable and poorly controlled.

Ongoing development

In 2004, further work funded by the Cardiff Partnership Fund, led to the creation of improved sensor material that was suitable for large scale, low cost production and readily added to any urinary catheter. BUI subsequently demonstrated the function of the sensor in clinical trials in spring 2011.

MBI Wales have now taken on the license to manufacture and distribute the sensor, and will hold the patents which have been granted for the EU, USA and Canada. The sensor has been CE marked as class 1 sterile and work is progressing well to get it included in the UK drug tariff.

Meet our experts

Professor David Williams

Professor David Williams

Theme Lead for Oral and Biomedical Sciences, Professor of Oral Microbiology, School of Dentistry

+44 (0)2922510654

Selected publications

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