NPL has developed the first sensor capable of measuring localised ultrasonic cavitation – the implosion of bubbles in a liquid when a high frequency sound wave is applied. The sensor will help improve safety in hospitals by ensuring that instruments are properly disinfected before they are used on patients.

Cavitation is one of the most effective cleaning processes and is used throughout the NHS to clean and to help disinfect surgical instruments. The process involves passing a high frequency sound wave through a disinfecting liquid to create bubbles that implode, the force of which removes contaminated particles from surrounding materials.

Until now there has been no accurate method of identifying how much cavitation takes place at different locations in a cleaning system, and therefore no measureable way to ensure the cleaning process is effective. NPL's new sensor changes this. By monitoring the acoustic signals generated when the clouds of bubbles implode, it uses the detected sound to identify how much cavitation is taking place at a given location, allowing equipment to be fine-tuned to produce the right amount of cleaning action. This also means that only the required energy is used, reducing costs and environmental impact.

The device won the 2009 Outstanding Ultrasonic Product Award from the Ultrasonic Industry Association.

For more information, please contact Mark Hodnett

Find out more about NPL's research in Ultrasound