Sensor takes breathing gas measurement to a new level

"Our sensor measures the oxygen content in people’s breath, which allows us to extrapolate to the blood oxygen concentration," says Mahmoud El-Safoury, project manager at Fraunhofer IPM.

The novel sensor is based on the principle of fluorescence quenching. A fluorescent layer is illuminated with light and emits light with a longer wavelength. When oxygen comes into contact with the layer, the emitted light is attenuated. The intensity of the attenuated light allows conclusions to be drawn about the oxygen concentration in the respiratory gas and therefore in the blood.

"Quenching is already used to determine the concentration of dissolved oxygen in liquids in sectors such as the food industry and at water and wastewater treatment plants, for example. It’s a novel method in medical engineering, though," says Dr. Benedikt Bierer, group manager at Fraunhofer IPM.

• Greater precision: the fluorescence sensor provides significantly more accurate results than pulse oximetry.
• Continuous measurement: Oxygen saturation can be monitored continuously throughout the day, in contrast to blood gas analysis, which is only carried out selectively.
• Painless application: The sensor can be integrated into breathing masks or breathing tubes and enables measurement without taking blood samples.
• Wide range of applications: The sensor is suitable for use in hospitals, ambulances and even for home care.

The sensor is currently being further developed and optimized at Fraunhofer IPM. Among other things, the researchers are investigating the cross-sensitivity to other gases and the influence of parameters such as humidity and temperature on the measurement signal. "There is a wide range of potential future applications — the tiny sensor can be used by paramedics, in hospital settings, and even at home by patients with lung disease," El-Safoury says.

COMPAMED-tradefair.com; Source: Fraunhofer IPM