Fraunhofer Institute for Physical Measurement Techniques IPM
Fraunhofer Institute for Physical Measurement Techniques IPM
Sauerstoff-Konzentration im Blut durch Atemgas-Analyse messen
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Fraunhofer IPM uses the effect of fluorescence quenching for a non-invasive miniaturized O2 sensor

Detecting oxygen in the respiratory air – prescisely and non-invasively

Based on the principle of fluorescence quenching, O2 concentrations in the breathing gas can by principle be measured very accurately directly in the breathing tube.

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Breath analysis by fluorescence quenching

Direct oxygen measurement via respiratory air

When ventilating patients or treating emergency patients with respiratory problems, it is important to reliably determine the the blood oxygen level. For a rough estimate of the arterial partial pressure of O2 (paO2), non-invasive pulse oximetry is the method of choice today. More accurate paO2 values can be determined using invasive blood gas analysis. However, this is time-consuming and cannot be performed continuously. For patients, the method is both painful and uncomfortable.

Fluorescence quenching is a promising principle for measuring the blood oxygen level. The method has been used very successfully for two decades to determine the concentration of dissolved oxygen in liquids. In fluorescence quenching, a fluorescent layer is irradiated with short-wave light. As a rule, the emitted light is of longer wavelength (and lower energy) than the excitation light. On contact with the target gas, the fluorescence is attenuated or completely suppressed, depending on the gas concentration.

Miniaturized, low-cost sensor for integration in breathing mask or breathing tube

Fraunhofer IPM uses the effect of fluorescence quenching for a non-invasive miniaturized O2 sensor that can be integrated into a breathing mask or breathing tube. The sensor is designed to provide real-time monitoring of the oxygen content in the respiratory air, which holds a number of advantages: In terms of sensitivity, the direct measurement clearly surpasses conventional methods for determining the blood oxygen level. The sensor can be manufactured comparatively inexpensively. Easy handling due to the integration into the ventilation system proofs to be time-saving.

In the Fraunhofer BREATH project, we are developing a cost-effective, fluorescence-based sensor system for the precise determination of the O2 concentration in respiratory air. The system is set to surpass the state of the art in terms of accuracy and cost efficiency and to replace existing measurement systems.

BREATH project

In the BREATH project, we are developing a non-invasive sensor for real-time monitoring of the oxygen content in the respiratory air based on the principle of fluorescence quenching.

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