In a joint effort of Lightwavelab team members from Leibniz -IPHT, RPTU and Fraunhofer ITWM, in collaboration with the Jena University Hospital, a gas sampling unit (GSU) was developed and tested for continuous gas sampling from a respirator. The GSU consists of a vacuum pump, pressure sensor, a set of automated valves and tubes connecting the respirator with a measurement cell. The automated valves are controlled by a computer in a way that the measurement cell is first evacuated to acquire a reference measurement. Subsequently the cell is filled with the exhaled gas from the respirator via a Vamos® pump and a sample measurement of exhaled gas is acquired to
complete a measurement cycle. For each measurement cycle information about the exhaled gas composition can be extracted from the acquired broadband infrared spectra without interfering with the respirator.

In a proof-of-principle experiment a ventilated test lung was spiked with a mixture of synthetic gases and the composition of the exhaled air was investigated every 7 minutes for a duration of 24 hours with a commercially available Fourier- transform infrared spectrometer. With the demonstrated stability and analytical capability of the presented GSU combined with more advanced spectroscopic techniques like field-resolved infrared spectroscopy we aim to monitor metabolites in critically ill patients over the entire physiologically relevant molecular concentration range in real time.

This development is one of the many steps on our mission of translating the spectroscopic methods which we are developing to real-life applications in medicine and biology.

Link to the publication: Borek-Dorosz et al., Sci. Rep. 16, 1 (2026)