Implementation of Fowler's method for end-tidal air sampling.

Area of Science:

• Biomedical Engineering
• Respiratory Physiology
• Analytical Chemistry

Background:

• Accurate breath analysis requires precise separation of dead space and end-tidal air.
• Existing methods may lack reproducibility or sufficient sample volume for detailed analysis.
• Standardized protocols are needed for reliable comparison of breathomics data.

Purpose of the Study:

• To present the design, realization, and testing of a novel CO(2)-triggered breath sampler.
• To enable separate collection of dead space and end-tidal air across multiple breaths.
• To enhance the quality and comparability of breath analysis studies.

Main Methods:

• Development of a CO(2)-triggered system for breath sampling.
• Implementation of a procedure for separate collection of dead space and end-tidal air.
• Testing of the system for breath-by-breath estimation of dead volume and subject comfort.

Main Results:

• The sampler successfully collects dead space and end-tidal air separately over multiple breaths.
• The system demonstrates advantages in sample volume, compound origin insights, reproducibility, and concentration.
• Breath-by-breath dead volume estimation and subject safety were confirmed.

Conclusions:

• The developed breath sampler is a high-quality, rapid, and reliable tool for respiratory analysis.
• This system facilitates improved insights into the origin of compounds in exhaled breath.
• The technology contributes to the development of standardized breath sampling protocols for the field.