Background: Analysis of volatile metabolites derived from the human breath or biofluids
provides noninvasive means of detecting and monitoring diseases that occur throughout the body. Diseases
arise from different mechanisms that cause alterations in normal physiological processes.
Mechanisms of disease (pathogenesis) result in the production of unique mixtures of abnormal volatile
organic compounds (VOCs), referred to as disease biomarker metabolites when associated with specific
diseases. Regardless of where disease biomarkers originate in the body, they are picked up by the
circulatory system and eventually expelled out through the lungs. Analysis of complex mixtures of
disease biomarkers provides effective diagnostic clues for detecting the presence of specific disease
processes occurring in the body.
Methods: Recent progress in the development of electronic-nose (e-nose) applications and technologies
for clinical examinations and human disease diagnoses are reviewed.
Results: Metabolomics has been useful in identifying biomarkers and mechanisms of disease, but is
often time-consuming and not easily applied to disease diagnosis. E-nose devices are relatively new
gas-sensing technologies that are small, simple, portable and particularly useful for noninvasive early
disease detection. Some major advantages of using e-noses for disease diagnoses are that they provide
quicker, more efficient diagnostic results and cause less stress, anxiety, and no pain to patients.
Conclusion: Recent advancements in the use of e-nose devices to detect complex mixtures of disease
biomarkers are providing the great potential for these instruments to facilitate and accelerate point-ofcare
clinical disease diagnoses.