Disease leaves a trace in every breath.

The journey of a breath, step by step

An illustration follows volatile organic compounds from lung cancer cells to the Breav eNose. Anatomy is drawn approximately to scale; the molecules are greatly enlarged so they can be seen.

1. Origin. It begins with a handful of cells. Cancer cells rewire their metabolism. Oxidative stress and lipid peroxidation release volatile organic compounds — aldehydes, alkanes, ketones, aromatics. In the animation, a small cluster of irregular malignant cells, surrounded by regular healthy cells, releases colour-coded volatile molecules. One hexanal molecule (C₆H₁₂O) is labelled and followed, and a line traces its path.
2. Bloodstream. The signal enters the blood. Small and volatile, these molecules diffuse through tissue into nearby capillaries and travel with the blood. In the animation, the molecules diffuse into a capillary running past the tumour and are carried along with red blood cells.
3. Alveolus. Exchanged at the alveoli. Across a membrane less than a micrometre thin, they pass from blood into air — the same exchange that delivers oxygen. In the animation, the capillary wraps an alveolus; the molecules cross its thin membrane from blood into air, alongside carbon dioxide leaving the blood.
4. Airways. Carried up and out. Up through the bronchial tree and the trachea, with every exhale. In the animation, pulling back, the stream leaves through an alveolar duct lined with alveoli, then climbs through bronchioles and bronchi to the trachea, pulsing with each exhale.
5. Exhale. Into a single breath. Each exhale carries hundreds of volatile compounds at parts-per-billion levels — a chemical fingerprint of what's happening inside. In the animation, a person in profile breathes out; the coloured molecules leave the mouth mixed with neutral air molecules.
6. Detection. Breav reads the fingerprint. A cross-reactive sensor array turns breath into a pattern; our models compare it against known disease signatures. In the animation, the breath enters the eNose; its twelve sensors light up in a class-specific pattern that becomes a fingerprint and converges on a reference signature. When the followed hexanal molecule binds to a sensor, the display shows an illustrative "Signature detected" result — not a diagnosis.