{
  "abstract": "BACKGROUND: Rebreathing of expired gases during prone infant sleeping contributes to hypoxic and hypercapnic exposure, even without airway obstruction. We investigated how anatomical, physiological, and environmental factors influence aerodynamic rebreathing. METHODS: A dynamically scaled in vitro model simulated prone nasal breathing corresponding to infants weighing 2 to 5 kg, with nostril diameters of 3.2 to 6.0 mm and breathing frequencies of 25 to 40 breaths/min. Ambient temperature and sleep-surface characteristics were varied. Rebreathing was quantified using tracer measurements, while flow visualization revealed the underlying aerodynamic mechanisms. RESULTS: Rebreathing exceeded 60% despite unobstructed nasal openings. Increasing ambient temperature from 23 to 30 degrees C increased rebreathing by 68 to 77%, while reducing simulated infant mass from 5 to 2 kg increased rebreathing by 39 to 46%. Fibrous surfaces increased rebreathing, particularly near inclined nasal openings. A novel finding was that increasing nostril diameter from 3.2 to 6.0 mm increased rebreathing by up to 50%. Flow visualization revealed vortical structures that retained expired fluid near the nasal openings, facilitating re-inspiration. CONCLUSIONS: Aerodynamic rebreathing depends strongly on simulated infant characteristics and sleeping environments. These findings are consistent with established safe-sleep recommendations and identify nostril diameter, for the first time, as a potentially important anatomical factor warranting clinical investigation.",
  "abstract_shown": true,
  "affiliations": [
    "Technion - Israel Institute of Technology"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 2,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "D. Greenblatt"
    },
    {
      "name": "N. Itzhak"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8sf57v08skgra.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.11.06.764821",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.11.06.764821v1.full",
  "id": "8sf57v08skgra",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.11.06.764821v1",
  "language": null,
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "physiology"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.11.06.764821v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-06",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/8sf57v08skgra.ris",
  "sources": [
    {
      "first_seen": "2026-11-10T00:23:31Z",
      "native_id": "10.64898/2026.11.06.764821",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.11.06.764821v1"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "biorxiv:physiology",
      "subfield": "physiology"
    }
  ],
  "title": "Quantifying and Visualizing the Invisible Hazard of Infant Rebreathing",
  "title_text": "Quantifying and Visualizing the Invisible Hazard of Infant Rebreathing",
  "type": "preprint",
  "updated_at": "2026-11-10T00:23:31Z",
  "url": "https://research.draconitic.com/paper/8sf57v08skgra",
  "venue": "bioRxiv",
  "versions": []
}