Airflow and odorant transport in the human nose: Implications for olfaction
Abstract
This thesis is mainly focused on applying modern fluid dynamics analysis techniques to airflow and mass transport through the human nose in order to achieve a better understanding of its critical physiological functions, especially for olfaction. ^ First, an anatomically accurate 3-D numerical nasal cavity model was developed from CT scans of an individual patient and can be used to determine airflow and odorant transport in the human nose, which may ultimately predict olfactory sensitivity. The model can be rapidly modified to depict various nasal anatomical aberrations, such as polyps or a deviated septum, that may alter nasal airflow and impair olfactory ability. The ability to model odorant transport through individualized models of the nasal passages holds promise for relating anatomical deviations to generalized or selective disturbances in olfactory perception and may provide important guidance for the treatment of nasal-sinus disease, occupational rhinosinusitis and for surgical interventions that seek to optimize airflow and improve deficient olfactory function. ^ Second, the numerical simulation of the odorant mucosal deposition process was compared with experimental deposition measurements in the human nose for a few commonly encountered odorants. The successful validation provides further insight into some of the odorant transport processes involved in the human nasal mucosa, e.g., odorant mucosal solubility and diffusivity, that are difficult to measure directly. The marriage of classical physiological experiments with modern fluid dynamics techniques holds the promise of creating a better understanding of peri-receptor transport processes. ^ Next, a lumped parameter mathematical model is proposed for human olfactory adaptation based on peri-receptor odorant transport. This model takes an unprecedented approach in exploring the possible role of odorant mucosal transport and clearance processes in olfactory adaptation, and postulates odorant diffusive flux as the olfactory stimulus. The model provides an accurate prediction of some human experimental data that was previously unaccounted for by the prevailing neural mechanisms, which suggests that physiochemical transport processes could play a much more important role in various aspects of human olfaction than is now appreciated. ^ Finally, nasal mucosal mass transfer coefficient (m.t.c.) is calculated, which provides a simplified way to estimate odorant mucosal uptake rate. ^
Subject Area
Engineering, Biomedical|Health Sciences, General
Recommended Citation
Kai Zhao,
"Airflow and odorant transport in the human nose: Implications for olfaction"
(January 1, 2004).
Dissertations available from ProQuest.
Paper AAI3125928.
http://repository.upenn.edu/dissertations/AAI3125928