Longitudinal Distribution of Ozone and Chlorine in the Human Respiratory Tract: Simulation of Nasal and Oral Breathing with the Single-Path Diffusion Model

2001 ◽  
Vol 173 (3) ◽  
pp. 137-145 ◽  
Author(s):  
Michele L. Bush ◽  
Wei Zhang ◽  
Abdellaziz Ben-Jebria ◽  
James S. Ultman
Keyword(s):  
Respiratory Tract ◽  
Diffusion Model ◽  
Longitudinal Distribution ◽  
Human Respiratory Tract ◽  
Oral Breathing ◽  
Single Path

Longitudinal distribution of ozone absorption in the lung: effects of respiratory flow

1994 ◽  
Vol 77 (2) ◽  
pp. 574-583 ◽  
Author(s):  
S. C. Hu ◽  
A. Ben-Jebria ◽  
J. S. Ultman
Keyword(s):  
Respiratory Tract ◽  
Longitudinal Distribution ◽  
Upper Airways ◽  
Ozone Absorption ◽  
Oral Breathing ◽  
Single Breath ◽  
Respiratory Flow ◽  
Human Lungs ◽  
S Uptake ◽  
Conducting Airways

In our previous work, we developed a bolus inhalation apparatus and measured the longitudinal distribution of ozone (O3) uptake in intact human lungs at a quiet respiratory flow of 250 ml/min. The objective of the present study was to determine the effect of alternative respiratory flows between 150 and 1,000 ml/s. Uptake was expressed as the O3 absorbed during a single breath relative to the amount of O3 in the inhaled bolus (lambda). Measurements of lambda were correlated with the penetration volume of the bolus into the respiratory tract (Vp). Vp in the range of 20–70 ml was considered to indicate upper airways (UA), the Vp interval of 70–180 ml was identified as lower conducting airways (CA), and Vp > 180 ml was associated with the respiratory air spaces (RA). During quiet oral breathing at 250 ml/s, lambda increased smoothly as Vp increased, with 50% of the inhaled O3 absorbed in the UAs and the remainder absorbed within the CAs such that no O3 reached the RAs. The effect of increasing the respiratory flow was to shift the lambda-Vp distribution distally such that significantly less O3 was absorbed in the UAs and CAs and some O3 reached the RAs. For example, at 1,000 ml/s, only 10% of the inhaled O3 was absorbed in UAs and 65% was absorbed in the CAs such that 25% reached the RAs.(ABSTRACT TRUNCATED AT 250 WORDS)

A model for deposition of stable and unstable aerosols in the human respiratory tract

AIHAJ ◽  
1979 ◽  
Vol 40 (12) ◽  
pp. 1055-1066 ◽  
Author(s):  
E. AUSTIN ◽  
J. BROCK ◽  
E. WISSLER
Keyword(s):  
Respiratory Tract ◽  
Human Respiratory Tract

Numerical assessment of natural respiration and particles deposition in the computed tomography scan airway with a glomus tumour

2021 ◽  
pp. 095440892110240
Author(s):  
Digamber Singh
Keyword(s):  
Computed Tomography ◽  
Respiratory Tract ◽  
Particle Deposition ◽  
Flow Characteristics ◽  
Glomus Tumour ◽  
Computed Tomography Scan ◽  
Human Respiratory Tract ◽  
Airflow Pattern ◽  
Human Airways ◽  
Tomography Scan

The human respiratory tract has a complex airflow pattern. If any obstruction is present in the airways, it will change the airflow pattern and deposit particles inside the airways. This is the concern of breath quality (inspired air), and it is decreasing due to the unplanned production of material goods. This is a primary cause of respiratory illness (asthma, cancer, etc.). Therefore, it is important to identify the flow characteristics in the human airways and airways with a glomus tumour with particle deposition. A numerical diagnosis is presented with an asymmetric unsteady-state light breathing condition (10 l/min). An in vitro human respiratory tract model has been reconstructed using computed tomography scan techniques and an artificial glomus tumour developed 2 cm above a carina on the posterior wall of the trachea. The transient flow characteristics are numerically simulated with a realizable (low Reynolds number) k–ɛ turbulence model. The flow disturbance is captured around the tumour, which influenced the upstream and downstream of the flow. The flow velocity pattern, wall shear stress and probable area of inflammation (hotspot) due to suspended particle deposition are determined, which may assist doctors more effectively in aerosol therapy and prosthetics of human airways illness.

A REVISED STYLIZED MODEL OF THE ADULT EXTRATHORACIC AND THORACIC AIRWAYS FOR USE WITH THE ICRP-66 HUMAN RESPIRATORY TRACT MODEL

2004 ◽  
Vol 86 (4) ◽  
pp. 337-352 ◽  
Author(s):  
Eduardo B. Farfán ◽  
Eun Young Han ◽  
Wesley E. Bolch ◽  
ChulHaeng Huh ◽  
Thomas E. Huston ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Human Respiratory Tract
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