A novel modelling approach to energy transport in a respiratory system

Abstract

In this paper, energy transport in a respiratory tract is modelled using the finite element method for the first time. The upper and lower respiratory tracts are approximated as a 1-dimensional domain with varying cross-sectional and surface areas, and the radial heat conduction in the tissue is approximated using the 1-dimensional cylindrical coordinate system. The governing equations are solved using 1-dimensional linear finite elements with convective and evaporative boundary conditions on the wall. The results obtained for the exhalation temperature of the respiratory system have been compared with the available animal experiments. The study of a full breathing cycle indicates that evaporation is the main mode of heat transfer, and convection plays almost negligible role in the energy transport. This is in-line with the results obtained from animal experiments.

A novel method to generate dynamic boundary conditions for airway CFD by mapping upper airway movement with non‐rigid registration of dynamic and static MRI

“…Computational fluid dynamics (CFD) simulations have been widely used to provide information about human airways, including airway resistance, energy expended during breathing (work of breathing), distribution of airflow, transfer of heat and moisture, and particle deposition . Other methods are unable to provide this level of information due to the impracticalities of using flow instrumentation in the airway.…”

“…Computational fluid dynamics (CFD) simulations have been widely used to provide information about human airways, including airway resistance, energy expended during breathing (work of breathing), distribution of airflow, transfer of heat and moisture, and particle deposition. [1][2][3][4][5][6] Other methods are unable to provide this level of information due to the impracticalities of using flow instrumentation in the airway. The metrics provided by CFD are becoming increasingly useful clinically and have been used to assess the effort of breathing in goiters [7][8][9] in transplanted tracheas, 10 stenotic pediatric tracheas, 11 and nasal obstruction.…”

Influence of ageing on human body blood flow and heat transfer: A detailed computational modelling study

“…To study heat transport in the human body, several different bioheat transfer models [27][28][29][30][31][32][33][34][35] were proposed in the recent past, ranging from simple lumped models to more complex realistic 3D representations of the body. Although most of these works introduce comprehensive modelling methodologies, ageing effects on the body's thermal energy balance are not generally taken into account.…”

Identification of dynamic load for prosthetic structures

“…In this study, an inverse technique was applied to identify the dynamic load acting on the 3‐unit implant‐supported fixed partial denture (I‐FPD) and teeth‐supported fixed partial denture (T‐FPD). First, the anatomical information is used to reconstruct the models (I‐FPD and T‐FPD) through medical image data obtained from imaging modalities, ie, computerized tomography (CT) images for FE modeling . Then a forward problem and a regularization technique were integrated to identify the dynamic load.…”

“…First, the anatomical information is used to reconstruct the models (I-FPD and T-FPD) through medical image data obtained from imaging modalities, ie, computerized tomography (CT) images for FE modeling. [38][39][40] Then a forward problem and a regularization technique were integrated to identify the dynamic load. After that, the responses can be obtained using the dynamic finite element analysis (FEA) through the forward models, and a deterministic "mapping" between the output responses and the input dynamic loads were generated.…”