Biomedical Engineering Reference
In-Depth Information
different spatial and temporal scales is presented by Chakraborty et al. (2007) and
provides a quantitative analysis of pulmonary gas exchange. This model applies a
convection-diffusion and reaction equation to quantify the transport and reaction
rates of different processes during lung ventilation and perfusion.
9.5
Summary
New developments continue to be made in the field of computational fluid and particle
dynamics for physiological functions. These developments open up new opportu-
nities for simulating and representing the different respiratory functions. Moving
meshes and fluid structure interactions allow for more realistic flow behaviour in
regions of the respiratory airways that are non-rigid, such as the pharyngeal walls
that are highly susceptible to collapse in apnoeic patients. Advanced particle/droplet
dynamics, such as breakup, collisions and turbulence, are important for drug de-
livery that is administered through the respiratory airways. Aqueous drug solutions
produce deformable particles that are prone to breakup while rigid solid particles are
relevant for airborne pollutants. The dosimetry of inhaled particles can be evaluated
by introducing an additional submodel that represents the behaviour of the particles
occurring under the respiratory surface walls. This submodel then needs to be cou-
pled with the CFPD simulations. Producing realistic whole-lung simulations is an
advanced topic, given the large number of terminal bronchioles and alveoli that need
to be considered. In addition, coupling of the air-blood gas exchange is required.
These topics are just some of the major advancements and trends occurring in the
computational modelling of the respiratory airways. This chapter aimed to provide an
insight into each of the topics, rather than a critical review. Nevertheless, the topics
presented should leave us with a sense of new opportunities and the multiple disci-
plines that are involved in the investigations of gas-particle flows in the respiratory
system.
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