1,720,995 research outputs found
Use of mathematical model to predict hemodynamics in cavopulmonary anastomosis with persistent forward flow
No full textToward optimal hemodynamics: computer modeling of the fontan circuit
No full textThe construction of efficient designs with minimal
energy losses is especially important for cavopulmonary
connections. The science of computational fluid dynamics
has been increasingly used to study the hemodynamic performance of surgical operations. Three-dimensional
computer models can be accurately constructed of typical
cavopulmonary connections used in clinical practice based
on anatomic data derived from magnetic resonance scans,
angiocardiograms, and echocardiograms. Using these
methods, the hydraulic performance of the hemi-Fontan,
bidirectional Glenn, and a variety of types of completion
Fontan operations can be evaluated and compared. This
methodology has resulted in improved understanding and
design of these surgical operations
Ten years of modelling to achieve haemodynamic optimisation of the total cavopulmonary connection.
No full textThe techniques of computational fluid dynamics are among the most powerful tools available to engineers dealing with the
motion of fluids and the exchange of mass, momentum,
and energy. They have recently been shown to
have an increasing number of applications to the
human cardiovascular system, including the fluid
dynamics of surgical reconstruction of congenitally
malformed parts of the cardiovascular system. In
vitro models are the alternative laboratory tools with
which to study fluid dynamics. The advantages of
computational fluid dynamics over the in vitro models
are the easy quantification of haemodynamic variables,
such as rates of flow, pressure, and distribution
of shear stress, and changes in geometric and fluid
dynamics parameters. Furthermore, using computational
fluid dynamics allows the development of
three-dimensional models to reproduce both the
complex anatomy of the investigated region and the
details of the surgical reconstruction, especially with
the recent developments in magnetic resonance
imaging. On the basis of the results, it is possible
quantitatively to evaluate the surgical correction.
This technology, which benefits greatly from the
continuous improvement in hardware and software,
enables cardiovascular experts and bioengineers to
look at the fluid dynamics of various cardiovascular
regions with increasing sophistication..
Computational transient simulations with varing degree and shape of pulmonic stenosis in models of the bidirectional cavopulmonary anastomosis.
No full textA computational pulsatile model of the bidirectional cavo-pulmonary connection: the influence of pulmonary forward flow.
No full textComputational fluid dynamics simulations in realistic 3-D geometries of the total cavopulmonary anastomosis: the influence of the inferior caval anastomosis.
No full textA mathematical model of circulation in the presence of the bidirectional cavopulmonary anastomosis in children with a univentricular heart.
No full textCalculating blood flow from Doppler measurements in the systemic-to-pulmonary artery shunt. A method based on computational fluid dynamics
No full textGlobal mathematical modelling of the Norwood circulation: a multiscale approach for the study of the pulmonary and coronary arterial perfusions.
No full textThe Norwood procedure involves three separate stages of operative corrections. The first stage involves re-fashioning the pulmonary trunk into a neo-aorta so that it is possible to
establish an unrestricted systemic circulation. An
interpositional, or systemic-to-pulmonary arterial,
shunt is then created between the neo-aorta and the
pulmonary arteries to allow pulmonary perfusion and
gas exchange. Two of the available options for the
systemic-to-pulmonary shunt are the central shunt
and the right modified Blalock-Taussig shunt. In the
setting of a central shunt, pulmonary perfusion is
derived from a conduit placed between the pulmonary
arterial bed and the neo-aorta whereas, in the modified
Blalock-Taussig shunt, the conduit is interposed
between one of the pulmonary arteries and the brachiocephalic
artery. In subsequent stages, pulmonary
perfusion is provided directly by deoxygenated blood.
This is achieved by connecting, first, the superior
caval vein, and then the inferior caval vein, to the pulmonary
arteries. It is usually during the second stage
that the systemic-to-pulmonary shunt is removed...
Computational Fluid Dynamic and Magnetic Resonance Analyses of Flow Distribution Between the Lungs After Total Cavopulmonary Connection
No full textTotal cavopulmonary connection is a surgical procedure
adopted to treat complex congenital malformations of the
right heart. It consists basically in a connection of both venae
cavae directly to the right pulmonary artery. In this paper a
three-dimensional model of this connection is presented, which is
based on in vivo measurements performed by means of magnetic
resonance. The model was developed by means of computational
fluid dynamics techniques, namely the finite element method. The
aim of this study was to verify the capability of such a model
to predict the distribution of the blood flow into the pulmonary
arteries, by comparison with in vivo velocity measurements.
Different simulations were performed on a single clinical case to
test the sensitivity of the model to different boundary conditions,
in terms of inlet velocity profiles as well as outlet pressure levels.
Results showed that the flow distribution between the lungs is
slightly affected by the shape of inlet velocity profiles, whereas it
is influenced by different pressure levels to a greater extent
- …
