Abstract
A general computational framework to modeling the left ventricle
of the human heart is being developed at University of Malaya. The
model is based on the fiber fluid developed by Peskin and McQueen.
The heart model is intended as a
computational framework and tool
for cardiologist and researcher to
generate prediction via simulation. To
assure the reliability of the model,
the underlying mathematics, physics
should be thoroughly validated.
There has been a worldwide effort
to build a virtual model in a computer
of the human heart together with
the dynamics. This endeavor
if successful, will go a long way
to improve the techniques used by
doctors to diagnose cardiac diseases,
to test cardiac related drugs more
efficiently and cheaply. Cardiac
surgeon can now rehearse the surgery
virtually in a computer and try out
risky procedures so as to come out
with the correct protocols which
can be shared, discussed and disseminated
among their colleagues.
Building the model in a computer
is not going to be easy since the
problems encountered are wide and
varied. But with computer technology,
improvement in terms of speed and
memory, the future looks bright as
far as computer resources are concerned. There
are a few centers in the world which
are still committed to building the
virtual model of the heart namely,
Auckland, Biomedical Institute – John
Hunter and Oxford, University of
Oxford – Denis
Nobel
There are also efforts by other universities including University of Malaya to build the Virtual Heart. Various approaches have been adopted in the building of the models. At Auckland, Hunters group is trying to simulate heart models whose behavior reflects the independently calculated activity of up to 12 million virtual cardiac cells. One has to map out how these ions flows in cardiac cells which leads to a heart beat and this requires supercomputing power. A human heart has a billion cells and the world’s
fastest supercomputer cannot simulate
the functionality of the cells in
real time. The Auckland model which
represents human, dog and mouse hearts
takes about 8 hrs or more of a supercomputer
for a single heart beat. The
model the Auckland group has adopted
basically shows the origin of electrical
activity at cellular level, how the
activation wave spreads to other
cells and the electrical wave is
converted to mechanical contraction
of the heart wall. The contraction
of the wall will cause the blood
to flow through the heart and the
energy is distributed through the
whole system.
There are also efforts by other
universities including University
of Malaya. We are interested in studying
the dynamics of the heart and have
implemented the “fiber-fluid” model.
The fiber-fluid model was first proposed
by David M. McQueen and Charles S.
Peskin. This computer model of the
heart was based on the anatomy and
mechanical properties of the heart
muscle fiber. The heart is represented
as elastic fibers within an uncompressible
fluid grid.
In this computation model, the fiber
is listed as fiber points, and the
fluid surrounding the boundaries
are represented by a rectangular
lattice. In this model, the motion
of a fluid and the motion of a fiber
immersed in, and interact with that
fluid.
But here in this model, the boundaries
of the fiber which makes up the muscle
are not rigid and their movement
is the result of forces imposed by
the movement of the surrounding fluid.
There are two entities here, the
fiber and the fluid both feeding
on each other. They form a coupled
system and in a computer, both the
motions are computed iteratively
and this makes the fiber-fluid model
difficult to simulate.
Biography
Professor Ir. Dr. Selvanathan
Narainasamy is the Dean of
the Faculty of Computer Science & Information
Technology, University Malaya. He
obtained his Bachelors Degree in
Physics in 1974, proceeding with
his Masters in Systems Engineering
(Software option) in 1986 and PhD
in 1994. Prof. Dr. Ir. Selvanathan
is a Chartered Engineer and is
registered as a MIEE (UK),
MIEM(M), BEM, PEng(M).
Dr Ir. N. Selvanathan is a lecturer in the area of Artificial Intelligence
. His research interests are in the area of Medical Imaging, Computer
Aided Design Modeling, Artificial Neural Network, Fuzzy Logic, Evolutionary Algorithms,
Quantum Algorithms, Virtual Reality and Models of Consciousness. His
interest also includes to seek for a higher truth from a synergy of Computers,
Quantum Physics, Cosmology and Philosophy . He has written a book
titled ‘The Quantum Brain’ which will be published soon. He has
published over 80 papers in Conferences and Journals. A Physicist, Engineer
and a Computer Scientist with 25 years of teaching experience
in Physics, Electronic Engineering and Computer Science. He has
supervised numerous projects at undergraduate & postgraduate levels. He
was involved in an European funded Parallel Processing Computer Project and
two IRPA funded research.
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