Department of Physics and Department of Computer Science
Duke University
now at
Department of Physics
Hofstra University
Among the most challenging issues in physiology is understanding
the dynamics of and developing the ability to control
cardiac tissue. Despite decades of research, about
a quarter of a million adults die every year in the USA from
sudden cardiac death, generally due to ventricular fibrillation.
Many properties of the heart are at least partially understood,
but the mechanisms responsible for initiation and maintenance
of potentially life-threatening arrhythmias remain unclear.
Experiments are difficult to perform due to
limitations associated with measuring information in
three-dimensional structures. For instance,
experimental techniques typically allow voltage data to be recorded on an
array of electrodes on the exterior and/or interior surfaces of the
heart. More recently, optical mapping using voltage-sensitive dyes
have been used to obtain voltage information at a higher spatial
resolution, but still only surface data is available.
Because understanding
the full three-dimensional dynamics from such limited data is
so difficult, computational physiology plays an extremely
important role in investigating the complex dynamics of cardiac tissue.
My research involves trying to understand better the dynamics
of arrthymias by simulating mathematical models of cardiac tissue
electrophysiological processes. While much of this work is focused on
physiology, some effort also must be spent researching simulation methods,
due to the heavy computational demands of many simulations.
Currently my collaborators and I are conducting research in several areas.
- Ventricular anatomy. Using the anatomical models of the structure of
rabbit ventricles (Vetter and McCulloch)
and the canine ventricles (McCulloch 1991) along with
various ventricular cell models (Luo and Rudy 1991, Fenton and Karma 1998),
we are exploring how geometry can affect arrhthmia formation and maintenance.
Collaborators: Flavio Fenton.
- Atrial anatomy. Using the anatomical model of Harrild and Henriquez
(Circ. Res. 2000) and the Courtemanche human atrial cell model
(Am. J. Phys. 1998), we are investigating how atrial geometry can affect
arrhythmia induction and maintenance. Long-range connections and
variations in conduction speed along specialized pathways can produce
complexity in ways not seen in ventricles.
Collaborators: Flavio Fenton, Craig Henriquez, Fagen Xie.
- 3d space-time adaptive mesh refinement. We have extended earlier
work (Phys. Rev. Lett. 84, 1343, 2000) in 2d to three space dimensions.
The method uses the adaptive mesh refinement formulation of
Marsha Berger
and her collaborators for problems in fluid dynamics.
Collaborators: Henry Greenside, Craig Henriquez.
- Adaptive mesh refinement in complex geometries. We have
extended earlier work in 2d and 3d for rectilinear geometries to
include irregular boundaries.
Collaborators: Flavio Fenton.
Three level adaptive mesh refinement calculation of the 2D
Luo-Rudy 1 model for a large square domain, 8 cm x 8 cm.
On the left, electric potential V is plotted and color coded
with dark blue for V > -5 mV,
red for -5 > V > -65 mV, and
yellow for V < -80 mV. The fronts appear as thin
dark blue lines. On the right is the
hierarchical Cartesian mesh structure. The yellow
and green regions correspond to the fine (level 2) and finest
(level 3) grids and track closely the fronts.
Elizabeth M. Cherry, "A Space-time Adaptive Mesh Refinement Method
for Simulating Complex Cardiac Electrical Dynamics," Ph.D. Thesis,
Duke University, 2000.
[Gzipped PS (3.0 MB)]
Recent and upcoming conference presentations:
SIAM Conference on Life Sciences. Contributions of Tissue Structures to Cardiac Arrhythmias. March 2002.
Biomedical Engineering Society Conference. The Role of Long-range and Interatrial Connections in Atrial Arrhythmias: A Simulation Study. October 2001.
Additional information:
Learn more about the heart and cardiovascular diseases:
Some Researchers Doing Related Work:
Cardiac Electrophysiology:
Adaptive Mesh Refinement:
| Department of Physics |
Room number: |
110 CHPHB |
| Hofstra University |
Office phone: |
516-463-7984 |
| 102 CHPHB |
Fax: |
516-463-3059 |
| Hempstead, NY
|
E-mail: |
elizabeth.cherry@hofstra.edu |
| 11549 |