Biomedical Engineering Reference
In-Depth Information
A key ingredient in the path toward reliable imaging using EIT is the
study of the conductivity changes as a function of the desired electroporation
result in tissue. The effects of electroporation on the conductivity are very
different from one case to another and depend on many factors such as the size
of the cells, the extracellular paths between cells, the extracellular medium,
and the equilibrium in the presence of a membrane with or without pores.
A robust model that will be able to predict the change in tissue conductivity
given the key parameters of the electroporation protocol and the tissue will be
an essential part of any method of monitoring electroporation by measuring
conductivity.
As for longer-term goals, a possible intermediate step on the way to a
more complete understanding of electroporation may be a mathematical model
that predicts the results of a certain electroporation protocol (e.g., no effect,
reversible electroporation or irreversible electroporation) as a function of the
electroporation parameters. These parameters may include the applied field,
the number of pulses, the duration of each pulse, the pulse repetition rate, the
shape of the pulse (square, trapezoidal, sine), and the carrier frequency of the
applied pulse, which does not necessarily need to be a direct current pulse. A
good model will need to take into account the behavior of a cell after it has
been electroporated since it is not unlikely that, even if the cell manages to
reseal, it may not be able to maintain its homeostasis and would die shortly
after the procedure.
Currently most of the studies in this field rely on past experience and
educated guesses or trial-and-error methods. This is useful for certain scenar-
ios, but when we need to consider other parameters as well, it may be too
cumbersome. For instance, when we plan a new electroporation protocol in a
temperature-sensitive environment, we can use the bioheat equation to esti-
mate the local increase in temperature because of the electroporation pulses.
Although the bioheat models are not perfected, they provide a very good base
for making an initial plan. What we need to complement that is a model
that can predict the results of the electroporation protocol. Such a tool would
be useful to find an optimal working point in which we obtain the required
results from the electroporation model while keeping the temperature within
the defined boundaries.
Pursuing these research directions may increase our knowledge of the basic
mechanisms of electroporation and open the way for numerous applications
of reversible and irreversible electroporation.
2.8 References
Abidor, I. G., Arakelyan, V. B., Chernomordik, L. V., Chizmadzhev, Y. A.,
Pastushenko, V. F., and Tarasevich, M. R. (1979). Electric breakdown of
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