Biomedical Engineering Reference
In-Depth Information
perspective, seeing the fusion of these goals as a joint
desire to extend basic knowledge and reach applied
goals.
Discussion box: ethics and the butterfly effect
The Butterfly Effect is the name for ''sensitive
dependence upon initial conditions,'' 27 as a postulate of
chaos theory. To engineers, the effect can mean that
a small change for good or bad can reap exponential
rewards or costs.
Edward Lorenz, at a 1963 New York Academy of
Sciences meeting, related the comments of
a ''meteorologist who had remarked that if the theory were
correct, one flap of a seagull's wings would be enough to
alter the course of the weather forever.'' Lorenz later
revised the seagull example to that of a butterfly in his
1972 paper ''Predictability: Does the Flap of a Butterfly's
Wings in Brazil Set off a Tornado in Texas?'' presented at
a meeting of the American Association for the
Advancement of Science, Washington, DC. In both
instances, Lorenz argued that future outcomes are
determined by seemingly small events cascading through
time. Engineers and mathematicians struggle mightily to
find ways to explain (and to predict) such outcomes of so-
called ill-posed problems. As engineers, we generally like
orderly systems so we prefer a well-posed problem; that
is, one that is uniquely solvable (i.e., a unique solution
exists) and one that is dependent upon a continuous
application of data. By contrast, an ill-posed problem
does not have a unique solution and can only be solved by
discontinuous applications of data, meaning that even
very small errors or perturbations can lead to large
deviations in possible solutions. 28 Finding the appropriate
times and places to solve ill-posed problems is
a promising area of mathematical and scientific research.
By extension, small changes for good or bad can
produce unexpectedly large effects. Upfront
considerations of possible losses of privacy in designing
information systems or possible malfunctions under
certain physiological constraints when designing medical
devices can prevent large problems down the road.
Allowing for and dutifully considering the ideas from any
member of the design team, no matter how junior, can
lead to a successful study and help avoid costly
mistakes. We sometimes hear after the fact how
someone had noticed a disturbing trend in a laboratory
study or an apparent cluster of effects in a group of early
adopters, but whose questions and complaints were
ignored until a larger data set eventually showed that the
device or drug caused unnecessary ill effects. Many
catastrophic failures, upon analysis, had at least one
internal memorandum from an engineer presciently
stating misgivings.
Engineers ignore this information at their peril. Ignoring
small details can lead to big problems.
Engineering bioethics and morality
I not only acknowledge but insist upon the fact that
morality only limits the range of morally acceptable
answers, it does not always provide a unique solution
to a moral problem. I hold that it is very rare that any
ethical theory, including mine, can resolve any
controversial ethical disagreement.
Bernard Gert 26 (twentieth-century ethicist)
The more complicated the problem, the less certain
and unique is the solution. Why does engineering at-
tract the best and brightest young minds? Surely, the
attraction goes beyond the mathematical and scientific
accolades. It goes beyond the sorting process of high
analytical and quantitative scores on college admission
exams. It must have something to do with a calling.
That calling is an integration of a myriad of factors and
variables. This integration is an uneasy one. It is si-
multaneously rewarding and risky, as are all great call-
ings. It incorporates the most basic and most complex
algorithms, given that it involves science and people,
respectively.
Humans are quite complex. Since engineering is
a human enterprise, it should come as no surprise that
applying the sciences to solve human problems is a com-
plicated business.
Mathematics has evolved to deal with such compli-
cations. In 1902, the mathematician Jacques Hadamard
defined a well-posed problem ( un probl`me bien pose )as
one that is uniquely solvable ( d´termin´ ). A year earlier
he defined ill-posed problems ( questions mal pos´es )as
those without a unique solution; that is, such problems
depend in a discontinuous way on the measurements so
that tiny errors can create very large deviations in the
solution. The modern rendition of this phenomenon is
the ''butterfly effect'' (see Discussion Box: Ethics and
the Butterfly Effect). Hadamard believed anything that
is physically important must be well posed. We now
know better that numerous engineering, medical, and
physical science problems are ill-posed. It can be argued
that engineering ethics cases may often be even less
uniquely solvable than some of the most complicated
physical and engineering problems, such as the tragic
case of Jesica Santillan, where a usually well-managed
variable (blood type) was mistakenly mismatched,
leading to a cascade of events that ended in tragedy
(rejection of the transplanted heart and subsequent
death).
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