Biomedical Engineering Reference
In-Depth Information
The other contrast between action and speculation,
however, is value-laden. There are times, deservedly or
not, when decision makers appear to suffer from ''analysis
paralysis.'' Decisions are always made with some degree of
uncertainty. The key dilemma for the designer is to know
when a sufficient amount of information about the risks
and the benefits of a design has been ascertained. The
sufficiency is a function of the severity of the outcome
(costs of being wrong) and the loss of a benefit (opportu-
nity risk). In some cases, a ''50/50'' flip of the coin decision-
making approach is sufficient, such as whether a bridge
between Chapel Hill and Durham should be painted
Carolina or Duke blue (although such decisions carry great
local import in the North Carolina Piedmont). Conversely,
a decision as to whether to set a drinking health standard at
10 parts per million (ppm) or 15 ppm for a pollutant can
account for a margin of waterborne diseases and even allow
for increased mortality if the higher concentration is ap-
plied. Speculation in the former case may lead to some
unhappy fans, but speculation in the latter case can
translate into increased morbidity and mortality.
Another way to think about activity is to consider
what one means by the opposite of active. At least two
very different antonyms must be considered. If some-
thing or someone is ''inactive'' they are idle. Another
antonym of active is passive. An active solution is one
that requires added energy, whereas a passive solution is
one that occurs as a matter of course. Sometimes, the
passive solution is preferable, as when a noninvasive,
homeopathic treatment is used instead of an invasive,
pharmaceutical approach to treat a similar malady. And,
at the other time, professional judgment dictates the
need to ''do something.''
Yes, engineers do things, and what we do should give
us great pride. Engineers are, by nature, a thoughtful and
outwardly directed lot. We are sympathetic to the needs
of others, beginning with our clients. In fact, designers, in
general, are optimistic and future-oriented. We see things
long before they take on physical reality. Thus, engineers
are highly suited to take a long view of things. Some faith
traditions may characterize us as having much ''faith.''
Our code calls us to be ''faithful agents.'' While this is
a statement about the trust that our clients place in us, it
is also a statement about our confidence and faith in our-
selves as professionals. This is the engineering perspec-
tive. We ''expect'' the medical device, or building, or water
supply to become real, to become ''substance.''
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Even
those engineers who are called in to fix things, such as
biomedical engineers finding ways to ameliorate human
suffering, environmental engineers who remediate haz-
ardous waste sites or failure analysts who look for ways to
prevent future disasters, always expect things to improve
with action.
Engineers are willing to stand behind our work (e.g.,
we build in feedback in the operation and maintenance
(O&M) process, we check progress continuously on
biomedical devices, install monitoring wells to ensure
waste cleanup is going as planned, and we work closely
with inspectors to incorporate lessons learned from
failure analyses). Hence, in addition to being faithful, we
adapt. In fact, adapting is a big part of design. The dy-
namism of biomedicine has been a fertile ground for
engineering for many centuries. A classic example was
the 1592 visit of Galileo to one of the first medical in-
stitutions in Padua, Italy.
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Galileo, acting as an engineer,
took the opportunity to lecture the future medical
practitioners and researchers on mathematical principles
including his own theories, as well as their applications
(notably the pendulum, thermoscope, and telescope).
Such applications led to an enhanced understanding of
physiology, such as studies by Galileo's student, Sanc-
torius, of human body temperature and pulse rates. One
student at Padua during Galileo's visit was William
Harvey, renowned for characterizing the circulatory
system, which he based on the mechanical and motion
laws expounded by Galileo. Such interplay between
medicine and engineering, while often subtle and in-
direct, has evolved into the more formal collaborations
we see today. Duke, Johns Hopkins, and other world
class biomedical engineering programs are co-located
and intellectually intertwined with leading medical
schools. But, the dynamic design processes of the con-
temporary engineers make for complicated ethical
challenges and none more so than those related to
biomedicine.
The stakes are very high in biomedicine. It is truly and
literally a matter of life and death. Not advancing the
state of biomedical science is simply not an ethical
option. Consequently, the typical precautions that may
hold for other areas of engineering need special consid-
erations when addressing biomedical challenges. For ex-
ample, the ''no action'' alternative is seldom satisfying to
biomedical practitioners. Not looking for a better device
or system that can improve the quality of a patient's life
is simply not acceptable. Risk assessors refer to this as
''opportunity risk.'' That is, if we simply seek the refuge
of no added risk, we may lose an opportunity to really
improve things. For example, nanotechnologies (using
systems that are only a few hundred molecules in size)
are fraught with risks, such as the chance that working at
this level may cause changes to self-replication and other
cellular signals, which could cause unknown damage.
However, if we do not seek the uses of nanotechnologies,
such as the application of highly efficient, biologically
inspired processes for drug delivery, we may lose the
opportunity to make the drugs more efficacious. If we
can use biologically inspired nanomanufacturing to syn-
thesize and deliver tumor-reducing drugs, it may be
possible to treat cancers that have heretofore been
untreatable. So, we must be bold in applying nascent
