Biomedical Engineering Reference
In-Depth Information
an x-ray of this procedure to document the catheterization. He later was awarded the
Nobel Prize for his efforts.
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1938: the first successful heart surgery was completed by Robert Gross.
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1944: Alfred Blalock and Helen Taussig performed the first successful bypass surgery.
1947: the first successful defibrillation was completed.
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1953: Charles Hufnagel implanted the first artificial heart valve.
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1958: the first pacemaker and coronary angiography was completed.
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1967: Christiaan Barnard successfully transplanted the first human heart.
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1977: Andreas Gr ¨ ntzig performed a balloon dilation of a stenosed coronary artery.
￿
1970s
1980s: Robert Jarvik and Willem Kolff worked on and successfully designed a
total artificial heart, which was first implanted in a patient in 1982.
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1986: the first metal stent was implanted into an artery.
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2000: tissue engineering and stem cells have been used to improve the function of
diseased cardiac tissue.
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Clearly, we have not discussed all of the critical studies and findings that have helped
to progress cardiovascular disease management, but this discussion highlights some of the
major advances.
1.5 DIMENSIONS AND UNITS
The solution to all engineering problems must include units. Dimensions are physical
quantities that can be measured, whereas units are arbitrary names that correlate to partic-
ular dimensions to make it relative (e.g., a dimension is length, whereas a meter is a rela-
tive unit that describes length). All units for the same dimension are related to each other
through a conversion factor. There are seven base dimensions that can be used to describe
all of the dimensions of interest in engineering and physics, among other disciplines. In
fluid mechanics we generally pick length, mass, time and temperature as base dimensions.
This makes force a function of length, mass and time (i.e., force is equal to mass
length/
time squared). Others define force as one of their base dimensions and define mass by
dividing force by the gravitational acceleration. This is the difference between English and
metric units. Metric units use gram, meter, and second to define the Newton. English units
use pound, foot, and second to define the slug.
Syst`me International d'Unit´s (SI) units were the first international standard for units.
English units followed later and are currently defined from SI units. The base unit for
length is the meter (m). One meter is defined as the distance traveled by light in a vacuum
during 1/299,792,458 of a second. One inch is defined as exactly 0.0254 m (1 in.
3
2.54 cm).
The base unit for time is the second (s). One second is defined as the time for 9,192,631,770
periods of the radiation of a cesium 133 atom transitioning between two hyperfine ground
states. The standard unit for mass is the kilogram (kg). A kilogram is defined by the mass
of a platinum-iridium cylinder that is housed at the International Bureau of Weights and
Measures (Paris, France). The base unit for temperature is the Kelvin (K). The Kelvin scale
is defined from absolute zero (where no heat remains in an atom) and the triple point of
water. From these four base units most of the parameters used in fluid mechanics can be
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