Biomedical Engineering Reference
In-Depth Information
Engineering Systems
Analysis of any engineering is based upon essential concepts: the concept of a
system under study and system balances. These concepts, after being introduced,
can be illustrated in the context of lung, gastrointestinal, cardiovascular and renal
physiology. Conceptual illustration of global bioengineering system is given in
Figs.
11.1
and
11.2
.
This approach is inevitable, since one of central goals of engineering is the
analysis and interpretation of the mechanisms, often from complex systems
(brain, circulation) in which all of the internal workings of the system are not
known. The human machine requires food and water for continued operation,
but the relationship between food intake and human health is complex and poorly
understood.
Engineering analysis invariably begins by
defi ning the system under study
.
The system might be a supporting beam in the bridge, the human body or individual
cell in the body, even molecule of the cell in the body. This analysis is accomplished
by identifying system boundaries.
System boundaries
are important part of description of the system, e.g. they are
physical sites of intersection
between the system under the study and the rest of the
world. There are often multiple choices for them, leading to alternate description of
the system under study.
When we decide to study or communicate information about a system, we fi rst
have to explicitly defi ne the boundaries to our description and what fl ows in and out
(Table
11.1
).
