From imagining what it might be like to create
our own city, to learning about the chemicals that
go into our food, we’ve already covered a good amount of
engineering history. Civil, mechanical, electrical, and chemical
are the four main branches of engineering. But there are many others! Some have been around for centuries, while
others have developed more recently and are
rapidly growing. Some have even broken off of existing branches
and are quickly becoming their own fields. One example of this is aerospace engineering,
which handles the design and construction of
air and spacecraft. This was a natural progression from
mechanical engineering, as we started
creating machines that could fly. Another example is environmental engineering,
which uses engineering practices, soil science, biology,
and chemistry to help find solutions to environmental problems. We’ll cover these and others in more detail later on,
but for now let’s focus on two of the more prominent
disciplines of engineering: industrial and biomedical. After we learn about the history of these two branches, we’re going to see what it would take to
use both of these fields to build and design
a fully-functioning artificial limb. So stick around! [Theme Music] Industrial engineering has been around as long
as we’ve had factories and other engineering systems. Just as mechanical engineers work with a bunch
of different parts to design a machine, industrial engineers work with many different
elements to devise an efficient system. And it’s not just the machines they have
to think about. They also have to consider the workers, materials,
energy flow, and communication that are needed to
provide the best product or service. Other branches of engineering often take apart
each system and analyze all of its parts separately,
before putting a system together. But industrial engineers do things a bit differently. They look at the system as a whole first and
then move on to see how the different parts
work together. Then they can focus on the specifics to achieve
the best results. It’s all about optimization. And one of the most important areas that industrial
engineers try to optimize is the assembly line. It’s where we can see the biggest improvements
in quality, delivery time, and cost. The drive to optimize the assembly line is
why many factories have switched over to more
automation instead of manual labor. And it’s caused the idea of “lights-out manufacturing”
to grow, which is where factories and manufacturing operations
don’t physically need humans there to run or operate. Some machines are far less concerned about
needing light, or heat and air conditioning,
for that matter. And they’re much less likely to complain. But we’re still a long wayfrom a world where
robots and machines run everything. Until then, we can learn a good deal from
Frederick Winslow Taylor, an American engineer who we see as the father of
industrial engineering and scientific management. Around 1881, Taylor introduced what we know
as time study. He found that the efficiency in a shop or factory could be greatly improved by looking at the workers and eliminating as much wasted time as was reasonably possible. His work led to major improvements in factory
production by focusing on one of the biggest
variables: people. Taylor’s teachings soon became widespread,
with his work titled The Principles of Scientific
Management being published in 1911. While industrial engineering might not be as flashy
as some of the other professions, it’s central to the
overall function of the other branches. It’s the backbone of our engineering skelton. It’s been in the background of engineering
ever since we built the first factories. Which brings us to one of the new fields of
engineering: biomedical. It’s often used synonymously with bioengineering,
but the two are not exactly the same. Biomedical engineering applies engineering
skills and principles to biology and medicine,
usually for the purpose of healthcare. It focuses on human and animal biology, whereas
bioengineering is typically used as a broader term that
can include other biological systems, like plants. Biomedical engineering focuses on advancements
that improve our health, from diagnosis and analysis of
medical conditions, to their treatment and recovery. This is where we’ll learn the skills to
try and make an artificial limb. Biomedical engineers differ a bit from the other
disciplines in that they often need to apply modern
biological principles to their designs. For example, you have to make sure that the
materials of an artificial organ don’t cause an
unwanted reaction inside the body, and that an artificial limb moves in similar
ways to its organic counterpart. As such, biomedical engineers need to have
a good working knowledge of many other fields in addition to biology, including mechanical
and electrical engineering, materials science,
and chemistry, to name a few. And biomedical engineering shows up in most
of our lives. Beyond artificial limbs and organs, we have
it thank for defibrillators, pacemakers, MRI
and CT scans, and insulin pumps. It’s striking to think that most of these technologies
weren’t around 50 or 100 years ago. That’s because biomedical and bioengineering
didn’t really show up until after World War II. There were certainly biomedical inventions
before that, but they were mostly left to the
doctors and physicians. Some of the earliest evidence for the practice that
we’ve found has been a 3,000 year-old wooden and
leather prosthetic toe found on an Egyptian mummy. Moving forward to about 200 years ago, the
French physician René Laënnec came up with an
important biomedical invention: the stethoscope. After being appointed as a physician in the
Necker Hospital in Paris in 1816, he developed the stethoscope in response to
how uncomfortable it was to have to lay your ear on
a person’s chest to listen to their heart or lungs. People who enjoy their personal space have
been thankful ever since. X-ray imaging was another early biomedical
discovery. In 1895, German physicist Wilhelm Conrad
Röntgen discovered X-rays while experimenting
with electric current flow. He took the first X-ray photographs, which
included the interiors of metal objects and
the bones of his wife’s hand. Even simple crutches and walking sticks can
be looked at as early biomedical devices. There was a medical problem, and people used what
they had available to them to improve their situation. But biomedical engineering didn’t really
take off until 1961, when the University of Pennsylvania offered the
Ph.D. Program of Biomedical Electronic Engineering,
the first in the United States. Now that the field was more established, one
of the biggest steps forward for biomedical
engineering was computers. With computers, we could begin to analyze data much
faster, which made it more efficient to evaluate patients,
and opened up new ways of doing so. Along with the invention of the internet, this is what’s allowed doctors and physicians to create a worldwide network of data to find medical patterns and correlations. It also led to new imaginingng opportunities
like the MRI and CT scans, which began to
pick up in the 1970’s. Moving forward, advancements in medical
instruments and electronics continue to be a
major goal of biomedical engineers. They continue to seek the answers to questions
like ‘How can we better take images of the body? Can we reduce any radiation involved? Can we come up with better analysis and measurement
systems? How many tests can we do from a single drop
of blood?’ But there are still some major challenges
that biomedical engineers are wrestling with. One of them is biological modeling. We want to know – how we can simulate the
body and what’s happening inside it. If we can get a realistic and reliable simulation,
then we can use it to run experiments on rather
than using a real person. It would allow us to both experiment in ways
that could be harmful to a real person and also
repeat tests more than we normally could. Another area we’d like to learn more about
is drug delivery. We want the medicine that we create to get
where it needs to go. This is because certain medicine and treatments
become less effective depending on where and
how they’re delivered. It’s also important to know how the body
will react to any implanted biomachines. This is where materials science really comes
in. One of the more interesting recent developments
here is called cell encapsulation. This is where we surround a cell in biomaterials
so that it’s protected inside the body. The materials can act as barriers to protect
a transplanted cell from being attacked by its
host’s immune system. The technology is somewhat new, but it has the
potential to do wonders for cell-based therapy. Materials are also important as we develop
prosthetics even further. When we’re replacing something like a hip
or a limb, there are many potential issues that
we need to worry about. Some of these include making sure that bacteria and
infections won’t thrive on the material we’ve implanted
and that the material is durable and will last a long time. Let’s look at what it might take to replace
a fully-functional leg. There are many more factors at play than we’ll
go over for now, but let’s look at the big ones. To start off, strength of materials is going
to be pretty important. We need the mechanical “bones” of the leg to not
only last, but to handle both the static and dynamic
forces that a leg goes through. A material that handles the constant stress
and strain of standing might not hold up well
to the forces that happen when we run. Once that’s figured out, we’ll need to look
into power and electrical engineering if we
want it to move, like one of our legs. This is also where programming and computer
science might play a big role. Furthermore, it’s not just the strong, rigid
materials that we’ll have to worry about. For instance, our knees and many parts of
our bodies contain cartilage, which act, in
part, as shock absorbers. There are also fluids in our knees that help
them move, called synovial fluids. Finding out how to replicate these, with
things like hyaluronic acid, could go a long way
in recreating an artificial leg. Now, once we’ve figured out the design for the leg,
we’ll want to go back to our teachings about industrial
engineering in order to make them in a factory. Not only will it be good to make them efficiently,
but we’ll also want to make sure they’re made
with the best possible quality. You see, we have the potential to do great
things when we apply what we’ve learned. Like most engineering pursuits, things really
come together when we combine at least a few
of the different fields. So today we started off by learning about
industrial engineering and the different factors
involved in an industrial system. We talked about Frederick Winslow Taylor,
the father of industrial engineering, and his
work with scientific management. Then we moved on to biomedical engineering and
bioengineering, along with their early inventions. Finally, we ended our lesson by talking about the future
of the biomedical field and saw what it might be like to
bring our teachings together in creating an artificial leg. Next time we’ll be moving on from our
history-based lessons into thermodynamic
and the laws of conservation. Thanks for watching and I’ll see you then. Crash Course Engineering is produced in association
with PBS Digital Studios. You can head over to their channel to check
out a playlist of their amazing shows, like The Art Assignment, Deep Look, and It’s
Okay to Be Smart. Crash Course is a Complexly production and this
episode of was filmed in the Doctor Cheryl C. Kinney
Studio with the help of these wonderful people. And our amazing graphics team is Thought Cafe.