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Major Advances in Bioengineering
 Artificial Joints
In 1994, a National Institutes of Health Consensus Panel declared that
total hip replacement is one of the most successful surgical procedures,
providing immediate and substantial improvement in a patient's pain,
mobility, and quality of life. More than 168,000 total hip replacements are
performed each year in the United States, according to the American Academy
of Orthopaedic Surgeons. THR involves
removing diseased or damaged bone in the upper end of the thigh bone
(femur) and the section of the lower pelvis into which the femur fits. The
bone is then replaced with a prosthesis, usually
made of a metal alloy or polyethelene (plastic)
components. Successful replacement of deteriorated, arthritic, and severely
injured hips has contributed to enhanced mobility and comfortable,
independent living for many people who would otherwise be substantially
disabled.
Magnetic Resonance Imaging (MRI)
In 1952, the Nobel Prize in Physics was awarded for the
discovery of nuclear magnetic resonance, which laid the groundwork for one
of the most unique and important inventions in medical imaging since the
discovery of the X-ray. Magnetic resonance imaging (MRI) is a method of
looking inside the body without using surgery, harmful dyes or radiation.
The method uses magnetism and radio waves to produce clear pictures of the
human anatomy. Although MRI is used for medical diagnosis, it uses a
physics phenomenon discovered in the 1930s in which magnetic fields and
radio waves, both harmless to humans, cause atoms to give off tiny radio
signals. It wasn't until 1970, however, that Raymond Damadian,
a medical doctor and research scientist, discovered the basis for using
magnetic resonance as a tool for medical diagnosis when he found that
different kinds of animal tissue emit response signals of differing length.
He also discovered differences in response signals between cancerous and
non-cancerous tissue, and among the response times of other kinds of
diseased tissue.
Heart Pacemaker
The
invention and development of the heart pacemaker illustrates the merging of
medicine and engineering. The device is a result of the collective efforts
and collaboration of people and organizations from both engineering and
medicine, and both public and private institutions. The pacemaker was the
first electronic device ever surgically implanted inside a human. First
developed in the 1960s, pacemaker typically refers to a small,
battery-powered device that helps the heart beat in a regular rhythm. Small
electrical charges travel to one or multiple electrodes placed next to the
heart muscle. Originally pacemakers sent one steady beat to the heart
through a single electrode. Today's pacemakers can sense when a heart needs
help and delivers just the right amount and duration of impulse---sometimes
through multiple electrodes---that maintain steady heart rate, even during
physical activity. While most pacemakers today are permanent implants, some
are used as temporary therapy for recovering heart patients.
Arthroscopy
Arthroscopy is a surgical procedure
orthopedic surgeons use to visualize, diagnose and treat problems inside a
joint. The word arthroscopy comes from two Greek words, "arthro" (joint) and "skopein"
(look), and literally means "to look within the joint." In an
arthroscopic examination, an orthopedic surgeon makes a small incision in
the patient's skin and then inserts pencil-sized instruments that contain a
small lens and lighting system to magnify and illuminate the structures
inside the joint. Light is transmitted through fiber optics to the end of
the arthroscope that is inserted into the joint. By attaching the
arthroscope to a miniature television camera, the surgeon is able to see
the interior of the joint through this very small incision. The camera
attached to the arthroscope displays the image of the joint on a television
screen, allowing the surgeon to look, for example, throughout the knee --
at cartilage and ligaments, and under the kneecap. The surgeon can
determine the amount or type of injury, and then repair or correct the
problem, if necessary.
Angioplasty
In 1977 in Zurich, Switzerland, a young German physician
named Andreas Gruentzig inserted a catheter into
a patient's coronary artery and inflated a tiny balloon, opening a blockage
and restoring blood flow to a human heart. Today more than 1 million
coronary angioplasties are performed each year worldwide, making it the
most common medical intervention in the world. Although this procedure was
first envisioned as simply an alternative to open heart bypass surgery in
only a handful of patients, today angioplasty accounts for more than half
of the treatments for coronary artery disease. Biomedical engineering and
advances in technology have not only optimized basic balloon angioplasty,
but also added the use of stents, lasers and other interventional devices
that restore normal blood flow while minimizing damage to the heart muscle.
Bioengineered Skin
The
burgeoning field of tissue engineering promises to be one of the most
significant biomedical areas of the new century. The hope is that,
eventually, whole organs could be manufactured to replace those that are
injured or diseased. The field's first contribution to health care took a
big step toward fulfilling these promises by producing artificial version
of the body's largest organ, skin. Skin is a difficult organ to transplant
because of its inherently strong immune defense system. Nevertheless, it
has a relatively simple structure, making it a good testing ground for the
talents of tissue engineers. Patients can have skin made to order that
combines collagen as a binder with living human cells. This is placed onto
a wound, usually a chronic ulcer or a burn, and
its cells become activated and gradually integrate with those of the
patient.
Kidney Dialysis
In
the United States, one in 16 people, or about 17 million, are at risk for
kidney disease. More than 300,000 Americans currently live with chronic
kidney failure resulting from disease, birth defect or injury. Virtually
all these patients would die if not for the aid of ongoing kidney dialysis.
Kidney dialysis artificially filters and removes waste products and excess
water from blood, a process normally performed by the kidneys. Although
often referred to as an artificial kidney, kidney dialysis is not a cure.
The procedure can, however, give damaged kidneys a rest and a chance to
recover normal function, or be used until the patient receives a
transplant. For many patients, kidney dialysis is a way of life. Kidney
dialysis was first developed by a Dutch physician, Willem Kolff, M.D., Ph.D. In the early 1940s, he began
searching for a way to use dialysis, the process by which particles pass
through a membrane, to treat patients with kidney failure. A sever shortage of materials due to the war forced Kolff to improvise, especially when it came to a
suitable membrane, the key component to the filtering process. Now, as the
number of dialysis patients continues to grow at a rate of about 7 percent
annually, and because costs for dialysis care are already more than $11
billion in the United States alone, research to find more efficient,
low-cost methods of treatment remains a priority for biomedical engineers.
Current efforts include not only improving the components of dialysis, such
as better dialysates and membranes, but also developing alternatives to
dialysis, such as a true artificial kidney, xenotransplantation, and
replacement kidneys through tissue engineering.
Heart-lung Machine
One
of the truly revolutionary pieces of medical equipment has been the
invention and development of the heart-lung machine. Before its
introduction to medicine in the 1950s, heart surgery was unheard of; there
was no way to keep a patient alive while working on the heart. Today, about
750,000 open-heart procedures are performed each year. During an open-heart
surgery, such as bypass surgery, the heart-lung machine takes over the
functions of the heart and lungs and allows a surgeon to carefully stop the
heart while the rest of the patient's body continues to receive oxygen-rich
blood. The surgeon can then perform delicate work on the heart without
interference from bleeding or the heart's pumping motion. Once the
procedure is over, the surgeon restarts the heart and disconnects the
heart-lung machine.
Note: Some resources in this section are provided by the US
Department of Labor, Bureau of Labor
Statistics and the Whitaker
Foundation.
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