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Feature
Article |
Designing
Engineering
Applications
For Medicine
In the Next Century
By Frank B. Cerra, M.D.
It was with great pleasure that I accepted the
honor of sharing with you some thoughts about designing engineering applications for
medicine in the next century. Founded in 1884, the IEEE has led the world in
development and implementation of electrical and electronic engineering, and computer
engineering and computer science. Indeed, the accomplishments in this area dominated the
20th century in virtually all areas of our life experience: business, banking,
transportation, science, health, devices, information and communications, and so much
more.
Here are four examples illustrating how the
technology has changed my life:
I was recently traveling in the Middle East.
While in a fairly remote place, I needed money. I was able to put my bank card from
Minneapolis into an ATM and out came cash in the local currency.
I am able to conduct dialogue, conferences,
and planning sessions with my colleagues in professional health education while they are
in Germany, Japan, and Australia.
I don't have to go to the shopping mall
anymore. I can be at home or at work and order just about anything I need, online, with at
least the same -- probably greater -- security than using my credit card with a real sales
person.
I recently had a patient with a suspected
brain tumor. The biopsy was performed with an automated, MRI-guided biopsy system. He went
home the same day. No operating room or long hospital stay, and with a much smaller
hospital bill!
The streams of innovation in engineering and
biology in the twentieth century have set the stage for a very exciting twenty-first, the
products of which will revolutionize the prevention and treatment of disease as well as
the promotion of health. Right now, this all resides in our visions and desires to make
the potential real. Making the reality will emanate from intellectual creativity and
innovation using the acquired knowledge in genomics, molecular and cellular biology, and
the various disciplines of engineering. There will be a marriage of the disciplines of
design, information sciences, engineering and biology that will require interdisciplinary
efforts, the creation of new disciplinary areas, new resources, and change. Discussing
this topic tonight tells us that we have already begun the process.
Two of the areas of innovation in engineering
that have profoundly affected medicine are computational technology and the ability to
"make machines small." The following four examples illustrate this point:
The digital data from whole body CT scans or
MRIs, can now be integrated into three-dimensional images that can be viewed in 360
degrees. This capacity has enabled facial reconstruction in children with inborn errors in
development, positioning of instruments in organs in order to sample tissue or deliver
therapy, enhanced diagnostic accuracy and planning of surgical interventions, and has
provided an effective supplement to the teaching and understanding of anatomy for medical
students and practitioners.
The assessment of gas tensions, such as
oxygen and carbon dioxide, in the blood of intensive care unit patients, is a critical
measurement. The measurement used to be very complex and take a lot of time (the van Slyck
method). Now, we use in-line sensors with continuous measurement in patients. Countless
lives have been saved with this capability.
When I treated my first patient with kidney
failure with the artificial kidney (a procedure called hemodialysis), the device was as
large as a desktop and took several hours to prepare. Now, with the development of
capillary technology, the device is small and the process quick and efficient.
Biologists have known about chromosomes for a
long time, and interest in genetics has been around since the time of Mendel. In the
twentieth century, Watson and Crick began a movement that would change biology forever:
the description of deoxyribonucleic acid -- DNA. This is the "stuff of life."
The characterization of the human genome will be completed in a few short years.
The major advances that have facilitated the
rapid progress of the past 15-20 years have stemmed from developments in the technology of
molecular biology and the science of molecular and cellular biology and genetics. These
areas have come to understand how cells talk internally and externally, how the protein
factories in the cell are regulated, and how the genetic material itself is organized and
works. These disciplines cut across the classic fields of biochemistry, microbiology,
anatomy, physiology, and pharmacology. These new fields have reorganized the way biology
is practiced and have promoted both interdisciplinary and interscholastic research.
New fields have emerged, such as genomics
and proteinomics. New support systems that will become new disciplines, such as computational
biology, biomathematics and bioinformatics, and bioengineering
have already developed or are developing now. These latter areas house the structural and
compositional data of genes and proteins. The end result of all this is primarily
descriptive. As stimulating as that is, for medicine, the key question is "so
what?" What good is the knowledge? What can it be used for? Will it prevent,
treat, or cure a disease? All frequently asked questions. And the resounding answer
to these questions is Yes! Yes! Yes! This is what the twenty-first century will
be about.
The following four examples illustrate some of
the bridging and co-mingling of biology and engineering that we have begun to see over the
past ten years:
The insertion of a new gene into a cell
remains one of the problems hindering progress with gene therapies for genetic diseases. A
favorite way to accomplish this is with viral vectors. This approach is difficult,
somewhat complicated, and modestly successful. A novel technology was recently developed:
a gun that shoots the new gene into the target cell on a particle of gold.
Cell culture systems have developed to the
extent that embryonic stem cells can be cultured. These cells have the capacity to
differentiate into almost any kind of cell, depending on the biologic factors or
messengers that they come into contact with. Achieving this milestone has made the vision
of growing new organs in culture a reality.
Liver cells are now placed into collagen
matrix and placed inside the lumens of capillary tubes. This is the same capillary
technology that is used for hemodialysis. These cells function and can be modulated with
other biologic agents to focus the desired biologic functions. This describes the
bioartificial liver, an extra corporeal device that is currently in clinical testing as a
treatment for liver failure.
What remains is the process of envisioning
possible scenarios and then working together to find real solutions. For the health of the
public, this is the promise and the potential that will take place in the next millennium.
Following are five hypothetical situations that I discussed with my engineer colleagues
and their possible solutions:
- My friend, John, develops acute fulminant hepatitis. Even
with support from the bioartificial liver, he progresses into coma from liver failure. A
call is placed to the in situ liver service and a few of John's normal liver cells are
taken to the lab. Over the period of a several days, John's liver cells are grown on an
artificial matrix with hepatic architecture. When the size of the left lateral liver
segment is reached, John's diseased liver is removed and the liver segment placed in situ.
Within a few weeks, the natural processes have grown a new liver and John will lead a
normal life.
- My engineer colleague's friend has a heart attack, from
which his heart will not recover. A call goes out to the Neo-organogenesis Unit that a new
heart is needed. They ask for his demographic profile, and come to the bedside and run a
genomic profile on the cells in his blood. Upon their return to the Unit, they then select
a heart of normal tissue and function, grown in vitro, and genetically engineered not to
reject, and replace his failing heart. He walks home from the hospital.
- Joan is working on the farm and severs her left arm at the
shoulder on a farm instrument. She is treated at her local hospital and recovers with a
mid-arm stump on the left, and is referred to the Regenerative Limb Center. As an
outpatient, she receives an implant device that is loaded with the necessary regulatory
and growth factors that can be released in the right place at the right time. Over the
next three months, Joan grows a new arm, forearm, and hand, and returns to normal life.
- Bill is injured in a car accident, cannot move both legs,
and has no feeling below his navel. He is taken to the Regional Research Trauma Center.
Their new three-dimensional NMR with 360-degree viewing localizes the spinal cord lesion
at the level of T8. A specially designed delivery device is placed in the blood supply to
the same area and sequentially releases the regulatory and growth agents that will control
the injury and regenerate the spinal cord. Bill leaves the hospital two weeks later
walking and with normal sensation.
- Scientists at the Translational Biology Institute of the
University of Minnesota are working with a group of clinicians to develop an agent that
can modify a receptor protein for a patient with diabetes. The lights go down and an image
of the receptor site, and then of the receptor protein in question, appears in the room.
The active site on the protein is identified and the structure of the activating agent
designed. Once completed, a simulation of function is run, and design refinement
undertaken. The completed design is then sent to the production unit and administered to
the patient. The blood sugar becomes normal.
These are a few of the numerous possibilities
that build upon the streams of discovery and innovation in engineering and biology --
visions that will become real in the twenty-first century. The potential to make these and
others real exists within us. We, the academic and corporate worlds, both public and
private, must work together to make them happen. These developments will undoubtedly
create new ethical, legal, and policy issues that will need to be resolved. That will also
be our obligation. Let us accept the opportunities, along with the accountabilities, and
move ahead.
The preceding is the text of an address
by Frank B. Cerra, M.D. to the Sections Congress '99 of the IEEE on 8 October 1999. The
theme of the Congress was Design of the Century. Please see George F. McClure's related editorial which appears in the May 2000 IEEE-USA
Perspectives entitled "Biomedical Engineering -- the New Frontier?"
[ IEEE-USA
]
Last Updated: May 3, 2000 |