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Biomedical
Engineering Student Invents Mechanical Leech
December
14, 2000 -- Leeches have been used in medicine for
more than 3,000 years and Patrick Cottler thinks thats long
enough.
The
benefits of using medicinal leeches, or Hirudo medicinalis, were
first recorded by Themison Laodicea in 50 B.C. Indigenous to Europe
and Southeast Asia, medicinal leeches feed on the blood of warm-blooded
mammals. Historically, they have been used for a variety of ailments
that bewildered the physicians of the day. Physicians of the Middle
Ages relied heavily upon them. Even Napoleons military surgeon,
Francois-Joseph-Victor Broussais, was such a firm believer in the
medical benefits of leeches that in 1833, he had more than 40 million
imported into France.
As
medical knowledge has grown over the past 150 years, the role of
the leech in healing has shrunk. However, leeches are still widely
used after plastic surgery and other treatments involving the reattachment
of skin flaps.
To
reestablish blood flow and promote healing in skin flaps after surgery,
surgeons not only must reattach arteries to enable the oxygen-rich
blood to flow into traumatized tissue, they also must ensure that
the blood flows through and out of the tissue into reconnected veins.
With plastic surgery in particular, reattached skin flaps present
a challenge in reestablishing blood flow. Strategically placed leeches
can suck blood from such tissue, restoring blood flow and promoting
healing.
Cottler
a research associate in biomedical engineering at the University
of Virginia, has invented a mechanical leech that he believes is
superior to natures blood suckers in several ways it
is just as effective in drawing blood through traumatized tissue
to reestablish blood flow, it doesnt migrate from the affected
site, it offers less risk of infection and its less likely
to disgust patients.
Cottler's
invention, which looks like a plastic box about two inches square,
holds a series of hypodermic needles attached to a tiny vacuum pumping
system that draws blood into a small, replaceable reservoir. The
box is placed on the skin flap, with the needles puncturing the
skin near the sutures. When activated, the vacuum pump draws blood
through the skin flap and into the reservoir.
The
invention won the Virginia Engineering Foundations 1999 award
for biomimicry, an annual contest for engineering students at U.Va.
who design machines that mimic biological processes.
Cottler
believes that his mechanical leeches to be called "smart
bandages" for marketing purposes offer enough advantages
to patients and hospitals that he is building a company around his
technology as he refines it.
"It's
been very exciting to adapt a technology, originally designed by
NASA, that will bring an age-old treatment into the 21st century,"
Cottler said.
The
U.S. space agency developed an actuator, a mechanical device that
creates negative pressure by sending electrical voltage through
a thin sheet of a chemical compound. Cottler has adapted the actuator
to supply the suction needed to draw the blood up through the needles
and into the reservoir in his device.
Cottler
defended his doctoral dissertation in biomedical engineering last
summer. In the fall, he launched Cottler Technologies, LLC as a
way to bring his idea to market. He has a patent pending for the
technology and has applied for a Small Business Innovation Research
(SBIR) grant to develop a working prototype of his invention.
If
that pans out, Cottler plans to seek a second grant to refine the
device, design it to work on battery power, and advance to animal,
and later, human testing.
After
that, who knows? The companys name Cottler Technologies
suggests there are more ideas where the mechanical leeches
came from.
Contact:
Charlotte Crystal, (804) 924-6858
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