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FOR IMMEDIATE RELEASE
September 14, 2009
Contact: Donna Krupa
Office: (301) 634-7209
dkrupa@the-aps.org
The Story of The
Development of Noninvasive Heart Care
New
article traces contributions of an engineer and physician collaborators
looking to assess the heart from the outside in
 BETHESDA,
Md. (September 14, 2009) – Fifty-one years ago the average American home
cost $30,000, Elvis Presley wooed listeners with Hard Headed Woman,
and the hula hoop was introduced. That same year, 1958, a team comprised of
a groundbreaking engineer -- Dean Franklin -- in concert with two
exceptional physicians -- Drs. Robert Rushmer and Robert Van Citters – was
laying the foundation for what would eventually become a radical new
approach to health care: the noninvasive imaging and treatment of the heart.
The discoveries of these pioneers would eventually lead to a doctor’s
ability to see the heart without cutting open the body; allow patients to
have their hearts monitored despite being miles away; and provide
reassurance to parents that a fetus’ heart was normal rather than waiting
until the offspring was born.
The details of these efforts are chronicled in a new
article, “Standing on the Shoulders of Giants: Dean Franklin and His
Remarkable Contributions to Physiological Measurements in Animals,” by R.
Dustan Sarazan and Karl T.R. Schweitz. The article appears in the September
2009 edition of Advances in Physiological Education (http://advan.physiology.org/cgi/content/full/33/3/144).
The American Physiological Society (APS;
www.the-aps.org) publishes the quarterly journal. The APS has been an
integral part of the scientific discovery process since it was founded in
1887.
Dean Franklin: Ultrasound, Ultrasonic Transit
Flow Meter, and Doppler Flow
Dean Franklin was a teenager during World War II, but
was drafted in 1950 and selected for training in radar. He subsequently
became chief instructor in the U.S. Army’s advanced radar school. In 1952,
he was recruited by Boeing to work on the BOMARC missile project and was
later hired as an electronics technician in the laboratory of Robert Rushmer
at the University of Washington Medical School.
Initially, Franklin’s role was limited to fabricating
the Whitney gauge, a relatively crude device that could be attached to a
dog’s heart tissue to measure cardiac dimensions. At the time, Rushmer was
pioneering the concept of collecting cardiovascular data from conscious
animals with implanted instrumentation, instead of the unconscious,
open-heart animals that were the standard. While working in Rushmer’s
laboratory Franklin melded what he learned about the cardiovascular system
with what he had learned about radar during his military service. With the
support of Dr. Rushmer, a pediatrician and physiologist with a great
interest in the heart, they were able to develop ultrasound instruments to
measure blood flow, despite the prevailing view of the late 1950s that
ultrasonic measurements of blood flow were impossible. Franklin’s device was
successful enough to be among the first breakthroughs to
use ultrasound for physiologic measurements.
It was used, for the first time, on conscious animals and eventually humans.
By 1962, Franklin and a colleague had invented the
first fully functional ultrasonic transit time flow meter, which measures
blood flow in intact arteries; the sonocardiometer, which measures the
dimensions of the heart; and the ultrasonic Doppler flow meter, which
measures the velocity of liquids containing suspended particles such as red
blood cells. As a result of these developments, a new generation of
scientists launched the first noninvasive ultrasound imaging devices, which
are now the industry standard in human medical technology. These devices are
descended directly from Franklin’s first flowmeter and sonocardiometer.
Scripps Clinic and the San Diego Zoo
That same year, Franklin joined Robert L. Van Citters
at the Scripps Clinic in San Diego and established a relationship with the
San Diego Zoo. Through this arrangement, the researchers had their first
opportunity to work with animals other than dogs. While at Scripps, Franklin
designed and built the first telemetry device for remote monitoring of
physiologic signals (other than temperature). It was first tested on an
exercising boxer dog at the Zoo hospital and subsequently was used for
telemetry experiments in baboons and a variety of other animal species
across the globe. The telemetry widely used in hospitals that we know today
evolved from these experiments.
Out of Africa, Into Alaska
After three years at Scripps, Franklin and Van Citters
conducted telemetered experiments in Kenya for the purpose of understanding
the effects of exercise in baboons in their natural habitat and the unusual
hemodynamic issues confronted by giraffes with the large hydrostatic
pressure gradient between their heads, their hearts and their feet. The pair
was successful in developing and implanting tiny devices in the heart that
the animals could wear for long periods. The devices, small implantable
blood pressure transducers, Doppler flowmeters and a radio telemetry system,
were surgically implanted, the animals recovered and the experimenters were
able to carry out long distance monitoring of blood pressure in the animals.
Franklin and Van Citters continued to focus more
sharply on the physiology of exercise, especially the distribution of blood
flow to various organs during extreme exercise. Classic physiology predicted
a reduction in renal flow during a fright reaction, though in one of the
African experiments, a baboon was threatened by a giraffe but its renal flow
did not change. Nor did it change among treadmill-exercising dogs in
experiments previously conducted in Rushmer’s laboratory.
Ultimately, Franklin and Van Citters used their
telemetery systems to study Alaskan sled dogs, similar to those in the
famous Iditarod race. They traveled to Alaska and instrumented several dogs,
surgically inserting flowmeters and pressure gauges. After the dogs
recovered from surgery and were reconditioned to their previous exercise
capacity, their performance was tested. They were able to run 20 consecutive
4-minute miles without showing any sign of exhaustion and no evidence of
blood flow deficit to visceral organs, even during extreme exercise.
Watch the Developments Unfold In Photographs and
Video
To watch the story unfold, view photographs
and videos online. The archives include:
Photographs
Videos
Collaboration Leads to Healthy Hearts
Dean Franklin’s work with ultrasound, the Doppler flow
meter and the sonomicrometer helped establish the field of medicine that is
now known as noninvasive clinical echocardiography. His accomplishments
could not have been realized without collaborating with Robert Rushmer and
Robert Van Citters and a broad supporting cast of engineers, physiologists,
fellows, technicians and animals. The collaborations that began 51 years ago
paved the way for the countless number of healthy hearts that beat today.
-30-
Physiology is the study of
how molecules, cells, tissues and organs function to create health or
disease. The American Physiological Society (APS;
www.the-APS.org/press) has been an integral part of the
discovery process since it was established in 1887.
To schedule an interview with
article co-author Dr. Sarazan please contact Donna Krupa at
301.634.7209 or
DKrupa@the-APS.org.
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