Human vision the model for video
From tanks to blood cells, applications of
Acton’s work limitless
by Andrew Shurtleff
rewarding pursuit is how Scott Acton characterizes the research
done in his Virginia Image and Video analysis lab.
By Dan Heuchert
It was collaboration at
first sight. Biomedical engineering professor Klaus Ley was attending
Scott Acton’s introductory seminar three years ago. He watched
as the new associate professor of electrical and computer engineering
showed off some of the video image-analysis technology he had
developed at Oklahoma State University. On the screen, a computer
tracked and outlined Tour de France cyclists filmed from above
— even as they passed under trees and other obstacles.
“If he can track cyclists from a helicopter,” Ley
recalls thinking, “he can track white blood cells.”
He introduced himself.
Two years later, in July 2002 — with funding from the National
Institutes of Health and the Whitaker Foundation — Acton
and Ley delivered what is believed to be the first system to automatically
track the movement of white blood cells in footage taken from
inside living, breathing blood vessels. The cells, also known
as leukocytes, typically help remove damaged tissue and fight
infections, but can sometimes turn on the body and attack healthy
tissue, leading to arthritis or heart disease.
The tracking system “has big implications for drug testing,
studying inflammatory disease and any study of cell motility,”
Though the system is still undergoing refinements, Ley and Acton
say they field requests almost weekly from companies interested
in developing the technology.
The leukocyte-tracking system is typical of the kind of work done
by Acton, 37, who grew up in Northern Virginia and earned an undergraduate
degree in electrical engineering from Virginia Tech. He was in
graduate school at the University of Texas, studying computer
design, when he took a class on “computer vision,”
which used human vision as a model for doing computer image analysis.
“I became hooked,” he recalled.
After working in private industry for AT&T, the MITRE Corporation
and Motorola, he joined the faculty at Oklahoma State before U.Va.
lured Acton and his lab — including three doctoral students,
all of whom have now received their degrees — back to his
home state in 2000. Renamed “Virginia Image and Video Analysis,”
or VIVA, his lab currently employs two professionals and eight
Their work has found an academic niche, he said. “There
are a lot of people building [imaging] machines, and some doing
image processing. We sort of have a nice niche in signal analysis.”
The commercial potential of VIVA’s work seems limitless.
Acton is currently working with cardiologists on a new project
to identify areas where blockages have caused damage to heart
function, called “wall motion defects.” By tracking
the heart’s motion in MRI video and comparing it to a database
of normal heart function, it will recognize and “light up”
damaged areas — a skill that can take years for cardiologists
“This technology is going to be useful technology,”
said Frederick H. Epstein, an associate professor of radiology,
who is leading the project.
There are other, non-medical applications of VIVA’s work.
Acton receives some funding from the military to work on automatically
tracking targets, and even specific parts of targets — the
hood of a military vehicle as it moves through an urban landscape,
for instance — via video analysis.
Acton works with all kinds of footage — regular video, ultrasound
and MRIs. Tracking tanks and blood cells uses “a lot of
the same principles,” he notes.
Image analysis actually breaks down into two parts. “Identifying
the cell to be tracked is a different problem than tracking it,”
he said. Speaking of the leukocyte program, he said, “The
first system made humans identify the cells, and then tracked
them. Now we’re trying to make the computer identify them.”
Tracking the identified objects can be tricky, as well. Cells
can change shape, or be obscured by other cells; military targets
can move, or the camera can shift perspective, altering an object’s
two-dimensional profile. Some applications seek to observe how
the tracked object interacts with its environs, while others seek
to isolate it and remove the clutter around it.
It’s a rewarding pursuit, Acton said. “The most exciting
part is probably the biomedical work.”
Another medical project VIVA is working on enhances ultrasound
images and more clearly defines the boundaries of various objects.
One potential use: allowing surgeons to “see” the
boundaries of a cancerous prostate gland as they implant radioactive
seeds to destroy a tumor.
imaging is done before the implantations, and surgeons hope the
target doesn’t move in the meantime. A radioactive seed
mistakenly left in the nearby rectum can cause serious complications,
Down the road, Acton sees another possible medical application
for his work. Each year, doctors worldwide order 4 billion complete
blood counts (“CBCs” for you “ER” fans),
a lab test that requires drawing blood and analyzing it under
Acton foresees a time when a machine will trans-illuminate a blood
vessel close to the surface of the skin — perhaps at the
bottom of the tongue, or under a fingernail — and examine
it with a microscope hooked up to a video processor. His technology
would then examine the video and recognize and “count”
the various elements of the bloodstream as they flowed by —
taking a CBC without drawing blood.
Acton will likely remain in great demand as a collaborator, said
Tom Skalak, chairman of the biomedical engineering department.
Acton’s work with Ley “is a great example of a real
merging of the minds, to address a real problem in medicine that
had not been addressed before,” he said.