cover 2006

Prof. Yuval Shahar
An Enterprising Magician
32 BGU NOW
W
hat happens when you cross a
math genius with a future
doctor? To that theoretical question
we give one answer: Prof. Yuval
Shahar. Shahar is one of the few who
have combined the study of
medicine (for a medical degree at
the Hebrew University of Jerusalem)
with mathematics and computers
(for a Masters degree at Bar-Ilan
University), which has placed him
at the forefront of the emerging field
of Medical Bioinformatics. After his
military service as a medic he won
a scholarship for a Masters program
at Yale University, where he studied
artificial intelligence (AI).
Two years later, he was accepted
to a doctoral program at Stanford
University headed by Prof. Edward
Shortliffe. Stanford is the academic
world’s center of medical
informatics and it was there that
Shahar was truly bitten by the
medical informatics bug. He was to
spend ten years in Stanford, first as
a doctoral student, then a faculty
member, and was the recipient of
several prestigious prizes and
awards, including a National
Institute of Health 5-year personal
FIRST award for research and an
award from the National Science
Foundation to develop his
theoretical work on temporal
reasoning.
Shahar came from Stanford to
BGU in 2000, joining the Department
of Information Systems Engineering,
which he now chairs. He also
established the Medical Informatics
Research Center (MIRC) which he
heads, thus making the jump from
theoretical to applied research.
Shahar and his team of researchers
use AI technology to develop
complex computer programs that
are capable of monitoring and
processing large amounts of data
over lengthy time periods. This
technology has earned Shahar the
reputation as an international expert
in automated medical-decision
support systems.
The names of these complex
computer programs have roots in
several languages: from the Hebrew
IDAN (epoch) and DeGel (flag) to
Vayduria (a Tibetan healer) to the
acronym KNAVE, for Knowledgebased
Navigation, Abstraction,
Visualization and Exploration. But
the one he describes with the most
enjoyment evokes associations in all
English-speakers: the Spock Hybrid
Runtime Application Model – or,
simply, “Spock,” named after Mr.
Spock of the 1960s TV series Star
Trek.
“Various medical associations in
the United States produce what they
call ‘guidelines’ for physicians,”
explains Shahar. “These are text
guides with explanations of how to
treat everything from hypertension
to diabetes and they are very useful,
but few physicians actually use
them because of lack of time. One
of my goals was to computerize
these guidelines into a more
available format for diagnostic
purposes. Also, these guidelines
often cover conditions in a general
way, such as ‘treatment of diabetes,’
while Spock allows greater
complexity, such as ‘diabetes in a
pregnant woman with high blood
pressure.’
“Another problem I wanted to
solve was the large amounts of data
that a physician must process in a
short amount of time. Family
doctors may treat patients who have
suffered from diabetes for decades;
these patients accumulate results of
tests with hundreds of items of data.
The physician must monitor these
patients for numerous complications
such as renal insufficiency,
neuropathy (numbness) of limbs,
ulcers or toxicity toward drugs – all
Spock suggests guidelines, but the physician
can overrule or modify them. It’s the doctor
who's in charge
this, again, in a typically short visit
that must address the patient’s
present complaints in the context of
accumulated data that may reveal
trends. Is it any wonder that the
physician is likely to miss subtle
patterns of change?
“That’s where the KNAVE visual
exploration module comes in. It
relies on the underlying IDAN
module, which performs what we
call temporal abstraction–
interpretation of clinical data
accumulating over time and their
summarization as clinically
meaningful patterns. We’ve found
that it takes only about ten minutes
to teach physicians how to use
KNAVE and a few seconds for the
IDAN/KNAVE combination to
review the online blood tests and
records and then tap the doctor on
the shoulder and say: this patient