The Centre for Medical
Informatics at the University of Maribor, Slovenia
Head: Prof. Dr. Peter
Kokol
Researchers: pela
Hleb - Babi, Vili
Podgorelec, Milan Zorman,
and Matej
progar
The main research areas covered by the Centre
for Medical Informatics are:
- Design methods for medical
information systems
- Intelligent systems
- Quality and complexity of information
systems
Design methods for medical information
systems
Mechanical systems increase
our physical abilities (we use cranes to lift
vast amounts, telescopes to see farther, etc.),
but. Intelligent systems are power tools for
heavy lifting in the information world - they
"complement, extend, and amplify" our
ability to think and solve problems. The
difference between intelligent systems and more
»usual« expert systems or knowledge-based
systems is that intelligent systems are not
necessarily smarter than expert or
knowledge-based systems in terms of the quantity
or types of knowledge or reasoning they employ;
in fact, the research and application challenges
are largely the same. However, intelligent
systems for the most part exploit additional
tools and technologies that make them easier to
use, easier to build and maintain, easier to
integrate with conventional information systems
and in addition an appropriate human interface is
required, targeted at the intended users.
To be able to design successful intelligent
medical systems (IMS) we must design them with an
appropriate design methodology but very
few, if any such methods exist in the real world.
Thereafter as a design framework we use the
MetaMet - a two-leveled system design approach
developed by the authors of this summary. The
MetaMet is defined as a process in which a
problem situation is transformed into an improved
situation - employing a computerised IMS -
appreciating the epistemology of the MetaMet, the
characteristics of the problem situation, recent
developments in IMS and related research and
science in general (standards, norms, technology,
etc.) and the principle of uncertainty performed
in an endless learning loop.
Intelligent systems
Medical knowledge is expanding
rapidly. Every-day responsibilities demand that
medical staff generate a vast amount of
statistical reports concerning detailed patient
information, accounting purposes, reimbursement,
insurance needs, treatments, research and a
myriad of others. The appearance of the new
computer-based information technology and
especially the introduction of intelligent
systems with their ability to learn has initiated
the possibility to enormously ease these routine
activities and enable the medical staff to devote
more time to enhanced creative work.
When looking at intelligent
medical systems, there is always the problem that
only successful systems are reported and that
therefore it is impossible to accurately estimate
the success rate. In the past twenty years,
hundreds of systems have been reported on, but
few are used. One of the success stories is the
database of drug interactions for pharmacies. Why
have so few of the systems been successful in the
medical field? A review done by one journal for
the whole of 1997 revealed 13 articles that dealt
with intelligent systems in medicine. Of these
13, one was evaluated thoroughly and is probably
usable outside the department where it was
developed. The others come under the "look
what we can build" heading. One that was
being developed as a teaching tool had no
discussion of the human interface or of a trial
with a novice. Statistical analysis where used
was often not an appropriate analysis. By
contrast, neural networks themselves,
evolutionary programming, automated decision
trees and similar can be used for statistical
analysis especially of non-parametrically
distributed data. Once again an appropriate human
interface is required, targeted at the intended
user in addition to the possibility of easy
integration into existing medical information
systems.
According to that we will
develop new design methods and new machine
learning methods. One of our most successful
methods is a hybrid one. In it we first construct
some decision trees and some neural networks
using conventional building techniques and
perform evolutionary computation on them. The
best individual neural networks are transformed
into decision trees and these then compete with
the best decision tree individuals and finally
after some iterations the optimal decision tree
and the optimal neural network are constructed
which can then be used as advanced adaptive
statistical tools. The whole construction process
is improved with the use of adaptive evolutionary
cost function, which represent a great
advancement over traditional genetic algorithmic
methods.
Quality and complexity of information
systems
Although the software metrics are becoming
more and more recognised in software engineering,
the field of measuring the complexity of software
is still not yet successful enough. The
traditional complexity metrics are language
dependent. We have to use a different metric to
assess the complexity of a program written in a
higher level programming language (even worse we
have to use a different metric or at least a
different tool for each programming language),
another metric for a program written in an
assembler language and some other metrics to
asses the complexity of object ore executable
code. But that is not all. A program or an
information system can be represented in many
other forms: requirements, specification,
documentation, user interfaces, etc. and all
those representations can be manifested in very
different appearances: written text, graphical,
symbolic, formal languages, etc. In addition the
output of a traditional complexity metric is a
number, usually without any "physical"
meaning and unit.
To overcome above problem we propose a
"language and form" independent metric
with critical values related to complexity,
information content and entropy called Alpha
metrics.
Alpha metric is based on the
fact that a computer program is a string of
symbols, and we can asses the complexity of a
string with the calculation of long range
correlation between symbols approach
successfully used in the DNA decoding and
recently on human writings. Long-range power law
correlations (LRC) have been discovered in a wide
variety of systems. Recognising a LRC is very
important for understanding the systems
behaviour, since we can quantify it with a
critical exponent - alpha. Quantification of this
kind of scaling behaviour for apparently
unrelated systems allows us to recognise
similarities between different systems, leading
to underlying unification. For example, the
recent research has shown that DNA sequences,
human writings and computer programs can be
analysed using very similar techniques.
In our research we would like
to analyse the use of alpha metric in:
-
assessing the complexity
of medical software using various methods
-
locating the
"unknown" parts of the programs
like viruses
-
comparing various
compilers for the same programming
language
-
analysing the complexity
of the program trough its life cycle
-
analysing the
"by-products" like
documentation, user interfaces, etc.
-
unifying principles of
computer programs and other systems
In both theoretical settings
and real world applications.
The CMI co-operates in some
national and international projects. The most
important are:
-
Tempus Phare: NICE
Nursing Informatics and Computer
aided Education NICE (proj.no.
SJEP-11574-96)
-
INSIST (proj.
no. L2-1640-0796-99)
-
INCOMPETENT -
(Intelligent Computer Support for Method
Engineering, proj.no. J2-0514-0796-98)