5. MEDICAL INFORMATICS
Introduction:
Medical Informatics can be described in brief as
computer support in medicine and health care in form of collection and
interpretation of data, decision-making and subsequent actions. Both data and
knowledge can be stored in computers, which in turn can assist human reasoning.
Before using computers in this crucial field of health care, it is essential to
understand how reliable data can be acquired, how information can be derived
from data, what type of knowledge is necessary for interpreting the data and how
this knowledge can be stored in computers. There are several advantages of using
computers in health care, but also a few fundamental limitations, especially
when used in Patient care. It helps
to order and structure computer applications with respect to strong and weak
aspects of using computers in health care.
Information
Processing:
The compute can support
following three stages of diagnostic-therapy cycle:
Ø
Data acquisition and transmission
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Data storage and retrieval
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Data processing and presentation
The major components of information processing system
are:
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Occasional users
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Routine users
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Experts
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Manual
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Bar code-reading devices
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Automated character recognition devices
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Systems that allow data entry by voice input.
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Automatic measuring devices
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Character-based interface
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Graphical interface
Rules
for the documentation of patient data in computers:
1.
Data should be acquired as close to the source of the data as possible.
2.
Data should be recorded by obeying strict rules of standardization.
3.
The original data should be stored, and if possible, human
interpretations should be stored only if the raw data they are based on are also
stored.
4.
Coding of data should be done only if there is no other way to present
the data, and it should preferably be done by the person making the observation.
5.
For all data entered, there should preferably be an on-line feedback to
the user to signal possible deviations from what should be expected.
6.
Persons who enter the data should ideally benefit from this data entry,
either because they will use the data later on or because it will improve the
quality of their work.
7.
Authentication (adding the coder's name and signature) and time stamping
of data improves the data quality.
Database
Management Systems:
A software shell around the data that assists the
user in all data storage and retrieval operations, controls the access to the
data and keeps a log file for all data transactions is called database
management system (DBMS). There are several database models such as relational
data model, hierarchical data model, network data model etc. Relational model (RDBMS)
is the most popular model in the present days. Several commercial RDBMS packages
like DB2, Oracle, Microsoft SQL, MYSQL etc. are available in the market which
work on different operating systems. Standard Query Language (SQL) is used for
manipulating databases.
Communication:
The
quality of communication between health care providers strongly influences the
quality of care. Communication is essential for those patients who are under the
shared care of several clinicians. Inefficient communication between these care
providers may have undesired effects such as the provision of conflicting
therapies or the duplication of diagnostic tests, thereby wasting financial
resources and negatively influencing the quality of care.
Local
Area Networking (LAN) is essential in the hospitals to connect PCs located in
various Clinical Departments and other facilities like Out Patient Dispensary (OPD),
Laboratories etc. with the main computer system running hospital information
system. Wide Area Networking (WAN) is used in the situation where hospital
buildings are located at far away distances. Internet is used for telemedicine
applications. Appropriate communication hardware and software are used to ensure
smooth transaction of data in the network.
Computer-based patient record:
The
traditional paper-based patient record used in a clinical setting generally
contains the notes of clinicians and other care providers. These notes are often
supplemented with data from other sources: laboratory test results and reports
describing the results of other tests that have been performed, such as X-rays,
pathology, ultrasound, lung function, and endoscopy. With the exception of
electrocardiograms, some images, or drawings, the majority of information in the
paper-based record involves data that can be expressed in characters and digits
(alphanumeric data).
For
more than 25 years people have tried to develop the Computer-based Patient
Records (CPR). The first developments were in a hospital setting and focused on
those parts of the patient record that were relatively easy to structure, such
as those containing diagnoses, laboratory test results, and medication data.
History of patient and the physical examination proved to be far more difficult
to collect in a structured format. The clinicians vary widely in the phrasing of
their findings and are reluctant to enter data directly into a computer, because
they felt that data entry on a terminal would be time-consuming and unfriendly
to the waiting patient. This resulted in the practice of medical transcription.
It
is widely recognized that patient descriptions created via structured data entry
are essential to obtain reliable patient data that are suitable not only for
patient care but also for example for decision-support and research. Although a
variety of combinations may occur, there are two main strategies for the
collection of structured data:
Biosignals:
All
living things, from cells to organisms, deliver signals of biological origin.
Such signals can be electric (e.g., the depolarization of a nerve cell or the
heart muscle), mechanical (e.g., the sound generated by heart valves), or
chemical (e.g., the PCO2 in
the blood). Such biosignals can be
of interest for diagnosis, for patient monitoring, and biomedical research.
The
processing of biosignals usually consists of following four stages: b
1.
Measurement or observation, that is signal acquisition
2.
Transformation and reduction of the signals
3.
Computation of signal parameters
that are diagnostically significant
4.
Interpretation or classification of the
signals.
Medical
Imaging:
Medical
imaging is to a large extent impossible without the use of computers. Computers
are applied in medical imaging to:
Security:
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Threats to confidentiality
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Threats to data integrity and availability
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Identify the threats
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Estimate the chances of Incident
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Estimate the expected damage
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List the considered measures
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Estimate the cost of each measure
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Relationship between threats and possible measures
Cost:
International
Medical Informatics Association (IMIA – http://www.imia.org
):
IMIA
plays a major global role in the application of information science and
technology in the fields of healthcare and research in medical, health and bio
informatics. The basic goals and objectives of the association are to:
Reference:
Handbook
of Medical Informatics
Editors: J. H. Bemmel, Erasmus University, Rotterdam
M. A. Musen, Stanford University, Stanford
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