5. MEDICAL INFORMATICS                                                                      

Meera Singh


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

Ø      Data storage and retrieval

Ø      Data processing and presentation

The major components of information processing system are:

Ø      Occasional users

Ø      Routine users

Ø      Experts

Ø      Manual

Ø      Bar code-reading devices

Ø      Automated character recognition devices

Ø      Systems that allow data entry by voice input.

Ø      Automatic measuring devices

Ø      Character-based interface

Ø      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.


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:


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:


Ø      Threats to confidentiality

Ø      Threats to data integrity and availability

Ø      Identify the threats

Ø      Estimate the chances of Incident

Ø      Estimate the expected damage

Ø      List the considered measures

Ø      Estimate the cost of each measure

Ø      Relationship between threats and possible measures 


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:


Handbook of Medical Informatics

Editors: J. H. Bemmel, Erasmus University, Rotterdam

M. A. Musen, Stanford University, Stanford

Web version: http://www.mieur.nl/mihandbook/r_3_3/handbook/home.htm