Clinical laboratory informatics

This section provides an introduction to informatics concepts, starting with definitions, progressing to hardware descriptions, and finishing with observations regarding the rate of developmental change in computing. 

Selecting the hardware correctly is generally a matter of determining or specifying capacity and compatibility with standards. Hardware capacity can usually be simplified to two aspects size and speed. 

in computer terms, uses idiosyncratic units in addition to the bit and byte. Outside the world of computing, the prefixes kilo, mega, giga, and tera ordinarily refer to 10, 10, 10, and 10, respectively. However, when used with byte, they refer instead to 2, 2 , 2, and 2 . That is, a kilobyte is not 1000 bytes but 1024 bytes. The reason is that addresses, the numbers that refer to the location of digital data, are binary numbers, so a kilobyte is the total number of bytes that can be addressed by a ten bit address, and it carries the kho prefix because it is the power of 2 closest to 1000. Likewise a megabyte is 1,048,576 bytes because it is the power of 2 closest to 1,000,000, and represents the number of locations addressable by 20 bits. 

In computer terminology, speed has two chief varieties clock speed and bandwidth. Clock speeds, which give an indication of how fast a processor runs, have units of Hertz (Hz), or cycles per second. In this case, standard prefix meanings are used, so one megaHertz is 10 cycles per second. The simplest computer instructions require one dock cycle to be executed, so a processor with a clock speed of one megaHertz would be able to execute one instruction in one microsecond, and a gigaHertz processor could execute one instruc- 

---

Professor of Pathology and Medical Informatics Oregon Health and Science University Portland, Oregon Clinical Laboratory Informatics... 

The NCCLS has an Area Committee on Automation and Informatics, which oversees the above standards and initiates new standards development projects. Current standards development projects include Data Content for Specimen Identification, Protocols to Vafidate Laboratory Information Systems, and Remote Access to Hospital Diagnostic Devices via tihe internet. In 2002, ASTM transferred to NCCLS the ownership and copyright of aU nine standards in its E31.13 group, including the two standards referenced above. These standards all relate to the clinical laboratory, with some of them simply preceding or overlapping the NCCLS automation standards. NCCLS is now in the process of evaluating which of these standards will be maintained and updated and which may be abandoned. 

Most analytical devices used in clinical laboratories are directly linked or connected via an electronic interface to a laboratory information system (LIS). In this progression, many different informatic functions (see Chapter 18) are used, including the electronic transfer of data from the analyzers to the LIS and ultimately into a patient s electronic medical record. This provides healthcare professionals with quick, accurate, and appropriate access to the patient s medical history and information. 

The boundaries between clinical chemistry and other areas of laboratory medicine are not always distinct. In many institutions, clinical chemists initiate and direct activities, such as laboratory informatics and POCT. In some areas of the world, the term clinical chemistry has long been used to include laboratory areas such as hemostasis, thrombosis testing, immunology testing, and parts of hematology that in the United States are not considered to be part of classical clinical chemistry. 

Cowan DP, ed. Informatics for the Clinical Laboratory A Practical Guide. Springer-Verlag New York. 2003. 

Assistant Professor of Biomedical Informatics, Director, Discovery Systems Laboratory Department of Biomedical Informatics Vanderbilt University School of Medicine Nashville, Tennessee Clinical Evaluation of Methods... 

---