1. Nomenclature Definition Nomenclature is systematic compilation of authorized terms or descriptors for a certain documentation task. Nomenclatures usually take the form of coding system. Nomenclature takes the form of a thesaurus. Nomenclature often called descriptors.

2. For example if you have recorded the descriptor (localization head) in documentation of pain symptoms, but have forgotten to record "characteristic: throbbing" you will miss the patient in a retrieval of all patients suffering a throbbing headache. For the sake of brevity nomenclature are usually provided with a code. As for classifications, assigning a code is called coding

3. Nomenclatures are useful 1. Retrieve the data on objects with a particular combination of attributes (ex. All patients having had a meniscectomy under epidural anesthesia). 2. Let computer programs process the information about objects  To translate it into another language.  To warn of contraindications  To suggest a treatment.

4. Retrieval quality: To measure the quality of the result of specific retrieval.  1. All relevant cases or patients have been retrieved.  2. The retrieved patients are all relevant.  3. Precision and recall for this purpose. These quality indicators are essential for the usefulness of a nomenclature.

5. Forms Just like classifications nomenclatures can have different constructions Hierarchy For easier orientation, extensive nomenclatures can exhibit hierarchical structures (ex. Can be based on a hierarchical concept system. Multiple axes or dimension: dividing the set of authorized terms into several semantic dimensions will lead to multiaxial nomenclatures. By checking the dimensions on after the other applicable descriptors, the completeness of indexing is improved. Moreover, the reduced complexity serves the user with better orientation. In contrast to multiaxial classifications (where you have to choose exactly one class in every axis ), you may well assign several descriptors per axis to one object.

6. Example Simple monoaxial nomenclature. Imagine this list of descriptors for the localization of pain: L1 head L2 Back L3 extremities L4 joints Assuming a hierarchical construction, this is a possible subdivision: L1 head L11 Face L12 Forehead L13 Temples L14 Skull By adding another partial nomenclature for the quality of pain, a tow axial nomenclature emerges: Q1 dull pressing Q2 Burning, hot Q3 Stabbing, searing Q4 Tearing A stabbing, hot pain at the wrist would be coded as (L3, L4,Q2,Q3) A dull pain at the forehead and a pressing pain at the temples would be two separate facts:( L12,Q1) AND (L13,Q1).

10. Checklist: nomenclature Nomenclatures are systematically complied sets of authorized terms or descriptors for a specific documentation task. As for classifications, rules can improve clarity. In contrast to classifications, the aim of a nomenclature is not to assign objects to categories but to describe them unambiguously and precisely in order to make them retrievable and processable. A nomenclature can be a simple alphabetical list of descriptors, or it can provide hierarchical structures to aid orientation. Dividing the set of authorized terms into different semantic dimensions creates a multiaxiality does not extend expressional power, but it facilitates handling.

11. A simple example The coding systems To record discharge diagnoses the neurological department of the ploetzberg medical center and medical school (PMC) has two coding systems: a classification and nomenclature. This is an excerpt from the classification K433,0 A. bailaris K433,1 A. carotis K 433,8 occlusion or other precerebral arteries This is an excerpt of the two –axial nomenclature Axis 1 morphology axis 2 topography M341- stenosis T45- Precerebral arteries M3411 STONOSIS DUE TO Calcification T4511 A. CAROTIS COMM T4512 A. carotis comm.sin M351- THROMBOSIS M3411 obturating thrombus At the neurological department the classification is used to tabulate the frequency of the diseases that were diagnosed over time. The nomenclature is intended to facilitate the retrival of cases with certain attributes.

12. A diagnosis The disease of the patient is diagnosed as “stenosis of the left arteries carotis communis with obstructive thrombosis. Using the coding system above, the diagnosis can indexed and classified as follows: Classification:K433.1 (occlusion or stenosis of the A.carotis) Indexing: M3511( Obturating thrombus) M3411(Stenosis due to calcification) T4512 (A. carotis comm..sin.) Coding the diagnosis of all patients of a health care institution in this way will enable the data management system to answer various questions.in the next paragraphs, we will give two typical example.

15. Typical use of a classification /; Classifications are intended to describe the set of all objects aggregated in one class,eg. As an answer to the question Q1 how many patient with the diagnosis falling into the class ’occlusion or stenosis of the precerebral arteries “ (K433.) have been treated in our institution in the previous year? Using a nomenclature? This information could also be obtained using the indexed diagnosis. You would have to look for the simultaneous appearance of the code T45- (Precerebral arteries) and the codes M351- (thrombus) or M341- (Stenosis). The problem is however to guarantee that. Topography and morphology are indexed completely for all patient. All relevant indices are taken into account in the query. A patient is not counted more than once (this would particularly bias the comparison of class frequencies).

16. Typical use of a nomenclature : Nomenclatures are designed for the retrieval of data objects using differentiated, flexibly formulated criteria, ex. As an answer to the following question: Q2: who are the patients that suffered from a thrombosis of the arteria carteria carotis communist without having a stenosis? To answer this question, you would look for the simultaneous appearance of the codes M 351- (Thrombus) and T451-( A. carotis comm.), but without the code-M341(stenosis)

17. Using a classification? This analysis is hardly possible when using the classified diagnosis because patients with and without stenosis belong to the same class, and the parts of the A. carotis are not differentiated. Using a classification for reteieval, the search criteria are limited to the classifying attributes. In our case, you could search, for example, for all cases with an occlusion or with a stenosis of the arteria carotis (K433.1) and subsequently browse the patient records to determine either the patient had a thrombosis without stenosis at the A. carotis comm.

18. Important of medical coding system In this topic we introduce important medical coding systems. There are many other systems, some of which are very common in their specialized filed. For specific research projects, dedicated coding systems must be developed. As even the most specialized systems usually serve multiple purposes, some of them externally motivated, they should be designed as an extension to a more general, standard system.