Biomedical Engineering Reference
Fig. 3.9 Screenshot of the WIPO web page to search for IPC codes by keywords
Many searches are not successful because they wrongly identify the technical
content of the invention and the choice of search terms. 27
The search carried out only by keywords may be not accurate and precise
because it is limited by:
• terminology issues: a patent is a document that is meant to be defended in court
(and not to be easily found in a database!) and therefore the language in use is a
compromise between the technical and the legal jargons (sometimes the inven-
tor uses neologisms);
• synonyms in different languages;
• incomplete databases (not all databases allow a full - text search) and databases
that store incorrect data (for example, metadata about the applicants and the
• speciic pieces of information may not be present in the text, but only in draw-
ings or in (mathematical or chemical) formulas, in genetic sequences, etc.
The use of an inadequate terminology can be an obstacle to the achievement of an
optimal search (especially in emerging technical fields). A good test to verify that
the terminology in use is appropriate is the International Patent Classification
If most of the documents obtained by a search are classified within an irrelevant
IPC section (or class), it means that the correct terminology was not used and it is
necessary to define a new set of keywords [ 25 ].
27 The percentage of information retrieval varies depending on the synonyms used.
28 Why was the Dewey decimal classification (conceived in 1873 and used in libraries all over
the world) not used and why had a special classification for patents to be devised? Mainly for
two reasons: the Dewey classification encompasses all knowledge (but arts, literature and phi-
losophy are not patentable) and it is not sufficiently broken down.