Guide to STN Patent Databases – Basic Version - Paton - TU Ilmenau

Types of search
19 Search by numeric properties
19.1 Numeric properties in patents
Numeric indications of physical or chemical properties play an important role in patents, for example:
Amount or weight
Concentration
Ratio of mixture
Frequency
Wave length
Temperature
Typically applicants avoid stating exact values in order to extend the scope of protection and to keep business
secrets. In patent applications they rather state wide ranges around the actually relevant or commercially
interesting values a practice that makes searching numeric properties in usual text documents even more difficult.
19.2 Problem
Intervals of numeric properties are difficult to find using conventional tools for fulltext searching:
Manually entering all possible values is cumbersome and error-prone, in particular if a larger interval is
wanted
A search by asequence of numbers often exceeds the system limits
The search is substantially incomplete
Consequently, numeric indications:
Must be semantically treated
Must be linked to their respective units
Units must be convertible
19.3 Numeric Property Search (NPS)
Numeric Property Search (NPS) makes it possible to search numeric indications in patent publications in the context
of the respective fulltext. Due to the numeric properties being indexed in the context of the document proximity
operators known from text searches can be employed to link numeric values and keywords. This search option has
been implemented in the AUPATFULL, CANPATFULL and PCTFULL databases.
Numeric properties are extracted from the fulltext and processed by STN for improved searching:
More than 30 chemical and physical properties in approx. 400 units
Units are converted automatically
All English text fields are included (TIEN, ABEN, CLMEN, DETDEN)
Numeric indications are kept in the context oft he fulltext (Proximity)
Full flexibility for searching: open or closed intervals, tolerances, exact values, magnitudes (nano-, milli-,
kilo-)
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