This search was designed to overcome a limitation in the IPC classifications. The IPC classifications treat the contents of a medical preparation and not its target. This search uses full text searches to look for preparations that act on blood enzymes. A comparable search of words in the abstract did not retrieve this record. In U.S. Patents Fulltext, the text searches are performed on inverted files of the text.
Scans are slower and are therefore performed on previously retrieved sets.
As will be discussed in more detail below, full text searches are good in the initial stages of a search when a broad net is used. Later stages of a search will move towards inventor searching for best accuracy. For this reason, it is omitted from the Web document.