Last week I introduced patent classification searching and gave reasons why it is still relevant in today’s keyword-centric search environment. Think about patent classification searching as if you were going to a library and looking for books about Canada’s involvement in World War II. You might put those words into a computer, or you might use the a well known method of classification, the Dewey Decimal Classification to start looking in Class 971 History/Canada. Using the classification system might lead you to find books that don’t have “Canada” in the title or abstract, such as a book about the Quebec Conference of 1943. Today I will give some tips on how to use classifications to your advantage when patent searching.
Once you have identified the best classifications, what is the best method for searching? Apart from viewing each document in detail, there several helpful methods to utilize the classifications selected from Part 1. Two great ways to utilize these classifications are: combining them with image flipping, and combining them with full text searching.
“Image flipping” is simply quickly cycling through patent drawings to identify relevant art. This technique works best in arts that are more drawing-oriented, such as Mechanical arts. Subject areas that are less drawing oriented such as Business Methods or Software may not find this method useful at all, since most patent drawings are either generic, or contain flowcharts that are not easily parsed by the searcher. Certain search systems are more suited for image flipping than others, with USPTO EAST being the most ideal. EAST is housed only at the US Patent and Trademark Office headquarters, available to public searchers at the Public Search Facility in Alexandria, VA from Monday to Friday, 8 AM to 8 PM. Since the data servers are on site there is no lag due to connecting to a server located in another location, which is the case with virtually every other search system that may be used. This quick response allows users to flip through document images at an extremely rapid rate, even automating the process for hands free operation. Users can choose to view the first drawing page only or cycle through all drawings, stopping at a button press to mark the document for later and more thorough viewing. Although EAST is the best search system for using the image flipping methodology, other search systems such as PatBase provide results lists that include a representative image for each document or family of documents within a classification, and Google Patents offers a “Cover View” that shows representative drawings of the search results.
Combining keyword searching with classification searching is a good way to narrow down results within a class that may be too large to flip through. It is best to use keywords that are more specific than the classification being searched, as well as using keywords that relate to a different part of the invention than the classification represents. Take the example of IPC code A61B 1/317 –
“Instruments for performing medical examinations of the interior of cavities or tubes of the body by visual or photographical inspection, e.g. endoscopes; for introducing through surgical openings, e.g. laparoscopes; for bones or joints, e.g. osteoscopes, arthroscopes.” Since the specific subclass 1/317 deals with osteoscopes and arthroscopes, it is not necessary to use these terms or any analogs in a combined keyword search. If the desired prior art reference is an arthroscope with an illuminating feature, you might try searching “(illuminating or LED or lamp)” in combination with A61B 1/317 to find relevant results. This reduces the chances that you may miss a reference that uses the word “scope” instead of the more specific “osteoscope” or “arthroscope” had you used keyword searching alone, for instance.
Another good way to combine keyword and classification searching is to build several groups of relevant classifications and combine them with full text searching. At some point into a patent search, the searcher should be able to identify a primary classification and several related classifications. At this point the searcher can combine the results from, say, the two best classes, the four best classes, and all classes. This way there are, from smallest to largest, four categories:
1. The primary classification
2. The two best classifications
3. The four best classifications
4. All related classifications
From that point, each keyword string can be searched alone and then limited by applying the four above schemes. This gives the searcher the ability to look at expanding results lists, from most specific (combined with the primary classification) to the least specific (not combined with any class). An experienced searcher can use this to keep hit counts narrow enough for close inspection at times and wide enough for cursory inspection at other times.
These two advanced classification searching techniques are far from the only ways to use patent classifications to your advantage. Michael White at The Patent Librarian’s Notebook, for example, has a great blog post on using Cross-References and Digests within the US Classification system.
For further tips on classification searching and other methods to get the most out of your patent search, find the best prior art, and leave no stone unturned, check out Patent Resources Group’s Art and Science of Patent Searching course. This comprehensive three day course takes place from April 11-13 in Bonita Springs, FL as well as from August 16-18 in both Alexandria, VA and Southfield, MI. Designed for patent attorneys and agents, inventors, paralegals and research managers, the course and its materials will be understood by anyone from the inexperienced to advanced practitioners.
Please let us know if you found this article interesting, if you have any questions about classification searching, or if you have your own tips and tricks. Just leave a comment below and who knows…Part 3 might just happen!
This post was contributed by Intellogist team member Chris Jagalla.