Expanded Means-Plus-Function Analysis Presents New Opportunities and Challenges

The Federal Circuit's en banc decision in Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir. 2015), expanded the potential application of 35 U.S.C. §112, ¶6, making it more likely that functional claim language will be construed as a means-plus-function limitation even in the absence of the word “means.” Patent claims that recite functions in connection with nonce words like “module,” “mechanism,” “element,” “device,” or even “processor” are now more likely to be deemed means-plus-function limitations. Whether a claim term is or is not subject to §112, ¶6 may be dispositive in some patent cases. For example, the specification must disclose a structure or algorithm for performing the means-plus-function limitation, and if no such structure is disclosed, the claim will be held invalid as indefinite. Recent cases applying Williamson have reached different results, with some decisions finding claims subject to §112, ¶6 and invalid for lack of structure and other decisions finding software claim terms to recite structural limitations not subject to §112, ¶6. While most of the decisions to date have been in the computer-related arts, interesting parallels exist in the life sciences and pharmaceutical fields. Below, we discuss recent decisions applying Williamson and provide practical insights and strategies for patent owners and accused infringers to consider when addressing the expanded application of §112, ¶6.