Tag Archives: means-plus-function

Means-Plus-Function Claims in Patent Eligibility and Infringement Analyses

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by Dennis Crouch

Means-plus-function claims have generally been disfavored because of the tendency of courts to  either (1) narrowly construe their scope when corresponding structure is detailed in the specification or (2) render them invalid as indefinite when the specification lacks sufficient corresponding structure. If Impact Engine's petition is well received, there is a good chance that this historically popular claim style will see a revival. 

The Federal Circuit's recent decision in Impact Engine v. Google has again raised the issue of over the proper treatment of MPF, this time regarding patent eligibility and infringement analyses. Appeal No. 22-2291  (Fed. Cir. July 3, 2024).  I had skipped a write-up of the non-precedential decision, but now Impact Engine has petitioned for en banc review, arguing that

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USPTO ARP Panel Restores MPF Sanity, but Still Rejects Xencor’s Claims

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by Dennis Crouch

In a new Appeals Review Panel (ARP), the USPTO has clarified the Office's position on means plus function claims -- explaining that the specification need not describe statutory equivalents to satisfy the written description requirement.  The outcome here shows value for the intentional use of means-plus-function limitations as a mechanism for expanding patent scope when genus claims are otherwise unavailable.

Still the court maintained the written description rejection on other grounds -- finding that the broad preamble "method of treating a patient" to be limiting and not adequately supported by the specification.  Perhaps on remand the patentee will amend the preamble to instead claim a "means of treating a patient." 

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