How should examiners interpret means-plus-function limitations?
This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.
According to MPEP 2182, examiners should interpret means-plus-function limitations in a manner consistent with the specification disclosure. The MPEP provides guidance on this interpretation:
- Consult the specification: “If the specification defines what is meant by the limitation for the purposes of the claimed invention, the examiner should interpret the limitation as having that meaning.”
- Exercise judgment: “If no definition is provided, some judgment must be exercised in determining the scope of the limitation.”
The MPEP emphasizes the importance of linking the structure to the function, citing B. Braun Medical, Inc. v. Abbott Labs:
“Structure disclosed in the specification is ‘corresponding’ structure only if the specification or prosecution history clearly links or associates that structure to the function recited in the claim.”
Examiners must carefully review the specification and prosecution history to ensure proper interpretation of means-plus-function limitations, avoiding overly broad or narrow interpretations that are not supported by the disclosure.