Word choice matters a great deal in the world of patenting. You’re using the English language to draw a picture around highly technical concepts. The precision with which this is done, down to the semantic level, can make all of the difference when it comes to your patent application being rejected or granted – and the future likelihood of your ability to assert your rights or defend against invalidation. Word choice too narrow or overly specific – and you can easily be designed around by competitors. Word choice too broad and only describing what something is vs what it does and you risk rejection or invalidation for what will be ruled as linguistic tricks to get more coverage than what you actually invented. The tension is real and the case law interpretation is fluid, but it all still comes down to determining if the chosen words will enable a person of ordinary skill in the art to carry out an invention – in the interest of other inventors being able to build on the idea, while also avoiding trespassing with infringement.
One very particular place this tension between breadth of coverage and specificity in enablement arises is with the concept of Means-Plus-Function claim language. In this month’s episode, Dr. Ashley Sloat, President and Director of Patent Strategy here at Aurora, leads a discussion, along with our all star patent panel, into the nuanced world of Means-Plus-Function claiming. The group digs into the statute, explores relevant case law in an analysis of the kinds of word choices that have and haven’t caused problems for inventors, and also provides some great drafting tips for de-risking the use of Means-Plus-Function claim language.
Ashley is joined today by our always exceptional group of IP experts including:
⦿ Kristen Hansen, Patent Strategist at Aurora
⦿ Dr. David Jackrel, President of Jackrel Consulting
⦿ David Cohen, Principal at Cohen Sciences
⦿ Shelley Couturier, Patent Strategist and Search Specialist
Before jumping into the deep with the panel, we also provide a quick primer on key concepts including specification vs claims, Section 112 enablement, functional claim language, and nonce words.
2. % of Patents that include at least one “means for”
claim limitation, grouped by patent issue date
https://patentlyo.com/patent/2011/07/the-frequency-of-means-plus-function-claims.html
3. Section 112(6) – Means plus Function
• Applicable. Recite a function without
reciting structure for performing the
function and limit the claims to the
structure, materials, or acts disclosed in the
specification
• Inapplicable. Recite both a function and the
structure for performing that function in the
claim
4. How is “claim construction” carried out?
1. Determine the claimed function
2. Identify the corresponding structure in the written
description of the patent that performs the function
Applied Med. Res. Corp. v. U.S. Surgical Corp., 448 F.3d 1324,
1332 (Fed.Cir.2006)
5. Getting around MPF
• If ”means” is not used, must be shown that persons of
ordinary skill in the art would not have understood
the term limitations to connote structure view of the
whole claim
• If MPF not desired, Applicant needs to show that a
particular claim element would be understood as
connoting “structure”
6. Halliburton Oil Well Cementing Co. v.
Walker, 329 U.S. 1 (1946)
• Invention added mechanical acoustical resonator to prior art
device for measuring distance to fluid surface in deep oil
wells
• Claims recite: "means associated with said pressure
responsive device for tuning said receiving means to the
frequency of echoes from the tubing collars of said tubing
sections to clearly distinguish the echoes from said couplings
from each other."
7. Williamson v. Citrix Online, LLC, 792 F.3d
1339 (Fed. Cir. 2015) - Indefinite
• (1) moved away from a strong presumption against MPF
interpretation absent “means” language and (2) established
the “nonce word” doctrine
• Focus must be appropriately placed on “whether the words of
the claim are understood by persons of ordinary skill in the
art to have a sufficiently definite meaning as the name for
structure.”
• Claim is indefinite (112(b)) - "if a person of ordinary skill in the
art would be unable to recognize the structure in the
specification and associate it with the corresponding function
in the claim"
8. Nonce Words
• Mechanism
• Module
• Device
• Unit
• Component
• Element
• Member
• Apparatus
• Machine
• System
• Circuit
• Detent mechanism
• Digital detector
• Reciprocating member
• Connector assembly
• Perforation
• Sealingly connected joints
• Eyeglass hanger member
Non-Nonce Words
Structural modifier +
nonstructural term
Non-structural modifier +
nonstructural term
9. • a “release means for retaining the guide in the
charged position”
• Construction: two functions — retaining the guide
in the charged position and releasing the guide
from the charged position
• Literal infringement: device performs the recited
function through structure that is the same as or
equivalent to the corresponding structure set forth
in the specification
Gregory Baran v. Medical Device
Technologies (Fed. Cir. 2010) - Indefinite
10. Tech. Licensing Corp. v. Videotek, Inc., 545
F.3d 1316, 1338 (Fed. Cir. 2008) - Definite
• “The question is not whether one of skill in the art would be
capable of implementing a structure to perform the function,
but whether that person would understand the written
description itself to disclose such a structure.”
• “Monitoring means”: spec describes node-to-node
communication system
• Expert testified that controllers + circuitry were corresponding
structure
• No circuit diagram, but it’s dep. on level of ordinary skill in the art
11. Tools For Checking Whether 112f Applies
•Description in spec denotes structure
•Dictionaries provide evidence word is
understood to be a noun denoting structure
•Evidence of structure for the term in the
Prior art
12. Software MPF
• Dyfan LLC v. Target (Fed. Cir. 2022) - Definite
• Code
• Application
• System
• VDPP LLC, v. Vizio, Inc. (Fed. Cir. 2022) - Definite
• Storage
• Processor
• Blackboard v. Desire2Learn (Fed. Cir. 2009) -
Indefinite
• Access Control Manager
13. Media Rights Capital v. Capital One Financial
Corporation (Fed. Circ. 2015) - Indefinite
• “Compliance Mechanism” and “Custom Media Device”
• Spec describes “how the ‘compliance Mechanism’ is
connected to and interacts with the other components of the
system, what processes the ‘compliance mechanism’
performs, and what structural subcomponents might
comprise the ‘compliance mechanism’
• Mechanism was tied to general computer – but no
corresponding algorithm was disclosed for all 4 functions of
the mechanism
14. TecSec, Inc. v. Int’l Bus. Machs. Corp., 731 F.3d 1336,
1347 (Fed. Cir. 2013) - Definite
• “system memory means” and “digital logic means”
• “a system memory is a specific structure that stores data”
• “digital logic means” was specifically disclosed in the
specification to be “comprised of structural elements,
including a system memory and specific modules and
subsystems”
15. Noah Sys., Inc. v. Intuit Inc. (Fed. Cir. 2012) – Indefinite
• “access means” and “communication means”
– No algorithm disclosed for one of two functions
• ‘To avoid purely functional claiming in cases involving computer-
implemented inventions, we have “consistently required that the
structure disclosed in the specification be more than simply a general
purpose computer or microprocessor.”
• Consequently, a means-plus-function claim element for which the only
disclosed structure is a general purpose computer is invalid if the
specification fails to disclose an algorithm for performing the claimed
function.
16. Drafting Tips
• MPF can be one of many claims types but not the
only claim type
• Assume that terms will be construed as MPF, and
draft accordingly
• Even structures known in the art should be given
structure in the description
• For software, include “algorithms” for all functions
of the MPF term