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Federal Circuit Addresses Computer-implemented Means-plus-function Claim Terms
Practical Law Legal Update 8-518-6640 (Approx. 4 pages)
Federal Circuit Addresses Computer-implemented Means-plus-function Claim Terms
by PLC Intellectual Property & Technology
| Published on 27 Mar 2012 • USA (National/Federal) |
In Ergo Licensing, LLC v. CareFusion 303, Inc., the US Court of Appeals for the Federal Circuit affirmed a district court's decision that certain claims are invalid as being indefinite where the specification failed to disclose sufficient corresponding structure for a computer-implemented means-plus-function term in the claims.
Key Litigated Issues
In Ergo Licensing, LLC v. CareFusion 303, Inc., the key issue for the US Court of Appeals for the Federal Circuit is whether the "control means" terms in Ergo's patents are indefinite means-plus-function terms under Title 35 Section 112, paragraph 6 of the US Code (Section 112, paragraph 6).
Background
Ergo Licensing, LLC sued CareFusion for infringing claims of US Patent No. 5,507,412 ('412 patent), which concerns an infusion system used to simultaneously meter and deliver fluids from multiple fluid sources into a patient's body. To meter the fluids, adjusting means are associated with each fluid source that influences the fluid flow. The adjusting means are tied to a central control device that permits the selective actuation and control of individual fluid flow sources through the adjusting means.
Before the Markman hearing, the parties stipulated that several claim terms were means-plus-function terms under Section 112, paragraph 6 including the terms "programmable control means" and "control means." The parties agreed that the analysis for both terms is the same and the function for the terms is "controlling the adjusting means." Ergo argued that the corresponding structure for "control means" is the recitation of "control device" throughout the specification.
The US District Court for the District of Maine held that these "control means" terms are indefinite because the specification does not disclose corresponding structures.
Outcome
In its March 26, 2012 decision, the Federal Circuit affirmed the district court's decision.
In its de novo review of the district court's decision, the Federal Circuit clarified the requirements of Section 112, paragraph 6 which allows a patent applicant to express a claim term as a means or step for performing a specified function. However, the applicant must still disclose in the specification the structure that corresponds to and performs the function. Relying on its own precedent, the Federal Circuit reiterated that the structure must be clearly linked or associated with the claimed function.
The Federal Circuit rejected Ergo's arguments that:
- The general disclosure in the specification of a "control device" meets the requirements of Section 112, paragraph 6 because a control device is:
- a generic structure known to persons skilled in the art; and
- synonymous with a general-purpose computer, even though a computer was not mentioned in the specification.
- Disclosure of an algorithm was not required because a general-purpose computer can perform the function.
General Disclosure of a "Control Device" is Insufficient under 35 U.S.C. § 112, Paragraph 6
The Federal Circuit held that, based on this set of facts, this generic disclosure of a "control device" is insufficient under Section 112, paragraph 6 and specifically noted that:
- The recitation of the term "control device" provides no more structure than the term "control means."
- Ergo's expert testimony demonstrated that "control device" is not a specific structure because even those skilled in the art would not recognize it as a known structure.
Computer Implemented Means-Plus-Function Terms Require an Algorithm
Citing its decision in Harris Corp. v. Ericsson Inc., the Federal Circuit reiterated that computer-implemented means-plus-function terms generally require the applicant to disclose the underlying algorithm in the specification (417 F.3d 1241 (Fed. Cir. 2005)). The algorithm must be a step-by-step procedure for accomplishing a given result and can be expressed in any understandable terms, including:
- A mathematical formula.
- In prose.
- As a flow chart.
- Any other manner that provides sufficient structure.
The Federal Circuit clarified that a general-purpose computer is sufficient structure only if the function requires no more than simple processing, which any general-purpose computer can do without special programming. Because the "control means" at issue in this case cannot be performed by a general-purpose computer without special programming, the claims are invalid.
Practical Implications
Applicants using computer-implemented means-plus-function claim terms must disclose in the specification the structure corresponding to the function beyond the recitation of a general purpose computer. If a general-purpose computer requires special programing to perform the corresponding claimed function, the specification must disclose the algorithm.