Last Month at the Federal Circuit
Last Month at the Federal Circuit

April 2012

Means-Plus-Function Limitations Are Indefinite Under 35 U.S.C. § 112, ¶ 2 Where A Specially Adapted Computer Is Required, But Patent Does Not Disclose Algorithm

Judges:  Newman (dissenting), Linn, Moore (author)
[Appealed from D. Me., Judge Singal]

In Ergo Licensing, LLC v. Carefusion 303, Inc., No. 11-1229 (Fed. Cir. Mar. 26, 2012), the Federal Circuit affirmed the district court’s holding that the terms “control means” and “programmable control means” are indefinite because the patent specification failed to disclose any corresponding structure.

Ergo Licensing, LLC (“Ergo”) accused Carefusion 303, Inc. (“Carefusion”) of infringing claims of U.S. Patent No. 5,507,412 (“the ’412 patent”), which relates to an infusion system used to meter and deliver fluids from multiple fluid sources into a patient’s body.  The infusion system includes adjusting means for controlling the fluid flow from the multiple fluid sources. Prior to the Markman hearing, the parties stipulated that several terms were means-plus-function terms, including the terms “programmable control means” and “control means.”  The asserted claims recited “programmable control means coupled with said adjusting means for controlling said adjusting means,” and the parties also agreed that the function of each of the terms is “controlling the adjusting means.”  The district court held that the “control means” terms were indefinite for failure to disclose corresponding structure, and Ergo appealed. 

On appeal, the Federal Circuit explained that 35 U.S.C. § 112, ¶ 2 requires that a patent specification “conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.”  The Court further explained that § 112, ¶ 6 provides that an applicant may express an element of a claim “as a means or step for performing a specified function . . . and such claim shall be construed to cover the corresponding structure . . . described in the specification and equivalents thereof.”  In exchange for the ability to use the means-plus-function language, a patent applicant must indicate what structure constitutes the means for performing the function.  If an applicant does not disclose structure for a means-plus-function term, the claim is indefinite.

“[A] general-purpose computer is sufficient structure if the function of a term such as ‘means for processing’ requires no more than merely ‘processing,’ which any general-purpose computer may do without special programming. If special programming is required for a general-purpose computer to perform the claims function, then the default rule requiring disclosure of an algorithm applies.”  Slip op. at 7.

Ergo argued that the corresponding structure for “control means” is a “control device” because such a generic structure is known to those skilled in the art.  In addition, Ergo argued that such a structure is synonymous with a general-purpose computer even though a computer is not recited in the specification.  Furthermore, Ergo argued that the specification describes additional structures, including that the control device has processing capabilities, can generate control commands, has memory, and has “programming means.”

The Federal Circuit disagreed, finding that none of the disclosures cited by Ergo constitutes structure for performing the claimed function.  In particular, the Court explained that “control device” provided no more structure than the term “control means,” and the description of “memory” was insufficient because memory is not a structure capable of performing the claimed function.  In addition, the Court found that expert testimony of Ergo demonstrated that those skilled in the art would not recognize “control device” as a known structure.  Specifically, Ergo’s expert described three different types of control devices that are commonly available, indicating that “control device” is not a specific structure.

The Federal Circuit also rejected Ergo’s argument that the specification provided adequate structure because one skilled in the art would understand “control device” to be a general-purpose computer.  The Court explained that even if it accepted that “control device” refers to a general-purpose computer, that would still not satisfy the requirements of § 112, ¶¶ 2 and 6.  In WMS Gaming Inc. v. International Game Technology, 184 F.3d 1339, 1348 (Fed. Cir. 1999), the Court explained that computer-implemented, means-plus-function terms are limited to algorithms disclosed in the specification.  The Court explained, therefore, that § 112, ¶ 6 requires more than just disclosure of a general-purpose computer, and disclosure of an algorithm is required to properly define the scope of a claim, except in the limited circumstance in which the claimed function can be achieved by any general-purpose computer without special programming, as discussed in In re Katz Interactive Call Processing Patent Litigation, 639 F.3d 1303, 1316 (Fed. Cir. 2011).  In this case, the Court found that the “control means” at issue cannot be performed by a general-purpose computer because the claimed function requires more than merely plugging in a general-purpose computer.  And the specification in this case does not describe any algorithm for performing the function of “controlling the adjusting means.”

Judge Newman, in a dissenting opinion, stated that the Court departed from established protocols of claim drafting.  In particular, Judge Newman explained that the claims of the ’412 patent were written in the standard manner of thousands of claims in electronic cyber-assisted technologies, and certain steps in the claims are controlled by a device according to known methods set forth in the specification.

Judge Newman also explained that the PTO did not find the claims inadequate for failure to describe a control means and the PTO’s expertise in this area warrants deference.  Furthermore, Judge Newman found that the content of the ’412 patent specification is appropriate and routine.  The invention, according to Judge Newman, is the overall system, which is described adequately in ten columns of text with four figures, including a detailed description of the function and operation of the control device.  She also explained that the ’412 patent specification made it clear that the invention is the arrangement of components, not any special component, and that the inventor is not claiming the control device as the invention.  Furthermore, the specification describes prior-art structures that perform control functions, and no party disputed that a person of skill in the art could routinely instruct a control device to perform the described control.

Judge Newman expressed concern that the Court’s holding in this case finds standard drafting procedures, as found in thousands of computer-assisted applications, to now be insufficient.  She argues, therefore, that precedent does not require a function to be implemented by a single structure and that standards set forth in the Court’s decisions have been met.