This week Professor Crouch has a graph that confirms that patents with at least one means-plus-function claim (indicated by "means for") have steadily dropped for decades, e.g., from 45% in 1989 to 10% today. It's no wonder since 35 USC 112 will not permit them to be broadly interpreted and recently the Federal Circuit tends to hold them indefinite and invalid.
The Federal Circuit describes means-plus-function claim in its recent decision: Ergo Licensing v. CareFusion: "Section 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." 35 U.S.C. § 112 (2006). 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." 35 U.S.C. § 112 ¶ 6. In exchange for the ability to use a generic means expression for a claim limitation, "the applicant must indicate in the specification what structure constitutes the means." Biomedino, LLC v. Waters Techs. Corp., 490 F.3d 946, 948 (Fed. Cir. 2007). Such structure "must be clearly linked or associated with the claimed function." Med. Instrumentation & Diagnostics Corp. v. Elekta AB, 344 F.3d 1205, 1219 (Fed. Cir. 2003). Failure to specify the corresponding structure in the specification amounts to impermissible pure functional claiming. Id. at 1211. "Although [§ 112 ¶ 6] statutorily provides that one may use means-plus-function language in a claim, one is still subject to the requirement that a claim `particularly point out and distinctly claim' the invention." In re Donaldson Co., 16 F.3d 1189, 1195 (Fed. Cir. 1994) (en banc). If an applicant does not disclose structure for a means-plus-function term, the claim is indefinite."
Let's see how this law plays out with respect to the facts in Ergo. There the '412 patent is described as a system to meter and deliver fluids into a patient. Each fluid is metered so different fluids may be delivered at different rates. To meter the fluids, adjusting means are associated with each fluid source to influence the fluid flow for each source. The adjusting means are coupled to a control device, which permits the selective actuation and control of individual fluid flow sources via adjusting means. The control device has data fields that describe the metering of the individual fluid flows. A screen and keypad can input information into the control device such as the metering rate for each fluid flow source.
For our discussion claim 1 is representative:
1. Multichannel metering system for metering preselected fluid flows, comprising:
a plurality of individual fluid flow sources;
a plurality of discharge lines, each line of said discharge lines being connected to a corresponding one of said fluid flow sources;
adjusting means associated with said fluid flow sources for acting on said fluid flow sources to influence fluid flow of said fluid flow sources;
programmable control means coupled with said adjusting means for controlling said adjusting means, said programmable control means having data fields describing metering properties of individual fluid flows;
an operating surface connected to said control means;
data input means for input of data into said control means, said data input means being at least partially connected to said operating surface;
data output means for output of data from said control means, said data output means being connected to said operating surface;
selector switch means forming a part of said data input means, said selector switch means including a plurality of selector switches, each selector switch being associated with a set of said fluid flow sources for representing segments of data fields belonging to a corresponding set of fluid flow sources on said operating surface, said each selector switch functionally connecting said data input means with said data fields belonging to said associated set of fluid flow sources.(emphasis added)
The Federal Circuit focused on the "programmable control means" italicized in claim 1. Ergo, the patent owner, argued the "control device" was a general purpose computer and the corresponding structure for the function recited in the programmable control means in claim 1. The Federal Circuit noted a general purpose computer could not perform the function recited in the programmable means. The Federal Circuit held saying the control device included memory did not help, because memory is not a structure capable of performing the function of controlling the adjustment means. Yet the Federal Circuit noted if the specification recited an algorithm to perform the function, the patent would have satisfied the definiteness requirement of 35 USC 112.
The Federal Circuit stated: "Until recently, we have consistently required "that the structure disclosed in the specification be more than simply a general purpose computer or microprocessor." See Aristocrat Techs. Austl. Pty Ltd. v. Int'l Game Tech., 521 F.3d 1328, 1333 (Fed. Cir. 2008). "Because general purpose computers can be programmed to perform very different tasks in very different ways, simply disclosing a computer as the structure designated to perform a particular function does not limit the scope of the claim to `the corresponding structure, material, or acts' that perform the function, as required by section 112 paragraph 6." Id. Requiring disclosure of an algorithm properly defines the scope of the claim and prevents pure functional claiming.
In re Katz Interactive Call Processing Patent Litigation identified a narrow exception to the requirement that an algorithm must be disclosed for a general-purpose computer to satisfy the disclosure requirement: when the function "can be achieved by any general purpose computer without special programming." 639 F.3d 1303, 1316 (Fed. Cir. 2011). In In re Katz, we held that "[a]bsent a possible narrower construction" of the terms "processing," "receiving," and "storing," the disclosure of a general-purpose computer was sufficient. Id. We explained that "[i]n substance, claiming `means for processing,' `receiving,' and `storing' may simply claim a general purpose computer, although in means-plus-function terms." Id. at 1316 n.11. In other words, 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 any special programming. Id. at 1316-17. If special programming is required for a general-purpose computer to perform the corresponding claimed function, then the default rule requiring disclosure of an algorithm applies. It is only in the rare circumstances where any general-purpose computer without any special programming can perform the function that an algorithm need not be disclosed."
Given these difficulties why did means-plus-function claims appear in 45% of the patents roughly two decades ago? I am not sure, but sometimes they correspond to what is invented. Further, they are easy to write. You simply recite "means for" and the function performed. Identifying a structure is not part of claim drafting. Further, it is easy to convert a method claim into a means-plus-function claim.
Despite the ease factor, most companies may want to limit their use in the broadest claim for several reasons. Recently, courts routinely invalidate mean-plus-function claims if it appears the structure is not highly detailed. Courts interpret means-plus-function claims to only cover the exact corresponding structure, i.e., no equivalents are afforded. And as a matter of experience, examiners do not interpret them so narrowly. Instead any means performing the recited function is relevant for raising a prior art rejection. Some may complain that this tendency in examination is unfair. But these problems at least in examination have been known for years. And unlike dissenting Judge Newman and patent blogger Gene Quinn, I don't think this case departs from recent Federal Circuit case law.
Copyright © 2012 Robert Moll. All rights reserved.