Guideposts for Defining Particular Problems for Analogous Art Inquiries

By Mark Ford, Kristian Blomquist, and Hailey Higginbotham

To qualify as prior art in an obviousness inquiry, a reference must be analogous to the claimed invention. Two separate tests are evaluated to determine whether a reference can qualify as analogous art to the claimed invention. First, the reference is analogous art if it is from “the same field of endeavor” as the claimed invention, “regardless of the problem addressed.” In re Clay, 966 F.2d 656, 659 (Fed. Cir. 1992). Second, even if the reference is not from the same field of endeavor as the claimed invention, the reference qualifies as analogous art if it “is reasonably pertinent to the particular problem with which the inventor is involved.” Id.

Properly defining the particular problem with which the inventor is involved is critical to ensuring that only analogous art is relied upon in obviousness inquiries. Indeed, whether a reference qualifies as analogous art can – and often does – turn on how the “particular problem with which the inventor is involved” is defined. If the “particular problem” is defined too broadly, references that are not analogous art may be improperly relied upon. On the other hand, if the “particular problem” is defined too narrowly, references that are analogous art may be improperly excluded from consideration.

To illustrate, consider a claimed invention that recites an insect trap that includes a uniquely shaped light as an attractant. A primary reference discloses all the elements of the insect trap, apart from the light, as the primary reference discloses use of a chemical attractant instead. A secondary reference discloses a lantern for camping but includes a light element that has the same unique shape as the light of the insect trap. The lantern is likely not from the same field of endeavor as the insect trap, so the question becomes is it “reasonably pertinent to the particular problem with which the inventor is involved”? The answer depends on how the problem is defined. If the problem is defined broadly, such as “how to create a more accommodating outdoor environment,” then the lantern could be considered analogous art. However, should all references that fall within such a broad category be considered analogous art for the insect trap? Alternatively, if the problem is defined narrowly, such as “how to eliminate insects using light attractants,” any references that fall within the scope of the second test would likely already be analogous art under the first test (same field of endeavor), thus rendering the second test superfluous.

This article aims to provide guidance for effectively defining the scope of the particular problem of a claimed invention for analogous art considerations. In particular, this article provides guideposts based on several relevant Federal Circuit opinions for assisting practitioners with analogous art considerations.

Sanofi-Aventis Deutschland GmbH v. Mylan Pharmaceuticals Inc.

The first guidepost is that to be analogous art under the second test a reference must be reasonably pertinent to the particular problem of the claimed invention; not to a problem of another reference.

In Sanofi-Aventis Deutschland GmbH v. Mylan Pharmaceuticals Inc., 66 F.4th 1373, 1374 (Fed. Cir. 2023), the Federal Circuit reviewed an appeal from an inter partes review (IPR) that invalidated claims of a granted patent. On appeal, the patent owner argued that the petitioner had not established that a first reference was analogous art. Id. at 1376–77. During the IPR, the petitioner did not argue that the first reference was reasonably pertinent to any problem faced by the inventor of the patent at issue. Id. Rather, the petitioner argued that the first reference was reasonably pertinent to a problem of a second reference, because “there is no functional difference between the problem of [the second reference] and the problem of the [claimed invention].” Id. The Federal Circuit was not persuaded by the petitioner’s arguments and held that the petitioner had not carried its burden to prove analogousness of the first reference. Id. at 1377. According to the Federal Circuit, “[the petitioner’s] arguments would allow a challenger to focus on the problems of alleged prior art references while ignoring the problems of the challenged patent.” Id. at 1378.

Sanofi highlights several important considerations. First, focusing on the problem of the claimed invention when relying on references from different fields of endeavor in obviousness inquiries is essential. Establishing the pertinence of a problem in one reference to a problem in a second reference does not establish that the first reference is analogous art, even if the second reference is analogous art. In addition, how a problem is defined in a claimed invention can have a significant impact on the scope of potential prior art. Practitioners should be cognizant of how the problem facing the inventor is described when drafting patent applications, to potentially limit the number of references that may qualify as analogous art.

Donner Tech., LLC v. Pro Stage Gear, LLC

The second guidepost is that the “particular problem with which the inventor is involved” cannot be so narrowly defined that only references from the same field of endeavor as the invention would qualify as prior art.

In Donner Tech., LLC v. Pro Stage Gear, LLC., 979 F.3d 1353 (Fed. Cir. 2020), the Federal Circuit reviewed an appeal from an IPR that maintained the validity of claims of a granted patent. The PTAB held that the petitioner did not establish that a reference, which was relied on in each of the petitioner’s obviousness arguments, was analogous art. Id. at 1359. The PTAB’s decision was based, in part, on its narrow identification of the purpose of the patent at issue, which was “to mount guitar effects on a pedal board.” Id. at 1360. The Federal Circuit found that the PTAB erred in its identification of the purpose of the patent at issue. Id. According to the Federal Circuit, the PTAB’s “characterization of the problem to which the claimed invention relates effectively collapses the field-of endeavor and reasonable-pertinence inquiries.” Id. The Federal Circuit, therefore, vacated the decision of analogousness by the PTAB. Id.

Donner Tech. thus provides a boundary on how narrow is too narrow when defining the particular problem. Specifically, the problem cannot be so narrowly defined that only art that is within the same field of endeavor as the patent at issue would qualify as analogous art.

In re Clay

The third guidepost is that differences in operational environments of a reference and operational environments of the claimed invention can impact a determination of analogousness under the second test.

In re Clay, 966 F.2d at 657 is an appeal from a decision by the Board of Patent Appeals and Interferences (“BPAI”) that found claims of a pending patent application obvious in view of two references. The technology at issue in the application was a process for storing refined liquid hydrocarbon product in a storage tank that included placing a gel in the dead volume of the tank to prevent loss of the hydrocarbon product. Id. One of the cited references disclosed use of a gel to fill anomalies in porous underground rocks to improve flow of oil toward a production well. Id. at 659. The applicant argued that this reference was non-analogous art. Id. at 658. The BPAI disagreed and found that the reference was analogous because both the reference and the application at issue were directed to the same problem of “filling [] dead space with something” and “maximizing withdrawal of petroleum stored in petroleum reservoirs.” Id. at 658–59.

The Federal Circuit reversed the BPAI’s decision, finding that the reference and the application were directed to different problems. Id. at 659–60. According to the Federal Circuit, the reference was directed to the problem of “recovering oil from rock” while the application at issue was directed to the problem of “preventing loss of stored product to tank dead volume.” Id. In addition to distinguishing the problem faced by the inventor, the Federal Circuit also identified and appeared to base its opinion, at least in part, on several differences in the operational environments between the reference and the application. For example, the Federal Circuit noted “[m]oreover, the subterranean formation of [the reference] is not structurally similar to, does not operate under the same temperature and pressure as, and does not function like [the claims’] storage tanks.” Id.

In re Clay suggests that differences in the physical environments in which a reference and a claimed invention operate can have an impact on whether the reference is analogous. Therefore, including a description of the environment in which a claim operates may serve to limit references from being considered analogous, especially if they operate in different physical environments. However, as highlighted in the Innovention Toys case below, the impact of environmental differences may be limited.

Innovention Toys, LLC v. MGA Entm't, Inc.

The fourth guidepost is that differences in physical and virtual environments between a reference and a claimed invention are not alone sufficient to make the reference non-analogous art under the second test.

In Innovention Toys, LLC v. MGA Entm't, Inc., 637 F.3d 1314, 1315 (Fed. Cir. 2011), the Federal Circuit reviewed an appeal from a District Court decision, in which the District Court held that two references directed to virtual games were non-analogous art to claims of a granted patent that were directed to a physical game. The appellant (who was accused of infringing the patent) argued that the references were analogous art because the references “teach the claimed game in electronic form” while the patent owner argued that the references “fail to disclose any physical, non-virtual game components [and, for this reason, are not] reasonably pertinent.” Id. at 21.

The Federal Circuit found that the references were analogous art despite the different environments (i.e., virtual vs. physical). The Federal Circuit, when identifying the problem faced by the inventor, referred to the patent itself on several occasions. According to the Federal Circuit:

the specification states that ‘[s]trategy games may differ in a variety of ways,’ such as in board layout, the number and types of playing pieces, and the manner in which each piece moves on the game board, and that ‘[e]ach of these variations affects the strategy of the play and the degree of skill required to play the game.’

Id. at 1322. The Federal Circuit concluded that the claimed invention relates to the “goal [of] designing a winnable yet entertaining strategy game,” which it identified as basic game elements. Id. Accordingly, the Federal Circuit Court held that “[b]asic game elements remain the same regardless of the medium in which they are implemented: whether molded in plastic by a mechanical engineer or coded in software by a computer scientist” and that the references were analogous art. Id. at 1322–23. The court vacated the District Court’s decision of non-obviousness. Id. at 1324.

Thus, the fact that a reference is designed to function in an electronic environment while a claimed invention is designed to function in a physical environment does not alone establish non-analogousness. One way to possibly avoid a situation like Innovention Toys is, if alternative environments are known, to identify and describe problems that are only applicable to the environment of the claimed invention. For example, identify and describe problems that are applicable only to the physical world.

Adherence to these guideposts should significantly increase the likelihood of successfully navigating analogous art issues whether they arise during litigation or prosecution.

Written by:

Mark Ford is a shareholder at Maschoff Brennan.  Mark’s practice focuses primarily on representing clients before the United States Patent and Trademark Office in post-grant proceedings, including inter-partes reviews, covered business method reviews, and reexamination proceedings. In addition to his post-grant practice, Mark is also an experienced litigator, having represented both plaintiffs and defendants in disputes involving a wide variety of technologies including fitness equipment, electrical and electromechanical systems, and computer software and hardware.

 Kristian Blomquist is a patent attorney at Maschoff Brennan.  He assists clients with patent preparation and prosecution in various technologies including optical systems, analog circuits, wireless communication devices and mechanical devices. Kristian is an Electrical Engineer with experience in wireless communication, semiconductors, analog IC design, and more. Prior to joining Maschoff Brennan, Kristian worked at L-3 Communications designing and verifying wireless communication systems and at Simtek Corporation verifying nvSRAM semiconductor chips.

Hailey Higginbotham is a Summer Clerk at Maschoff Brennan.  She is currently securing her J.D. at Brigham Young University’s J. Ruben Clark Law School.

About Maschoff Brennan

Maschoff Brennan provides legal counsel and representation to some of the world’s most innovative companies. With over 30 attorneys and offices in the technology-focused regions of Utah and California, our attorneys are known

Republished with permission of The Patent Lawyer