Key Takeaways

  • Analogous art determines whether prior art is relevant enough to render a new invention obvious under 35 U.S.C. §103.
  • It must be either from the same field of endeavor or reasonably related to the inventor’s problem.
  • The MPEP 2141.01(a) provides the framework examiners use to evaluate analogous art, guiding rejections for obviousness.
  • Recent cases, such as LKQ Corp. v. GM Global Tech. Operations, have reshaped the role of analogous art in design patent analysis.
  • Knowing how to argue non-analogous art can help inventors overcome an examiner’s rejection and strengthen their patent claims.
  • Analogous art analysis applies differently in utility versus design patents—courts are increasingly harmonizing standards between them.
  • Inventors should understand how to traverse obviousness rejections based on non-analogous art to protect novel inventions effectively.

What is Analogous Art?

Analogous art refers to a method of criteria that patent reviewers and courts use to determine whether an idea is too similar to another invention and therefore qualifies as prior art. When looking at a patent application, the reviewer will determine whether the idea is novel and non-obvious to a person of ordinary skill in the claimed field of endeavor.

Some ideas and inventions are so diverse or remote that a person of unordinary skill would be highly unlikely to understand them. If the idea or art is this unique and diverse, it is often referred to as non-analogous and doesn't qualify under the prior art requirement of patent review. However, analogous art that is too similar to another invention or idea will likely not qualify for patent protection.

The analogous art test is very specific. Art is considered analogous when:

  • It is reasonably similar to the problem that the inventor faced; or
  • It is from the same field as the previously claimed invention.

If art is non-analogous, a patent reviewer cannot reject the application solely based on the art, especially if the idea relates to a different field or industry. No inventor could feasibly know about every teaching and idea across all industries. If the idea has a different purpose than other analogous art, the inventor might not have heard of that idea. This cannot be qualified as analogous art in a legal setting or the patent review process.

In order to qualify for a patent, an idea must logically lead to the inventor solving a problem without being too obvious to the ordinary person in the related field.

In the chemical arts, one example of analogous art related to a particulate composition used to inhibit fungus growth in animal foodstuff. The references of this composition were concerned with absorbing biologically active materials on carriers, so the teachings in those references would be pertinent to the problems in other references of the invention.

In another example, an inventor was working to prevent electrostatic buildup in PFTE tubing, which was caused by hydrocarbon fuel flow. Prior art references in this invention showed rubber hose art, which referenced the electrostatic buildup problem. PFTE tubing and rubber are both used by hose manufacturers, causing them to experience similar problems. The solution for the PFTE tubing electrostatic buildup also solved a problem in rubber hosing.

Analogous art examples also exist in other industries. One of the most common industries is mechanical arts. In a simple mechanical invention, the inventor must explore a broad spectrum of prior art. In a court case from 2004, a patent application claimed specific bristle configurations on a hairbrush. When the USPTO Board reviewed the rejection of the claims, the original rejection was made on the basis of claims made on a patent held on a toothbrush. In this example, the court upheld the rejection because the USPTO Board claimed that the application for a hairbrush referred to any bodily hair. Technically, a toothbrush could be used to comb facial hair, so the court ruled that it was within the field of the applicant's endeavor.

Another mechanical example of analogous art occurred when a patent applicant claimed an invention of a double-acting high-pressure gas transmission line compressor could also be used as a double-acting piston pump. Pumps and compressors have essentially the same structure and function, so the field included both types for moving fluids.

In the electrical arts, one example includes a cardiac pacemaker that included a runaway inhibitor to prevent malfunction. In order to make this work, the pacemaker prevented pulses from emitting at too high of frequency rates. The references disclosed circuits that were used in high power, but the court determined that someone of ordinary skill in the art of pacemaker design would look to other solutions for rate-limiting problems. The outcome in this case was analogous art.

In a design case, an inventor of a contemporary coffee table fought that it had a unique design. The courts looked at designs of other contemporary furniture and found that these would reasonably fall within the scope of a designer with ordinary skill in the industry. Simple aspects of an invention, such as the shape or overall functionality, can be considered analogous art when someone of ordinary skill in the area could come to the same conclusion about its purpose.

The Legal Basis of Analogous Art

Analogous art is foundational to the obviousness test under 35 U.S.C. §103. According to the Manual of Patent Examining Procedure (MPEP) §2141.01(a), prior art is considered “analogous” if it is either from the same field of endeavor as the claimed invention or if it is reasonably pertinent to the particular problem the inventor faced. If the prior art fails both tests, it is deemed non-analogous and cannot be used to reject a claim for obviousness.

The “person of ordinary skill in the art” (POSITA) is a central concept here. This hypothetical figure represents a professional familiar with the relevant field’s technologies and problems. The test for analogous art examines what this person would reasonably consider when addressing the problem solved by the invention.

For example, a patent examiner cannot combine a reference from a completely unrelated field unless that reference addresses a similar problem. This ensures inventors are only denied protection for inventions that would truly be obvious to peers in their area of expertise.

Why is Analogous Art Important?

When applying for a patent, the process is long and expensive. Some applications take months or even years to be processed by the United States Patent and Trademark Office (USPTO). Filing an application, only to have it rejected because your idea qualifies as analogous art, can cause a lot of frustration. Understanding analogous art and how reviewers look for it can help inventors avoid wasting time and money to try to patent an idea that will not qualify for protection.

In a recent case that went to the Court of Appeals of the Federal Circuit, a company called Natural Alternatives, LLC received a patent for use of desugared beet molasses to remove ice from the roads. The Patent Trial and Appeal Boards (PTAB) invalidated the patent because the reviewers felt the process of using desugared beet molasses was too obvious. The court overturned the board's invalidation of the patent based on the analogous art rule as well as the fact that the PTAB couldn't provide any specific reasons why a person of ordinary skill would have used this method.

Analogous Art and the Obviousness Standard

Analogous art is closely tied to obviousness determinations—a cornerstone of patentability. The Supreme Court’s decision in KSR v. Teleflex emphasized a flexible approach to evaluating obviousness, requiring examiners and courts to consider whether a skilled artisan would have combined prior art references to arrive at the claimed invention.

When determining whether references are analogous, courts apply a two-part test:

  1. Is the reference from the same field of endeavor?
  2. If not, is the reference reasonably pertinent to the problem the inventor was addressing?

If both answers are “no,” the reference is non-analogous and cannot be used to render an invention obvious.

This framework ensures inventors are not penalized for innovations that cross into new or unconventional disciplines. For example, using aerospace engineering techniques in medical device design could be non-analogous if the two fields don’t share a common problem or purpose.

What Could Happen When You Use Analogous Art?

When considering whether an idea qualifies as analogous art, you must defend your invention by making sure the USPTO reviewers satisfy the requirements of the analogous art test. By doing so, you can protect your idea and avoid having the application for patent protection rejected based on the concept of analogous art.

Another legal example of this concept involved a case between QXQ and Circuit Check. Circuit Check held patents related to marking interface plates that were used for testing circuit boards. The company filed a suit against QXQ for infringement, but QXQ claimed that a previous company had already used similar methods, so Circuit Check's patents were invalid based on analogous art. Those methods, according to QXQ, were visible in rock carvings. The issue arose as to whether prior art qualifies as analogous art when applied to the obviousness clause of patent review.

In its ruling, the court stated that it was not surprising that the inventor didn't look to rock carvings to improve the process of painting dots on interface plates for the purpose of testing valuable circuit boards. The machining technique shown in the rock carvings was not in a similar industry; therefore it did not pass the analogous art test.

In another example, challenged claims of a patent on portable X-ray devices related to detection means that were not structurally attached to the device. In a prior art patent, an inventor described a portable X-ray device used in the field of dentistry, which had separate X-ray detectors and generators. In this case, the portable X-ray device in question was not obvious to someone of ordinary skill level because the prior art related to dentistry. It also showed that the patent application described a plastic shell packaging, which provided better image quality. This plastic shell differentiated the new invention from the previous application.

The petitioner, in this case, didn't articulate the problems well, leaving it up to the review board to make a decision.

Traversing Obviousness Rejections Based on Non-Analogous Art

When the U.S. Patent and Trademark Office (USPTO) issues an obviousness rejection based on analogous art, the applicant can traverse the rejection by arguing that the cited reference does not meet the analogous art criteria. This requires showing that:

  • The cited reference is outside the same field of endeavor; and
  • It does not address a problem reasonably related to the inventor’s problem.

Applicants can rely on MPEP §2141.01(a) and relevant case law to support their arguments. For instance, in In re Klein, the court found that a reference on bottle closures was not analogous to an invention for mixing sugar-water solutions for bird feeders, as the problems addressed were unrelated.

A strong traversal response might include:

  • A clear definition of the invention’s field;
  • Evidence showing the purpose or problem differs from the prior art; and
  • Technical reasoning or expert declarations reinforcing why a POSITA would not have consulted the cited reference.

This approach not only preserves patent rights but also strengthens the record in case of appeal or litigation.

What Could Happen When You Don't Use Analogous Art?

If you submit an application for a patent on an idea that is considered non-analogous art, you might be more likely to qualify for patent protection. When your idea passes the analogous art test, the application for a patent could be rejected based on this fact. Analogous art can be hard to prove or dispute since the decision is ultimately based on the perspective of the reviewer.

Cases relating to physics and chemicals can also have different requirements. A similar underlying principle in another field of endeavor might not be enough to qualify an invention or process as analogous art. Applying the same scientific principle in a different way could be unique enough to be seen as non-analogous art.

One example of this concept is seen in a case between Tissue Transplant Technology Ltd. & Human Biologics of Texas Ltd. and Mimedx Group, Inc. This case involved placental membrane tissue grafts and using an asymmetric label to help a surgeon determine the proper orientation of the tissue graft. Another company had used a mark on a lens implant to make sure that it was properly orientated when placed in the patient. The synthetic corneal lens implant was considered to be chemically and structurally distinct from the placental membrane tissue grafts, and therefore this was not a case of analogous art.

In July 2015, the PTAB issued a final decision on the Petition for Inter-Parties Review, submitted by SkyHawke Technologies, LLC. In this written decision, the PTAB covered the two cited references qualified as analogous art. If so, they should be combined to render certain claims obvious that were made within the application. This patent, referred to as 566, covered a handheld computerized unit for recording, advising, and reporting golf data, along with the method of operation. The claims in question relate to a computer with a display screen used for user interaction before, during, and after a game. A person of ordinary skill might be able to recognize both references as being in the same field: human-computer interaction, thus rendering this patent as analogous art.

The holder of patent 566 disagreed, claiming that the prior art referenced is not in the same field of endeavor. In fact, this patent covered a product that was only for recording and reporting sports information. In its final decision, the PTAB rejected both claims as being too broad or too restrictive and requested a more objective form of evidence from the holder of patent 566.

Analogous Art in Design Patents and the LKQ Decision

Analogous art has traditionally been applied differently in design patents than in utility patents, but recent developments have changed that landscape. In LKQ Corp. v. GM Global Tech. Operations LLC (2024), the Federal Circuit abolished the long-standing Rosen–Durling test and brought design patent obviousness analysis closer to the KSR framework used for utility patents.

Under this updated approach, design examiners must now assess whether a prior art design is analogous—that is, whether it is reasonably pertinent to the same visual impression or aesthetic problem as the claimed design. The decision clarified that design patent comparisons should not be overly rigid, emphasizing a more flexible, common-sense evaluation of related designs.

This ruling significantly broadens what can qualify as analogous art in design contexts. For example, an examiner may now cite references from adjacent product categories (like furniture and lighting fixtures) if their visual designs address similar aesthetic problems.

For inventors and practitioners, this means:

  • Greater scrutiny of cross-industry design similarities;
  • More nuanced application of the analogous art test to ornamental features; and
  • A need for clearer explanations in design patent applications regarding intended use and design purpose.

Practical Strategies for Inventors and Practitioners

Understanding how analogous art operates allows inventors to anticipate examiner objections and strengthen their applications:

  1. Define the Field Early: Clearly specify your invention’s field and problem in the application to narrow the scope of potential analogous art.
  2. Document the Problem Solved: Provide context showing how your invention addresses a unique challenge not contemplated in cited prior art.
  3. Highlight Differences in Purpose: Even if physical similarities exist, differing functions or problems can disqualify prior art as analogous.
  4. Use Expert Declarations: Expert testimony can help establish what a POSITA would reasonably consider pertinent.
  5. Cite Relevant Case Law: Reference decisions such as In re Clay, In re Bigio, and In re Klein to support non-analogous arguments.

Taking these proactive measures helps inventors avoid costly rejections and protect innovative contributions more effectively.

Frequently Asked Questions

  1. What is the difference between analogous and non-analogous art?
    Analogous art is prior art that a person of ordinary skill in the field would logically consider relevant to solving a problem; non-analogous art is unrelated and cannot be used to show obviousness.
  2. How does the MPEP define analogous art?
    Under MPEP §2141.01(a), prior art is analogous if it’s from the same field of endeavor or reasonably related to the inventor’s problem.
  3. Does the LKQ decision affect utility patents?
    No, it primarily affects design patents, aligning their obviousness tests more closely with the KSR standard used for utility patents.
  4. How can I overcome an obviousness rejection using analogous art arguments?
    You can argue that the examiner’s cited reference isn’t from the same field or doesn’t address the same problem, supported by technical reasoning or expert declarations.
  5. Should inventors consult a patent attorney for analogous art issues?
    Yes. Because analogous art rejections hinge on nuanced legal and technical analysis, an experienced patent attorney—such as one available through UpCounsel—can help craft effective responses and strengthen patent protection.

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