WHEN IS PRIOR ART ANALOGOUS?
| November 29, 2019
Airbus v. Firepass
November 8, 2019
Lourie, Moore, and Stoll
Summary:
To determine whether a reference is “analogous prior art,” one must first ask whether the reference is from the same “field of endeavor” as claimed invention. If not, one must ask whether the reference is “reasonably pertinent” to the particular problem addressed by the claimed invention.
As phrased by the CAFC here, a reference is “reasonably pertinent” if
an ordinarily skilled artisan would reasonably have consulted in seeking a solution to the problem that the inventor was attempting to solve, [so that] the reasonably pertinent inquiry is inextricably tied to the knowledge and perspective of a person of ordinary skill in the art at the time of the invention.
Thus, one should consider (i) in which areas one skilled in the art would reasonably look, and (ii) what that skilled person would reasonably search for, in trying to address the problem faced by the inventor. Accordingly, courts or examiners should consider evidence cited by the parties or the applicant that demonstrates “the knowledge and perspective of a person of ordinary skill in the art at the time of the invention.”
If a reference fails both the “field of endeavor” and the “reasonably pertinent” tests, it is not analogous prior art and not available for an obviousness rejection.
Background:
Challenger Airbus filed an inter partes reexamination against a patent owned by Firepass. The examiner rejected the claims at issue here as being obvious over the Kotliar reference in view of other prior art. The examiner also rejected other claims, not in issue here, as being obvious over Kotliar in view of four prior references (Gustafsson, the 1167 Report, Luria, and Carhart).
The claimed invention is an enclosed fire prevention and suppression system (for instance, computer rooms, military vehicles, or spacecraft), which extinguishes fire with an atmosphere of breathable air. The inventor found that a low-oxygen atmosphere (16.2% or slightly lower), maintained at normal pressure, would inhibit fire and yet be breathable by humans. Normal pressure is maintained by added nitrogen gas.
The patent contains the following independent claim that was added during the reexamination:
A system for providing breathable fire-preventive and fire suppressive atmosphere in enclosed human-occupied spaces, said system comprising:
an enclosing structure having an internal environment therein containing a gas mixture which is lower in oxygen content than air outside said structure, and an entry communicating with said internal environment;
an oxygen-extraction device having a filter, an inlet taking in an intake gas mixture and first and second outlets, said oxygen-extraction device being a nitrogen generator, said first outlet transmitting a first gas mixture having a higher oxygen content than the intake gas mixture and said second outlet transmitting a second gas mixture having a lower oxygen content than the intake gas mixture;
said second outlet communicating with said internal environment and transmitting said second mixture into said internal environment so that said second mixture mixes with the atmosphere in said internal environment;
said first outlet transmitting said first mixture to a location where it does not mix with said atmosphere in said internal environment;
said internal environment selectively communicating with the outside atmosphere and emitting excessive internal gas mixture into the outside atmosphere;
said intake gas mixture being ambient air taken in from the external atmosphere outside said internal environment with a reduced humidity; and
a computer control for regulating the oxygen con-tent in said internal environment.
The Board of Appeals reversed the examiner’s rejection, finding that Kotliar is not analogous prior art. The Board stated that the examiner had not articulated a “rational underpinning that sufficiently links the problem [addressed by the claimed invention] of fire suppression/prevention confronting the inventor” to the disclosure of Kotliar, “which is directed to human therapy, wellness, and physical training.” Significantly, the Board did not consider Airbus’ argument that “breathable fire suppressive environments [were] well-known in the art,” stating that the four references, relied on by Airbus, were not used by the examiner for the rejection of the claims in issue here.
Discussion:
The CAFC began its analysis by citing the “field of endeavor” and the “reasonably pertinent” tests mentioned above.
With respect to “field of endeavor,” the CAFC agreed with the Board. The Court explained that the disclosure of the references is the primary focus, but that courts and examiners must also consider each reference’s disclosure in view of the “the reality of the circumstances” and “weigh those circumstances from the vantage point of the common sense likely to be exerted by one of ordinary skill in the art in assessing the scope of the endeavor.”
Here, the Board found that the “field of endeavor” for the patent to be “devices and methods for fire prevention/suppression,” citing the preamble of the claim, the title and specification of the patent. Kotliar, on the other hand, concerns “human therapy, wellness, and physical training,” based on its title and specification. The Board concluded that Kotliar was outside the field of endeavor of the claimed invention, particularly in view of the fact that Kotliar never mentions “fire.”
The CAFC found that the Board’s conclusion is supported by substantial evidence.
Airbus argued that the Board should have considered the four references—Gustafsson, the 1167 Report, Luria, and Carhart—to which show that “a POSA would have known and appreciated that the breathable hypoxic air produced by Kotliar is fire-preventative and fire-suppressive, even though Kotliar does not state this” (emphasis in original). The CAFC disagreed, stating that Board’s failure to consider these references, if error, was harmless error. The CAFC explained that
a reference that is expressly directed to exercise equipment and fails to mention the word “fire” even a single time—falls within the field of fire prevention and suppression. Such a conclusion would not only defy the plain text of Kotliar, it would also defy “common sense” and the “reality of the circumstances” that a factfinder must consider in determining the field of endeavor.
The CAFC, however, came to the opposite conclusion with respect to the “reasonably pertinent” test. As with the “field of endeavor” test, the Board had failed to consider the four references. The CAFC found that this was a mistake.
In determining whether a reference is “reasonably pertinent” to the particular problem addressed by the claimed invention, for assessing whether a reference is analogous prior art, the court or the examiner should consider (i) in which areas one skilled in the art would reasonably look, and (ii) what that skilled person would reasonably search for, in trying to address the problem faced by the inventor. A court or examiner should therefore consider evidence cited by the parties or the applicant that demonstrates “the knowledge and perspective of a person of ordinary skill in the art at the time of the invention.”
Here, the four references are relevant to the question of whether one skilled in the art of fire prevention and suppression would have reasonably consulted references relating to normal pressure, low-oxygen atmospheres to address the problem of preventing and suppressing fires in enclosed environments. As stated above, the four references—Gustafsson, the 1167 Report, Luria, and Carhart—to which show that “a POSA would have known and appreciated that the breathable hypoxic air produced by Kotliar is fire-preventative and fire-suppressive, even though Kotliar does not state this” (emphasis in original). These references, the CAFC stated, could therefore lead a court or an examiner to conclude that one skilled in the field of fire prevention and suppression would have looked to Kotliar for its disclosure of a hypoxic room, even though Kotliar itself is outside the field of endeavor.
The CAFC therefore vacated the Board’s decision and remanded the case for the Board to consider whether Kotliar is analogous prior art in view of the four references.
Takeaway:
In resolving the “reasonably pertinent” test, courts and examiners must look at all the evidence of record.
