Obviousness Must Consider Function / Intended Use of Prior Art Device

August 2, 2022

On July 22, 2022, the Patent Trial and Appeal Board (PTAB) reversed an examiner’s assertion of obviousness in the case of Ex parte Jaeger (Appeal 2021-002641, USSN 15/559,117). The issue in Jaeger was whether the addition of known element to a prior art device was obvious where the combination was not consistent the purpose / operation of the prior art device.

The main claim on appeal in Ex parte Jaeger recited, with underlined portions having been added in prosecution,

[a] device comprising:
a filter holder, the filter holder comprising a tip portion;
a nonwoven article disposed on an exterior surface of the tip portion of the filter holder; and
an adaptor attached to the filter holder, the adaptor defining an aperture,
wherein the adaptor is either attached to the filter holder in series and distal to the tip portion of the filter holder or attached to the filter holder in a Y-shaped configuration.

In prosecution, after certain novelty rejections, the final clause was added to claim 1.  This resulted in a reject over the applicant’s own reference, US 2012/0009588 A1 (Rajagopal), combined with US 5,807,312 (Dzwonkiewicz) and a tertiary reference dispatched as cumulative prior to the appeal.  On appeal, the examiner argued that the above claim was obvious over Rajagopal and Dzwonkiewicz, alleging that Rajagopal described all features, but for the adaptor in the last two clauses of the claim.  

Rajagopal’s arrangement of a handle and a housing is shown above, which was agreed to provide neither an adaptor attached to the filter holder in series and distal to the tip portion of the filter holder, nor an adaptor attached to the filter holder in a Y-shaped configuration. The examiner argued that Dzwonkiewicz (FIG. 1, excerpted below) disclosed an adaptor (26) defining an aperture (28), wherein the adaptor is attached to the filter holder (22) in series and distal to the tip portion (18). 

The examiner argued that Dzwonkiewicz remedied Rajagopal’s lack of an “adaptor attached to the filter holder, the adaptor defining an aperture.” The examiner argued that Dzwonkiewicz’s adaptor would have be obvious to use in Rajagopal’s holder (1) to allow adding further reagents to a liquid sample in Rajagopal’s holder to enhance the detection of live cells; and (2) that as more concentration agent added, less incubation time is needed to capture the same amount of microorganisms.

The applicant provided the following images to exemplify the claimed arrangement, with element 108 being the relevant “adaptor.”

The applicant argued that

[t]o attach an adaptor to the filter holder [550] of Rajagopal in series and distal to the tip portion of the filter holder or to attach an adaptor to the filter holder in a Y-shaped configuration would add unnecessary structures to the device. This is at least because the housing 510 of Rajagopal already has an opening in its upper receptacle 520 to add components (a liquid sample, cell concentration agents, additional reagents for the sample, etc.) No motivation has been established for attaching an adaptor to the filter holder 550 of Rajagopal to provide means to add additional reagents to the liquid sample that is located in the housing 510 instead of simply adding any further components directly into the housing the same way “a liquid sample is transferred into the upper receptacle 520 of the housing 510” (paragraph [0133] of Rajagopal).

The applicant conceded that what a device does or how it is to be used may not differentiate a device recited in a claim being examined.  However, the applicant argued that the mode of operation and intended use of a primary prior art device is highly relevant to the determination of whether or not there would have been any reason to modify that device.  Appeal Brief, p. 16, ¶ 2.  The applicant argued that simply because an element was capable meeting a claim limitation does not support a finding of obviousness, citing In re Kahn, 431 F.3d 977, 988 (Fed. Cir. 2006) and KSR.

The applicant insisted that there would have been no particular reason to attach a filter holder in the distal location claimed, nor to increase the complexity, in Rajagopal’s device at least due to Rajagopal’s need for a simple, reliable test for detecting live cells, with the solution to that need being a device with reagents in conveniently available receptacles in Rajagopal’s device.  Appeal Brief, p. 16, ¶ 4, and p. 17, ¶ 2.  The applicant pointed out that some embodiments in Rajagopal would have to change their mode of operation to function with the proposed modification to meet the claims.  The applicant summarized that the proposed modification

would require a user to measure the additional reagent and add the reagent through the aperture of the adaptor, where the reagent would have to travel down the length of the housing 510, through at least one drain channels, and through a filter on the tip - all in the opposite direction as the flow of liquid sample 540 when the plunger 550 is urged down the housing 510, thereby risking releasing material that had desirably been caught in the filter – just to get to the portion 542 of the liquid sample 540 containing the cell concentration agent 530 to participate in any test reactions. Plus, in any instance where the device includes a one-way valve 697, the additional reagent would not ever get to the portion 542 of the liquid sample 540 containing the cell concentration agent 530 to participate in any test reactions because the one-way valve 697 is configured to only allow fluid flow in the opposite direction. In contrast, Rajagopal teaches a device in which the premeasured test materials are arranged in sequential vertical order, from higher receptacles to lower receptacles, in order of their inclusion in the test. For at least these reasons, one of ordinary skill in the art would not have had any motivation to add to the device of Rajagopal an adaptor defining an aperture in which the adaptor is attached to the filter holder in series and distal to the tip portion of the filter holder

Appeal Brief, p. 20, ¶ 4.

In siding with the applicant, the PTAB quoted KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398 (2007), stating that “a patent composed of several elements is not proved obvious merely by demonstrating that each of its elements was, independently, known in the prior art.”  KSR 550 U.S. at 418.  The PTAB took the position that the examiner failed to explain why a person of ordinary skill in the art would have added “more concentration agent at a later point in time through what appears to be a complicated and unnecessary modification of Rajagopal’s device, rather than simply add more concentration agent to Rajagopal’s device at the starting point.”  The PTAB compared this approach to “[a]t best, … say[ing] no more than that a skilled artisan, once presented with the two references, would have understood that they could  be combined.  USSN 15/559,117, Dec. on Appeal of July 22, 2022, p. 5, ¶ 4.

The PTAB, citing to Belden Inc. v. Berk-Tek LLC, 805 F.3d 1064, 1073 (Fed. Cir. 2015), restated that such an approach is insufficient to establish obviousness, because it does not imply a motivation to pick out two references and combine them to arrive at the claimed invention.  The Jaeger decision reminds us that while the intended use may not distinguish a device for which a patent is sought, an obviousness rejection adding an element to a prior art device must not negate the intended use, purpose, or mode of operation of a prior art device.