Even with Narrowing Claim Construction, PTAB Finds Dependent Claims Obvious on Remand

In Fitbit, Inc. v. Valencell, Inc., IPR2017-00319, Paper 73 (Apr. 5, 2021), on remand from the Federal Circuit, the Board determined the patentability of several previously omitted dependent claims and found them unpatentable as obvious.

Fitbit petitioned for Inter partes review of Valencell’s patent directed to a method of generating data output containing physiological and motion-related information, arguing that several of its claims were obvious.  In its original Final Written Decision, the Board found the patent’s sole independent claim to be obvious. But the Board refused to consider the obviousness argument of several dependent claims because, in the Board’s view, the obviousness challenge of these claims relied on improper claim construction and some of these claims also had dependency errors.

On appeal, the Federal Circuit vacated the Board’s decision and remanded for determination of patentability of these claims on the obviousness ground. The Court explained that the Board’s narrow construction may have no significance here and the dependency errors could be corrected through the parties’ agreement.  On remand, Fitbit again argued that the challenged dependent claims were unpatentable as obvious.

The key dispute was whether the asserted prior art references disclosed a key claim limitation present in the dependent claims: an “application-specific interface (API).”  In its original petition, the petitioner treated “application-specific interface (API)” as identical to “application programming interface.” In its original Final Written Decision, the Board found this construction to be overly broad. Instead, the Board construed “application-specific interface (API)” to mean “an interface which enables a particular application to utilize data obtained from hardware.”  Under this claim construction, an “application-specific interface (API)” is directed to a particular application, rather than broadly to different applications.  

On appeal, the Federal Circuit affirmed the Board’s construction, but noted that “the Board’s narrowing construction . . . may have no significance, where, as here, the claimed ‘application-specific interface’ performs the same function as an application programming interface, i.e., enabling a particular application to utilize data obtained from hardware.”

On remand, as in the original petition, Fitbit presented two independent obviousness grounds.  Valencell challenged each ground, arguing that because the application programming interfaces disclosed in the asserted references were generically applicable to different applications, they were not used with a particular application, as required by the claim under the Board’s construction.  Also, Valencell argued, even if the references’ interfaces could be used by a particular application, they were not directed to a particular application because they were designed to be interoperable—the opposite of application specific. 

In response, Fitbit argued that just because the interfaces could be used in different applications did not mean that they could not be applied to a “particular application.”  Rather, the interfaces could be used with a variety of particular applications, acting on information depending on the goal of the application.  By tailoring the interface to specific applications and devices, the references thus expressly taught interfaces directed to a particular application, regardless of whether those interfaces were also interoperable with other applications, Fitbit argued.

On the first ground, the Board agreed with Fitbit, ruling that the asserted references’ interfaces performed the same function as the recited “application-specific interface,” because not only were the interfaces used by a particular application, they could also be specifically tailored to each particular application.  Regarding the second ground, the Board found that Fitbit had not carried its burden to prove that the application programming interface disclosed in the references was specific enough to be an application-specific interface.  Having found that the challenged patent was obvious over the first ground, however, the Board found each of the challenged claims unpatentable as obvious.