In DoggyPhone LLC v. Tomofun LLC, No. 2023-1791 (Fed. Cir. Nov. 21, 2024), the Federal Circuit affirmed the District Court’s summary judgment of noninfringement, concluding that Tomofun’s “Furbo” pet camera did not infringe Claim 7 of U.S. Patent No. 9,723,813. The patent describes an Internet Canine Communication System (ICCS) that enables remote interaction between owners and pets by combining treat dispensing, audio/video communication, and pet-initiated engagement. The central issue was whether Furbo’s system performed in a manner consistent with the limitations of Claim 7, particularly those involving the delivery module and initiation of live transmission based on pet input.

At the claim construction stage, the District Court examined three key terms: “food dispenser,” “delivery module,” and “begins transmission…in response to input from the pet.” The court held that “food dispenser” had sufficient structural meaning and did not invoke 35 U.S.C. § 112(f), while “delivery module” did invoke § 112(f) as a nonce term. However, the delivery module was not indefinite because the patent disclosed sufficient corresponding structure, such as a treat carousel. The court interpreted the “begins transmission” limitation according to its plain meaning, allowing a broad range of pet inputs to trigger system responses without requiring mechanical specificity.

Despite these favorable constructions, the District Court later granted summary judgment in favor of Tomofun. It found that Furbo’s piston-based treat dispensing mechanism was structurally different from the patented carousel design, failing the “way” and “result” requirements under § 112(f). More importantly, the court determined that Furbo’s live video feed only began when the user actively responded to a notification—thus, the system did not “begin transmission…in response to input from the pet” as required. The microphone and video functions operated independently and were not responsive to pet input in the claimed manner.

On appeal, the Federal Circuit affirmed the ruling by focusing exclusively on the “begins transmission” limitation. It found that the claim required direct and immediate initiation of transmission by the pet’s input, which Furbo’s user-initiated design did not satisfy. The court rejected the argument that indirect triggering—such as barking followed by a user clicking a notification—met the limitation. Because this limitation alone was dispositive, the court did not need to address the remaining grounds.

The case underscores key claim drafting lessons, particularly in the IoT and software context. Temporal and causal phrases like “begins in response to” must be supported in the specification with clarity regarding whether direct or indirect actions suffice. Use of § 112(f) terms requires detailed structural support to survive invalidity challenges, and even with favorable construction, litigants must prove that the accused device performs each function in a substantially similar way. DoggyPhone’s failure to raise the doctrine of equivalents on appeal further limited its options. The outcome reinforces the importance of precise claim language and robust specification support when drafting interactive system patents.