DCT

2:26-cv-02334

Fuzhou Biwenna E Commerce Co Ltd v. Hyperice IP Subco LLC

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I. Executive Summary and Procedural Information

  • Case Name: Fuzhou Biwenna E-Commerce Co., Ltd. v. Hyperice IP Subco, LLC
  • Parties & Counsel:
  • Case Identification: 2:26-cv-02334, W.D. Wash., 07/02/2026
  • Venue Allegations: Venue is asserted based on Defendants' patent enforcement activity directed at Amazon.com, Inc., which maintains substantial operations in Seattle, Washington, and which resulted in the removal of Plaintiff's product listings.
  • Core Dispute: Plaintiff seeks a declaratory judgment that its foldable massage gun products do not infringe Defendant's patent related to a quick-connect mechanism for massage heads.
  • Technical Context: The technology concerns percussive massage devices, specifically the mechanism used to attach and detach interchangeable massage heads to the device's reciprocating piston.
  • Key Procedural History: Defendants accused Plaintiff's products of infringement through Amazon's intellectual-property complaint process, leading to the removal of Plaintiff's listings. The asserted patent previously survived a Post-Grant Review (PGR2024-00053), in which the Patent Trial and Appeal Board (PTAB) issued a Final Written Decision finding the challenged claims not unpatentable and construed a key claim term.

Case Timeline

Date Event
2013-07-01 '482 Patent - Earliest Priority Date
2024-01-02 '482 Patent - Issue Date
2026-04-20 PTAB Issues Final Written Decision in PGR2024-00053
2026-07-01 Amazon Notifies Plaintiff of Listing Removals
2026-07-02 Complaint for Declaratory Judgment Filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 11,857,482 - "Massage Device Having Variable Stroke Length"

  • Patent Identification: U.S. Patent No. 11,857,482, "Massage Device Having Variable Stroke Length", issued January 2, 2024.

The Invention Explained

  • Problem Addressed: The patent's background section notes that prior art massaging devices can be bulky, hot, noisy, and difficult to use for extended periods of time '482 Patent, col. 1:29-34 The invention specifically addresses the convenience of changing massage heads during use.
  • The Patented Solution: The invention describes a "quick-connect system" that allows a user to rapidly switch between different massaging heads '482 Patent, col. 6:47-56 This system uses magnets in both the piston and the massage head shaft, which attract each other to hold the head "firmly in place" once it is slid into the piston's bore '482 Patent, col. 6:57-67 '482 Patent, col. 7:1-4 A key feature is the ability to perform this change without turning the device off, as the head is designed to "easily slip into the opening... even while the piston... is moving" '482 Patent, col. 7:10-12
  • Technical Importance: A mechanism for quickly swapping massage heads, particularly during operation, enhances the versatility and user experience of a percussive therapy session.

Key Claims at a Glance

  • The complaint identifies independent claims 1, 32, and 34 as being at issue Compl. ¶12
  • Independent Claim 1 (Apparatus):
    • a housing;
    • a piston having a proximal and distal end, with a substantially cylindrical bore at the distal end;
    • a motor configured to cause the piston to reciprocate at a first speed;
    • a drive mechanism controlling a predetermined stroke length; and
    • a "quick-connect system" configured to secure a first massaging head "by a proximal end of the massaging head being slid into the bore "while the piston reciprocates" the predetermined stroke length at the first speed."
  • Independent Claim 32 (Method): Recites a method of assembling a percussive massager including the step of securing a massaging head "by sliding the first massaging head into the bore "while the piston reciprocates"."
  • Independent Claim 34 (Apparatus):
    • a housing;
    • a piston;
    • a motor configured to cause the piston to reciprocate at a first speed;
    • a drive mechanism; and
    • a "quick release connector" at the distal end of the piston, configured to secure a first massaging head ""while the piston reciprocates" a predetermined stroke length at the first speed," where the head has a "substantially cylindrical pocket" to receive the connector.

III. The Accused Instrumentality

Product Identification

  • The complaint identifies "foldable massage gun products with heat and cold functionality" sold by Plaintiff Fuzhou Biwenna E-Commerce Co., Ltd. under the Napre brand, referenced by a series of Amazon Standard Identification Numbers (ASINs) Compl. ¶19 Compl. ¶20

Functionality and Market Context

  • The complaint alleges the Accused Products utilize a "groove-and-protrusion, alignment-and-rotation twist-lock structure" to attach the massage heads Compl. ¶24
  • The attachment process is described as requiring a user to align two protrusions on the piston with two grooves inside the massage head's bore, insert the piston, and then manually rotate the head to lock it in place Compl. ¶26
  • A central allegation is that this entire process must be performed "while the motor is stopped" Compl. ¶26 The complaint cites the product's user guide, which expressly warns: "Do Not Replace Head During Use" and "Always make sure the device is turned off and unplugged before attempting to remove or insert the massage head" Compl. ¶27
  • Figure 1 of the complaint provides an image of the assembled accused product Compl. ¶25, Fig. 1 Figures 2 and 3 detail the components of the twist-lock mechanism, showing the grooves inside the massaging head and the corresponding protrusions on the piston Compl. ¶¶25-26, Figs. 2-3 Figure 5 shows the interior of the heat-and-cold head, illustrating a similar groove structure Compl. ¶31, Fig. 5

IV. Analysis of Infringement Allegations

The complaint seeks a declaratory judgment of non-infringement. The following table summarizes the plaintiff's core argument that its products do not meet a key limitation of the asserted claims.

U.S. Patent No. 11,857,482 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
a quick-connect system ... configured to secure the first massaging head ... by a proximal end of the massaging head being slid into the bore while the piston reciprocates the predetermined stroke length at the first speed. The Accused Products use a twist-lock mechanism that requires the motor to be stopped. A user must align protrusions with grooves, insert the head, and manually rotate it to lock. The user manual explicitly forbids replacing the head during use. ¶¶24, 26, 27, 29 col. 6:52-56
  • Identified Points of Contention:
    • Scope Questions: The central dispute concerns the meaning of "quick-connect system" (and the related "quick release connector") and the functional requirement that the head be secured "while the piston reciprocates". The plaintiff argues its "power-off, twist-lock" mechanism is fundamentally different from the "hot-swappable," magnet-based system described in the '482 Patent Compl. ¶¶24, 29
    • Technical Questions: The case may turn on whether the accused product is technically capable of, or designed for, head attachment during operation. The plaintiff provides evidence, including user manual warnings, to suggest it is not Compl. ¶27 The defendant may argue that the claims only require the capability of such a connection, regardless of user instructions.
    • Doctrine of Equivalents and Estoppel: Plaintiff alleges that finding infringement under the doctrine of equivalents would vitiate the "while the piston reciprocates" limitation Compl. ¶¶38-39 The complaint also raises the possibility that prosecution history estoppel, based on positions taken during the prior PGR proceeding, may bar an equivalents theory Compl. ¶19

V. Key Claim Terms for Construction

  • The Term: "quick-connect system" (Claim 1) / "quick release connector" (Claim 34)

  • Context and Importance: The definition of this term is central to the non-infringement argument. Plaintiff contends its manual twist-lock system, which requires alignment and power-off, does not qualify as "quick." Practitioners may focus on this term because its construction during a prior Post-Grant Review (PGR) proceeding provides significant context.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: A defendant could argue that, in the absence of an explicit definition, the term should be given its plain and ordinary meaning, covering any connection that does not require tools and is relatively fast.
    • Evidence for a Narrower Interpretation: The specification consistently links the "quick-connect system" to the ability to switch heads "without turning off the massaging device" '482 Patent, col. 6:55-56 Most significantly, the complaint states that during the PGR, the PTAB construed the related limitation in claim 34 to mean a structure "that is specifically designed and adapted to quickly and easily secure the first massaging head to the piston regardless of rotational alignment while the piston reciprocates..., not merely capable of doing so" Compl. ¶16 Plaintiff relies on this construction to argue its products do not infringe Compl. ¶18 Compl. ¶30

  • The Term: "while the piston reciprocates"

  • Context and Importance: This functional limitation appears in all asserted independent claims and is the primary basis for the plaintiff's non-infringement theory. The dispute is whether the accused products, which are allegedly designed for power-off head replacement, meet this requirement.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: A defendant might argue the term does not require the connection to always happen while reciprocating, only that the system is configured to allow it.
    • Evidence for a Narrower Interpretation: The plain language suggests the action of securing the head occurs concurrently with the piston's movement. The patent specification describes a system where the head can "easily slip into the opening even while the piston... is moving" '482 Patent, col. 7:10-12 Plaintiff's evidence, including the user manual and the description of the twist-lock mechanism, supports an interpretation that its products are designed specifically not to operate this way Compl. ¶¶26-27 The PTAB's construction requiring a structure "specifically designed and adapted" for this function further supports a narrower reading Compl. ¶16

VI. Other Allegations

  • Indirect Infringement: The complaint preemptively argues against any potential claim of induced infringement. It alleges that because the Accused Products' user manuals instruct users to turn the device off before changing the head, the plaintiff does not encourage or instruct anyone to perform the allegedly infringing act of attaching a head "while the piston reciprocates" Compl. ¶40
  • Willful Infringement: The complaint does not contain allegations of willful infringement against the plaintiff.

VII. Analyst's Conclusion: Key Questions for the Case

  • A core issue will be one of claim construction and issue preclusion: To what extent will the PTAB's construction of a key limitation from the prior PGR proceeding-requiring a structure "specifically designed and adapted" for attachment "while the piston reciprocates" and "regardless of rotational alignment"-be adopted or considered persuasive by the district court?
  • A key evidentiary question will be one of technical and design mismatch: Does the evidence show that the accused "twist-lock" mechanism is merely advised against being used during operation, or is it technically designed in a way that it cannot meet the claim requirement of securing the head while the piston reciprocates, as construed?
  • A central legal question will concern the doctrine of equivalents: If no literal infringement is found, can the patentee successfully argue that a "power-off, twist-lock" system is equivalent to a "power-on, slide-in" system, or would such a theory, as the plaintiff argues, impermissibly vitiate an explicit claim limitation?
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