Wrist SP Biotech LLC v. Zepp Health Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Wrist SP Biotech, LLC (Delaware)
  • Defendant: Zepp Health Corporation (China)
  • Plaintiff’s Counsel: Ramey LLP
• Case Identification: 6:23-cv-00633, W.D. Tex., 08/25/2023
• Venue Allegations: Plaintiff alleges venue is proper because Defendant is a foreign corporation, making venue appropriate in any judicial district where it is subject to personal jurisdiction.
• Core Dispute: Plaintiff alleges that Defendant’s Amazfit Band 7 smart fitness tracker infringes a patent related to wrist-worn biotelemetry systems.
• Technical Context: The technology concerns wearable health monitoring devices, specifically pulse oximeters that are integrated directly into a wristband for continuous or on-demand measurement.
• Key Procedural History: The complaint does not mention any prior litigation, Inter Partes Review (IPR) proceedings, or licensing history related to the patent-in-suit.

Case Timeline

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

U.S. Patent No. 9,392,970 - "Biotelemetry system", Issued July 19, 2016

The Invention Explained

• Problem Addressed: The patent describes prior art biotelemetry systems as often being "tethered to large monitoring systems" (’970 Patent, col. 1:26-28). It specifically identifies a limitation in existing wrist-worn pulse oximeters where the display module is on the wrist, but the sensor itself is still placed on a fingertip and connected by a tether, which impairs function and utility (’970 Patent, col. 1:55-61).
• The Patented Solution: The invention proposes a portable, and potentially disposable, biotelemetry system where the sensor components are integrated directly into a banding mechanism worn on an extremity like the wrist (’970 Patent, Abstract; col. 2:32-35). This design eliminates the need for a separate, tethered sensor, aiming to improve portability and ease of use, particularly in "point of care" settings (’970 Patent, col. 1:28-31; Fig. 3B).
• Technical Importance: The described approach sought to improve the "portability, functionality and efficiency" of biometric monitoring by creating a fully integrated, untethered wrist-worn device (’970 Patent, col. 1:28-31).

Key Claims at a Glance

• The complaint asserts at least independent claim 1 (Compl. ¶18).
• The essential elements of independent claim 1 include:
  • (a) "two or more disposable pulse oximeter sensor modules," each containing a light emitting source and a photodetector on a substrate.
  • (b) A "banding mechanism" configured to be worn around the wrist, which has an "integral pocket" to receive the sensor modules.
  • (c) A "strut enveloped lengthwise within said banding mechanism" that causes the band to coil around the wrist when bending pressure is applied.
  • (d) A "window area" on the band's skin-contacting surface to allow light to pass to and from the sensor modules.
  • (e) A "signal processing unit" that receives signals from the photodetector to determine blood oxygen levels.
• Plaintiff reserves the right to assert additional claims (Compl. ¶24).

III. The Accused Instrumentality

Product Identification

The complaint identifies "Zepp's Amazfit Band 7" as an exemplary accused instrumentality (Compl. ¶16).

Functionality and Market Context

The complaint alleges the Amazfit Band 7 is a product that Defendant develops, manufactures, and sells in the United States (Compl. ¶4). The complaint itself does not describe the specific technical functionality of the product beyond what can be inferred from the infringement allegation, namely that it is a wrist-worn device that performs pulse oximetry. The complaint suggests the product is sold to consumers through online channels like Amazon.com (Compl. ¶8, n.1). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint states that a claim chart is attached as Exhibit B, which "describes how the elements of an exemplary claim 1 from the ’970 Patent are infringed by the Accused Products" (Compl. ¶24). However, this exhibit was not included with the filed complaint. The complaint’s narrative allegations are limited to the assertion that Defendant directly infringes "at least claim 1" by "making, using, testing, selling, offering for sale and/or importing" the Accused Products (Compl. ¶18). The complaint does not provide specific factual allegations that map features of the Amazfit Band 7 to the individual limitations of claim 1.

Identified Points of Contention

Given the language of claim 1 and the nature of the accused product, the infringement analysis may raise several key questions.

• Scope Questions: A central question will be whether the accused product, a modern consumer smartwatch, can be said to meet the limitation of "two or more disposable pulse oximeter sensor modules" (’970 Patent, col. 8:50). The term "disposable" may suggest a device intended for limited, single-patient, or short-term use, which may be at odds with the integrated, rechargeable nature of a consumer electronic device. Further, it will be a point of contention whether the accused product contains "two or more" such "modules" as claimed.
• Technical Questions: A key factual question will be whether the Amazfit Band 7 contains a "strut enveloped lengthwise" that effectuates coiling and ligature through "bending pressure," as required by claim 1(c) (’970 Patent, col. 8:62-66). The complaint does not provide any evidence that the accused product uses such a specific "snap-bracelet" style closure mechanism, as opposed to a more conventional buckle or clasp.

V. Key Claim Terms for Construction

Term: "a strut enveloped lengthwise within said banding mechanism" (from claim 1(c))

• Context and Importance: This term appears to define a specific mechanical structure for securing the device to the wrist. Practitioners may focus on this term because the infringement analysis could turn on whether the accused product’s band contains an analogous internal component that causes "coiling" or if it uses a different, non-infringing fastening method.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The term "strut" is not explicitly defined, which could support an argument that any internal stiffening or shaping element within the band meets the limitation.
  • Evidence for a Narrower Interpretation: The patent describes this element as part of a "pocketed strut" that, when "bending pressure" is applied, "results in the coiling of the strut and ligature of the banding mechanism around the wrist" (’970 Patent, col. 8:62-66, col. 8:1-4). This language could support a narrower construction limited to a self-coiling or "snap-bracelet" type of structure.

Term: "disposable pulse oximeter sensor modules" (from claim 1(a))

• Context and Importance: The "disposable" nature of the sensor modules is a critical limitation. Infringement will likely depend heavily on whether the integrated sensor package of a consumer smartwatch can be considered "disposable."
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent does not provide a specific lifespan or material definition for "disposable," potentially allowing an argument that any non-permanent or replaceable component qualifies. The specification notes the system may be used for extended periods of "more than a year," which might argue against a strictly single-use definition (’970 Patent, col. 3:14-15).
  • Evidence for a Narrower Interpretation: The specification describes the system as being useful in settings where it can be included in a "standard first aid kit" for laypersons to use (’970 Patent, col. 3:19-22). The specification also highlights features like being "optionally wireless, disposable and modular" (’970 Patent, col. 2:52-53). This context may support a narrower interpretation tied to low-cost, replaceable components intended for clinical or short-term field use, rather than a durable, rechargeable consumer product.

VI. Other Allegations

Indirect Infringement

The complaint alleges that Defendant induces infringement by its customers and is liable for contributory infringement (Compl. ¶19). The allegations are based on Defendant supplying the technology with knowledge of the ’970 patent, thereby enabling its customers to infringe. The complaint does not plead specific facts demonstrating intent, such as references to user manuals or advertising that instruct on an infringing use.

Willful Infringement

Plaintiff alleges that "Defendant has made no attempt to design around the claims" and "did not have a reasonable basis for believing that the claims of the ’970 Patent were invalid" (Compl. ¶¶20-21). These allegations form the basis for a claim of willful infringement, though no facts regarding pre-suit knowledge are asserted.

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

1. A core issue will be one of definitional scope: Can the claim term "disposable pulse oximeter sensor modules" be construed to read on the integrated, rechargeable, and long-term-use sensor system found in a consumer product like the Amazfit Band 7? The resolution of this question may be dispositive for infringement.

2. A key evidentiary question will be one of structural presence: Does the accused product's band incorporate the specific "strut" mechanism that causes "coiling" as recited in claim 1? As the complaint provides no details on the product's actual construction, this will be a central factual dispute to be resolved during discovery.