Encelion LLC v. Mobvoi Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Encelion LLC (New Mexico)
  • Defendant: Mobvoi, Inc. (Cayman Islands)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 2:25-cv-01106, E.D. Tex., 11/06/2025
• Venue Allegations: Venue is alleged to be proper because Defendant is a foreign corporation, and has committed acts of patent infringement in the district, causing harm.
• Core Dispute: Plaintiff alleges that Defendant infringes a patent related to wearable pulse sensors that use magnetic fields to measure arterial expansion and infer a user's hydration status.
• Technical Context: The technology relates to non-optical methods for monitoring physiological signals like heart rate in wearable devices, a significant area of innovation in the health and fitness technology market.
• 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. 11,471,072 - "Pulse sensor, system, and method for using a pulse sensor"

• Patent Identification: U.S. Patent No. 11,471,072, "Pulse sensor, system, and method for using a pulse sensor," issued on October 18, 2022.

The Invention Explained

• Problem Addressed: The patent describes the need to infer a person's hydration status non-invasively. It notes that during dehydration, blood viscosity increases, which alters the characteristics of a person's pulse wave, specifically the relationship between the main systolic peak and the secondary diastolic hump from wave reflection (’072 Patent, col. 1:16-45). Conventional sensors may struggle to accurately capture these nuanced changes, especially while rejecting spurious measurements caused by the user's general movement (’072 Patent, col. 2:1-4).
• The Patented Solution: The invention proposes a pulse sensor that uses a magnet placed over an artery and a magnetometer to detect its movement (’072 Patent, Abstract). As the artery expands and contracts with each pulse, the magnet tilts, causing a measurable change in its magnetic field (’072 Patent, col. 7:42-53; Fig. 2B). The system analyzes this signal to determine not only the pulse rate but also a "modulation" value, defined as the ratio of the systolic peak to the diastolic hump (’072 Patent, col. 16:46-51). By tracking this modulation and pulse rate against a historical baseline, the system can infer dehydration and output a prompt to the user, for example, to drink fluids (’072 Patent, col. 1:59-63).
• Technical Importance: This magnetic-based approach provides an alternative to common photoplethysmography (PPG) optical sensors, potentially offering different performance characteristics for measuring nuanced pulse wave dynamics relevant to physiological states like hydration (’072 Patent, col. 1:5-15).

Key Claims at a Glance

The complaint does not specify which claims are asserted, stating only that infringement is of "at least the exemplary claims of the '072 Patent also identified in the charts incorporated into this Count" via an unattached exhibit (Compl. ¶11). Claim 1 is the first independent claim of the patent.

• Independent Claim 1: A non-transitory computer readable medium with instructions to perform a method comprising:
  • Measuring a physical periodic motion of a peripheral artery, with each motion including a "modulation" and a pulse rate, where modulation corresponds to a difference or ratio between systolic and diastolic humps.
  • Receiving the modulation and pulse rate with a microcontroller and saving them to a buffer memory as a history.
  • Determining at least one "limit" (for modulation, pulse rate, or blood flow) from the history.
  • Writing the limit to a non-transitory computer readable medium.
  • Comparing one or more new measured instances of modulation and pulse rate to the limit.
  • Outputting a prompt to a user if the measured instances fall outside the limit.

III. The Accused Instrumentality

Product Identification

The complaint does not name any specific accused products in its main body (Compl. ¶¶1-19). It refers to "Exemplary Defendant Products" that are identified in charts incorporated by reference from an exhibit that was not attached to the publicly filed complaint (Compl. ¶11, ¶16).

Functionality and Market Context

The complaint does not provide sufficient detail for analysis of the accused instrumentality's specific functionality or market context.

IV. Analysis of Infringement Allegations

The complaint references, but does not include, claim chart exhibits that detail its infringement theories (Compl. ¶16, ¶17). The narrative allegations state that the unspecified "Exemplary Defendant Products" practice the technology of the ’072 Patent, satisfying all elements of the asserted claims either literally or under the doctrine of equivalents (Compl. ¶11, ¶16). The complaint alleges that Defendant directly infringes by making, using, and selling these products, and also by having its employees internally test them (Compl. ¶11-12). No probative visual evidence provided in complaint.

Because the complaint provides no specific mapping of accused functionality to claim elements, a detailed points-of-contention analysis is not possible. The core of the dispute will depend on evidence introduced during discovery regarding how the accused products' sensors operate and how their software processes physiological data to generate user alerts.

V. Key Claim Terms for Construction

• The Term: "modulation"

• Context and Importance: This term is central to the patent's asserted point of novelty—using a specific feature of the pulse waveform to infer hydration. The definition of "modulation" will determine whether the data processing in the accused products performs the function required by Claim 1.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: Claim 1 defines the term as corresponding "to a difference or ratio between systolic peak and diastolic hump." (’072 Patent, col. 21:24-28). This use of "or" could support a construction that covers any algorithm calculating either the difference or the ratio.
  • Evidence for a Narrower Interpretation: The specification repeatedly links this modulation to a specific technical goal: inferring hydration based on changes in blood viscosity (’072 Patent, col. 1:39-45). A defendant may argue that the term should be limited to calculations performed for this purpose, and that Figure 10, which explicitly labels the systolic maximum (1004) and diastolic hump (1006), illustrates the specific waveform features that must be measured (’072 Patent, col. 16:46-51).

• The Term: "limit"

• Context and Importance: The entire alerting function of the claimed method depends on comparing measured data to a "limit." Whether the defendant's alert thresholds or logic fall within the scope of this term is a critical infringement question.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The term is used broadly in independent Claim 1, simply requiring the system to "determin[e] ... at least one limit" from historical data (’072 Patent, col. 21:31-35). This suggests any form of dynamically generated threshold could suffice.
  • Evidence for a Narrower Interpretation: Dependent claims provide specific methods for calculating this limit, such as setting it at "two standard deviations greater than a mean function value" (Claim 4) or as a "derivative of the slope times a constant" (Claim 5) (’072 Patent, col. 22:15-34). A defendant might argue these specific embodiments should inform a narrower construction of "limit" in the independent claim, requiring more than a simple, static threshold.

VI. Other Allegations

• Indirect Infringement: The complaint alleges induced infringement, stating that Defendant distributes "product literature and website materials" that instruct and encourage end users to use the accused products in a manner that directly infringes the ’072 Patent (Compl. ¶14-15).
• Willful Infringement: The basis for willfulness appears to be post-suit knowledge. The complaint alleges that service of the complaint itself provides Defendant with "actual knowledge of infringement," and that any continued infringement thereafter is willful (Compl. ¶13-14). No pre-suit knowledge is alleged.

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

1. Evidentiary Proof of Operation: A primary question will be factual and technical: What specific algorithms do the accused products use to analyze pulse data and generate alerts? Plaintiff will need to establish through discovery that the accused systems measure a waveform feature corresponding to the patent's "modulation" and compare it against a dynamically derived "limit" as claimed.
2. Definitional Scope: The case may turn on claim construction, specifically whether the term "modulation," rooted in the patent's detailed description of systolic and diastolic humps for hydration monitoring, can be construed to cover the particular waveform analytics used in Defendant's products.
3. Indirect Infringement and Intent: A key issue for the inducement claim will be whether Defendant's user manuals and marketing materials provide instructions that, when followed, necessarily result in the performance of all steps of the asserted method claims, and whether Defendant possessed the requisite intent for such inducement.