DCT

6:23-cv-00632

Wrist SP Biotech LLC v. Masimo Corp

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 6:23-cv-00632, W.D. Tex., 08/25/2023
  • Venue Allegations: Plaintiff alleges venue is proper because Defendant conducts business in the district, has committed acts of infringement in the district, and advertises, markets, and sells products there.
  • Core Dispute: Plaintiff alleges that Defendant’s pulse oximeter sensor infringes a patent related to a pulse oximeter designed for placement on the palm of the hand.
  • Technical Context: The technology concerns non-invasive medical sensors for monitoring blood oxygen saturation, a key biometric indicator in both clinical and remote patient care settings.
  • Key Procedural History: The patent-in-suit is a continuation of an earlier application that matured into U.S. Patent No. 10,448,870, indicating a developed prosecution history for the underlying technology. The complaint does not mention any prior litigation or post-grant proceedings.

Case Timeline

Date Event
2013-05-20 '015 Patent Priority Date
2022-05-17 '015 Patent Issue Date
2023-08-25 Complaint Filing Date

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

U.S. Patent No. 11,331,015 - *"Pulse oximeter sensor"*

  • Patent Identification: U.S. Patent No. 11,331,015, “Pulse oximeter sensor,” issued May 17, 2022.

The Invention Explained

  • Problem Addressed: The patent describes shortcomings with conventional pulse oximeters, particularly those attached to fingertips or worn on the wrist. These designs are allegedly prone to signal disruption from patient movement, such as wrist flexion or finger curling, which can interfere with the accuracy of biometric readings (’015 Patent, col. 2:1-12).
  • The Patented Solution: The invention proposes a pulse oximetry sensor assembly specifically designed for attachment to the "lower half of the palm or the ulnar edge of the palm" (’015 Patent, Abstract; col. 2:13-15). This location is asserted to be more stable and less affected by hand and wrist movements. The sensor uses a light emitting source and a detector to measure light scattered from the surface and underlying tissues of the palm to determine blood oxygenation (’015 Patent, col. 2:15-22). Figure 10 illustrates the placement of the sensor (10) on the ulnar edge of the palm (UEP) (’015 Patent, Fig. 10).
  • Technical Importance: By proposing an alternative anatomical placement site, the invention aims to improve the reliability and portability of pulse oximetry monitoring, making it more effective for "point of care" applications in stable, chronic, or emergency medical settings (’015 Patent, col. 1:28-33).

Key Claims at a Glance

  • The complaint asserts at least independent claim 1 (Compl. ¶18, ¶24).
  • The essential elements of independent claim 1, a method claim, include:
    • Attaching a pulse oximetry sensor assembly to the ulnar edge of a palm, where the assembly comprises several distinct components:
      • An elongate body with a light emitting source and a detector shielded from electromagnetic interference.
      • A skin-contacting film made of elastomeric material with an adhesive surface and openings for the light source and detector.
      • An insulating tape covering the top surface of the elongate body.
      • A means for transmitting signals from the detector to a processing unit.
      • A cover film made of elastomeric material that covers the other layers and has a transparent window for visualization.
    • Transmitting signals to the signal processing unit.
    • Reading output data from the signal processing unit.
  • The complaint reserves the right to assert additional claims (Compl. ¶18, ¶24).

III. The Accused Instrumentality

Product Identification

  • The complaint identifies "Masimo's LNCS-NEO-L-3 Pulse Oximeter" as an exemplary accused product (Compl. ¶16).

Functionality and Market Context

  • The complaint identifies the accused instrumentality as a pulse oximeter but does not provide specific details regarding its technical operation, construction, or method of use (Compl. ¶16). The complaint does not allege facts concerning the product's commercial importance or market position beyond its general availability throughout the United States (Compl. ¶22).

IV. Analysis of Infringement Allegations

The complaint alleges that Defendant infringes at least claim 1 of the ’015 Patent by making, using, selling, and importing the Accused Products (Compl. ¶18). It further states that an attached Exhibit B provides a claim chart detailing this infringement; however, no such exhibit was filed with the complaint (Compl. ¶24). The complaint does not contain a narrative infringement theory describing how the accused device performs the steps of the asserted method claim.

No probative visual evidence provided in complaint.

  • Identified Points of Contention:
    • Method vs. Apparatus: Since claim 1 is a method claim reciting the step of "attaching a pulse oximetry sensor assembly to the ulnar edge of a palm," a central question will be whether Defendant, a product seller, performs these steps or induces its customers to perform them.
    • Anatomical Placement: A key factual question will be whether the accused oximeter is designed for, or its instructions direct, placement on the "ulnar edge of a palm" as required by the claim.
    • Structural Correspondence: The infringement analysis will depend on whether the physical construction of the accused oximeter includes the specific multi-layered structure recited in claim 1, including the "skin-contacting film," "insulating tape," and "cover film with a transparent window."

V. Key Claim Terms for Construction

  • The Term: "ulnar edge of a palm"

    • Context and Importance: This term is central to the patent's stated point of novelty, which is moving the sensor to a more stable anatomical location. The outcome of the infringement analysis may depend heavily on whether the location where the accused product is used falls within the scope of this term.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification frequently refers more generally to "the lower half of the palm or the ulnar edge of the palm," which may support a construction that is not strictly limited to the absolute edge of the hand (’015 Patent, col. 2:13-15).
      • Evidence for a Narrower Interpretation: The patent’s figures, such as Figure 10 and Figure 14, depict very specific placements relative to the fifth digit (5D) and underlying metacarpal (5MC) and carpal bones (’015 Patent, Figs. 10, 14). This could support a narrower construction tied to these specific illustrated embodiments.

  • The Term: "a skin-contacting film formed of elastomeric material"

    • Context and Importance: Practitioners may focus on this term because claim 1 recites a multi-component sensor assembly with distinct layers. Whether the accused product's structure can be mapped to this specific claimed element will be critical for a finding of literal infringement.
    • Intrinsic Evidence for Interpretation:
      • Evidence for a Broader Interpretation: The specification suggests flexibility in materials, noting that various "medical grade polymers, woven or non-woven cloths or fabrics or films" could be used for the skin-protecting pad, a similar layer (’015 Patent, col. 9:53-56). This could suggest the term does not require a highly specific material.
      • Evidence for a Narrower Interpretation: Claim 1 explicitly requires a "skin-contacting film" that is distinct from the "cover film" and "insulating tape." A party could argue that these limitations require separate, discernible layers, and that a product with a more integrated, unitary construction does not meet the claim.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges both induced and contributory infringement. It asserts that Defendant knowingly induces its customers to infringe and contributes to that infringement by supplying the technology, which is alleged to be a material part of the invention and not a staple article of commerce (Compl. ¶19).
  • Willful Infringement: The complaint does not use the word "willful" but includes allegations that may support a finding of willfulness. It alleges Defendant made "no attempt to design around the claims" and "did not have a reasonable basis for believing that the claims of the ‘015 Patent were invalid" (Compl. ¶¶20-21). The prayer for relief requests enhanced damages pursuant to 35 U.S.C. § 284 (Compl. ¶D, p. 6).

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

  1. A core issue will be one of anatomical scope: Does the instructed or intended use of the accused Masimo oximeter involve placement on the "ulnar edge of a palm" as that term is construed in light of the patent's specification and figures?
  2. A second central issue will be one of indirect infringement: Given that the asserted claim is a method claim, the case may turn on what evidence Plaintiff can produce to show that Defendant specifically intended for and instructed its customers to perform the claimed method of attaching and using the sensor in the infringing manner.
  3. A final key evidentiary question will be one of structural correspondence: Does the accused product embody the specific, multi-layered construction required by claim 1, including a distinct "skin-contacting film," "insulating tape," and "cover film," or is there a material difference in its physical structure that places it outside the claim's scope?