DCT

3:19-cv-01100

Masimo Corp v. Sotera Wireless

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Key Events
Complaint

I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 3:19-cv-01100, S.D. Cal., 06/12/2019
  • Venue Allegations: Venue is alleged to be proper as to Sotera based on its regular and established place of business in the Southern District of California. Venue is alleged as to Hon Hai Precision Industry Co., Ltd. ("Foxconn") under 28 U.S.C. § 1391(c)(3).
  • Core Dispute: Plaintiff alleges that Defendants’ ViSi Mobile Monitoring System, a wearable patient monitor, infringes nine patents related to the physical design of body-worn monitors and advanced systems for managing physiological alarms.
  • Technical Context: The technology concerns wearable medical devices that continuously monitor multiple vital signs, designed to increase patient mobility and reduce the burden of "alarm fatigue" on clinicians through intelligent alarm processing.
  • Key Procedural History: The complaint alleges that Defendants had knowledge of the patents-in-suit due in part to previous trade secret misappropriation litigation asserted by Plaintiff against Defendant Sotera, which may be relevant to allegations of willful infringement.

Case Timeline

Date Event
2002-03-25 Earliest Priority Date for ’735, ’300, ’623, ’108 Patents
2008-07-29 Earliest Priority Date for RE244, RE249, RE353 Patents
2010-01-19 Earliest Priority Date for ’994 Patent
2010-04-27 Earliest Priority Date for RE218 Patent
2017-10-17 U.S. Patent No. 9,788,735 Issues
2017-10-24 U.S. Patent No. 9,795,300 Issues
2018-01-23 U.S. Patent No. 9,872,623 Issues
2019-02-05 U.S. Reissue Patent No. RE47,218 Issues
2019-02-19 U.S. Reissue Patent No. RE47,244 Issues
2019-02-19 U.S. Reissue Patent No. RE47,249 Issues
2019-02-26 U.S. Patent No. 10,213,108 Issues
2019-04-09 U.S. Patent No. 10,255,994 Issues
2019-04-16 U.S. Reissue Patent No. RE47,353 Issues
2019-06-12 Complaint Filing Date

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

U.S. Patent No. 9,788,735 - "Body Worn Mobile Medical Patient Monitor"

The Invention Explained

  • Problem Addressed: The patent's background describes how conventional patient monitoring systems are limited by the "patient cable connection between sensor and monitor," which tethers patients, complicates their relocation, and requires expensive upgrades to the installed base of hospital equipment (’735 Patent, col. 2:21-36).
  • The Patented Solution: The invention is a body-worn medical monitor with an ergonomic design intended to minimize cable clutter and tangling. It proposes placing the communication port for a sensor (e.g., a pulse oximeter on a finger) on a side of the monitor's housing that faces the patient's hand when worn on the arm. This configuration is described as creating a shorter and more direct cable path, improving patient comfort and mobility (’735 Patent, Abstract; col. 6:29-45; Fig. 4A).
  • Technical Importance: This design approach sought to make wearable, multi-parameter monitoring more practical in a clinical setting by addressing cable management, a persistent issue affecting patient comfort and workflow efficiency (Compl. ¶12).

Key Claims at a Glance

  • The complaint asserts independent claim 20 (’735 Patent, col. 16:30-67; Compl. ¶28).
  • The essential elements of independent claim 20 include:
    • A body-worn portable patient monitoring device for on-patient and remote monitoring.
    • A pulse oximetry sensor (with a light emitter, detector, and cable) configured to be wrapped around a digit.
    • A blood pressure sensor and an additional sensor arrangement (e.g., for temperature or respiration).
    • A housing secured to the lower arm by a strap, with a display on its front side.
    • A first sensor port positioned on a "face of a first side of the housing" that is configured to face the patient's hand.
    • Specific geometric configurations, including that the cable path is "substantially perpendicular to the face of the first side of the housing" and that the housing's front side is "raised from the strap."
    • Second and third sensor ports for the other sensors.
    • A rechargeable battery, signal processing arrangements to process analog and digital signals from the sensors, and a wireless transmitter.

U.S. Patent No. 9,795,300 - "Wearable Portable Patient Monitor"

The Invention Explained

  • Problem Addressed: The patent addresses the same problem of patient tethering by physical cables in conventional monitoring systems, which restricts patient mobility (’300 Patent, col. 2:21-36).
  • The Patented Solution: The invention is a wearable, battery-powered monitor that serves as a central hub for multiple different types of physiological sensors. It describes a device with a plurality of sensor interfaces capable of receiving different signal types (e.g., analog and digital), processing the data, displaying it locally, and then combining the information "into a single digital word or bit stream" for efficient wireless transmission to a remote monitoring station (’300 Patent, Abstract; col. 11:54-67).
  • Technical Importance: This technology describes a unified platform for untethered, continuous monitoring, allowing data from disparate sensor types to be aggregated on the patient and transmitted wirelessly, enhancing both patient freedom and data accessibility for clinicians (Compl. ¶12).

Key Claims at a Glance

  • The complaint asserts claims 16-20; claim 16 is the lead independent claim (’300 Patent, col. 14:52-16:11; Compl. ¶40).
  • The essential elements of independent claim 16 include:
    • A battery-powered wearable physiological monitoring device.
    • A plurality of sensor communication ports for different sensor types (e.g., pulse oximetry, blood pressure, ECG).
    • A plurality of sensor interfaces, including one configured to receive a first signal with "analog information" and a second to receive a second signal with "digital information."
    • A display on the face of the device.
    • A processor to display measurements on the display.
    • A transmitter configured to "combine information... into a single digital word or bit stream," modulate it, and wirelessly transmit it.
    • A battery making the device portable and wearable by a patient.

U.S. Patent No. 9,872,623 - "Arm Mountable Portable Patient Monitor"

  • Patent Identification: "Arm Mountable Portable Patient Monitor," issued January 23, 2018.
  • Technology Synopsis: This patent describes an arm-mountable monitoring device configured for on-patient monitoring and wireless data transmission. The claims focus on specific physical arrangements of the housing, display, and multiple sensor ports to facilitate ergonomic connection to sensors on a patient's hand and body.
  • Asserted Claims: Claims 1-16 (Claim 1 is independent) (Compl. ¶52).
  • Accused Features: The complaint alleges that the physical configuration of the ViSi Mobile Monitor—including its arm-mountable housing, display, wrist strap, and multiple sensor ports—infringes the ’623 Patent (Compl. ¶55).

U.S. Reissue Patent No. RE47,218 - "Adaptive Alarm System"

  • Patent Identification: "Adaptive Alarm System," issued February 5, 2019.
  • Technology Synopsis: The invention seeks to reduce the frequency of false clinical alarms by employing an adaptive alarm threshold. Instead of a fixed limit, the system determines a patient's baseline physiological value over a period of time and sets a second, adjusted alarm threshold that is offset from this dynamic baseline.
  • Asserted Claims: Claims 1-10 and 12-18 (Claim 1 is independent) (Compl. ¶64).
  • Accused Features: The ViSi Mobile Monitor's hardware processors are accused of infringing by determining oxygen saturation values, and when a value exceeds a first threshold, accessing and applying a second, adjusted alarm threshold for a subsequent period (Compl. ¶67).

U.S. Reissue Patent No. RE47,244 - "Alarm Suspend System"

  • Patent Identification: "Alarm Suspend System," issued February 19, 2019.
  • Technology Synopsis: This technology addresses "alarm fatigue" by enabling parameter-specific alarm delays or suspension periods. The system allows for different physiological parameters (e.g., SpO2 vs. HbCO) to have different, tailored alarm suspension times, corresponding to the different clinical response times required for each parameter.
  • Asserted Claims: Claims 1-2, 6, 8, 9, 13-15, and 18-26 (Claim 1 is independent) (Compl. ¶76).
  • Accused Features: The processors in the ViSi Mobile Monitor are alleged to infringe by initiating a "parameter-specific alarm delay or suspension period" that is selected from a plurality of different possible periods corresponding to different physiological parameters (Compl. ¶79).

U.S. Reissue Patent No. RE47,249 - "Alarm Suspend System"

  • Patent Identification: "Alarm Suspend System," issued February 19, 2019.
  • Technology Synopsis: This patent is directed to a system with parameter-specific "alarm hold" periods. When an alarm condition is detected, the system holds an indication of the alarm for a predetermined, parameter-specific period before activating the audible or visual alert, allowing transient conditions to resolve without triggering an alarm.
  • Asserted Claims: Claims 1-2, 6-9, 13-15, and 18-24 (Claim 1 is independent) (Compl. ¶88).
  • Accused Features: The ViSi Mobile Monitor's processors are accused of infringing by accessing a parameter-specific alarm hold period, holding an alarm indication for that period, and subsequently activating the alarm if the condition persists (Compl. ¶91).

U.S. Patent No. 10,213,108 - "Arm Mountable Portable Patient Monitor"

  • Patent Identification: "Arm Mountable Portable Patient Monitor," issued February 26, 2019.
  • Technology Synopsis: This invention describes an arm-mountable monitor that receives physiological information from a plurality of sensors at different measurement sites via wired connections. It focuses on the physical arrangement of the housing, display, and sensor ports, particularly a first port designed for a thumb-type pulse oximetry sensor with a wire path perpendicular to the side of the housing.
  • Asserted Claims: Claims 1-22 (Claim 1 is independent) (Compl. ¶100).
  • Accused Features: The ViSi Mobile Monitor is accused of infringing based on its configuration as an arm-mountable device with a housing, wrist strap, multiple sensor ports for wired connections, a display, and a wireless transmitter (Compl. ¶103).

U.S. Patent No. 10,255,994 - "Physiological Parameter Alarm Delay"

  • Patent Identification: "Physiological Parameter Alarm Delay," issued April 9, 2019.
  • Technology Synopsis: This patent describes a system for reducing alarm frequency by delaying an alarm notification until the underlying physiological condition persists for a predetermined delay time. The invention also includes a reporting module that can simulate the effect of different delay times on alarm frequency to help clinicians optimize settings.
  • Asserted Claims: Claims 1-8 (Claim 1 is independent) (Compl. ¶112).
  • Accused Features: The ViSi Mobile Monitor's processors are alleged to infringe by detecting an alarm condition and delaying notification for a predetermined time. The system's reporting module is accused of infringing claims related to simulating the effect of different alarm delays (Compl. ¶115).

U.S. Reissue Patent No. RE47,353 - "Alarm Suspend System"

  • Patent Identification: "Alarm Suspend System," issued April 16, 2019.
  • Technology Synopsis: This invention relates to a system that initiates different, parameter-specific alarm suspension periods. After a physiological parameter satisfies an alarm threshold, the system suspends the alarm for a duration corresponding to that specific parameter, and activates the alarm only after that period has passed if the condition persists.
  • Asserted Claims: Claims 1-2, 5-9, 13-15, and 18-25 (Claim 1 is independent) (Compl. ¶124).
  • Accused Features: The processors of the ViSi Mobile Monitor are accused of infringing by determining that an alarm suspension should be initiated for a "parameter-specific alarm suspension period of time" that is different from at least one other such period for another parameter (Compl. ¶127).

III. The Accused Instrumentality

Product Identification

  • Defendants’ ViSi Mobile Monitoring System (Compl. ¶25).

Functionality and Market Context

  • The ViSi Mobile Monitoring System is a wearable, multi-parameter patient monitoring platform designed for continuous vital signs monitoring, including pulse oximetry, pulse rate, respiration rate, blood pressure, and temperature (Compl. ¶25, ¶31). The complaint provides a diagram from the product's user manual illustrating the complete ViSi Mobile Monitoring System as worn by a patient, including the wrist-worn monitor and various cabled sensors attached to the thumb, chest, and upper arm (Compl. p. 8). The system comprises a wrist-worn ViSi Mobile Monitor that serves as a hub for various wired sensors, including a thumb sensor, a blood pressure cuff module, and a chest sensor (Compl. ¶25). Data from these sensors is processed by the monitor and can be displayed locally and transmitted wirelessly via an 802.11b transmitter to a separate "ViSi Remote Viewer" (Compl. ¶31). The complaint alleges that the product line is intended to compete with Plaintiff's products (Compl. ¶9).

IV. Analysis of Infringement Allegations

9,788,735 Infringement Allegations

Claim Element (from Independent Claim 20) Alleged Infringing Functionality Complaint Citation Patent Citation
a body worn portable patient monitoring device configured to provide on-patient and remote monitoring... The ViSi Mobile is a body worn portable patient monitoring device configured to provide on-patient and remote monitoring of patient physiological parameters. ¶31 col. 16:30-33
a pulse oximetry sensor configured to be wrapped around a digit of a patient... comprising: a light emitter... a light detector... and a cable... The ViSi Mobile includes a pulse oximetry sensor configured to be wrapped around a patient’s thumb, which includes a light emitter, a light detector, and a cable. ¶31 col. 16:34-43
a housing configured to be secured to a lower arm of the patient... a strap mountable to the back side of the housing... The ViSi Mobile has a housing and a strap configured to secure the housing to the lower arm of the patient. ¶31 col. 16:44-48
a display positioned on a front side of the housing that is opposite a back side of the housing, the display configured to show a status of the portable patient monitoring device and one or more parameter measurements... The ViSi Mobile includes a display on a front side, opposite a back side, configured to show device status and multiple parameter measurements. ¶31 col. 16:49-55
a first sensor port positioned on a face of a first side of the housing, wherein: the face of the first side of the housing is configured to face toward a hand having the digit... The ViSi Mobile includes a first sensor port positioned on a face of a first side of the housing, which is configured to face toward the hand of the patient under measurement. ¶31 col. 16:59-17:4
the cable is configured to run from the first sensor port, at least part way along a path substantially perpendicular to the face of the first side of the housing... The cable of the thumb sensor is configured to run from the first sensor port along a path substantially perpendicular to the face of the first side of the housing. ¶31 col. 17:10-15
a second sensor port positioned on the housing and configured to provide wired electrical communication with the blood pressure sensor arrangement... The ViSi Mobile includes a second sensor port positioned on the housing to provide wired electrical communication with the blood pressure sensor. ¶31 col. 17:40-43
a transmitter positioned within the housing and configured to: wirelessly transmit a transmit signal including the information indicating the measurements... The ViSi Mobile includes an 802.11b transmitter within the housing configured to wirelessly transmit a signal indicating the measurements of multiple physiological parameters to a separate computing device. ¶31 col. 18:19-27

9,795,300 Infringement Allegations

Claim Element (from Independent Claim 16) Alleged Infringing Functionality Complaint Citation Patent Citation
A battery-powered wearable physiological monitoring device... configured to communicate with multiple types of sensor arrangements... The ViSi Mobile is a battery-powered wearable physiological monitoring device configured to communicate with multiple types of sensor arrangements. ¶43 col. 14:52-56
a plurality of sensor communication ports including: a first... port... with a first type of physiological sensor... a second... port... with a second type... a third... port... with a third type... The ViSi Mobile has three sensor communication ports, each configured for wired communication with a different type of sensor (pulse oximetry, blood pressure, ECG). ¶43 col. 14:57-15:10
a plurality of sensor interfaces including a first sensor interface configured to receive a first signal from a first sensor arrangement..., the first signal including analog information; a second sensor interface configured to receive a second signal from a second sensor arrangement..., the second signal including digital information... The ViSi Mobile includes a first sensor interface to receive a first signal from a pulse oximetry sensor that includes analog information, and a second sensor interface to receive a second signal from a blood pressure sensor that includes digital information. ¶43 col. 15:11-19
a transmitter configured to: combine information indicative of the one or more signals into a single digital word or bit stream... modulate the baseband signal... wirelessly transmit... The ViSi Mobile combines information into a single digital word or bit stream for transmission, encodes it to generate a baseband signal, modulates the signal, and wirelessly transmits it. ¶43 col. 15:35-42
a battery configured to provide power to at least the processor, the display, the transmitter, and the first sensor arrangement... such that the wearable physiological monitoring device is portable and wearable by a patient. The ViSi Mobile includes a single cell Li-ION battery configured to power the processor, display, transmitter, and first sensor, making the device portable and wearable. ¶43 col. 15:43-49
  • Identified Points of Contention:
    • Scope Questions: For the ’735 patent, the claim language recites a highly specific physical arrangement, including a port on a "face of a first side of the housing" and a cable path "substantially perpendicular" to that face. An issue for the court will be whether the physical construction of the accused ViSi Mobile Monitor meets these precise geometric limitations.
    • Technical Questions: For the ’300 patent, claim 16 requires receiving a first signal with "analog information" and a second with "digital information." The complaint alleges the ViSi Mobile's pulse oximetry signal is analog and its blood pressure signal is digital. A technical question will be whether the signals generated by the accused sensors and processed by the accused interfaces meet these specific characterizations as claimed. Further, the method by which the accused device is alleged to "combine information... into a single digital word or bit stream" will likely be a point of technical dispute.

V. Key Claim Terms for Construction

  • The Term: "a face of a first side of the housing" (’735 Patent, Claim 20)

  • Context and Importance: This structural term is central to the claimed ergonomic design of the wearable monitor. The infringement analysis for the ’735 patent may depend on whether this term is construed to cover the specific location of the sensor port on the accused ViSi Mobile Monitor. Practitioners may focus on this term because its definition dictates the required physical placement of a key component.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification does not provide an explicit definition of "face" or "side," which may suggest the terms should be given their plain and ordinary meaning, potentially covering any major external surface of the monitor housing (Compl. ¶31).
    • Evidence for a Narrower Interpretation: The patent's abstract links this port location to the functional goal of creating a path to the digit that is "shorter than any other path from any other side of the housing" (’735 Patent, Abstract). Figures such as FIG. 4A depict the port (414) on a distinct side surface (411) of the housing, separate from the front face containing the display, which could be used to argue for a narrower construction limited to such a non-front/back surface.

  • The Term: "combine information... into a single digital word or bit stream" (’300 Patent, Claim 16)

  • Context and Importance: This term defines how data from multiple, disparate sensors is aggregated before wireless transmission. The technical operation of the accused device's data packaging protocol will be compared against the court's construction of this claim element.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The specification describes using a "multiplexer" that "combines multiple digital word or serial bit streams into a single digital word or bit stream" (’300 Patent, col. 12:1-3). This language may support a construction that encompasses standard data multiplexing techniques used to transmit multiple data sources over a single communication channel, such as packaging different data types into a single 802.11b frame (Compl. ¶43).
    • Evidence for a Narrower Interpretation: A party could argue that the phrase "single... bit stream" requires a more specific form of low-level data serialization or interleaving, rather than merely encapsulating distinct data packets for different parameters within a higher-level transmission protocol. The specification's reference to generating "a baseband signal" from this combined stream could be used to argue for a specific type of signal processing beyond simple packet aggregation (’300 Patent, col. 12:3-4).

VI. Other Allegations

  • Indirect Infringement: For each asserted patent, the complaint alleges active inducement under 35 U.S.C. § 271(b). The allegations are based on Defendants marketing and selling the ViSi Mobile Monitoring System with the knowledge and intent that customers will use it in an infringing manner, supported by the provision of "directions, demonstrations, guides, manuals, [and] training for use" (e.g., Compl. ¶33-34, ¶45-46). The complaint also alleges contributory infringement under 35 U.S.C. § 271(c), stating the accused system's components are material parts of the inventions, are not staple articles of commerce, and are known to be especially adapted for an infringing use (e.g., Compl. ¶35, ¶47).
  • Willful Infringement: The complaint alleges that infringement has been and continues to be willful, deliberate, and intentional for all asserted patents. The basis for this allegation includes Defendants' alleged pre-suit knowledge of Masimo's patents, gained through monitoring Masimo's patent portfolio, hiring former Masimo employees, and as a result of prior trade secret litigation between the parties. The complaint also establishes post-suit knowledge as of the date of filing (e.g., Compl. ¶32, ¶36).

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

This case presents a broad challenge to a competing patient monitoring system, asserting infringement across nine patents covering both physical device design and alarm management software logic. The resolution will likely depend on the court's findings on two central themes:

  • A core issue will be one of structural interpretation: Do the specific, detailed geometric limitations in the asserted hardware patents—such as the precise location, orientation, and cable path of a "first sensor port on a face of a first side of the housing"—read on the physical construction of the accused ViSi Mobile Monitor, or do they represent a distinct design?
  • A key evidentiary question will be one of algorithmic correspondence: Does the software operating on the ViSi Mobile Monitor's processors perform the specific, multi-step logical processes required by the alarm management patents, such as creating adaptive thresholds from dynamic baselines or initiating parameter-specific suspension periods, or is there a fundamental mismatch in the underlying technical operation of the alarm systems?