DCT
1:18-cv-00644
Boston Scientific Corp v. Nevro Corp
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Boston Scientific Corp. and Boston Scientific Neuromodulation Corp. (Delaware)
- Defendant: Nevro Corp. (Delaware)
- Plaintiff’s Counsel: Young Conaway Stargatt & Taylor LLP
- Case Identification: 1:18-cv-00644, D. Del., 07/18/2018
- Venue Allegations: Venue is alleged to be proper as Defendant is a Delaware corporation and thus a resident of the district. The complaint also alleges Defendant regularly transacts business and derives substantial revenue from sales within the district.
- Core Dispute: Plaintiff alleges that Defendant’s Senza I and Senza II spinal cord stimulation (SCS) systems infringe nine patents related to critical features of SCS systems, including battery management, device programming, and telemetry.
- Technical Context: The technology at issue involves spinal cord stimulation (SCS) systems, which are implantable medical devices used to manage chronic pain by delivering electrical pulses to the spinal cord.
- Key Procedural History: The complaint notes prior litigation between the parties, with Nevro having sued Boston Scientific in the Northern District of California in 2016. It also alleges that Nevro hired at least 48 former Boston Scientific employees, including individuals named as inventors on several of the patents-in-suit, which is presented as a basis for Defendant’s knowledge of the asserted patents.
Case Timeline
| Date | Event |
|---|---|
| 1999-07-27 | Priority Date for U.S. Patent No. 7,177,690 |
| 1999-07-27 | Priority Date for U.S. Patent No. 7,496,404 |
| 1999-10-01 | Priority Date for U.S. Patent No. 6,381,496 |
| 2000-03-17 | Priority Date for U.S. Patent No. 9,162,071 |
| 2001-12-04 | Priority Date for U.S. Patent No. 6,993,384 |
| 2001-12-04 | Priority Date for U.S. Patent No. 7,822,480 |
| 2002-04-30 | Issue Date for U.S. Patent No. 6,381,496 |
| 2002-10-18 | Priority Date for U.S. Patent No. 7,127,298 |
| 2002-12-03 | Priority Date for U.S. Patent No. 7,853,330 |
| 2006-01-31 | Issue Date for U.S. Patent No. 6,993,384 |
| 2006-01-30 | Priority Date for U.S. Patent No. 8,682,447 |
| 2006-10-24 | Issue Date for U.S. Patent No. 7,127,298 |
| 2007-02-13 | Issue Date for U.S. Patent No. 7,177,690 |
| 2009-02-24 | Issue Date for U.S. Patent No. 7,496,404 |
| 2010-10-26 | Issue Date for U.S. Patent No. 7,822,480 |
| 2010-12-14 | Issue Date for U.S. Patent No. 7,853,330 |
| 2011-01-01 | Nevro launches Senza I System in Europe and Australia |
| 2014-03-25 | Issue Date for U.S. Patent No. 8,682,447 |
| 2015-01-01 | Nevro launches Senza I System in the United States |
| 2015-10-20 | Issue Date for U.S. Patent No. 9,162,071 |
| 2017-01-01 | Nevro receives CE Mark for Senza II System in Europe |
| 2018-01-01 | Nevro receives FDA approval for Senza II System in the United States |
| 2018-07-18 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 7,496,404 - "Rechargeable Spinal Cord Stimulator System," issued February 24, 2009
The Invention Explained
- Problem Addressed: The complaint alleges the patent addresses initiating and controlling power consumption and charging in an implantable pulse generator (IPG) with a rechargeable battery (Compl. ¶37). This suggests a need to manage the power state of a rechargeable implantable device to ensure operational integrity and protect its electronic components.
- The Patented Solution: The invention provides a system with "power source protection circuitry" that monitors the voltage of a rechargeable battery (Compl. ¶37). This circuitry automatically disconnects the battery from the IPG's integrated circuit if the voltage drops below a "power disconnect level" and reconnects it when the voltage rises above a "power reconnect level" after recharging (Compl. ¶38; ’404 Patent, col. 4:20-35). This prevents the device from operating on insufficient power and allows it to safely resume operation once sufficiently charged.
- Technical Importance: This technology is foundational for ensuring the reliability and safety of active implantable medical devices that rely on rechargeable power sources, preventing electronic malfunction due to undervoltage conditions (Compl. ¶1, 14).
Key Claims at a Glance
- The complaint asserts independent claim 7 (Compl. ¶38).
- The essential elements of Claim 7 are:
- A spinal cord stimulation system comprising an implantable pulse generator (IPG).
- The IPG includes a housing, a rechargeable power source within the housing, and an integrated circuit coupled to the power source.
- A processor electrically coupled to the integrated circuit that controls stimulation based on the power source's voltage.
- Power source protection circuitry that controls the electrical connection and disconnection between the power source and the integrated circuit.
- The protection circuitry disconnects the power source if its voltage falls below a power disconnect level and reconnects it if the voltage rises above a power reconnect level.
- The complaint does not explicitly reserve the right to assert dependent claims for this patent.
U.S. Patent No. 7,127,298 - "Switched-Matrix Output for Multi-Channel Implantable Stimulator," issued October 24, 2006
The Invention Explained
- Problem Addressed: The complaint describes a need to drive multiple electrodes using fewer current sources, which serves to reduce the amount of internal circuitry and save space within a multi-channel implantable stimulator (’298 Patent, col. 1:24-34; Compl. ¶50). This addresses the technical challenge of miniaturizing complex, multi-channel implantable devices without sacrificing functionality.
- The Patented Solution: The patent discloses a "switched-matrix output system" that uses groups of switches to connect one or more current sources to a larger number of electrode contacts (’298 Patent, col. 2:1-12). This architecture permits the use of fewer current sources to drive multiple electrodes, with the constraint that "only one-active-electrode subset" can be activated at any given time (Compl. ¶50).
- Technical Importance: This matrix switching approach allows for more compact and efficient designs for multi-channel implantable stimulators, a key factor in medical device manufacturing and patient comfort (Compl. ¶50).
Key Claims at a Glance
- The complaint asserts independent claim 1 (Compl. ¶51).
- The essential elements of Claim 1 are:
- A stimulation output switching system for a multi-channel stimulator having M electrode contacts and N current sources, where M is greater than N.
- N groups of switches, with each group coupled to one of the N current sources.
- Each of the N groups of switches includes M switches, with each of the M switches being uniquely coupled to one of the M electrode contacts.
- A control system for activating the switches, wherein only one active-electrode subset may be activated at any given time.
- The complaint does not explicitly reserve the right to assert dependent claims for this patent.
U.S. Patent No. 8,682,447 - "Apparatus and Method for Determining the Relative Position and Orientation of Neurostimulation Leads," issued March 25, 2014
- Technology Synopsis: The patent covers an apparatus and method for determining and displaying the relative position and two-dimensional orientation of implanted neurostimulation leads (Compl. ¶63). This is achieved by conveying electrical stimulation energy from the IPG into patient tissue (Compl. ¶63).
- Asserted Claims: The complaint asserts at least claim 10, which is directed to an apparatus (Compl. ¶64).
- Accused Features: The Senza Systems are accused of infringing by determining the relative position of implanted leads and displaying their two-dimensional orientation (Compl. ¶64).
U.S. Patent No. 6,993,384 - "Apparatus and Method for Determining the Relative Position and Orientation of Neurostimulation Leads," issued January 31, 2006
- Technology Synopsis: This patent covers technology for determining the relative orientation of implanted leads by measuring impedance vectors between the lead electrodes (Compl. ¶76). The lead's position is inferred by identifying the relative minima and maxima of the measured impedance values (Compl. ¶77).
- Asserted Claims: The complaint asserts at least claims 1 and 24, which are directed to a method and an apparatus, respectively (Compl. ¶76, 77).
- Accused Features: The Senza Systems are accused of infringing by measuring impedance vectors between electrodes to infer and determine the relative position of implanted leads (Compl. ¶77).
U.S. Patent No. 7,853,330 - "Apparatus and Method for Determining the Relative Position and Orientation of Neurostimulation Leads," issued December 14, 2010
- Technology Synopsis: The patent claims a method for determining the relative position of implanted leads by measuring both monopolar and bipolar electrical impedance (Compl. ¶89). These measurements are used to determine the amplitude of a field potential, which in turn is used to determine the relative positions of the leads (Compl. ¶89).
- Asserted Claims: The complaint asserts at least claim 1, a method claim (Compl. ¶90).
- Accused Features: The Senza Systems are accused of infringing by measuring impedance between electrodes to infer the relative position of the implanted leads (Compl. ¶90).
U.S. Patent No. 7,822,480 - "Apparatus and Method for Determining the Relative Position and Orientation of Neurostimulation Leads," issued October 26, 2010
- Technology Synopsis: This patent covers a system that uses a specific On-Off Keying (OOK) modulation technique to transmit control data from an external device to an implantable medical device (Compl. ¶100). The signal distinguishes between logic '0' and '1' bits using different pulse widths, and bit transitions are marked by a change between ON and OFF states (Compl. ¶100).
- Asserted Claims: The complaint asserts at least claim 1, a system claim (Compl. ¶101).
- Accused Features: The Senza Systems are accused of infringing by using this unique OOK modulation to transmit data from the charger to the implantable device (Compl. ¶101, 102).
U.S. Patent No. 6,381,496 - "Parameter Context Switching for an Implanted Device," issued April 30, 2002
- Technology Synopsis: The patent is directed to "context switching," which allows a user to change a currently active set of operational parameters in an implantable device with a different, pre-defined set of operational parameters (Compl. ¶113). This allows for rapid changes in the device's therapeutic output.
- Asserted Claims: The complaint asserts at least claim 1, an apparatus claim (Compl. ¶114).
- Accused Features: The Senza Systems are accused of infringing by providing context switching functionality that allows users to change operational parameters (Compl. ¶114, 115).
U.S. Patent No. 7,177,690 - "Implantable System Having Rechargeable Battery Indicator," issued February 13, 2007
- Technology Synopsis: This patent describes an implantable medical device system with a replenishable power source (e.g., a rechargeable battery) (Compl. ¶126). The system includes an external programmer that can communicate with the implant and includes means for recording battery charging information for later recall, as well as a status indicator for the power source (Compl. ¶126).
- Asserted Claims: The complaint asserts at least claim 1, a system claim (Compl. ¶127).
- Accused Features: The Senza Systems, which include a rechargeable IPG and external patient remotes, programmers, and chargers that store and display battery charging information, are accused of infringement (Compl. ¶127, 128).
U.S. Patent No. 9,162,071 - "Method for controlling telemetry in an implantable medical device based on power source capacity," issued October 20, 2015
- Technology Synopsis: The patent describes a power-saving method for controlling telemetry in an implantable device (Compl. ¶139). The device listens for a first and second type of telemetry, but if the power source voltage falls below a threshold, it discontinues listening for the first type while continuing to listen for the second, thereby conserving energy (Compl. ¶139).
- Asserted Claims: The complaint asserts at least claim 1, a method claim (Compl. ¶140).
- Accused Features: The Senza Systems are accused of infringing by transmitting control data using the claimed telemetry control method based on battery voltage (Compl. ¶140, 141).
III. The Accused Instrumentality
Product Identification
- Nevro Corp.’s Senza I Spinal Cord Stimulation System and Senza II Spinal Cord Stimulation System (Compl. ¶2).
Functionality and Market Context
- The Senza Systems are neuromodulation devices designed to treat chronic intractable pain by delivering electrical stimulation to spinal cord nerves (Compl. ¶15, 17). The systems consist of an implantable pulse generator (IPG) that is rechargeable, percutaneous leads implanted within the spinal column, an external charger, a patient remote control, and a clinician programmer (Compl. ¶15). The IPG is described as producing "current-regulated, charge-balanced, biphasic, capacitively-coupled, rectangular output pulses" (Compl. ¶15). The complaint alleges that the Senza II System is identical to the Senza I system with respect to the accused functionalities (Compl. ¶39, 52, 65, 78, 91, 102, 115, 128, 141).
- The complaint alleges the Senza Systems are direct competitors to Boston Scientific's SCS products and form the basis of a market where only four primary competitors exist (Compl. ¶1, 24).
IV. Analysis of Infringement Allegations
No probative visual evidence provided in complaint.
U.S. Patent No. 7,496,404 Infringement Allegations
| Claim Element (from Independent Claim 7) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a spinal cord stimulation system comprising an implantable pulse generator (IPG), the IPG including a housing... | The Senza Systems are SCS systems that include an IPG with a housing. | ¶38 | col. 5:10-14 |
| a rechargeable power source contained within the housing... | The Senza IPG contains a rechargeable power source. | ¶15, 38 | col. 5:15-16 |
| an integrated circuit contained within the housing and coupled to the rechargeable power source... | The Senza IPG contains an integrated circuit coupled to the rechargeable power source. | ¶38 | col. 5:17-18 |
| a processor electrically coupled to the integrated circuit, wherein the processor is configured to control stimulation delivered by the IPG based on a voltage of the rechargeable power source... | The Senza IPG includes a processor that controls stimulation based on the voltage of the rechargeable battery. | ¶38 | col. 5:19-22 |
| power source protection circuitry that controls the electrical connection and disconnection between the rechargeable power source and the integrated circuit... | The Senza IPG includes power source protection circuitry that controls the connection and disconnection between the battery and the integrated circuit. | ¶38 | col. 5:23-26 |
| wherein the protection circuitry is configured to disconnect the rechargeable power source from the integrated circuit if the voltage of the rechargeable power source falls below a power disconnect level... | The protection circuitry disconnects the rechargeable battery from the integrated circuit if the battery voltage falls below a power disconnect level. | ¶38 | col. 5:27-30 |
| and to reconnect the rechargeable power source to the integrated circuit if the voltage of the rechargeable power source rises above a power reconnect level. | The protection circuitry reconnects the rechargeable battery if the voltage rises above a power reconnect level. | ¶38 | col. 5:31-34 |
- Identified Points of Contention:
- Scope Questions: The analysis may focus on whether the term "power source protection circuitry" can be construed to cover the general "battery management circuitry and methods" alleged to be in the Senza Systems (Compl. ¶39). The dispute could turn on whether the accused circuitry operates based on specific, predetermined "power disconnect" and "power reconnect" voltage levels as required by the claim, or if it employs a different power management scheme.
- Technical Questions: A key evidentiary question will be how the Senza Systems' circuitry actually functions. What evidence does the complaint provide that the accused product performs the specific connect/disconnect functions based on discrete voltage thresholds, rather than, for example, simply entering a general low-power state or issuing a warning to the user?
U.S. Patent No. 7,127,298 Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A stimulation output switching system for a multi-channel stimulator having M electrode contacts and N current sources... wherein M is greater than N... | The Senza I System's IPG includes a stimulation output switching system with multiple electrode contacts and at least one current source (DAC), where the number of contacts exceeds the number of sources. | ¶51 | col. 5:5-8 |
| N groups of switches, wherein each group of the N groups of switches is coupled to one of the N current sources... | The Senza IPG uses a switched-matrix output system. | ¶51 | col. 5:9-11 |
| each of the N groups of switches comprising M switches, and each of the M switches being uniquely coupled to one of the M electrode contacts... | The switched-matrix output activates multiple electrode contacts. | ¶51 | col. 5:12-14 |
| a control system for activating the switches, wherein only one active-electrode subset may be activated at any given time. | The IPG uses the switched-matrix output to permit the use of at least one DAC to output to electrode contacts. | ¶51 | col. 5:15-18 |
- Identified Points of Contention:
- Scope Questions: The central issue may be the construction of "switched-matrix output system." The question for the court will be whether Nevro's use of DACs to activate multiple electrode contacts constitutes the claimed architecture of "N groups of switches" with "M switches" each, or if it represents a technologically distinct approach to multichannel stimulation.
- Technical Questions: The infringement analysis will likely depend on the specific hardware architecture of the Senza IPG. Does it functionally permit "only one active-electrode subset" to be activated at any given time, as the claim requires, or can multiple, independent subsets of electrodes be activated simultaneously? The complaint's allegations are at a high level of functionality and do not detail the specific constraints of the accused system's operation (Compl. ¶51).
V. Key Claim Terms for Construction
For the ’404 Patent:
- The Term: "power source protection circuitry"
- Context and Importance: This term is central to claim 7 and defines the core protective function of the invention. Practitioners may focus on this term because its scope will determine whether Nevro's "battery management circuitry" (Compl. ¶39), which may perform a variety of power-related functions, infringes the specific connect/disconnect function recited in the claim.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent specification may describe the "protection circuitry" in functional terms, suggesting that any circuit that protects the integrated circuit from undervoltage by controlling its connection to the power source could fall within the claim's scope (’404 Patent, Abstract).
- Evidence for a Narrower Interpretation: The detailed description and figures may disclose specific circuit diagrams or embodiments for the "protection circuitry" (’404 Patent, Fig. 4A). Such disclosures could be used to argue that the term is limited to the particular structures shown, or equivalents thereof, rather than any functional equivalent.
For the ’298 Patent:
- The Term: "switched-matrix output system"
- Context and Importance: This term defines the structural arrangement that allegedly allows for a reduction in the number of current sources. The infringement determination for claim 1 hinges on whether the accused Senza IPG embodies this specific system architecture, as opposed to another method of multichannel output control.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent abstract describes the invention as a "switched-matrix output that allows the stimulator to use one or more current sources to drive multiple electrodes" (’298 Patent, Abstract). This broad functional language may support an interpretation that covers various switching arrangements that achieve this result.
- Evidence for a Narrower Interpretation: The detailed description explains that the system "utilizes groups of switches connected between one or more current sources and electrode contacts" (Compl. ¶50; ’298 Patent, Fig. 3). This language, particularly the reference to distinct "groups of switches," might be used to argue for a narrower construction that does not read on different types of multiplexing or output control architectures.
VI. Other Allegations
- Indirect Infringement: For each asserted patent, the complaint alleges induced infringement. The allegations are based on Defendant’s marketing materials, instructional videos, physician and patient manuals, and the in-person guidance provided by Defendant’s clinical and sales staff, which allegedly instruct and encourage users to operate the Senza Systems in an infringing manner (e.g., Compl. ¶40, 53).
- Willful Infringement: The complaint asserts that Nevro's infringement has been willful. This allegation is based on Nevro's alleged actual and constructive knowledge of the Asserted Patents arising from its position as a direct competitor, its alleged practice of monitoring Boston Scientific's patent portfolio, prior litigation between the parties, and its hiring of numerous former Boston Scientific employees, including named inventors on several of the patents-in-suit (Compl. ¶23-33).
VII. Analyst’s Conclusion: Key Questions for the Case
- A central issue will be one of technical implementation: Do the accused Senza Systems' power management and stimulation output circuits operate in a manner that meets the specific structural and functional limitations of the asserted claims, or are there fundamental distinctions in their architecture and operation? The case will likely require a deep technical dive into how the accused products work compared to the patented inventions.
- A key question for willfulness and damages will be the imputation of corporate knowledge: To what extent can the knowledge of former Boston Scientific employees, some of whom are inventors on the patents-in-suit, be legally attributed to Nevro to establish pre-suit knowledge of the patents and deliberate infringement?
- The outcome will likely turn on claim construction: The definitions of key terms such as "power source protection circuitry" (’404 Patent) and "switched-matrix output system" (’298 Patent) will be dispositive. Whether these terms are construed broadly to cover functional equivalents or narrowly to specific disclosed embodiments will likely determine the outcome of the infringement analysis for the lead patents.