Nevro Corp v. Boston Scientific Neuromodulation Corp

1. Case Identification

• Case #: IPR2019-01313
• Patent #: U.S. Patent No. 7,496,404
• Filed: July 15, 2019
• Petitioner(s): Nevro Corp.
• Patent Owner(s): Boston Scientific Neuromodulation Corp.
• Challenged Claims: 1-5, 7, 9, 11-17

2. Patent Overview

• Title: Rechargeable Spinal Cord Stimulation System with Battery Management
• Brief Description: The ’404 patent describes a rechargeable spinal cord stimulation (SCS) system used for treating chronic pain. The system includes an implantable pulse generator (IPG) with a replenishable power source, an external charger for transcutaneous recharging, and integrated battery management and protection circuitry.

3. Grounds for Unpatentability

Ground 1: Claims 1-5 are obvious over Holsheimer, Munshi, Schulman, and Wang.

• Prior Art Relied Upon: Holsheimer (Patent 5,501,703), Munshi (Patent 5,411,537), Schulman (Patent 4,197,850), and Wang (Patent 5,702,431).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Holsheimer taught a foundational SCS system with an IPG and a detachably connected electrode array. To address the known problem of limited battery life, a person of ordinary skill in the art (POSA) would have incorporated the transcutaneous recharging system taught by Munshi, which discloses a rechargeable battery in a bioimplantable device. To ensure safe operation and prevent battery damage from over-discharge, a POSA would have added the power protection circuitry from Schulman, which teaches disconnecting stimulation circuitry at low voltage levels and re-enabling it upon recharge. Finally, to ensure efficient energy transfer, a POSA would have incorporated the alignment circuitry taught by Wang, which provides a feedback mechanism to indicate proper coil alignment.
  • Motivation to Combine: The primary motivation was to improve upon Holsheimer's basic SCS system by incorporating well-known, desirable features to create a more robust and user-friendly product. This involved solving the known limitations of limited battery life (via Munshi), the need for power management in rechargeable systems (via Schulman), and the need for efficient coil alignment for transcutaneous charging (via Wang).
  • Expectation of Success: A POSA would have had a high expectation of success because all references relate to analogous implantable electrical stimulation systems. Combining these known solutions—rechargeability, power protection, and alignment feedback—involved applying predictable technologies to achieve their expected functions in a single device.

Ground 2: Claims 7, 9, and 13-17 are obvious over Holsheimer, Munshi, and Schulman.

• Prior Art Relied Upon: Holsheimer (Patent 5,501,703), Munshi (Patent 5,411,537), and Schulman (Patent 4,197,850).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground asserted that the combination of Holsheimer and Munshi teaches the basic rechargeable SCS system, and Schulman was added to teach the specific power management and protection features recited in claims 7, 9, and 13-17. Petitioner contended that Schulman explicitly discloses monitoring battery voltage and issuing commands to manage stimulation, such as disconnecting circuitry when voltage drops below a selected level and reconnecting it when the voltage rises after recharging. Claim 7’s limitations for a processor that stops and restarts stimulation based on voltage thresholds were argued to be directly taught by Schulman’s protection circuitry designed for power conservation and preserving data in volatile memory.
  • Motivation to Combine: A POSA implementing the rechargeable system of Holsheimer/Munshi would have recognized the need to protect the device from the potential dangers of a fully discharged battery. Schulman directly addressed this problem by providing a system to power down non-essential circuits at low voltage and reinitiate operation safely upon recharge, making it an obvious addition for safety and reliability.

Ground 3: Claims 11-12 are obvious over Holsheimer, Munshi, Schulman, and Rutecki.

• Prior Art Relied Upon: Holsheimer (Patent 5,501,703), Munshi (Patent 5,411,537), Schulman (Patent 4,197,850), and Rutecki (Patent 5,330,515).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the prior combinations by adding Rutecki to teach features recited in claims 11 and 12. Specifically, Rutecki was cited for teaching an "external trial stimulator (ETS)" used for pre-implantation evaluation and a more detailed programming system including a handheld "programming wand" and an associated computer (clinician programmer). While Holsheimer taught a basic external programmer, Petitioner argued that Rutecki provides the specific implementation of a trial stimulator and a two-part programming system as claimed.
  • Motivation to Combine: The motivation was to incorporate industry-standard clinical practices into the core rechargeable SCS system. A POSA would have known that testing therapy efficacy with an ETS prior to permanent implantation was a standard and desirable step. Likewise, providing a sophisticated clinician programmer to work with a handheld wand was a known method for managing device parameters, making Rutecki's teachings an advantageous addition.

4. Key Claim Construction Positions

• "alignment between the primary and secondary coils" (Claim 1): Petitioner argued this term did not require a specific construction for the IPR. It asserted that the prior art discloses the limitation under both the Patent Owner’s proposed narrow construction (“...reflected impedance is at a minimum”) and the broader construction previously adopted by the Board in a related case (“...achieving a relative position...to permit energy transfer”).
• "means for using household AC power..." (Claim 3): Petitioner construed this as a means-plus-function term under §112(6). The function is "using household AC power to charge up the rechargeable power source in the power source charger." The corresponding structure was identified as a charging base station, an AC power line, and their equivalents.
• "means for non-invasively recharging..." (Claim 15): Petitioner also construed this as a means-plus-function term. The function is "non-invasively charging the replenishable power source." The corresponding structure was identified as an external power source, a power amplifier, an external coil, an internal coil, and their equivalents.

5. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-5, 7, 9, and 11-17 of the ’404 patent as unpatentable under 35 U.S.C. §103.