PTAB

IPR2018-00141

Nevro Corp. v. Boston Scientific Neuromodulation Corp.

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1. Case Identification

2. Patent Overview

  • Title: Systems and Methods for Charging a Battery of an Implantable Medical Device
  • Brief Description: The ’933 patent discloses a system for transcutaneously recharging an implantable medical device. The system addresses the problem of overheating in the external charger, particularly when both the charger’s own battery and the implant’s battery are being charged simultaneously, by implementing specific charging algorithms to manage heat generation.

3. Grounds for Unpatentability

Ground 1: Claims 1, 4, 34, 35, and 40 are obvious over Schommer.

  • Prior Art Relied Upon: Schommer (Patent 7,286,881).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Schommer, which discloses an external charger for an implantable device, teaches all elements of the challenged claims. Schommer’s external charger has its own rechargeable battery and is controlled by a microprocessor. Critically, Schommer’s system performs a series of checks, including the battery status of both the external charger and the implantable device, to determine if charging is needed. Petitioner asserted this process meets the key claim limitation of making a "dual determination" about the charge status of both batteries before enabling the charging circuits. Schommer's microprocessor (212) was identified as the claimed "control circuitry" that implements this logic. For dependent claim 4, which adds reducing power during simultaneous charging, Petitioner pointed to Schommer's disclosure of monitoring temperature and limiting energy transfer (e.g., by reducing the duty cycle) to prevent overheating.
    • Motivation to Combine: This ground relied on the knowledge of a person of ordinary skill in the art (POSA) to make minor, obvious modifications to Schommer's disclosed process. Petitioner argued that although Schommer does not explicitly state its battery status checks occur simultaneously, a POSA would have been motivated to perform the checks for both batteries at the same time, before initiating any charging event. This modification would provide full system context before taking action, improving the efficiency and safety of the charging system by reducing delays and ensuring all conditions are known.
    • Expectation of Success: A POSA would have had a high expectation of success in implementing this simultaneous check, as it amounted to a predictable and routine software or firmware modification in the microprocessor-controlled system disclosed by Schommer.

Ground 2: Claim 48 is obvious over Schommer in view of Veselic.

  • Prior Art Relied Upon: Schommer (Patent 7,286,881) and Veselic (Application # 2004/0164708).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground challenged claim 48, which depends on claim 34 and adds limitations requiring the external charger to have a housing, a DC-DC regulator, and a port for receiving a DC voltage generated by the regulator. Petitioner asserted Schommer taught the base system, including the external charger contained within a housing. Veselic was introduced to teach the remaining elements. Veselic discloses a battery charger for portable devices that includes a port (e.g., a USB port) for receiving power from various DC sources and a DC-DC voltage regulator to convert the input to a constant DC output voltage suitable for charging.
    • Motivation to Combine: A POSA would combine Veselic’s teachings with Schommer’s device to improve portability and user convenience. Schommer's charger is a portable device, and Veselic expressly teaches the advantages of using a standardized DC input like USB over proprietary AC power supplies, as it provides travelers with more charging options. Petitioner argued it would have been an obvious design choice to incorporate a universal DC charging port and the necessary DC-DC regulator from Veselic into Schommer’s portable charger to enhance its functionality.
    • Expectation of Success: The combination was presented as simple and predictable. By the ’933 patent’s priority date, incorporating USB ports and DC-DC regulators into portable electronic devices was a well-known, routine practice for designers.

4. Key Claim Construction Positions

  • Petitioner argued that the phrases “implementing an algorithm to controllably enable...” (claim 1) and “programmed to control...” (claim 34) were central to the dispute and required a specific construction based on prosecution history disclaimer.
  • Proposed Construction: These terms require the control circuitry to "decide per an algorithm to enable the battery charging circuit and the transmitter based on the simultaneous, dual determination (and not independent determinations) that both the external battery and the implant battery require charging."
  • Significance: This construction was based on arguments made by the patentee during prosecution to distinguish the claims from the Meadows prior art. The patentee had argued that Meadows made two independent determinations, whereas the invention made a simultaneous, dual determination and acted upon that unified assessment. Petitioner contended this disclaimer narrowed the claim scope, and that the prior art met this narrower construction.
  • Means-Plus-Function: Petitioner also asserted that the "control circuitry" limitations should be construed as means-plus-function elements under §112, ¶ 6. However, Petitioner argued that even under this narrower construction, the prior art (e.g., Schommer's microprocessor 212 executing the disclosed charging process) disclosed the corresponding structure and was therefore obvious.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1, 4, 34, 35, 40, and 48 of the '933 patent as unpatentable.