PTAB

IPR2020-00176

Med El Elektromedizinische GeraETe GesmbH v. Sonova AG

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Percutaneous or transcutaneous access into the body
  • Brief Description: The ’681 patent discloses implantable medical devices for providing access into the body. The challenged claims relate to transcutaneous devices, which use an external part and a subcutaneous part held together by magnetic force across the skin for passage-free connection and signal transfer.

3. Grounds for Unpatentability

Ground 1: Claims 6-9 and 11 are obvious over Dormer in view of Goldberg

  • Prior Art Relied Upon: Dormer (Patent 4,352,960) and Goldberg (Patent 3,766,928).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Dormer disclosed a transcutaneous coupling device for a hearing aid that met nearly all limitations of the challenged claims. Dormer’s device used internal and external magnets for alignment and inductive coils for signal transfer. Dormer explicitly suggested that its magnetic slugs could be replaced by a "ring magnet disposed along the periphery of the pot-type core-half." However, Dormer did not specify the magnetization orientation of this ring magnet. Goldberg, in the context of implantable heart pacers, taught the use of "diametrically magnetized" ring magnets. This specific magnetization orients the north and south poles at opposite ends of a diameter, making them "essentially parallel" to the skin surface when implanted, thus supplying the missing element from Dormer.
    • Motivation to Combine: Petitioner contended that Dormer and Goldberg both addressed magnetic coupling for implantable medical devices. A person of ordinary skill in the art (POSITA), seeking to implement Dormer's suggestion of a ring magnet, would have considered the finite and well-known methods of magnetizing such a component. Goldberg taught a workable, predictable solution—diametrical magnetization—for a similar application. Furthermore, Petitioner argued that Dormer's own teaching of achieving a "single, predetermined alignment" motivated the use of a magnet with laterally separated poles, a characteristic provided by Goldberg's diametrical magnetization.
    • Expectation of Success: A POSITA would have had a high expectation of success. Combining the known technique from Goldberg (diametrical magnetization) with Dormer's device was a straightforward design choice among a few predictable options, yielding no more than the expected result of a securely aligned transcutaneous connection.

Ground 2: Claim 12 is obvious over Dormer and Goldberg in view of Ely

  • Prior Art Relied Upon: Dormer (Patent 4,352,960), Goldberg (Patent 3,766,928), and Ely (Patent 3,749,853).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground builds on the Dormer/Goldberg combination and addresses the additional limitation of claim 12, which requires "at least one conduit extending through the external part." Dormer's external component is part of a hearing aid that includes a microphone. Ely taught an improved microphone system for hearing aids that included a casing defining a "front-to-back acoustic conduit." Petitioner asserted that incorporating Ely's conduit into the microphone casing of Dormer's external hearing aid component would satisfy this final limitation.
    • Motivation to Combine: The primary motivation was to improve the performance of the hearing aid disclosed in Dormer. A POSITA building Dormer’s hearing aid device would have consulted the hearing aid art to implement its microphone. Ely provided an explicit motivation by teaching that its acoustic conduit design resulted in a "simple, compact, low cost" hearing aid that was highly directional and less sensitive to physical obstruction. These are desirable attributes for any hearing aid, including Dormer's.
    • Expectation of Success: The combination was merely the application of a known technique (Ely's conduit) to improve a similar device (Dormer's hearing aid) in a predictable way. A POSITA would have expected that adding a sound conduit to Dormer’s microphone would predictably improve its directionality, as taught by Ely.

Ground 3: Claim 9 is anticipated by Hooven

  • Prior Art Relied Upon: Hooven (Patent 4,676,772).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Hooven, which disclosed a non-invasively adjustable valve for draining cerebrospinal fluid (CSF), taught every element of method claim 9. Hooven's system constituted a method for the "withdrawal of...substances into or from inside a living being" (the CSF). The device included an implanted "magnetic wrench 70" (a permanent magnet) placed under the scalp (the outer surface) with its poles extending parallel to that surface. An "external functional element" (a bar magnet 75) was placed on the scalp over the implanted wrench and was retained by a "magnetic field" to adjust the valve. Petitioner contended this arrangement directly mapped to all limitations of claim 9.

4. Key Claim Construction Positions

  • "in the area of the outer surface": Petitioner argued this term, based on the specification and prosecution history, should be construed to mean "near the skin or the bone adjacent the skin."
  • "inductive, capacitive or other passage-free connection...": Petitioner proposed this phrase refers to "a paired relationship between an implanted element interacting via energy with an external element without a physical passage between the inside and outside of the body."
  • "at least one conduit": Petitioner contended this term should be given its ordinary meaning of "a pipe, tube, or the like, for conveying water or other fluid." This construction was supported by the specification's description of conduits for fluids and the prosecution history, where the term was added to distinguish a prior art reference that had a solid external part.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 6-9, 11, and 12 of the ’681 patent as unpatentable.