PTAB

IPR2019-00405

Cardiovascular Systems Inc v. Shockwave Medical Inc

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1. Case Identification

2. Patent Overview

  • Title: SHOCKWAVE BALLOON CATHETER SYSTEM
  • Brief Description: The ’371 patent relates to a balloon angioplasty catheter system that includes a shockwave generator, specifically an arc generator with a pair of electrodes, positioned inside the inflatable balloon. The system is designed to generate mechanical shockwaves to break up or crack calcified stenotic lesions within a patient's blood vessels.

3. Grounds for Unpatentability

Ground 1: Obviousness over Levy, AAPA, and an Electrode-Based Art - Claims 1-6, 11, and 14-16 are obvious over Levy as modified by AAPA in combination with Mantell, Uchiyama, or Willneff.

  • Prior Art Relied Upon: Levy (EP 0571306), Admitted Prior Art Angioplasty (AAPA), Mantell (Application # 2010/0036294), Uchiyama (Japanese Application # S62-275446), and Willneff (German Application DE 3038445 A1).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Levy discloses the core invention of a shockwave angioplasty catheter with a shockwave generator inside a balloon to disintegrate arterial plaque, but using a laser source. Petitioner asserted that AAPA, as described in the ’371 patent itself and other references, teaches the conventional features of an angioplasty catheter, such as an elongated carrier with a guidewire lumen. To provide the claimed electrode-based arc generator, Petitioner pointed to Mantell, Uchiyama, and Willneff. Each of these references allegedly teaches a device with a pair of electrodes inside a fluid-filled balloon on a catheter to generate therapeutic shockwaves.
    • Motivation to Combine: Petitioner asserted a person of ordinary skill in the art (POSITA) would have been motivated to substitute the laser-based shockwave generator in Levy with the electrode-based systems of Mantell, Uchiyama, or Willneff. The primary motivations were to reduce the high cost and mitigate the known overheating issues associated with laser systems. Petitioner argued that prior art, such as Bhatta (Patent 5,152,768), established that laser and electrohydraulic lithotripsy (EHL) systems were well-known, interchangeable alternatives for generating shockwaves to fracture calcified deposits.
    • Expectation of Success: A POSITA would have a reasonable expectation of success because the underlying physical principle for generating the shockwave—creating a plasma bubble in a liquid that rapidly collapses—is identical for both laser and electrode-based systems. Substituting one known shockwave source for another in an existing angioplasty device to achieve a predictable result was presented as a routine design choice.

Ground 2: Obviousness over Willneff, AAPA, and Angioplasty Application Art - Claims 1-4, 6, 11, and 15-16 are obvious over Willneff as modified by AAPA in combination with Levy or Mantell.

  • Prior Art Relied Upon: Willneff (German Application DE 3038445 A1), Admitted Prior Art Angioplasty (AAPA), Levy (EP 0571306), and Mantell (Application # 2010/0036294).

  • Core Argument for this Ground:

    • Prior Art Mapping: In this alternative ground, Petitioner started with Willneff as the primary reference, arguing it teaches the core claimed concept: a catheter with an electrode-pair shockwave generator enclosed within an inflatable balloon for therapeutic applications. Petitioner then asserted that a POSITA would have combined Willneff's generator with the features of a standard AAPA catheter (e.g., a guidewire lumen) to create a device suitable for intravascular procedures. References like Levy and Mantell were cited as evidence that applying shockwaves inside a balloon to treat arterial plaque (angioplasty) was a known and desirable application for such a device.
    • Motivation to Combine: The motivation was to apply Willneff’s known therapeutic tool (an electrode-in-balloon shockwave generator) to the well-established field of angioplasty. A POSITA would have sought to implement Willneff’s system in a standard, modern angioplasty catheter (the AAPA) to improve safety and efficacy for treating calcified lesions, an application explicitly contemplated by references like Levy and Mantell.
    • Expectation of Success: Success would have been expected, as this combination merely involved integrating a known functional component (Willneff's generator) into a standard platform (AAPA catheter) for a known purpose (intravascular lithotripsy), which is a common and predictable engineering exercise.

  • Additional Grounds: Petitioner asserted numerous other obviousness grounds, primarily by adding single, well-known elements to the core combinations above to meet various dependent claim limitations. These included adding Hayes (Patent 7,309,324) for non-compliant balloon material, Duchamp (Application # 2002/0082553) for compliant material, Naimark (Patent 7,569,032) for stress risers on the balloon surface, Beyar (Application # 2006/0190022) for a sensor to detect reflected energy, Bhatta (Patent 5,152,768) for a nozzle that also serves as a reflecting electrode, and Schultheiss (Application # 2007/0239082) for an R-wave detector to synchronize shockwaves with the cardiac cycle.

4. Key Claim Construction Positions

  • Petitioner argued that certain claim terms should be given their plain and ordinary meaning as understood by a POSITA. Two key proposed constructions were:
    • "angioplasty catheter": "a flexible tube configured to be inserted into a blood vessel for use in a medical procedure to widen narrowed or obstructed blood vessels."
    • "angioplasty balloon": "an inflatable sac that is configured to be inserted into a blood vessel for use in a medical procedure to widen narrowed or obstructed blood vessels."
  • These constructions were central to Petitioner’s strategy of applying prior art that described functionally equivalent devices for treating vessel blockages, even if the art did not explicitly use the exact terms "angioplasty catheter" or "angioplasty balloon."

5. Key Technical Contentions (Beyond Claim Construction)

  • A central technical contention underpinning multiple grounds was the direct interchangeability of laser-based and electrode-based shockwave generators. Petitioner repeatedly argued that by the time of the invention, a POSITA would have understood that both systems functioned by creating plasma-induced stress waves in a liquid-filled environment. This functional equivalence, allegedly shown in references like Bhatta, was key to the argument that substituting one for the other (e.g., substituting Levy's laser with Mantell's electrodes) would have been an obvious design choice to reduce cost and avoid thermal issues.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-17 of the ’371 patent as unpatentable under 35 U.S.C. §103.