PTAB

IPR2019-00123

Cook Incorported v. Medtronic Inc

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Medical Devices Using Shape Memory Alloy Displaying Stress-Induced Martensite
  • Brief Description: The ’141 patent discloses medical devices, such as stents, made from a pseudoelastic shape-memory alloy (SMA). The core inventive concept is the use of an SMA that exhibits reversible stress-induced martensite (SIM) behavior at body temperature, which allows the device to be deployed without requiring a change in temperature, unlike prior art devices that relied on temperature-induced martensite (TIM) behavior.

3. Grounds for Unpatentability

Ground 1: Obviousness over Cragg, Pops, and Tanaka - Claims 1-22 are obvious over Cragg in view of Pops and Tanaka.

  • Prior Art Relied Upon: Cragg (a 1983 journal article), Pops (a 1970 journal article), and Tanaka (Patent 4,490,112).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Cragg disclosed the foundational medical device: a coiled nitinol stent delivered via a catheter and guidewire. However, Cragg’s stent was made from an SMA that relied on a temperature-induced (TIM) effect for deployment, which required cooling the device with saline to prevent premature transformation. Petitioner asserted that the key missing limitation—a pseudoelastic SMA displaying reversible stress-induced (SIM) behavior at body temperature—was well-known in the art. Specifically, Pops taught copper-zinc-silicon and copper-zinc-tin SMAs exhibiting the claimed reversible SIM behavior at body temperature (36°C). Similarly, Tanaka taught an implantable medical device (an orthodontic system) using a nitinol alloy that exhibited the same "ultraelastic" (SIM) behavior at body temperature (37°C).
    • Motivation to Combine: Petitioner asserted that the primary motivation to combine the references originated from Cragg itself. Cragg explicitly identified "difficulties" with its TIM-based stent, including its broad transformation temperature range and the inconvenient need to flush the catheter with cold saline. Cragg suggested these problems could be "overcome by the development of a wire with a more precise transition temperature." Petitioner contended a POSITA would have been motivated to replace Cragg's TIM-based alloy with a known SIM-based alloy, such as those disclosed in Pops or Tanaka, to predictably solve these known problems. This substitution would eliminate the need for temperature manipulation, a known "source of substantial inconvenience for physicians," and allow for deployment simply by removing the mechanical restraint of the catheter.
    • Expectation of Success: Petitioner argued a POSITA would have had a high expectation of success because the modification was a simple substitution of one known material (a TIM SMA) for another known material (a SIM SMA) to achieve the predictable result of deployment without temperature change.

Ground 2: Obviousness over Cragg, Tanaka, and Suzuki - Claims 1-22 are obvious over Cragg in view of Tanaka and Suzuki.

  • Prior Art Relied Upon: Cragg (a 1983 journal article), Tanaka (Patent 4,490,112), and Suzuki (a 1982 journal article).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground mirrored the arguments of Ground 1, with Cragg providing the base stent device and Tanaka providing the teaching of a suitable SIM-based alloy. The argument focused on substituting Cragg's TIM nitinol alloy with Tanaka's specifically disclosed SIM nitinol alloy, making the substitution even more direct. Petitioner introduced Suzuki as additional evidence that SIM-based ("super-elastic") nitinol alloys were known for use in implantable medical devices (e.g., orthodontics, clamping bones) and were considered a direct alternative to TIM-based alloys.
    • Motivation to Combine: The motivation was again to solve the known "difficulties" in Cragg. Suzuki provided a powerful, explicit motivation by teaching that SMAs with SIM behavior are "used in medical fields, in the same way as" SMAs with TIM behavior. Suzuki further stated that such alloys were "of major interest for functional materials." Petitioner asserted this language would have directly taught and encouraged a POSITA to make the substitution in Cragg’s device. The fact that the substitution would be between two different types of nitinol—the same base material used by Cragg—provided further motivation.
    • Expectation of Success: Petitioner argued the expectation of success was clear, as the substitution involved swapping one nitinol alloy for another to gain a well-understood and predictable benefit.

4. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-22 of the ’141 patent as unpatentable under 35 U.S.C. §103.