PTAB

IPR2013-00269

Lombard Medical Technologies v. Medtronic Inc

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1. Case Identification

2. Patent Overview

  • Title: Medical Devices Incorporating SIM Alloy Elements
  • Brief Description: The ’141 patent discloses a medical device, such as a stent, comprising a shape memory alloy (SMA) element capable of displaying stress-induced martensite (SIM) at body temperature. The device also includes a placement tool, such as a catheter, for delivering the SMA element into a mammal.

3. Grounds for Unpatentability

Ground 1: Obviousness over Balko, Kirk-Othmer, and Foster - Claims 1-10 and 18-22 are obvious over Balko in view of Kirk-Othmer and Foster.

  • Prior Art Relied Upon: Balko (Patent 4,512,338), Kirk-Othmer (a 1982 encyclopedia chapter on shape memory alloys), and Foster (Patent 4,485,805).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Balko disclosed a medical device with a Nitinol (a type of SMA) wire coil stent delivered via a sheath, which met nearly all limitations of the independent claims. Balko’s coil was taught to have a transition temperature below body temperature and exhibit thermally-induced martensite (TIM). Petitioner contended that, based on fundamental thermodynamic principles, any Nitinol alloy exhibiting TIM inherently also exhibits stress-induced martensite (SIM) and pseudoelasticity, as claimed. Kirk-Othmer was cited as general knowledge in the art, teaching the inherent pseudoelastic and shape memory properties of Nitinol. Foster was cited for its disclosure of using a guide wire to insert a medical device, a feature missing from Balko but a well-known technique.
    • Motivation to Combine: A POSITA would combine these references to improve the functionality of Balko's device. Specifically, a POSITA would have been motivated to utilize the known properties of Nitinol described in Kirk-Othmer to optimize the performance of Balko’s stent and would have found it obvious to incorporate a standard guide wire, as taught by Foster, for more precise placement.
    • Expectation of Success: A POSITA would have had a high expectation of success because the combination involved applying well-understood, predictable properties of Nitinol (from Kirk-Othmer) and incorporating a conventional component (Foster's guide wire) into an existing device (Balko's stent).

Ground 2: Anticipation by Dotter - Claims 1-10 and 18-22 are anticipated by Dotter.

  • Prior Art Relied Upon: Dotter (Patent 4,503,569).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Dotter, which was considered during prosecution, disclosed every element of the challenged claims. Dotter described a Nitinol coil graft prosthesis delivered via a catheter into a blood vessel. The coil was disclosed to exhibit thermal transformation (TIM), and Dotter taught that its transition temperature could be manipulated over a wide range, including body temperature. Petitioner argued that Dotter’s Nitinol coil, because it exhibits TIM, inherently possesses the claimed properties of pseudoelasticity and the ability to display SIM at body temperature when constrained by the delivery catheter. Dotter also disclosed the use of an inner guide catheter, satisfying the guide wire limitation.

Ground 3: Obviousness over Miyauchi and Cragg - Claims 1-5 and 18-22 are obvious over Miyauchi in view of Cragg.

  • Prior Art Relied Upon: Miyauchi (Japanese Patent Publication No. S58-46923) and Cragg (a 1983 article in Radiology).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Miyauchi, which was not considered during prosecution, disclosed a Nitinol manipulation tool for insertion into a body cavity that explicitly could be transformed to its martensitic state by either temperature or stress. This directly taught the core concept of stress-induced martensite at body temperature. Cragg disclosed a Nitinol coil stent delivered via catheter, which could be repositioned by withdrawing it back into the catheter—a process that inherently induces stress to deform the alloy.
    • Motivation to Combine: A POSITA would have found it obvious to apply Miyauchi’s clear teachings on using stress to transform a Nitinol device to the clinically relevant Nitinol coil stent disclosed by Cragg. Both documents relate to shape memory alloy devices for use in body cavities, making the combination straightforward for improving device placement and functionality.
    • Expectation of Success: The combination was a simple application of a known principle (stress-induced transformation from Miyauchi) to a known device (the Cragg stent), ensuring a high expectation of success.

  • Additional Grounds: Petitioner asserted that claims 1-5 and 18-22 are anticipated by Cragg; that claims 6-10 are obvious over Dotter in view of Miyauchi; and that all challenged claims are invalid for obviousness-type double patenting over Patent 5,597,378.

4. Key Technical Contentions (Beyond Claim Construction)

  • Petitioner’s primary technical contention, central to all grounds, was that the Patent Owner overcame prosecution rejections by misrepresenting the properties of Nitinol. The Patent Owner relied on a declaration from an expert, Dr. Middleman, who stated that special, expensive treatment was required to make Nitinol exhibit SIM. Petitioner argued this was false, presenting expert testimony that any Nitinol capable of TIM inherently exhibits SIM as a matter of fundamental thermodynamics. Petitioner further submitted a later deposition of Dr. Middleman from an unrelated litigation in which he admitted he was not an expert in SIM and could not recall what it was, thereby invalidating the basis on which the claims were allowed.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-10 and 18-22 of the ’141 patent as unpatentable.