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 system comprising a shape memory alloy (SMA) element, such as a Nitinol stent, and a delivery device. The purported invention is the use of an SMA element that displays stress-induced martensite (SIM) at body temperature, allowing it to be deformed for delivery and then revert to its original shape upon deployment without temperature changes.

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 entry on Shape Memory Alloys), and Foster (Patent 4,485,805).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued this combination taught every element of the challenged claims. Balko disclosed a medical device with a Nitinol wire coil (memory alloy element) delivered via a hollow sheath (placement device). Kirk-Othmer, a general reference on SMAs, taught that Nitinol inherently exhibits pseudoelasticity, the property underlying stress-induced martensite (SIM). Foster disclosed the use of a standard guidewire for positioning medical devices.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine Balko's Nitinol device with the well-known, inherent properties of Nitinol described in Kirk-Othmer. The claimed SIM behavior was not a special, undiscovered property but an intrinsic characteristic of the material Balko used. Adding a guidewire as taught by Foster was a simple, conventional modification to improve device placement.
    • Expectation of Success: A POSITA would have a high expectation of success, as the combination merely applied the known, predictable properties of Nitinol to a known device (a stent) and utilized a standard component (a guidewire).
    • Key Aspects: This ground mirrored the examiner’s rejection during prosecution, which Petitioner contended was only overcome by a misleading expert declaration.

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 limitation of the challenged claims. Dotter described a Nitinol coil stent delivered via a catheter into a blood vessel. Dotter taught that the coil's transition temperature could be set at or near body temperature. Based on the central technical argument that any Nitinol alloy exhibiting thermally-induced martensite (TIM) inherently also exhibits SIM, Petitioner argued that Dotter's device necessarily displayed the claimed SIM behavior at body temperature when constrained by the delivery catheter.
    • Key Aspects: This argument relied on the principle of inherency, contending that the claimed SIM functionality was a necessary and undisclosed property of the device described in Dotter. Petitioner also presented an alternative ground that, should Dotter be found not to anticipate, the claims are at least obvious over Dotter.

Ground 3: Invalidity for Obviousness-Type Double Patenting - Claims 1-10 and 18-22 are invalid over claims of Jervis ’378.

  • Prior Art Relied Upon: Jervis (Patent 5,597,378).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued the challenged claims of the ’141 patent are patentably indistinct from, and obvious variants of, claims in the earlier, commonly owned ’378 patent to the same inventor. The petition provided a claim chart mapping limitations of the ’141 patent claims to corresponding, nearly identical limitations in claims of the ’378 patent.
    • Motivation to Combine (Rationale): The core of the argument was that the ’141 patent, which expires years after the ’378 patent, represented an improper extension of the patent monopoly for the same invention. Petitioner contended that the minor differences in claim language between the two patents were trivial and would have been obvious to a POSITA.
    • Key Aspects: Petitioner argued that the safe harbor provisions of 35 U.S.C. §121 did not protect the ’141 patent from this challenge. The safe harbor applies to patents arising from a divisional application filed as a result of a restriction requirement, but Petitioner asserted that the ’141 patent issued from a continuation application, not a divisional, and that no restriction requirement was ever finalized.

  • Additional Grounds: Petitioner asserted additional challenges, including that claims 1-5 and 18-22 are anticipated by Cragg (a 1983 radiology article), and that these same claims are obvious over Miyauchi (a Japanese patent publication) in view of Cragg. Further, claims 6-10 were alleged to be obvious over Dotter in view of Miyauchi. These grounds relied on similar inherency and combination rationales.

4. Key Technical Contentions (Beyond Claim Construction)

  • Inherent Nature of SIM in Nitinol: The petition’s central technical premise, supported by an expert declaration, was that all Nitinol alloys capable of thermally-induced martensite (TIM) transformation are inherently also capable of stress-induced martensite (SIM) transformation. Petitioner argued no "special treatment" is required to elicit this property, contrary to the patent owner’s arguments during prosecution.
  • Misleading Prosecution History: Petitioner heavily contended that the ’141 patent was issued based on a false premise. The patent owner overcame the examiner’s obviousness rejection by submitting a declaration from Dr. Middleman, who was presented as an expert on SIM. Petitioner provided deposition testimony from a later litigation where Dr. Middleman allegedly admitted he was not an expert in SIM and could not even recall its meaning, thereby invalidating the basis upon which the patent was granted.

5. Relief Requested

  • Petitioner requests institution of an inter partes review (IPR) and cancellation of claims 1-10 and 18-22 of Patent 6,306,141 as unpatentable.