PTAB

IPR2019-00257

Symmetry Surgical Inc v. Teleflex Medical Inc

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Petition

1. Case Identification

2. Patent Overview

  • Title: Ligating Clip With Integral Penetrating Hook
  • Brief Description: The ’675 patent is directed to a polymeric surgical ligating clip for clamping blood vessels adjacent to connective tissue. The purported improvement over the prior art is a cutting edge, defined by the convergence of two convex surfaces, that extends along the curved outer surface of the clip’s hook member to sever tissue during closure.

3. Grounds for Unpatentability

Ground 1: Claims 1-6 are obvious over Oh II in view of Transue

  • Prior Art Relied Upon: Oh II (Patent 5,062,846) and Transue (European Patent Publication No. EP0201344 A2).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that claim 1 of the ’675 patent is a Jepson claim, with the preamble copied verbatim from claim 1 of Oh II. Therefore, Oh II was argued to disclose every element of the preamble, including a polymeric ligating clip with two legs, a hinge, and a hook member for latching. The only element not disclosed by Oh II is the claimed improvement: a cutting edge on the hook member formed by two convex surfaces. Transue was argued to disclose a polymeric ligating clip with a penetrating member designed to cut tissue, where the penetrating member is formed by the convergence of two convex side surfaces.
    • Motivation to Combine: Petitioner argued that Oh II provides a clear motivation to modify its design. Oh II discloses two embodiments for its cutting mechanism: a preferred version with a protruding sharp point that poses a hazard to surrounding tissue after closure, and an alternate version without the point that has merely "satisfactory" cutting performance. Petitioner contended a person of ordinary skill in the art (POSITA) would be motivated to find a solution that provides effective cutting without the post-closure hazard. A POSITA would look to known designs for tissue-penetrating clips, such as Transue, and substitute Transue’s penetrating member—formed by two convex surfaces—onto the Oh II clip.
    • Expectation of Success: A POSITA would expect this combination to succeed because it involves substituting a known type of cutting element (from Transue) for another (from Oh II) to achieve the predictable result of effective tissue cutting without leaving a hazardous protruding point.

Ground 2: Claims 1-6 are obvious over Oh II in view of Wilson I

  • Prior Art Relied Upon: Oh II (Patent 5,062,846) and Wilson I (Patent 5,554,164).
  • Core Argument for this Ground:
    • Prior Art Mapping: As in Ground 1, Petitioner argued Oh II taught all preamble elements of claim 1. Wilson I, by the same inventor as the ’675 patent, was asserted to disclose a curved surgical knife for cutting tissue. The knife blade in Wilson I is explicitly described as having a non-linear cutting edge formed by upper and lower portions shaped as cubic parabolas, which necessarily have convex surfaces. This design was created to solve the problem of tissue "wisping" (incomplete cutting).
    • Motivation to Combine: The motivation to modify Oh II’s design remained the same: to improve cutting performance while eliminating the post-closure tissue damage risk. Petitioner argued that a POSITA seeking to improve the cutting function of the Oh II clip would look to the field of surgical cutting instruments for known, effective blade designs. Wilson I, which addresses the specific problem of efficiently severing tissue, provided an exemplary design. A POSITA would combine the teachings by incorporating the parabolic, convex-surface cutting edge from Wilson I onto the hook member of the Oh II clip.
    • Expectation of Success: A POSITA would have a reasonable expectation of success in applying the cutting edge geometry from a surgical knife (Wilson I) to a surgical clip (Oh II) to improve the clip’s tissue-severing capabilities, as both devices operate in the same technical field and on the same medium (body tissue).

Ground 3: Claims 1-6 are obvious over Oh II in view of Austin

  • Prior Art Relied Upon: Oh II (Patent 5,062,846) and Austin (Patent 4,283,854).

  • Core Argument for this Ground:

    • Prior Art Mapping: The argument began with Oh II disclosing the preamble of claim 1. Austin was argued to disclose a hunter's knife for skinning and eviscerating animals, which involves cutting tissue. The knife blade in Austin was shown to have a continuous sharp cutting edge formed by two convex surfaces that extend inwardly from the side of the blade.
    • Motivation to Combine: With the same motivation to improve the cutting element of the Oh II clip, a POSITA would consider cutting implements from analogous arts. Petitioner contended that a knife for cutting animal tissue, such as Austin, is analogous art. Austin provided a clear, established example of a cutting edge created by the convergence of two convex surfaces. A POSITA would have been motivated to replace the problematic cutting point of Oh II with the well-understood and effective cutting edge design from Austin.
    • Expectation of Success: The application of a known cutting edge configuration from a tool designed to cut tissue (Austin) to another device intended to cut tissue (the Oh II clip) was argued to be a straightforward design choice with a high probability of yielding predictable results.

  • Additional Grounds: Petitioner further argued that dependent claims 2-6 are obvious because they are word-for-word copies of dependent claims from the Oh II patent. As these claims add only features already present in the primary reference, they are unpatentable for the same reasons as independent claim 1.

4. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-6 of the ’675 patent as unpatentable under 35 U.S.C. §103.