PTAB

IPR2015-00640

Freedom Innovations LLC v. Blatchford Products Ltd

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Prosthetic Ankle Joint Mechanism
  • Brief Description: The ’991 patent describes a prosthetic foot and ankle assembly that uses a hydraulic piston-and-cylinder mechanism to provide continuously damped resistance to ankle flexion over a fixed range of dorsi-plantar motion.

3. Grounds for Unpatentability

Ground 1: Claims 1 and 3-8 are obvious over Koniuk in view of Mortensen

  • Prior Art Relied Upon: Koniuk (Patent 6,443,993) and Mortensen (Patent 4,212,087).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Koniuk, a self-adjusting prosthetic ankle, disclosed nearly every limitation of the challenged claims. Koniuk taught a prosthetic foot and ankle assembly with a fixed range of motion, a hydraulic damping mechanism, and mechanical abutments acting as flexion limiters. Petitioner contended Koniuk’s joint mechanism provided resistance predominantly through hydraulic damping, as required by dependent claim 7.
    • Motivation to Combine: Petitioner asserted that while Koniuk suggested the use of a single hydraulic cylinder, it did not explicitly detail a linear piston assembly with two independently adjustable valves. Mortensen, which taught a hydraulic control for a prosthetic leg, was alleged to supply this missing element by disclosing a single, linear hydraulic cylinder with two one-way adjustable valves to independently preset resistance for flexion and extension. A POSITA would have been motivated to implement Koniuk's suggested single-cylinder design using Mortensen's well-known and predictable valve system to achieve adjustable damping. Mortensen also taught a resilient O-ring for cushioning, relevant to claims 5 and 8.
    • Expectation of Success: A POSITA would have had a high expectation of success because both references related to hydraulic control in prosthetics, and combining a known valve system (Mortensen) with a known ankle joint (Koniuk) constituted routine design.

Ground 2: Claims 1-9 are obvious over Townsend in view of Mortensen

  • Prior Art Relied Upon: Townsend (Application # 2004/0117036) and Mortensen (Patent 4,212,087).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Townsend disclosed a prosthetic foot and ankle with a two-way adjustable hydraulic piston-cylinder assembly providing continuous damping. Townsend taught two variable controls for presetting dorsi-flexion and plantar-flexion damping resistance, flexion limiters in the form of mechanical abutments, and a conventional pyramid alignment interface (addressing dependent claims 2 and 9).
    • Motivation to Combine: To the extent Townsend's disclosure of two adjustable control valves was deemed insufficient, Petitioner argued a POSITA would have looked to Mortensen. Mortensen taught a distinct, separate bypass adjustable valve system for prosthetic limbs. A POSITA would have been motivated to combine Mortensen's established valve system with Townsend's ankle to improve the granularity of hydraulic control, a known design goal in the art. Further, Mortensen’s teaching of a resilient O-ring was argued to render the "resilient elastomeric pad" of claim 8 obvious.
    • Expectation of Success: Success would have been expected, as the combination involved improving one prosthetic device (Townsend) with a known functional component from another (Mortensen) to achieve a predictable enhancement in performance.

Ground 3: Claims 1 and 3-8 are obvious over Gramnas in view of Mortensen

  • Prior Art Relied Upon: Gramnas (Application # 2004/0044417) and Mortensen (Patent 4,212,087).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Gramnas disclosed an adjustable hydraulic ankle joint featuring a two-chamber piston-cylinder that provided "stepless" hydraulic damping within a range fixed by mechanical end-stops. The resistance to flexion in Gramnas's joint mechanism was argued to be entirely hydraulic. Gramnas also satisfied the claim 3 limitation requiring the flexion axis to be located anterior to the piston's central axis.
    • Motivation to Combine: Petitioner asserted Gramnas did not explicitly teach two independently adjustable valves for presetting resistance based on user needs. Mortensen, however, taught a two-valve system allowing a user to control and adjust flexion resistance. A POSITA would have been motivated to incorporate Mortensen's adjustable valve system into the Gramnas device to achieve "individual adaption" of the prosthesis for users of different weights or for different activities, a recognized objective in the field.
    • Expectation of Success: The combination was presented as predictable, as it involved adding a known adjustability feature (from Mortensen) to a hydraulic ankle joint (Gramnas) to provide user customization, a routine step in prosthetic design.
  • Additional Grounds: Petitioner asserted additional obviousness challenges, including combinations of Koniuk, Mortensen, and Hellberg (Patent 6,398,817) for claim 2, and various combinations including Townsend to address claim 9, which relied on similar rationales for combining known pyramid alignment interfaces and piston arrangements.

4. Key Claim Construction Positions

  • "said resistance" (claim 7): Petitioner proposed this term be construed as "resistance to ankle flexion provided by the joint mechanism." This construction was argued to be necessary to distinguish the resistance provided by the claimed hydraulic mechanism from other potential sources of resistance, such as a resilient foot blade.
  • "predominantly provided by hydraulic damping" (claim 7): Petitioner proposed this term be construed to mean that "resistance to movement in the dorsi and/or plantar direction by the joint mechanism is predominantly provided by hydraulic damping rather than resilient biasing." This construction supported the argument that prior art teaching a joint mechanism with purely hydraulic resistance (no springs or elastomers) met the limitation.

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-9 of Patent 8,740,991 as unpatentable.