Ethicon Endo Surgery Inc v. Covidien AG

1. Case Identification

• Case #: IPR2015-01274
• Patent #: 7,887,536
• Filed: May 27, 2015
• Petitioner(s): Ethicon Endo-Surgery, Inc.
• Patent Owner(s): Covidien AG
• Challenged Claims: 1-13

2. Patent Overview

• Title: Electrosurgical Instrument Having a Safe Mode
• Brief Description: The ’536 patent relates to bipolar electrosurgical forceps for open surgical procedures. The device uses a combination of mechanical clamping pressure and electrosurgical current to seal and sever tissue, featuring non-conductive stop members to regulate the gap between jaw members and a channel for a cutting knife.

3. Grounds for Unpatentability

Ground 1: Obviousness over Witt, Tetzlaff, and Yates - Claims 1-4 and 7-13 are obvious over Witt in view of Tetzlaff and Yates.

• Prior Art Relied Upon: Witt (Application # 2002/0107517), Tetzlaff (WO 00/24330), and Yates (Statutory Invention Registration No. H1,904).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Witt, the primary reference, disclosed the core structure of an electrosurgical instrument with opposing jaws, a ratchet mechanism for locking, and a knife channel for cutting. Tetzlaff was asserted to supply the claimed non-conductive stop members on the jaw surfaces, which it taught are critical for controlling the gap distance (0.001 to 0.006 inches) and pressure to ensure a proper tissue seal. Because neither Witt nor Tetzlaff specified pressure values, Petitioner contended that Yates supplied the claimed pressure range (3 kg/cm² to 16 kg/cm²), disclosing that such pressures are appropriate for effective electrosurgical coagulation.
  • Motivation to Combine: A POSITA would combine these references because Witt itself cited Tetzlaff as relevant prior art, directly motivating a skilled artisan to incorporate Tetzlaff’s teachings. Both Witt and Tetzlaff emphasized the importance of controlling pressure and gap distance for effective sealing, and Tetzlaff provided the explicit solution of using stop members with specific dimensions. As both base references lacked specific pressure values, a POSITA would have been motivated to consult a reference like Yates to determine optimal, known pressure ranges to ensure the efficacy of the combined device.
  • Expectation of Success: A POSITA would have a reasonable expectation of success because the combination involved applying known solutions (Tetzlaff's stop members, Yates's pressure ranges) to a conventional electrosurgical forceps design (Witt) to achieve the predictable benefits of improved sealing consistency and safety.

Ground 2: Obviousness over Witt, Tetzlaff, Yates, and Stern - Claims 5-6 are obvious over the combination of Witt, Tetzlaff, and Yates in view of Stern.

• Prior Art Relied Upon: Witt (Application # 2002/0107517), Tetzlaff (WO 00/24330), Yates (Statutory Invention Registration No. H1,904), and Stern (Patent 5,443,463).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the combination in Ground 1. For claim 5, which required a conductive knife adapted for connection to an electrosurgical energy source, Petitioner argued that Stern disclosed precisely this feature. Stern taught an energized cutting blade that slides between the jaws to cut tissue after coagulation. For claim 6, which added a spring-biased knife that automatically retracts, Petitioner argued that Witt itself disclosed a spring-loaded cutting member in an alternative embodiment, making it obvious to apply this feature to the primary embodiment's sliding knife.
  • Motivation to Combine: The motivation to add Stern's teaching to the base combination was to enhance the instrument's functionality. A POSITA would seek to create a single tool capable of both sealing and electrosurgical cutting to improve efficiency and reduce instrument exchanges during surgery. Since the base combination already included a mechanical knife from Witt, it would be a simple and logical step to make that knife conductive and connect it to a power source as taught by Stern to gain the known benefits of electrosurgical cutting.
  • Expectation of Success: Success was predictable because connecting a metallic cutting blade to a power source was a well-understood concept in electrosurgery, and Stern demonstrated its feasibility in a similar forceps device.

Ground 3: Obviousness over Tetzlaff, Stern, and Yates - Claims 1-5 and 7-13 are obvious over Tetzlaff in view of Stern and Yates.

• Prior Art Relied Upon: Tetzlaff (WO 00/24330), Stern (Patent 5,443,463), and Yates (Statutory Invention Registration No. H1,904).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground used Tetzlaff as the primary reference, which disclosed bipolar forceps with shafts, jaws, stop members for gap control, and a ratchet mechanism. Petitioner asserted that Tetzlaff, while mentioning the need to cut tissue post-sealing, lacked an integrated cutting mechanism. This deficiency was allegedly remedied by incorporating the knife and knife channel taught in Stern and Yates. The pressure range limitation was met by Yates, as argued in Ground 1.
  • Motivation to Combine: The primary motivation was to improve the Tetzlaff device by adding a cutting function, a known area for advancement in surgical tool design. Tetzlaff's own disclosure of cutting as a subsequent step to sealing created a clear reason for a POSITA to integrate a knife. Stern and Yates provided known, compatible designs for adding a knife channel and blade to a bipolar forceps instrument, making them logical sources for this modification to create a more versatile, single-use instrument.
  • Expectation of Success: A POSITA would expect success as incorporating a cutting blade into forceps was a common design modification in the field, and the components were all designed for use in standard electrosurgical systems.
• Additional Grounds: Petitioner asserted additional obviousness challenges, including grounds substituting Yates ’270 (Patent 5,688,270) for its teachings on stop members and offset electrodes, and a ground adding Wales (Patent 5,800,449) for its explicit teaching of a spring-biased knife return mechanism for claim 6.

4. Key Claim Construction Positions

• "Disposed On": Petitioner argued this term should be construed as "put in place on." This construction was proposed to encompass elements that are either integrally formed with or separately affixed to a component, consistent with its usage in the specification.
• "Interlocking Positions": Petitioner contended this term requires "at least two different interlocking positions." This construction was based on the plural form of "positions," arguing that a ratchet mechanism that interlocks in only a single position would not meet the plain meaning of the claim language, which is relevant to the functionality of the claimed ratchet.

5. Key Technical Contentions (Beyond Claim Construction)

• Priority Date Entitlement: Petitioner dedicated significant argument to establishing that the ’536 patent was only entitled to a priority date of October 30, 2002, not the earlier 1998 date asserted. The core contention was that the critical "knife channel" limitation, required by all challenged claims, was new matter first disclosed in the application filed on that 2002 date. This later priority date was crucial for establishing that key references, such as Witt and Tetzlaff, qualify as prior art.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-13 of the ’536 patent as unpatentable.