PTAB

IPR2014-00753

Brainlab AG v. Sarif Biomedical LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: COMPUTER-ASSISTED MICROSURGERY METHODS AND EQUIPMENT
  • Brief Description: The ’725 patent describes an apparatus and method for computer-assisted microsurgery that allows preoperative images (e.g., MRI, CT scans) to be used in real time during a procedure. The invention purports to solve prior art limitations by separating the image-acquisition phase from the surgical phase. It uses a fixed, absolute reference system (e.g., cameras mounted in the room) to independently track the real-time positions of the patient and a surgical tool via attached markers (trihedrons), and then correlates these positions with the preoperative image data.

3. Grounds for Unpatentability

Ground 1: Claim 1 is Anticipated by Allen

  • Prior Art Relied Upon: Allen (Patent 4,991,579).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Allen discloses an image-guided surgical system that teaches every element of independent claim 1. Allen describes obtaining preoperative images (CT, MRI) in a fixed internal coordinate system defined by fiducial implants in the patient. During surgery, it uses sensors (a robotic arm and an imaging system) to track the patient's position in an external coordinate system. A computer correlates the two coordinate systems. Petitioner contended Allen discloses an articulated tool support (robotic arm or radiation source support) integral with a fixed reference frame, an image database, sensors to supply patient position signals, and a computer adapted to determine correspondence, display the tool's position on screen, and control the tool (a surgical laser).
    • Key Aspects: The anticipation argument relied on Allen's disclosure of a computer-guided laser and multiple articulated supports as inherently meeting the limitations for the claimed tool support, even if not explicitly used for the laser itself.

Ground 2: Claim 1 is Obvious over Schulz in view of Taylor

  • Prior Art Relied Upon: Schulz (Patent 5,622,170) and Taylor (Patent 5,445,166).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Schulz discloses nearly all elements of claim 1, including a system that uses optical sensors to track markers on a surgical tool and a patient, correlating their positions with a preoperative image database for display. However, Schulz's system is primarily for a manually guided tool. Taylor was argued to supply the missing element of a computer-controlled articulated tool support by describing a "positioning apparatus" with multiple links and arms that is computer-controlled for manipulating a surgical tool.
    • Motivation to Combine: A POSITA would combine Schulz's advanced tracking and visualization system with Taylor's robotic tool control to improve surgical precision, prevent mistakes, and free the surgeon to focus on higher-level tasks. Both references address the same problems in the field of computer-assisted surgery.
    • Expectation of Success: The combination involved applying a known robotic control system (Taylor) to a known image-guidance system (Schulz), which represented a predictable integration of established technologies for a clear benefit.

Ground 3: Claim 11 is Obvious over Schulz, Heilbrun, and Glassman

  • Prior Art Relied Upon: Schulz (Patent 5,622,170), Heilbrun (Patent 5,389,101), and Glassman (Patent 5,086,401).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that method claim 11 is obvious over the combination. The base combination of Schulz (optical tracking) and Heilbrun (using cameras as sensors) was said to teach all steps of claim 11 except for the final step of "automatically controlling the tool." This base system is for a surgeon-guided tool. Glassman was introduced to teach this missing step, as it discloses an image-directed robotic surgery system (for hip replacement) that uses a preoperative image database to plan the surgery and then automatically mills out bone with a real-time controlled robot.
    • Motivation to Combine: A POSITA would be motivated to integrate Glassman's proven automated robotic control into the more flexible image-guided framework of Schulz/Heilbrun. This would achieve a fully automated system, a known goal in the art, to improve accuracy and reduce surgeon fatigue.
    • Expectation of Success: Combining these known elements—image guidance, optical tracking with cameras, and robotic automation—was a straightforward application of existing technologies to achieve a more advanced and automated surgical system.

  • Additional Grounds: Petitioner asserted numerous other obviousness challenges against claims 2-10 based on various combinations of Allen, Schulz, Taylor, Heilbrun, and Henrion (Patent 5,868,675) to add features like specific camera sensors (from Heilbrun) and trihedron-based markers (from Henrion) to the base combinations.

4. Key Claim Construction Positions

  • Petitioner argued that several key claim terms were indefinite under 35 U.S.C. §112 because they are means-plus-function limitations that lack corresponding structure in the ’725 patent specification.
  • "articulated tool support": Petitioner proposed construing this term as "a computer-controlled mechanism adapted to move a microsurgery tool through plural axes, the mechanism including at least one arm having at least one joint between its ends."
  • "computer adapted to...control position and displacements of the tool..." (Claim 1): Petitioner contended this term invokes §112, ¶6 (pre-AIA) because "computer" is a generic term that does not provide sufficient structure for performing the claimed control function. The specification was alleged to be devoid of any algorithm or specific architecture for how the computer would control the tool, merely stating that an inverse transformation "mak[es] it possible."
  • "means for determining coordinates of the tool..." (Claims 1, 5): Petitioner argued this is a means-plus-function term for which the specification provides no corresponding structure. The patent allegedly describes determining tool position via sensors tracking a trihedron, but the claim requires determining coordinates "based on data from the image data base," a function for which no specific method or structure is disclosed.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-11 of the ’725 patent as unpatentable.