PTAB

IPR2016-00868

Minerva Surgical Inc v. Hologic Inc

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Key Events
Petition

1. Case Identification

2. Patent Overview

  • Title: Method and Device for Detecting Perforation of a Body Cavity
  • Brief Description: The ’183 patent describes methods and devices for endometrial ablation. The disclosed procedure involves inserting an ablation device, inflating the uterus with a fluid medium to create working space, and using a pressure sensor to monitor for perforations in the uterine wall before or during the ablation treatment.

3. Grounds for Unpatentability

Ground 1: Claims 1, 4, 6, 7, 9, 11-13, and 15 are obvious over Masterson in view of Bolduc.

  • Prior Art Relied Upon: Masterson (Patent 5,891,094) and Bolduc (Patent 3,871,374).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Masterson discloses all key elements of the independent claims, including an endometrial ablation method that uses a thermally conductive fluid to distend the uterus and a pressure sensor to monitor intrauterine pressure. The sensor is configured to alert a user to abnormal conditions, such as a leak. Petitioner asserted that Bolduc, which is directed to monitoring uterine integrity, explicitly teaches using a pressure sensor to detect whether a predetermined pressure can be achieved, noting that pressure will not be attained in a ruptured (i.e., perforated) uterus.
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would have been motivated to apply Bolduc’s explicit teaching of pressure-based perforation detection to Masterson’s ablation system. This combination would improve the safety and maximize the usefulness of the pressure sensor already present in Masterson’s device, confirming that leaks detected by Masterson’s sensor could be caused by perforations, as taught by Bolduc.
    • Expectation of Success: A POSITA would have had a high expectation of success because both references are directed to uterine instruments, and the combination merely involves using a known pressure sensor for its intended and understood purpose—detecting pressure loss indicative of a perforation.

Ground 2: Claims 1-4, 6, 7, 9, and 11-15 are obvious over Isaacson in view of Goldrath.

  • Prior Art Relied Upon: Isaacson (International Publication No. WO 97/24074) and Goldrath (Patent 5,503,626).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Isaacson discloses an electrosurgical device for endometrial ablation that introduces an isotonic fluid into the uterus and uses pressure transducers to monitor fluid pressure, explicitly stating that "the possibility of a uterine perforation can be detected by these means." To the extent Isaacson is not explicit enough, Goldrath teaches an ablation system that measures fluid pressure to determine if fluid is escaping the uterus into the patient’s body, which would occur if the uterus were perforated, and terminates the procedure if excessive fluid absorption is detected.
    • Motivation to Combine: A POSITA would have been motivated to use the pressure-based safety and detection methods of Goldrath with Isaacson’s ablation device. This would improve treatment safety by confirming that pressure changes detected by Isaacson's transducers correspond to dangerous fluid leakage, a known risk explicitly addressed by Goldrath. The combination represents the application of a known safety feature to a similar, known device.
    • Expectation of Success: Success was predictable, as the combination simply uses pressure sensors as taught by both references to monitor for a known complication (perforation and fluid escape) in fluid-distended uterine procedures.

Ground 3: Claim 5 is obvious over Masterson, Bolduc, and Himmelstein.

  • Prior Art Relied Upon: Masterson (Patent 5,891,094), Bolduc (Patent 3,871,374), and Himmelstein (Patent 4,542,643).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground builds on the Masterson and Bolduc combination from Ground 1 to address the limitations of dependent claim 5, which requires monitoring pressure for a "predetermined period of time." Petitioner argued that Himmelstein, which discloses a method for detecting fluid leakage from a container, explicitly teaches monitoring pressure decay over a "preselected period of time" to determine if a leak is present.
    • Motivation to Combine: A POSITA seeking to improve the reliability of the perforation test in the Masterson/Bolduc system would have looked to well-established leak testing methods. Himmelstein provided a known and logical solution: instead of a single point-in-time pressure check, monitoring for pressure loss over a set duration would provide a more robust and reliable indication of a leak, thereby increasing the safety of the ablation procedure.
    • Expectation of Success: A POSITA would have expected success, as applying a standard, time-based pressure decay test (Himmelstein) to a pressurized body cavity (the uterus in Masterson/Bolduc) is a straightforward application of fundamental mechanical principles.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including: (1) adding Isaacson to the Masterson/Bolduc combination to teach RF energy ablation (claims 2, 3, 14); (2) adding Benaron to the Masterson/Bolduc combination to teach a user override function for safety interlocks (claims 8, 10); (3) adding Himmelstein to the Isaacson/Goldrath combination to teach monitoring for a predetermined time (claim 5); and (4) adding Benaron to the Isaacson/Goldrath combination to teach the user override function (claims 8, 10).

4. Key Claim Construction Positions

  • "inflation medium": Petitioner argued that based on the specification, this term should be construed to mean "a liquid or gas delivered into the uterus to slightly pressurize the uterine cavity."
  • "perforation": Petitioner argued that this term should be given its common and ordinary meaning in the field, referring to "damage to the wall of the uterus, such as a rupture caused by accident or disease." This construction is central to linking the prior art's disclosure of detecting "leaks" or "ruptures" via pressure loss to the claimed "perforation."

5. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-15 of the ’183 patent as unpatentable under 35 U.S.C. §103.