Imperative Care Inc v. Inari Medical Inc

1. Case Identification

• Case #: IPR2025-01264
• Patent #: 12,016,580
• Filed: July 8, 2025
• Petitioner(s): Imperative Care, Inc.
• Patent Owner(s): Inari Medical, Inc.
• Challenged Claims: 1, 5-6, 9-30, 33-34

2. Patent Overview

• Title: Retrieval System and Methods for Use
• Brief Description: The ’580 patent relates to methods and systems for the intravascular treatment and removal of clot material from a blood vessel. The technology involves using a catheter-based system with an elongated shaft for aspiration, a pressure source, and an attachment member to facilitate the introduction of interventional devices.

3. Grounds for Unpatentability

Ground 1: Claims 1, 5, 9, 11-14, 18, 21-22, 24-28, 30, 33-34 are anticipated by or obvious over Garrison.

• Prior Art Relied Upon: Garrison (Application # 2015/0173782).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Garrison, which discloses a system for aspirating unwanted material from a patient’s vasculature, teaches every limitation of independent claim 1. Garrison allegedly described positioning a catheter (elongated shaft) proximate to a clot. Crucially, Petitioner asserted that Garrison disclosed the key method steps that the Examiner found lacking in the prior art during prosecution: pre-charging a vacuum in a pressure source (e.g., a locking syringe) while the connection to the flow line is closed, and subsequently fluidly connecting the pressure source to the shaft by opening a valve (e.g., stopcock) to apply the pre-charged vacuum and aspirate the clot. Garrison also allegedly disclosed using an attachment member (proximal hub) that can include a hemostasis valve, advancing interventional devices through the shaft, and engaging a second portion of clot material after aspirating a first portion.
  • Key Aspects: Petitioner contended the Examiner overlooked Garrison’s explicit disclosure of pre-charging a vacuum, which was the central reason for allowance of the ’580 patent.

Ground 2: Obviousness of Claims 1, 5-6, 9, 11-18, 21-30, 33-34 over Garrison in view of Schaffer.

• Prior Art Relied Upon: Garrison (Application # 2015/0173782) and Schaffer (Application # 2003/0225379).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground asserted that to the extent Garrison does not disclose certain features of the attachment member, such as the use of buttons for unsealing (claim 6) or a specific filament-based valve mechanism (claim 15), these features were disclosed by Schaffer. Schaffer described an adjustable-opening "fluid stasis valve" for use with catheters that includes spring-loaded actuator buttons. Pressing the buttons unseals the valve to permit device insertion, and releasing them allows the valve to seal around the device. Schaffer’s valve included a flexible tubular structure ("seal module") and U-shaped actuating members that Petitioner argued meet the "filament" limitation.
  • Motivation to Combine: Petitioner argued a POSITA would combine Garrison with Schaffer for several reasons: (1) Garrison expressly suggested using an "adjustable-opening valve" with its catheters, which Schaffer provided; (2) Schaffer’s valve performed the same function as the hemostasis valve in Garrison—allowing device introduction while minimizing blood loss; (3) Schaffer’s spring-biased, button-actuated design would simplify the operation of Garrison's system; and (4) it represented a combination of known elements to achieve a predictable result.
  • Expectation of Success: A POSITA would have had a high expectation of success as both references related to hemostasis valves for catheter systems, and combining them involved known methods of attaching valves to catheter hubs.

Ground 3: Obviousness of Claim 10 over Garrison in view of Aklog and/or Laub.

• Prior Art Relied Upon: Garrison (Application # 2015/0173782), Aklog (Patent 8,734,374), and Laub (Application # 2017/0043066).

• Core Argument for this Ground:

  • Prior Art Mapping: Claim 10 requires the method of claim 1 to be performed in a "pulmonary blood vessel." Petitioner argued that while Garrison primarily focused on treating cerebral occlusions, Aklog and Laub explicitly disclosed systems and methods for removing clot material from the pulmonary circulation (i.e., treating pulmonary embolisms). Both Aklog and Laub disclosed aspiration systems with the same general components as Garrison: a catheter, tubing, a filter, and a pressure source.
  • Motivation to Combine: Petitioner asserted a POSITA would have been motivated to apply Garrison's method to pulmonary arteries because the general procedure for aspirating blood clots is similar regardless of the vessel location. The petition cited expert testimony and the prior art to show it was common and routine practice to use and adapt aspiration catheters designed for one part of the vasculature (e.g., cerebral) for use in another (e.g., pulmonary), often by simply upsizing the components. The known danger of pulmonary embolisms would have motivated a POSITA to try any effective thrombectomy system, like Garrison's, for that application.
  • Expectation of Success: The similarities between the systems in Garrison, Aklog, and Laub, and the established practice of adapting such systems for different vascular territories, would have provided a POSITA with a reasonable expectation of success.

• Additional Grounds: Petitioner asserted numerous other obviousness challenges, including combinations of Garrison with Hartley (Application # 2003/0116731) as an alternative disclosure for a rotating hemostasis valve, and Goff (WO 2006/124307) for features related to a removable filter chamber. Further grounds combined these primary references with Aklog and Laub to challenge claim 10.

4. Key Claim Construction Positions

• Petitioner argued that the term "filament" (claims 15-17), which the patent does not define, should be construed based on a purported incorporation by reference to mean at least "one or more threads, lines, cords, ropes, ribbons, flat wires, sheets, or tapes." Petitioner contended this construction was consistent with prior PTAB decisions and that the term should not be limited to require flexibility, as the claimed function of "loosening" the filament can be accomplished with either rigid or flexible structures. This construction is central to the argument that Schaffer's relatively rigid U-shaped actuating members qualify as "filaments."

5. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under Fintiv, stating that the co-pending district court litigation was in its very early stages. At the time of filing, no trial date had been set, and the court had vacated the claim construction schedule pending a motion to stay. Petitioner also provided a Sotera stipulation, promising not to pursue in district court any ground raised or that reasonably could have been raised in the IPR if review is instituted.

6. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 1, 5-6, 9-30, and 33-34 of the ’580 patent as unpatentable.