Imperative Care Inc v. Inari Medical Inc

1. Case Identification

• Case #: IPR2026-00215
• Patent #: 12,239,333
• Filed: January 16, 2026
• Petitioner(s): Imperative Care, Inc.
• Patent Owner(s): Inari Medical, Inc.
• Challenged Claims: 1, 4-5, 7, 10-11, 13, 15-28

2. Patent Overview

• Title: Retrieval System for Engaging and Removing Unwanted Material
• Brief Description: The ’333 patent discloses a medical system for removing unwanted material, such as blood clots, from a patient's vasculature. The system comprises an aspiration catheter, a tubing system, and an inline clot collection reservoir with a filter to separate aspirated clots from blood.

3. Grounds for Unpatentability

Ground 1: Claims 1, 4-5, 7, 10-11, 13, and 15 are anticipated or obvious over Goff.

• Prior Art Relied Upon: Goff (WO 2006/124307).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Goff, which discloses systems for filtering aspirated materials, teaches every limitation of the challenged claims. Goff’s system includes a filter assembly (the claimed "clot collection reservoir") with a housing defining a sealed chamber, a first port coupled to an aspiration catheter, and a second port coupled to an aspiration source. Goff's filter element, which can have a "substantially cylindrical" or "cup-shaped" geometry, is removably positioned within the housing to collect solid material like disrupted clots. Petitioner further contended that even if Goff's filter orientation differs from that claimed, reversing it represents a simple, predictable design choice.
  • Motivation to Combine (for §103 grounds): A POSITA would be motivated to reverse the orientation of Goff’s filter element because it presented a binary choice (inflow port at the open end vs. closed end of the filter). This modification would have been an "obvious to try" solution to optimize clot collection and visualization, a benefit Goff itself acknowledges.
  • Expectation of Success (for §103 grounds): A POSITA would have a reasonable expectation of success because Goff describes its ports as "conventional connectors" attached via standard medical tubing, making the reversal a simple and predictable modification with no required structural changes.

Ground 2: Claims 1, 4-5, 7, 10-11, 13, 15-17, and 19-21 are obvious over Garrison in view of Goff or Lee.

• Prior Art Relied Upon: Garrison (Application # 2015/0173782) and Goff (WO 2006/124307) or Lee (Application # 2008/0097410).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Garrison discloses a complete aspiration system for removing clots, including an aspiration catheter, aspiration source, user-actuatable valve, hemostasis valve, and an inline filter (the claimed reservoir). While Garrison provides the overall system framework, Goff or Lee provide specific, improved filter designs that meet the detailed claim limitations, such as a housing with two end portions and a removable filter.
  • Motivation to Combine (for §103 grounds): A POSITA would combine Garrison's system with the filter from Goff or Lee for predictable reasons. The filters serve the same purpose—separating clots from blood. A POSITA would be motivated to substitute the more advanced filter of Goff (allowing easy removal and observation of the filter element) or Lee (designed to prevent spills upon removal) into Garrison’s system. This represents the substitution of one known element for another to obtain the predictable result of improved filtering and usability.
  • Expectation of Success (for §103 grounds): Success would be reasonably expected because both the base system (Garrison) and the proposed filters (Goff, Lee) are designed for the same purpose and use conventional connectors and tubing. Integrating them would be a routine task for a POSITA.

Ground 3: Claims 18 and 22-25 are obvious over Garrison and Goff/Lee combined with Schaffer and Hartley/Eller.

• Prior Art Relied Upon: Garrison (Application # 2015/0173782), Goff (WO 2006/124307), Schaffer (Application # 2003/0225379), and Hartley (Application # 2003/0116731) or Eller (Patent 9,980,813).

• Core Argument for this Ground:

  • Prior Art Mapping: This ground builds on the system of Garrison and Goff by adding prior art for the specific hemostasis valve limitations of claims 18 and 22-25. Garrison teaches a hemostasis valve but does not detail its mechanism. Schaffer discloses an adjustable-opening hemostasis valve with a tubular member, actuator buttons, and U-shaped actuating members that constrict the tubular member. Hartley and Eller teach using flexible filaments (a string or wire) to constrict a valve, which Petitioner argued would be an obvious replacement for Schaffer’s more rigid members.
  • Motivation to Combine (for §103 grounds): A POSITA would be motivated to incorporate a known adjustable-opening valve, like the one taught by Schaffer, into Garrison’s aspiration system. Furthermore, a POSITA would be motivated to substitute the flexible "string" from Hartley or "wire" from Eller for Schaffer's actuating members to achieve a better, more conforming seal around instruments of various sizes and shapes—a known objective in hemostasis valve design. This was presented as an obvious design choice from a finite number of known solutions to improve sealing performance.
  • Expectation of Success (for §103 grounds): A POSITA would reasonably expect success in combining these elements, as they are all well-known components of thrombectomy systems. Modifying Schaffer's valve by replacing one type of constricting element (U-shaped members) with another (a flexible filament) would be a straightforward mechanical adaptation.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including combinations substituting Lee for Goff and Eller for Hartley. Further grounds combined the Garrison system with Laub (Application # 2017/0043066) to argue that using larger catheter sizes (e.g., 16, 20, or 22 French) as recited in claims 26-28 would have been obvious for treating different types of clots, such as pulmonary embolisms.

4. Arguments Regarding Discretionary Denial

• Petitioner stipulated that if the Board institutes this IPR, Petitioner will not pursue in the co-pending district court litigation the grounds asserted in the petition or any other ground that could have been reasonably raised in this IPR. This stipulation was made to address the Fintiv factors and argue against a discretionary denial under §314(a).

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1, 4-5, 7, 10-11, 13, and 15-28 of the ’333 patent as unpatentable.