DCT

3:24-cv-03117

Inari Medical Inc v. Imperative Care Inc

Key Events

Amended Complaint

I. Executive Summary and Procedural Information

Parties & Counsel:
- Plaintiff: Inari Medical, Inc. (Delaware)
- Defendant: Imperative Care, Inc. (Delaware)
- Plaintiff’s Counsel: Perkins Coie LLP
Case Identification: 5:24-cv-03117, N.D. Cal., 05/29/2025
Venue Allegations: Venue is alleged as proper based on Defendant maintaining its principal place of business in Campbell, Santa Clara County, California, which is within the Northern District of California.
Core Dispute: Plaintiff alleges that Defendant’s Symphony Thrombectomy System infringes eleven patents related to systems and methods for the intravascular removal of blood clots.
Technical Context: The technology concerns catheter-based medical devices used in thrombectomy procedures to treat venous thromboembolism (VTE), a life-threatening condition involving blood clots in deep veins (DVT) or pulmonary arteries (PE).
Key Procedural History: The complaint details pre-suit correspondence beginning in September 2023, wherein Plaintiff notified Defendant of its patent rights. Defendant allegedly refused to provide a sample of the accused product for analysis, citing proprietary concerns, and later responded to the infringement allegations by arguing the patents were invalid based on prior art. Plaintiff alleges it subsequently acquired and analyzed a system, confirming its infringement theories before filing suit.

Case Timeline

Date	Event
2016-11-01	Inari receives initial FDA clearance for FlowTriever system
2017-02-01	Inari receives FDA clearance for ClotTriever system
2018-05-01	Inari receives expanded FDA clearance for FlowTriever for treating PE
2018-08-13	Earliest priority date for ’910, ’333, ’005, ’691, ’580, ’669, 12-’333 Patents
2020-01-01	Truvic Medical, Inc. is incorporated (approximate)
2021-07-01	Imperative Care acquires Truvic Medical, Inc.
2023-01-17	U.S. Patent No. 11,554,005 issues
2023-02-01	Truvic receives FDA clearance for Symphony system for DVT treatment
2023-06-15	Truvic begins marketing and selling its Symphony system (approximate)
2023-07-11	U.S. Patent No. 11,697,012 issues
2023-09-05	U.S. Patent No. 11,744,691 issues
2023-09-29	Inari sends first notice letter to Defendant regarding alleged infringement
2023-12-01	Truvic replies to Inari, refusing to provide a sample system for analysis
2023-12-19	U.S. Patent No. 11,844,921 issues
2024-01-09	U.S. Patent No. 11,865,291 issues
2024-04-24	Inari sends second letter to Truvic with additional infringement allegations
2024-04-30	U.S. Patent No. 11,969,333 issues
2024-05-07	U.S. Patent No. 11,974,910 issues
2024-06-25	U.S. Patent No. 12,016,580 issues
2024-10-08	U.S. Patent No. 12,109,384 issues
2024-12-03	U.S. Patent No. 12,156,669 issues
2025-02-14	Inari notifies Defendant via e-mail of forthcoming 12-’333 Patent
2025-03-04	U.S. Patent No. 12,239,333 issues
2025-05-29	Third Amended Complaint filed

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 11,974,910 - “System for Treating Embolism and Associated Devices and Methods”

Issued: May 7, 2024

The Invention Explained

Problem Addressed: The patent family specification describes prior art clot-removal devices as often being highly complex, leading to manufacturing and quality control difficulties, causing trauma to the treatment vessel, and being ineffective at capturing clot material (’005 Patent, col. 2:33-44).
The Patented Solution: The invention is a clot treatment system featuring two distinct aspiration assemblies that can operate in a telescoping manner (’910 Patent, Abstract). A smaller, second catheter is advanceable through a larger, first catheter to reach distal clots. Each catheter is connected to its own pressure source via a dedicated fluid control device, allowing for independent or coordinated aspiration (’910 Patent, col. 4:59-5:2; Compl. ¶66). This dual-assembly design allows for more versatile and targeted clot removal in varied vascular anatomies.
Technical Importance: This telescoping catheter approach provides physicians with extended reach and enhanced control for removing clots in challenging and distal segments of a patient's vasculature (Compl. ¶20).

Key Claims at a Glance

The complaint asserts independent claim 1 and dependent claim 3 (Compl. ¶67).
Independent Claim 1 requires:
- A clot treatment system for treating a pulmonary embolism.
- A first clot aspiration assembly, including a first catheter, a first pressure source, and a first fluid control device.
- The first fluid control device is movable between a first position (pressure source disconnected) and a second position (pressure source connected), allowing the pressure source to generate vacuum while disconnected.
- A second clot aspiration assembly, including a second catheter (16 French or greater) advanceable through the first catheter, a second pressure source, and a second fluid control device with similar movable positions.

U.S. Patent No. 11,969,333 - “System for Treating Embolism and Associated Devices and Methods”

Issued: April 30, 2024

The Invention Explained

Problem Addressed: The shared specification identifies the same problems as the ’910 Patent: prior art devices were complex, traumatic to blood vessels, and inefficient at clot capture (’005 Patent, col. 2:33-44).
The Patented Solution: The patent describes a method for treating deep vein thrombosis by first "pre-charging" a vacuum in a system before applying it to the clot (’333 Patent, Abstract). The method involves advancing an aspiration catheter to the thrombus, generating vacuum pressure in a clot canister while a valve between the canister and catheter is closed, and then opening the valve to apply the stored vacuum, thereby aspirating the clot material (’333 Patent, col. 4:17-25). The system also includes a filter within the canister to separate the captured clot from aspirated blood.
Technical Importance: Pre-charging the vacuum allows for a more rapid and powerful initial suction compared to methods where vacuum is generated concurrently with aspiration, potentially improving the ability to dislodge and capture adherent thrombi (see, e.g., ’691 Patent, claim 14 preamble, "accelerated response").

Key Claims at a Glance

The complaint asserts independent claim 20 and dependent claim 22 (Compl. ¶91).
Independent Claim 20 requires a method comprising the steps of:
- Advancing an aspiration catheter proximate to a deep vein thrombosis.
- Generating vacuum pressure within a clot canister via an aspiration source while a valve between the catheter and canister is in a first, closed position.
- Moving the valve to a second, open position to apply the vacuum pressure to the catheter, aspirating the clot and blood into the canister.
- The clot canister includes a filter to separate the blood from the captured clot.

U.S. Patent No. 11,554,005 - “System for Treating Embolism and Associated Devices and Methods”

Issued: January 17, 2023
Technology Synopsis: This patent, from the same family as the ’910 and ’333 patents, discloses a vacuum aspiration system with an improved hemostasis valve. The valve is configured to receive a second catheter and direct it through a first catheter while maintaining a seal (Compl. ¶116; ’005 Patent, cl. 1). The valve uses a filament loop and a spring-biased actuator to constrict a collapsible lumen.
Asserted Claims: Independent claim 10 (Compl. ¶117).
Accused Features: The hemostasis valve within the controller handles of the Symphony system, which allegedly includes a support, an actuator with a movable member, a collapsible lumen, and a spring-configured filament loop to constrict the lumen (Compl. ¶121, 123-124).

U.S. Patent No. 11,744,691 - “System for Treating Embolism and Associated Devices and Methods”

Issued: September 5, 2023
Technology Synopsis: This patent discloses an aspiration system with an "accelerated response" architecture. It comprises an aspiration pump connected to a first chamber, and a removable second chamber (e.g., a canister) positioned between the pump and the aspiration catheter. A user-actuatable valve allows negative pressure to build up in both chambers before being connected to the catheter, causing a rapid pressure decrease to aspirate the clot (Compl. ¶136; ’691 Patent, cl. 14).
Asserted Claims: Independent claim 14 and dependent claim 22 (Compl. ¶137).
Accused Features: The Symphony system, which includes the Truvic Generator (aspiration pump and first chamber) and a removable clot canister on the controller handle (second chamber) with a user-actuatable valve (vacuum control lever) (Compl. ¶144, 146-147).

U.S. Patent No. 11,844,921 - “Hemostasis Valves and Methods of Use”

Issued: December 19, 2023
Technology Synopsis: This patent discloses a hemostasis valve with an active tensioning mechanism. The valve comprises an elongate member defining a lumen, an actuator coupled to the member via a filament, and a biasing member (e.g., a spring) configured to bias the actuator to a constricted and sealed first position (Compl. ¶161-162; ’921 Patent, cl. 1). Claim 10 adds a second actuator, filament, and biasing member.
Asserted Claims: Independent claims 1 and 10 (Compl. ¶163).
Accused Features: The hemostasis valve in the Symphony controller handles, which is allegedly operated by buttons (actuators) coupled to filament lines that loop around a tubular lumen, with torsion springs (biasing members) biasing the valve to a constricted position (Compl. ¶167, 169, 171).

U.S. Patent No. 11,697,012 - “Hemostasis Valves and Methods of Use”

Issued: July 11, 2023
Technology Synopsis: Part of the same family as the ’921 patent, this patent claims an aspiration catheter system that includes the hemostasis valve as a component on the catheter's proximal end. The valve has a constricting mechanism with a first actuator, a first filament looped around a collapsible sidewall, and a first spring to move the actuator and tighten the loop (Compl. ¶186; ’012 Patent, cl. 1).
Asserted Claims: Independent claim 1 (Compl. ¶187).
Accused Features: The Symphony system's aspiration catheters, which have controller handles on their proximal ends containing the accused hemostasis valves with their alleged button actuators, filament loops, and torsion springs (Compl. ¶190, 192, 196).

U.S. Patent No. 11,865,291 - “Hemostasis Valves and Methods of Use”

Issued: January 9, 2024
Technology Synopsis: Similar to the ’921 and ’012 patents, this patent claims a valve comprising a support, an actuator with a first member movably coupled to the support, a collapsible lumen, a filament loop, and a spring configured to move the first member to pull the filament and reduce the lumen's diameter (Compl. ¶209; ’291 Patent, cl. 1).
Asserted Claims: Independent claim 1 (Compl. ¶210).
Accused Features: The Symphony hemostasis valve, alleged to have a plastic support, a button-and-lever actuator mechanism movably coupled to it, a collapsible lumen, a filament loop, and torsion springs that pull the filament to constrict the lumen (Compl. ¶213-215, 217-219).

U.S. Patent No. 12,016,580 - “Single Insertion Delivery System for Treating Embolism and Associated Systems and Methods”

Issued: June 25, 2024
Technology Synopsis: This patent claims a method for intravascular clot treatment involving a sequence of aspiration followed by mechanical intervention. The method includes aspirating a first portion of a clot, then unsealing an attachment member (e.g., a hemostasis valve) on the catheter, advancing an interventional device through it to engage a second portion of the clot, and then withdrawing the device (Compl. ¶231; ’580 Patent, cl. 1).
Asserted Claims: Independent claim 1 and dependent claims 18 and 19 (Compl. ¶233).
Accused Features: The use of the Symphony system with its ProHelix device, which allegedly performs the claimed method steps of aspiration, unsealing the hemostasis valve by pushing buttons, advancing the ProHelix, engaging the clot, collecting it in a filter chamber, and removing the filter (Compl. ¶240, 246-249).

U.S. Patent No. 12,109,384 - “Hemostasis Valves and Methods of Use”

Issued: October 8, 2024
Technology Synopsis: This patent, from the same family as the ’921 patent, claims a valve assembly with a tubular member, two flexible filament loops, and a pair of actuators. Each actuator acts on a portion of both filaments, and they move between a first tensioned position that constricts the lumen and a second loosened position that allows it to open (Compl. ¶264; ’384 Patent, cl. 1).
Asserted Claims: Independent claim 1 and dependent claim 3 (Compl. ¶265).
Accused Features: The Symphony hemostasis valve, alleged to have a tubular member, two braided filament loops, and a pair of button-lever actuators, where each actuator acts on both filaments to constrict or loosen the lumen (Compl. ¶268, 270, 272-274).

U.S. Patent No. 12,156,669 - “Single Insertion Delivery System for Treating Embolism and Associated Systems and Methods”

Issued: December 3, 2024
Technology Synopsis: This patent, from the same family as the ’580 patent, claims an aspiration system comprising a vacuum source, a catheter, a filter chamber with a housing and filter, a flow controller, and a hemostasis valve. The system is configured with two distinct fluid paths: a first path for aspiration through the filter chamber, and a second path for passing an interventional device through the hemostasis valve (Compl. ¶288-289; ’669 Patent, cl. 15).
Asserted Claims: Independent claim 15 (Compl. ¶290).
Accused Features: The Symphony system, which is alleged to include a vacuum source (Truvic Generator), a catheter, a filter chamber (clot container), a flow controller (vacuum control lever), and a hemostasis valve arranged in the claimed configuration (Compl. ¶294, 296, 297, 305, 307).

U.S. Patent No. 12,239,333 - “Single Insertion Delivery System for Treating Embolism and Associated Systems and Methods”

Issued: March 4, 2025
Technology Synopsis: This patent claims a clot collection reservoir with a partially transparent housing, a first port for the catheter, a second port for the aspiration source, and a removable, substantially cylindrical filter positioned within the chamber. The filter is configured to enclose an interior region around the second port, trapping clot material while allowing blood to be drawn through (Compl. ¶317; 12-’333 Patent, cl. 1).
Asserted Claims: Independent claim 1 (Compl. ¶319).
Accused Features: The clot collection reservoir on the Symphony controller handles, which is alleged to be a partially transparent housing with two ports and a removable cylindrical filter that allows blood evacuation while trapping the clot (Compl. ¶322-323, 329, 331, 337).

III. The Accused Instrumentality

Product Identification

The accused instrumentality is Defendant’s Symphony Thrombectomy System (“Symphony system”) and its various components, including the 24F Symphony Catheter, 16F Symphony Catheter, Truvic Generator, Truvic Canister, and Symphony ProHelix device (Compl. ¶9, 28).

Functionality and Market Context

The Symphony system is a medical device intended for the non-surgical removal of blood clots from blood vessels using controlled aspiration (Compl. ¶28). The complaint alleges its design mirrors that of Plaintiff's FlowTriever system, sharing features such as telescoping aspiration catheters (a 16F catheter capable of being advanced through a 24F catheter), the use of an external vacuum pump and generator, a removable clot-filtering canister, and a hemostasis valve (Compl. ¶32). The system can be used with the Symphony ProHelix, an interventional device advanced through the catheter to mechanically engage and disrupt clot material (Compl. ¶28). An annotated diagram from Defendant's brochure shows the 24F and 16F catheters and their controller handles (Compl. p. 19). The complaint states the system received FDA clearance for treating Deep Vein Thrombosis (DVT), but alleges it is also promoted and used by physicians for treating Pulmonary Embolism (PE), a so-called "off-label" use for which Defendant is allegedly seeking formal FDA clearance (Compl. ¶29, 31, 71).

IV. Analysis of Infringement Allegations

U.S. Patent No. 11,974,910 Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A clot treatment system for treating clot material comprising a pulmonary embolism in a vasculature of a patient...	The Symphony system is used by doctors in clinical trials for the treatment of pulmonary embolisms, and Defendant is seeking FDA clearance for this purpose.	¶71	’910 Patent, col. 1:1-3
a first clot aspiration assembly, including: a first catheter; a first pressure source; and a first fluid control device...	The system includes a 24F catheter, a vacuum pump and clot canister (pressure source), and a controller handle with a lever-operated Dual-Action Vacuum Control (fluid control device).	¶72	’910 Patent, col. 1:4-6
wherein the first fluid control device is movable between (a) a first position in which the first pressure source is fluidly disconnected from the first catheter and (b) a second position in which the first pressure source is fluidly connected...	The lever-operated control has an "off" position that fluidly disconnects the vacuum source from the 24F catheter and an "on" position that fluidly connects it.	¶73	’910 Patent, col. 1:7-11
wherein the first pressure source is configured to generate vacuum pressure while the first fluid control device is in the first position, and wherein, upon movement...the vacuum pressure is applied to the first catheter...	The vacuum pump creates vacuum in the clot canister while the lever is "off"; moving the lever to "on" applies this vacuum to the catheter to generate suction.	¶74	’910 Patent, col. 1:12-18
a second clot aspiration assembly, including: a second catheter advanceable through the first catheter, wherein the second catheter has a size of 16 French or greater...	The system includes a 16F catheter that can be advanced (telescoped) through the 24F catheter to position its distal end proximate to a pulmonary embolism. An image from the product brochure depicts this telescoping capability (Compl. p. 26).	¶75	’910 Patent, col. 1:19-26
a second pressure source; and a second fluid control device...movable between (a) a first position...disconnected...and (b) a second position...connected...	The system includes a vacuum pump and canister (pressure source) and a controller handle for the 16F catheter with its own lever-operated control having "on" and "off" positions.	¶76-77	’910 Patent, col. 1:27-33
wherein the second pressure source is configured to generate vacuum pressure while the second fluid control device is in the first position, and wherein, upon movement...the vacuum pressure is applied to the second catheter...	The vacuum pump creates vacuum in the canister while the 16F handle lever is "off"; moving the lever to "on" applies this vacuum to the 16F catheter to aspirate the embolism.	¶78	’910 Patent, col. 1:34-42

U.S. Patent No. 11,969,333 Infringement Allegations

Claim Element (from Independent Claim 20)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A method of treating a deep vein thrombosis within a vasculature of a patient, the method comprising:	The Symphony system is used to perform thrombectomy for DVT, its FDA-indicated use, via vacuum aspiration.	¶96	’333 Patent, col. 1:1-3
advancing an aspiration catheter at least partially through the vasculature...such that a distal end portion...is positioned proximate to the deep vein thrombosis...	The method involves advancing the 16F or 24F Symphony catheter through a patient's vasculature to a position near the DVT clot.	¶97-98	’333 Patent, col. 2:1-5
wherein a lumen of the aspiration catheter is fluidly coupled along a fluid path to a clot canister and an aspiration source proximal to the clot canister;	The lumens of the catheters are fluidly coupled through the controller handle to a clot canister and a vacuum pump (aspiration source) located proximal to the canister.	¶99	’333 Patent, col. 2:5-9
generating vacuum pressure within the clot canister via the aspiration source while a valve...is in a first position that inhibits fluid flow...	The user sets the vacuum control lever on the handle to the "OFF" position, which actuates a valve to inhibit flow, while the Truvic Generator (aspiration source) generates vacuum in the canister. An image from the product Instructions for Use depicts setting the handle levers to the "OFF" position before turning on the generator (Compl. p. 41).	¶100-101	’333 Patent, col. 2:10-16
moving the valve from the first position to a second position thereby applying the vacuum pressure to the lumen of the aspiration catheter such that at least a portion of the deep vein thrombosis and blood are aspirated into the clot canister...	The user moves the vacuum lever to the "ON" position, which opens the valve and applies the pre-charged vacuum to the catheter lumen, aspirating the clot into the canister.	¶102	’333 Patent, col. 2:17-23
and wherein the clot canister includes a filter configured to filter the blood from the portion of the deep vein thrombosis.	The clot canisters of the 16F and 24F handles contain a filter that separates aspirated clot material from blood, allowing the blood to pass through.	¶103	’333 Patent, col. 2:24-26

Identified Points of Contention

Scope Questions: Claim 1 of the ’910 Patent is directed to a system for treating a "pulmonary embolism." The complaint alleges infringement based on off-label use and clinical trials, as the accused product's FDA clearance is for DVT (Compl. ¶71). This raises the question of whether the sale of a system for an approved use can directly infringe a claim directed to a different, unapproved use, and what level of evidence of such use is required.
Technical Questions: A central technical question may arise from the "first pressure source" and "second pressure source" limitations of the ’910 Patent. The complaint alleges that the single Truvic Generator and canister combination serves as both sources, distinguished only by which catheter handle they are connected to (Compl. ¶72, ¶76). The analysis may turn on whether this configuration meets the claim requirement for two distinct pressure sources, or if the patent requires two physically separate vacuum-generating apparatuses.

V. Key Claim Terms for Construction

The Term: "a first pressure source" and "a second pressure source"

Patent: ’910 Patent, cl. 1
Context and Importance: This terminology is critical because the claim requires two distinct aspiration assemblies, each with its own pressure source. The complaint alleges that a single vacuum pump and canister combination fulfills both the "first" and "second" pressure source limitations depending on which catheter it services (Compl. ¶72, 76). The viability of the infringement claim may depend on whether a single apparatus can be construed as two separate "sources" in this context.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes a pressure source as generally configured to "generate...a vacuum" and can include "a pump...or...one or more syringes" (’005 Patent, col. 6:50-54). This functional language may support an argument that the operational combination of the pump/canister with a specific catheter assembly constitutes a "source," allowing one physical pump to serve as two distinct claimed sources.
- Evidence for a Narrower Interpretation: The patent's figures depicting a two-catheter system show two physically separate pressure sources (1040 and 1140), each connected to a respective catheter assembly (’005 Patent, Fig. 11). The use of the distinct terms "first" and "second" may suggest to a fact-finder that two structurally separate apparatuses are required.

The Term: "fluid control device"

Patent: ’910 Patent, cl. 1
Context and Importance: The claim requires this device to be "movable between (a) a first position in which the first pressure source is fluidly disconnected... and (b) a second position in which the first pressure source is fluidly connected," which enables the vacuum pre-charging function. Practitioners may focus on whether the accused system's simple on/off lever meets this two-part functional requirement.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the element broadly as a "valve or other fluid control device" and notes it can be a "stopcock" or a "clamp" (’005 Patent, col. 6:5-19). This may support construing the term to cover any mechanism that can open and close the fluid path.
- Evidence for a Narrower Interpretation: The claim language itself describes a specific sequence of operation: the pressure source is "configured to generate vacuum pressure while the first fluid control device is in the first position." This functional language could be interpreted to require more than a simple on/off switch, but a device specifically integrated into a system designed for pre-charging.

VI. Other Allegations

Indirect Infringement

The complaint alleges inducement of infringement by alleging Defendant sells the Symphony system and provides Instructions for Use (IFU), brochures, and animation videos that teach and direct physicians to use the system in an infringing manner (Compl. ¶81-82, 106-107). It further alleges that Defendant's sales representatives attend procedures and instruct physicians on methods of use, including for the off-label treatment of pulmonary embolisms (Compl. ¶82).

Willful Infringement

Willfulness is alleged based on Defendant’s knowledge of the patents-in-suit. The complaint states that Plaintiff provided pre-suit notice to Defendant via letters and e-mails beginning in September 2023, including specific notice of the patent applications that would issue as the ’910 and ’333 Patents (Compl. ¶84, 109). The complaint alleges that Defendant has continued its infringing activities despite this knowledge and the filing of the original and amended complaints (Compl. ¶86, 111).

VII. Analyst’s Conclusion: Key Questions for the Case

A core issue will be one of claim scope and construction: can a single vacuum pump and canister, which provides aspiration to two separate catheters via independent controls, satisfy the claim requirement for "a first pressure source" and "a second pressure source," or does the patent demand two physically separate vacuum-generating units?
A second central issue will be one of direct infringement and use: for claims directed to treating a "pulmonary embolism," what is the evidentiary threshold to prove infringement by a system that is FDA-cleared only for DVT, and does promotion for off-label use and evidence from clinical trials suffice to establish direct infringement by the Defendant's customers?
A key evidentiary question will be one of functional operation: does the accused system’s on/off vacuum lever perform the specific, two-state function of the claimed "fluid control device"—enabling vacuum generation while fluidly disconnected and then applying that stored vacuum when fluidly connected—or is there a mismatch in its technical method of operation?