Prior art — US Patent 11969333

As a senior US patent analyst, I have reviewed the prior art cited in US Patent 11,969,333. Below is an analysis of the most relevant references and their potential impact on the patent's claims.

Analysis of Prior Art for U.S. Patent No. 11,969,333

The core innovation of US Patent 11,969,333 centers on a system and method for removing emboli by using a pre-charged vacuum source connected to an aspiration catheter via a large-bore, short-length tube to generate a rapid, high-volume suction force. The key features claimed are the specific dimensions of the connecting tubing (≥ 0.25-inch diameter, ≤ 48 inches long), the use of a large-volume syringe (≥ 60 mL) to create the vacuum, and the rapid pressure equalization time (less than one second).

Upon review of the patent's cited references, the following prior art is considered most relevant:

1. U.S. Patent No. 8,784,434 B2 ("'434 patent")

Full Citation: Tu, Thomas, et al. Methods and apparatus for treating embolism. U.S. Patent 8,784,434, filed March 15, 2013, and issued July 22, 2014.
Assignee: Inari Medical, Inc.
Brief Description: The '434 patent, also assigned to Inari Medical, discloses a system for treating embolisms, particularly pulmonary embolisms. It describes a catheter-based system for removing or treating blood clots. The '434 patent serves as foundational work for the system described in the '333 patent, detailing the general approach of endovascular clot treatment.
Potential Anticipation of Claims:
- Claims 1 and 12: The '434 patent describes the general components of a catheter-based thrombectomy system, including catheters and methods for removing clots from blood vessels. However, it does not explicitly disclose the specific dimensional limitations of the tubing connecting the catheter to a collection canister, nor the rapid pressure equalization characteristic that are central to the independent claims of the '333 patent. Therefore, while it provides essential background and context, it is unlikely to anticipate the specific limitations of claims 1 and 12 of the '333 patent on its own. It is more likely to be considered in an obviousness analysis (35 U.S.C. § 103).

2. U.S. Patent No. 9,526,864 B2 ("'864 patent")

Full Citation: Thress, John Coleman, et al. Retraction and aspiration device for treating embolism and associated systems and methods. U.S. Patent 9,526,864, filed June 9, 2015, and issued December 27, 2016.
Assignee: Inari Medical, Inc.
Brief Description: This patent, also assigned to Inari Medical, describes a device that combines mechanical retraction with aspiration for embolism treatment. The system includes an interventional device that can be used to engage a clot, along with an aspiration catheter.
Potential Anticipation of Claims:
- Claims 1-20: The '864 patent focuses on the combination of a mechanical device with aspiration. The '333 patent, while mentioning the optional use of an interventional device, primarily claims a system and method defined by its specific aspiration fluidics (large-bore tube, pre-charged vacuum). The '864 patent does not appear to teach the specific dimensions of the tubing or the sub-one-second pressure equalization time required by the independent claims of the '333 patent. It provides context for the use of aspiration in such procedures but does not directly anticipate the narrowly defined parameters of the '333 patent's claims.

3. U.S. Patent Application Publication No. 2018/0193043 A1 ("'043 application")

Full Citation: Rosen, Oved, et al. Devices and methods for treating vascular occlusion. U.S. Patent Application Publication No. 2018/0193043, filed April 26, 2017.
Assignee: Inari Medical, Inc.
Brief Description: This application details a clot removal system that includes a sheath, a self-expanding funnel, and a thrombus extraction device. The system is designed to engage and remove a thrombus from a blood vessel, and it mentions the use of aspiration in conjunction with the mechanical device.
Potential Anticipation of Claims:
- Claims 1-20: Similar to the '864 patent, the '043 application describes a system that may incorporate aspiration. However, its primary focus is on the mechanical components for clot engagement and removal. The application does not specify the critical dimensions of the aspiration tubing, the use of a pre-charged, large-volume syringe, or the rapid pressure equalization that are the defining features of the '333 patent's claims. Thus, it does not appear to directly anticipate these claims.

Summary Conclusion

The prior art cited by US Patent 11,969,333, much of which originates from the same assignee, Inari Medical, establishes the broader context of catheter-based thrombectomy using aspiration. However, none of the reviewed citations appear to explicitly disclose the combination of features that define the independent claims of the '333 patent, namely:

A connecting tube with an inner diameter of at least 0.25 inches.
The same tube having a length of no more than 48 inches.
The use of a ≥ 60 mL syringe to create a vacuum.
The achievement of pressure equalization in less than one second.

These specific parameters are presented in the '333 patent as a novel and non-obvious combination that results in a surprisingly effective "vacuum burst" for clot aspiration. While the general components (catheter, suction source, connecting tube) are known, the claimed combination of specific dimensions and performance characteristics appears to be the novel contribution. Therefore, direct anticipation under 35 U.S.C. § 102 by these specific references is unlikely. The ongoing litigation, particularly the IPR proceeding, will likely focus on whether this specific combination of known elements would have been obvious to a person of ordinary skill in the art.