Cardiovascular Systems Inc v. Cardio Flow Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Cardiovascular Systems, Inc. (Delaware)
  • Defendant: Cardio Flow, Inc. (Delaware)
  • Plaintiff’s Counsel: Robins Kaplan LLP
• Case Identification: [Cardiovascular Systems, Inc.](https://ai-lab.exparte.com/party/cardiovascular-systems-inc) v. [Cardio Flow, Inc.](https://ai-lab.exparte.com/party/cardio-flow-inc), 18-cv-01253, D. Minn., 02/07/2019
• Venue Allegations: Venue is alleged to be proper as both parties have their principal places of business in Ramsey County, Minnesota, where the events giving rise to the claims occurred.
• Core Dispute: Plaintiff alleges that Defendant breached multiple prior agreements, including a settlement agreement, by developing an atherectomy device and prosecuting patents related to "Solid Counterweights," a technology Plaintiff claims exclusive ownership of.
• Technical Context: The dispute centers on rotational atherectomy devices, which are catheter-based tools used to remove atherosclerotic plaque from arteries by rotating an abrasive element at high speeds.
• Key Procedural History: The complaint outlines a complex history of agreements and litigation concerning the "Counterweight Invention" originally developed by Dr. Leonid Shturman while employed by Plaintiff's predecessor. Key events include a 2008 arbitration award and a 2008 settlement agreement affirming Plaintiff's ownership, followed by a 2012 settlement agreement with Dr. Shturman's widow that granted Plaintiff exclusive rights to practice the invention using "Solid Counterweights" while granting the widow rights to "Fluid Inflatable Counterweights." Defendant is the assignee of the widow's rights and is alleged to be bound by the 2012 agreement.

Case Timeline

Date	Event
1998-06-01	Plaintiff acquires intellectual property rights from Dr. Shturman's company, SMS.
2002-02-01	Dr. Shturman disassociates with Plaintiff and SMS.
2006-07-13	Priority Date for U.S. Patent 8,454,638.
2008-05-05	SMS Arbitration Award finds Plaintiff owns the "Counterweight Invention."
2008-09-04	Shturman Settlement Agreement entered, affirming Plaintiff's ownership rights.
2009-04-03	Priority Date for U.S. Patent 8,663,260.
2009-11-01	Dr. Shturman dies.
2012-08-27	Nadirashvili Settlement Agreement grants Plaintiff exclusive rights to "Solid Counterweights."
2013-06-04	U.S. Patent 8,454,638 issues.
2014-03-04	U.S. Patent 8,663,260 issues.
2018-02-16	Plaintiff gives Defendant notice of alleged material breach of the Settlement Agreement.
2018-03-16	Defendant disputes being in breach of the Settlement Agreement.
2019-02-07	First Amended Complaint filed.

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

The complaint lists numerous patents that Plaintiff alleges Defendant incorrectly claims to own (Compl. ¶20). These are analyzed as the patents-in-suit for this ownership dispute.

U.S. Patent 8,454,638 - Atherectomy Device Supported by Fluid Bearings (Issued 06/04/2013)

The Invention Explained

• Problem Addressed: The patent background describes the risk of abraded particles migrating downstream and blocking smaller blood vessels during rotational atherectomy procedures, and notes that prior art devices designed to prevent this were often of complicated construction (Compl., ’638 Patent, col. 1:49-54; col. 2:1-9).
• The Patented Solution: The invention is a rotational atherectomy device featuring a flexible, hollow drive shaft with an abrasive element and solid support elements. A key feature is that fluid is pumped through the drive shaft and exits through outflow channels in the solid support elements. This outflow creates a "fluid bearing"—a thin layer of fluid—between the rotating support elements and the stationary vessel wall, which serves to stabilize the device during operation (Compl., ’638 Patent, Abstract; col. 3:1-9).
• Technical Importance: The use of fluid bearings represents a method to enhance the stability of a high-speed rotational device within a delicate blood vessel, potentially reducing vessel trauma and improving the predictability of the ablation.

Key Claims at a Glance

• The complaint does not assert specific claims for infringement, as this is an ownership dispute. Claim 1 is the sole independent claim and is representative of the disputed technology.
• Essential elements of Claim 1 include:
  • A rotatable, flexible drive shaft with a fluid delivery lumen.
  • An abrasive element mounted on the drive shaft with its center of mass offset from the shaft's central axis.
  • A distal solid counterweight and a proximal solid counterweight mounted to the drive shaft, positioned on either side of the abrasive element.
  • The counterweights are configured to act as counterweights to the offset abrasive element.
  • Each counterweight defines an outflow channel in fluid communication with the lumen, configured to output fluid to form a fluid bearing between the counterweight and a vessel wall.
• The complaint does not explicitly reserve the right to assert dependent claims.

U.S. Patent 8,663,260 - Rotational Atherectomy Device with Eccentric Abrasive Element and Method of Use (Issued 03/04/2014)

The Invention Explained

• Problem Addressed: The patent background highlights the clinical challenge of performing atherectomy in tortuous iliac arteries, particularly for older patients who may need other procedures like transcatheter aortic valve replacement that require passage through the iliacs. It also notes the difficulty of controlling an abrasive element moved back and forth by pushing and pulling on only one end of a long, flexible drive shaft (Compl., ’260 Patent, col. 3:1-8; col. 3:20-33).
• The Patented Solution: The invention is a rotational atherectomy device and method specifically for treating long vessels like the iliac artery. The core concept is a drive shaft long enough to extend through the entire artery, with elongated portions extending out of the patient through two different access points (e.g., the femoral arteries in both legs). This "through-and-through" access allows an operator to move the abrasive element by pulling on either end of the drive shaft, providing more precise control and avoiding the drive shaft buckling that can occur when pushing (Compl., ’260 Patent, Abstract; col. 3:45-54).
• Technical Importance: This dual-access, "pull-pull" control system offers a solution to the mechanical challenges of navigating and ablating plaque within long, curved, and often heavily calcified peripheral arteries.

Key Claims at a Glance

• The complaint does not assert specific claims for infringement. Device claim 5 is representative of the disputed technology.
• Essential elements of Claim 5 include:
  • A flexible, rotatable drive shaft with an elongated proximal portion, an elongated distal portion, and an eccentric abrasive element mounted between them.
  • A pair of counterweights mounted on the elongated portions, spaced away from the abrasive element.
  • The drive shaft is configured for extending throughout an entire length of an artery, with one elongated portion extending out of the patient through a first access opening and the other through a second access opening.
  • A pair of prime movers, with each elongated portion of the drive shaft configured to be connected to one of the prime movers.
• The complaint does not explicitly reserve the right to assert dependent claims.

Multi-Patent Capsule: U.S. Patent 8,936,589

• Patent Identification: U.S. Patent 8,936,589, "Rotational Atherectomy Device with Fluid Inflatable Support Elements and Distal Protection Capability," issued 01/20/2015.
• Technology Synopsis: This patent describes an atherectomy device that uses fluid-inflatable support elements instead of solid ones. These elements can be inflated once the device is in position, providing stabilization during the procedure while allowing for a smaller profile during insertion and removal. The fluid flow is also designed to create a retrograde flow to capture and remove abraded debris (Compl., ’589 Patent, Abstract).
• Asserted Claims: N/A. Representative independent claims are 1 and 12.
• Accused Features: Plaintiff alleges it is the exclusive owner of any patents that incorporate the "Counterweight Invention" and/or "Solid Counterweights," and that Defendant's claim of ownership over this patent violates prior agreements (Compl. ¶19, 20).

Multi-Patent Capsule: U.S. Patent 9,089,362

• Patent Identification: U.S. Patent 9,089,362, "Rotational Atherectomy Device with Eccentric Abrasive Element and Method of Use," issued 07/28/2015.
• Technology Synopsis: This patent is a continuation of the family including the ’260 Patent and claims a similar atherectomy device for treating the iliac artery. It describes a flexible, rotatable drive shaft with an eccentric abrasive element and counterweights, designed to extend through the entire iliac artery with access from two different peripheral arteries for "pull-pull" control ('362 Patent, Abstract).
• Asserted Claims: N/A. Representative independent claim is 1.
• Accused Features: Plaintiff alleges it is the exclusive owner of any patents that incorporate the "Counterweight Invention" and/or "Solid Counterweights," and that Defendant's claim of ownership over this patent violates prior agreements (Compl. ¶19, 20).

Multi-Patent Capsule: U.S. Patent 9,192,405

• Patent Identification: U.S. Patent 9,192,405, "Rotational Atherectomy Device with Fluid Inflatable Support Elements and Two Torque Transmitting Coils," issued 11/24/2015.
• Technology Synopsis: This patent discloses an atherectomy device that combines fluid-inflatable support elements with a drive shaft constructed from two torque-transmitting coils. This dual-coil design aims to improve torque transmission and control for the rotating abrasive element, while the inflatable elements provide stabilization (Compl., ’405 Patent, Abstract).
• Asserted Claims: N/A. Representative independent claims are 1 and 11.
• Accused Features: Plaintiff alleges it is the exclusive owner of any patents that incorporate the "Counterweight Invention" and/or "Solid Counterweights," and that Defendant's claim of ownership over this patent violates prior agreements (Compl. ¶19, 20).

III. The Accused Instrumentality

Product Identification

The "FreedomFlow™" atherectomy device, which is described as being developed or in the process of development by Cardio Flow (Compl. ¶17).

Functionality and Market Context

The complaint alleges that the FreedomFlow™ device "incorporates one or more Solid Counterweights or an equivalent thereof" (Compl. ¶17). This alleged feature is the basis for the claim that Cardio Flow's development of the device constitutes a breach of the Nadirashvili Settlement Agreement, which grants exclusive rights to "Solid Counterweights" technology to CSI (Compl. ¶15, 17). The complaint provides no further technical details on the device's operation or market status.

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

This section is not applicable. The complaint does not allege patent infringement but rather breach of contract and seeks a declaratory judgment of patent ownership.

V. Key Claim Terms for Construction

This section is not applicable. The central dispute does not turn on the construction of patent claim terms but on the contractual definition of "Solid Counterweights" provided in a prior settlement agreement (Compl. ¶15).

VI. Other Allegations

This section is not applicable. The complaint does not allege indirect or willful infringement.

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

The dispute centers on a series of contracts and assignments rather than a direct patent infringement analysis. The outcome will likely depend on the court's interpretation of these prior agreements and the technical nature of Defendant's activities. The key questions for the court appear to be:

• Contractual Scope: Does the technology embodied in the disputed patents and the in-development FreedomFlow™ device fall within the contractual definition of "Solid Counterweights"—"a support element or counterweight that is incapable of being inflated by fluid"—to which Plaintiff holds exclusive rights under the 2012 settlement agreement?
• Chain of Title: Can Plaintiff definitively establish an unbroken chain of ownership of the underlying "Counterweight Invention" through the multiple employment, asset purchase, arbitration, and settlement agreements detailed in the complaint, thereby superseding the ownership claims of the defendant?
• Material Breach: Does Defendant's alleged development of a device incorporating "Solid Counterweights" and its prosecution of patents claiming such technology constitute a material breach of the 2012 settlement agreement, by which Defendant is bound as an assignee?