ABS Global Inc v. Cytonome St LLC

1. Case Identification

• Case #: IPR2017-02097
• Patent #: 8,529,161
• Filed: October 5, 2017
• Petitioner(s): ABS Global, Inc.; Genus plc
• Patent Owner(s): CYTONOME/ST, LLC
• Challenged Claims: 1-20

2. Patent Overview

• Title: Multilayer Hydrodynamic Sheath Flow Structure
• Brief Description: The ’161 patent discloses microfluidic systems and methods for controlling the position of a particle-containing sample within a flow channel. The system uses hydrodynamic focusing, achieved by introducing fluid through a series of inlets that intersect a primary flow channel at distinct adjustment regions.

3. Grounds for Unpatentability

Ground 1: Claims 1-20 are anticipated by Wada under 35 U.S.C. §102.

• Prior Art Relied Upon: Wada (Patent 6,506,609).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Wada, which relates to focusing microparticles in microfluidic systems, discloses every limitation of the challenged claims. Independent claims 1 and 9 require a microfluidic system with a primary flow channel, a primary adjustment region with a first set of inlets, and a secondary adjustment region with a second set of inlets downstream of the first. Petitioner mapped these limitations to Wada’s Figure 23, which illustrates a system with a main channel intersected by a series of offset microchannels. The first intersecting microchannel was identified as the claimed "primary adjustment region," and a subsequent downstream microchannel was identified as the "secondary adjustment region." Petitioner contended that the introduction of sheath fluid through these sequential inlets in Wada adjusts the sample in at least two different directions, as required by the claims.
  • Key Aspects: Petitioner asserted that Wada’s teachings of horizontal and vertical focusing, which can be performed sequentially, inherently satisfy the claim limitations for adjusting a sample in two different directions. Further, Petitioner argued that the specific movements recited in the dependent claims (e.g., "aligning," "focusing," "orienting," "positioning") are all inherent results or the explicit purpose of the hydrodynamic focusing systems described in Wada, particularly for applications like flow cytometry.

Ground 2: Claims 1-20 are obvious over Wada in view of Micronics 2001 under 35 U.S.C. §103.

• Prior Art Relied Upon: Wada (Patent 6,506,609) and Micronics 2001 (Weigl et al., “Design and Rapid Prototyping of Thin-Film Laminate-Based Microfluidic,” Biomedical Microdevices 3(4):267-274 (2001)).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground was presented as an alternative to anticipation. Petitioner argued that even if Wada does not explicitly disclose every specific type of adjustment recited in the dependent claims, a person of ordinary skill in the art (POSITA) would have found it obvious to configure the system taught by Wada to achieve these results. Wada expressly teaches that its microfluidic hydrodynamic focusing systems are "highly effective" for use in flow cytometry applications, which rely on precise particle manipulation. The adjustments recited in the dependent claims—such as aligning, focusing, and positioning particles—are the fundamental objectives of using such systems in flow cytometry.
  • Motivation to Combine: A POSITA would be motivated to apply the teachings of Wada for its intended purpose of precisely controlling particle streams in applications like flow cytometry. Micronics 2001 does not add a new structural element but rather informs what a POSITA would have considered routine and achievable. The motivation was to implement Wada's system to perform the well-known and necessary particle adjustments for effective analysis, as detailed in the dependent claims.
  • Expectation of Success: Micronics 2001 was cited to demonstrate that a POSITA would have had a high expectation of success. It described how microfluidic devices for cell analysis, including those for 3-dimensional hydrodynamic focusing, could be rapidly designed, prototyped, and tested (often within 24 hours) using commercially available software and routine fabrication techniques. This established that configuring a system like Wada's to achieve the specific adjustments claimed in the ’161 patent was a predictable and routine design choice, not an inventive leap.

4. Key Claim Construction Positions

• "Adjusted" / "Adjusting": Petitioner argued that under the broadest reasonable interpretation, these terms should be construed to mean "moved" or "moving." This construction was based on the plain meaning of "adjust" and supported by the various types of movements specified in the dependent claims (e.g., aligning, focusing, orienting), all of which constitute a form of movement.
• "Focusing": Consistent with the construction of "adjusting," Petitioner asserted that "focusing" should also be construed as "moving" or "moved." The ’161 patent specification consistently uses "focus" to describe the movement of fluids and particles via hydrodynamic forces, and Petitioner argued it carries no meaning distinct from "adjusting" in the context of the claims.
• "primary alignment region": Petitioner contended this phrase in claim 1 is a typographical error and should be construed as "primary adjustment region." This interpretation was based on the term’s logical antecedent within the same claim clause and its consistent use elsewhere in the claims.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under §325(d) would be inappropriate because the primary reference, Wada, was not substantively considered during the original prosecution of the ’161 patent. Although Wada was cited in an Information Disclosure Statement (IDS), it was submitted after a notice of allowance had already issued. The IDS did not specify any relevant pages, columns, or figures, and the examiner did not use Wada as a basis for any rejection. Therefore, Petitioner asserted that the arguments presented in the petition were not the "same or substantially the same" as those previously considered by the USPTO.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-20 of the ’161 patent as unpatentable.