Leica Microsystems Inc v. Regents Of University Of Michigan

1. Case Identification

• Case #: IPR2020-01165
• Patent #: 7,277,169
• Filed: June 26, 2020
• Petitioner(s): Leica Microsystems, Inc.
• Patent Owner(s): The Regents of the University of Michigan
• Challenged Claims: 1-26

2. Patent Overview

• Title: Fluorescence Detection System
• Brief Description: The ’169 patent discloses a fluorescence detection system for analyzing samples containing multiple fluorophores. The system uses a single light source and a non-linear optical member to generate a "supercontinuum white light pulse" that comprises an "entire spectrum of white light," which simultaneously excites the various fluorophores. A time-resolving detector is then used to detect the resulting fluorescence.

3. Grounds for Unpatentability

Ground 1: Obviousness over Folestad and Secondary References - Claims 1-3, 6-10, 12, 15-21, and 24-26 are obvious over Folestad in view of Laporte, Marriott, or Wittmershaus.

• Prior Art Relied Upon: Folestad (WO 2001/22063) in view of one of Laporte (a 2004 SPIE paper), Marriott (a 1991 journal article), or Wittmershaus (a 1985 paper).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Folestad discloses a detection system that is structurally indistinguishable from the system claimed in the ’169 patent. Folestad’s system includes a single source (Ti:sapphire laser), a non-linear member (a water-filled cuvette) to generate a supercontinuum white light pulse, and a time-resolving detector (a streak camera). The primary difference asserted was that Folestad describes testing a "pharmaceutical sample," not explicitly one containing a plurality of fluorophores. The secondary references (Laporte, Marriott, and Wittmershaus) each teach preparing and analyzing various samples (e.g., rat brain, labeled cells, spinach leaves) that inherently contain multiple fluorophores and using time-resolved techniques to measure their fluorescence.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSA) would combine these references by using the known samples from Laporte, Marriott, or Wittmershaus in Folestad’s known detection system. The motivation was simple: to use a known apparatus to analyze a known type of sample, a common and routine practice in microscopy. Petitioner contended this amounted to an unpatentable new use for an old and obvious system.
  • Expectation of Success: A POSA would have had a high expectation of success, as the combination merely applied a known measurement technique (Folestad's system) to a known type of sample (e.g., Laporte's rat brain). The results, such as the excitation of the known fluorophores by Folestad’s broadband pulse, would have been entirely predictable.

Ground 2: Obviousness over Marriott and Birk - Claims 1-3, 5-8, 10, 12, 14-17, 19-21, 23-24, and 26 are obvious over Marriott in view of Birk.

• Prior Art Relied Upon: Marriott (a 1991 journal article) in view of Birk (Patent 6,611,643).

• Core Argument for this Ground:

  • Prior Art Mapping: Marriott discloses a time-resolved fluorescence microscopy system for analyzing samples with multiple fluorophores. Marriott’s system uses either a narrow-band laser or a mercury arc lamp as its excitation source, noting the arc lamp provides a "continuous light spectrum." Birk discloses a supercontinuum white light generation system—using a laser, a non-linear medium like a photonic crystal fiber, and generating a pulse from 300 nm to 1600 nm—and teaches its advantages for microscopy.
  • Motivation to Combine: A POSA would combine these references because Birk expressly teaches that its supercontinuum source is superior to arc lamps, providing higher luminance and the ability to excite a wider range of fluorophores. This provided a direct motivation to replace the inferior arc lamp in Marriott's system with the improved supercontinuum source taught by Birk to achieve these known benefits.
  • Expectation of Success: Substituting one known illumination source for an improved, known illumination source to achieve predictable advantages (better signal, broader excitation) would have been a straightforward modification with a high expectation of success.

• Additional Grounds: Petitioner asserted additional obviousness challenges based on combinations of the above art with Zeylokovich (a 2003 journal article teaching the use of sapphire or photonic crystal fibers as specific non-linear materials) and Alfano (a 1989 book teaching that the duration of a supercontinuum pulse is nearly identical to the input laser pulse).

4. Key Claim Construction Positions

• Petitioner submitted that no express claim construction was necessary to resolve the proceeding. However, for clarification, Petitioner addressed the term "a member having a non-linear refractive index" (claims 2, 10, 20).
• Petitioner argued this term should be interpreted broadly to describe any material that exhibits a non-linear refractive index in the presence of an ultrafast laser pulse and is capable of generating a supercontinuum pulse. This construction supports the view that the water-filled cuvette in Folestad and the photonic crystal fiber in Birk meet this limitation.

5. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under 35 U.S.C. §325(d) because the primary references (Folestad and Marriott) are materially different from the prior art considered by the examiner during prosecution.
• Petitioner also argued against discretionary denial under Fintiv, stating that institution is strongly favored. Key reasons included:
  • Petitioner would promptly move to stay the co-pending district court litigation.
  • To avoid duplicative efforts, Petitioner would stipulate not to pursue the same invalidity grounds in the district court.
  • There is limited overlap between the IPR and the litigation, as several challenged claims are not asserted in the district court case.
  • The merits of the petition are strong, particularly the argument that the ’169 patent claims an unpatentable new use for an old system taught by Folestad.

6. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-26 of the ’169 patent as unpatentable.