NOTE: This disposition is nonprecedential.

 

United States Court of Appeals 

for the Federal Circuit ______________________ 

LEICA MICROSYSTEMS, INC.,

Appellant

v.

REGENTS OF THE UNIVERSITY OF MICHIGAN,

Appellee

______________________ 

2022-1445

______________________ 

Appeal from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in No. IPR2020-

01165.

______________________ 

Decided: April 24, 2023

______________________ 

ANDREW RYAN SOMMER, Greenberg Traurig LLP, 

McLean, VA, argued for appellant. Also represented by 

VIVIAN KUO, Washington, DC.

 RUSSELL TONKOVICH, Kramer Alberti Lim & Tonkovich 

LLP, Burlingame, CA, argued for appellee. Also represented by AIDAN BREWSTER, ROBERT KRAMER. 

______________________ 

Before LOURIE, DYK, and STARK, Circuit Judges.

Case: 22-1445 Document: 42 Page: 1 Filed: 04/24/2023
LEICA MICROSYSTEMS, INC. v. 

REGENTS OF THE UNIVERSITY OF MICHIGAN

2

LOURIE, Circuit Judge. 

Leica Microsystems, Inc. (“Leica”) appeals from a final 

written decision of the United States Patent and Trademark Office Patent Trial and Appeal Board (“the Board”) 

holding that Leica failed to show that claims 1–26 of U.S. 

Patent 7,277,169 (the “’169 patent”) were unpatentable as 

obvious. See Leica Microsys. Inc. v. Regents of the Univ. of 

Mich., No. IPR2020-01165, Paper No. 26 (P.T.A.B. Jan. 7, 

2022), J.A. 1–27 (“Decision”). For the reasons provided below, we affirm. 

BACKGROUND

Regents of the University of Michigan (“Regents”) own 

the ’169 patent, which describes a fluorescence detection 

system that detects light that is emitted from a sample after it is struck with an excitation light. The system uses 

ultrafast white light optical pulses to excite fluorophores

and a detector to detect the emitted light. Claims 1, 10, 

and 19 are the three independent claims, each reciting a

fluorescence detection system for testing a sample, comprising a single-source white light generation system and 

a time-resolving detector for receiving fluorescence. Representative claim 1 is presented below:

1. A fluorescence detection system for testing 

a sample, said sample having a plurality of 

fluorophores, said fluorescence detection system comprising: 

a single-source white light generation system 

outputting a supercontinuum white light

pulse comprising an entire spectrum of white 

light, said supercontinuum white light pulse 

exciting the plurality of fluorophores of the 

sample to emit fluorescence; and

a time-resolving detector receiving said fluorescence and at least a portion of said supercontinuum white light pulse, said timeCase: 22-1445 Document: 42 Page: 2 Filed: 04/24/2023
LEICA MICROSYSTEMS, INC. v.

REGENTS OF THE UNIVERSITY OF MICHIGAN

3

resolving detector separating said fluorescence from said portion of said supercontinuum white light pulse.

’169 patent, col. 7 ll. 43–55. 

Relevant to this appeal, Leica petitioned for inter 

partes review (“IPR”) of claims 1–26, asserting that the 

claims would have been obvious over PCT application WO 

01/022063 (“Folestad”) in view of various secondary references, including Wittmershaus.1 Folestad discloses a 

method of analyzing a turbid pharmaceutical sample (e.g., 

a tablet) using white light from a laser excitation source. 

Wittmershaus describes a method for analyzing fluorophores in chlorophyll from spinach leaves using a fluorescence detection system.

The Board concluded that Leica had not shown an adequate rationale for combining Folestad with other secondary references, including Wittmershaus. The Board 

rejected Leica’s expert testimony as conclusory and lacking 

evidentiary support, also holding that there was no evidence that Folestad would have provided any improvement 

or benefit over Wittmershaus. The Board also rejected 

Leica’s showing that substituting one sample for another 

in the same system was routine. Finally, the Board held 

that the record lacked evidence regarding whether a skilled 

artisan would have configured the system in Folestad to 

measure fluorescence as required by the claims in the ’169 

patent. 

Leica appealed the Board’s decision. We have jurisdiction under 28 U.S.C. § 1295(a)(4)(A). 

1 Bruce Wittmershaus et al., Picosecond studies at 

77 K of energy transfer in chloroplasts at low and high excitation intensities, 806 BIOCHIMICA ET BIOPHYSICA ACTA 93

(1985).

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DISCUSSION

We review the Board’s legal determinations de novo, In 

re Elsner, 381 F.3d 1125, 1127 (Fed. Cir. 2004), and the 

Board’s factual findings for substantial evidence, In re 

Gartside, 203 F.3d 1305, 1316 (Fed. Cir. 2000). A finding 

is supported by substantial evidence if a reasonable mind 

might accept the evidence as adequate to support the finding. Consol. Edison Co. v. NLRB, 305 U.S. 197, 229 (1938). 

 Leica argues that the Board applied too rigid an obviousness analysis, focusing too heavily on the references 

themselves and not considering the background knowledge 

of a skilled artisan, in violation of KSR Int’l Co. v. Teleflex 

Inc., 550 U.S. 398 (2007). Leica also contends that the 

Board’s finding that sample substitution was not simple 

was unsupported by substantial evidence. Leica asserts 

that the Board improperly focused on unclaimed sample 

preparation techniques, which, even if relevant, fell within 

the routine abilities of the skilled artisan. Leica further 

argues that the claimed invention is nothing more than a 

new use of Folestad’s old system, and that a new use of an 

old system would not be patentable. 

Regents respond that the Board’s finding that there 

was no motivation to combine Folestad and Wittmershaus 

was supported by substantial evidence, that the Board did 

not misapply the law of obviousness, and that the Board 

did not err in finding that Wittmershaus disclosed highly 

specialized sample preparation for use in highly specialized

fluorescence detection systems. Regents also assert that 

the Board did not err in crediting Regents’ expert and rejecting Leica’s expert’s testimony as conclusory. Regents 

further contend that the claimed invention and the Folestad reference describe different systems for different purposes, and so the claimed invention is not merely a new use 

of Folestad’s old system. 

We agree with Regents that the Board’s finding that 

there was no motivation to combine Folestad with 

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Wittmershaus was supported by substantial evidence. In 

arriving at its conclusion, the Board found that Leica’s proposed combination of Folestad with Wittmershaus required 

replacing Folestad’s teachings of detection of transmitted 

or reflected radiation with Wittmershaus’s detection of fluorescence. Decision at 16–17, J.A. 16–17. The Board further found that the record lacks evidence regarding 

whether and how a skilled artisan would have configured 

Folestad to measure fluorescence. Decision at 18, J.A. 18. 

In other words, one would have needed to modify Folestad 

to arrive at the claimed invention. 

The Board also credited expert testimony from both 

parties in determining whether a skilled artisan would 

have been motivated to make the modifications necessary 

to combine Folestad and Wittmershaus. It is within the 

discretion of the Board to weigh the evidence of record. 

Tiger Lily Ventures Ltd. v. Barclays Cap. Inc., 35 F.4th 

1352, 1365–66 (Fed. Cir. 2022); see also Shoes by Firebug 

LLC v. Stride Rite Child.’s Grp., LLC, 962 F.3d 1362, 1371 

(Fed. Cir. 2020) (“[I]t is not for us to second-guess the 

Board’s assessment of the evidence.”). Here, the Board did 

just that. We therefore hold that the Board’s finding that 

a skilled artisan would not have been motivated to combine 

Folestad with Wittmershaus was supported by substantial 

evidence. 

CONCLUSION

We have considered Leica’s remaining arguments but 

find them unpersuasive. For the foregoing reasons, we affirm the Board’s final written decision. 

AFFIRMED

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