United States Court of Appeals 

for the Federal Circuit ______________________ 

MEDTRONIC, INC., MEDTRONIC VASCULAR, 

INC.,

Appellants

v.

TELEFLEX INNOVATIONS S.À.R.L.,

Appellee

______________________ 

2021-2356, 2021-2358, 2021-2361, 2021-2363, 21-2365

______________________ 

Appeals from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in Nos. IPR2020-

00126, IPR2020-00128, IPR2020-00132, IPR2020-00135, 

IPR2020-00137. 

______________________ 

Decided: May 24, 2023

______________________ 

TASHA JOY BAHAL, Wilmer Cutler Pickering Hale and 

Dorr LLP, Boston, MA, argued for appellants. Also represented by MARK CHRISTOPHER FLEMING, HANNAH ELISE 

GELBORT, MADELEINE C. LAUPHEIMER; BRITTANY BLUEITT 

AMADI, JENNIFER L. GRABER, Washington, DC. 

 J. DEREK VANDENBURGH, Carlson, Caspers, Vandenburgh & Lindquist PA, Minneapolis, MN, argued for appellee. Also represented by PETER M. KOHLHEPP, TARA 

CATHERINE NORGARD, JOSEPH W. WINKELS. 

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2 MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 

 ______________________ 

Before MOORE, Chief Judge, LOURIE and DYK, Circuit 

Judges. 

Opinion for the court filed by Circuit Judge LOURIE. 

Dissenting opinion filed by Circuit Judge DYK. 

LOURIE, Circuit Judge. 

Medtronic, Inc. and Medtronic Vascular, Inc. (collectively, “Medtronic”) appeal from five final written decisions 

of the United States Patent and Trademark Office Patent 

Trial and Appeal Board (“the Board”) finding that Itou1

does not qualify as prior art to related U.S. Patents 

8,048,032, RE45,380, RE45,776, RE45,760, and RE47,379 

(collectively, “the challenged patents”) under pre-AIA firstto-invent provisions, and Medtronic had therefore not 

shown the challenged claims to be unpatentable. Medtronic, Inc. v. Teleflex Innovations S.À.R.L., IPR2020-

00126 (P.T.A.B. Jun. 7, 2021) (“Decision”), J.A. 1–75; Medtronic, Inc. v. Teleflex Innovations S.À.R.L., IPR2020-

00128 (P.T.A.B. Jun. 7, 2021), J.A. 76–150; Medtronic, Inc. 

v. Teleflex Innovations S.ÀR.L., IPR2020-00132 (P.T.A.B. 

Jun. 7, 2021), J.A. 151–222; Medtronic, Inc. v. Teleflex Innovations S.À.R.L., IPR2020-00135 (P.T.A.B. Jun. 7, 2021),

J.A. 223–98; Medtronic, Inc. v. Teleflex Innovations 

S.À.R.L., IPR2020-00137 (P.T.A.B. Jun. 7, 2021), J.A. 299–

373.2 For the reasons provided below, we affirm.

1 U.S. Patent 7,736,355 to Itou et al. (“Itou”). 

2 The five final written decisions in the IPRs consolidated on appeal share similar sections on conception and 

reduction to practice. The decision in Medtronic, Inc. v. Teleflex Innovations S.À.R.L., IPR2020-00126 (P.T.A.B. Jun. 

7, 2021), J.A. 1–75, is representative and cited throughout 

as such. 

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MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 3

BACKGROUND

The challenged patents, developed by Vascular Solutions Inc. (“VSI”) but now owned by appellee Teleflex Innovations S.À.R.L. (“Teleflex”), all descend from a common 

application filed on May 3, 2006 and share a common specification. The challenged patents are directed to guide extension catheters that use a tapered inner catheter that 

runs over a standard coronary guidewire to reduce the likelihood that a guide catheter will dislodge from the coronary 

artery’s opening (i.e., ostium). See, e.g., ’032 patent, col. 1 

ll. 32–36, col. 2 ll. 53–59.

According to Teleflex, VSI conceived the claimed invention in early 2005 and then worked to develop it under the 

“GuideLiner” name. Teleflex asserts that what was known 

as the “rapid exchange” or “RX” version of the GuideLiner 

practices the challenged patents. Decision, J.A. 17. However, in the same time period, VSI also worked on developing an “over-the-wire” or “OTW” version of the GuideLiner, 

which was more akin to the prior art guide extension catheters and does not practice the challenged patents. Id. at

J.A. 19. Because the over-the-wire GuideLiner was more 

similar to devices already in existence, it had fewer challenges to overcome and work on it progressed more rapidly 

than for the rapid exchange device. Id. at J.A. 36. The

rapid exchange GuideLiner eventually entered the market 

in 2009. Id. at J.A. 61. 

Medtronic filed thirteen petitions for inter partes review (“IPR”) of the challenged patents, eleven of which 

were instituted and five of which are consolidated in this 

appeal. These five IPR petitions asserted Itou as the primary prior art reference under pre-AIA 35 U.S.C. § 102(e)

(2012). Following institution, Teleflex filed a consolidated 

response addressing conception and reduction to practice, 

asserting that Itou did not qualify as prior art because the 

claimed inventions were (1) conceived prior to Itou’s filing 

date of September 23, 2005 (i.e., the critical date), and (2) 

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4 MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 

were (a) actually reduced to practice before the critical date 

or (b) diligently pursued until their constructive reduction 

to practice through their effective filing in May 2006. In 

support of its contentions, Teleflex submitted numerous 

declarations, including from inventors and noninventors, 

as well as nearly 75 documentary exhibits including inventor lab notebooks, internal company memoranda and 

presentations, invoices and sales orders, photographs, engineering drawings, and documents from outside patent 

counsel. Decision, J.A. 13. 

The Board found that the evidence demonstrated that 

the claimed inventions were (1) conceived no later than August 2005, i.e., before the critical date, and (2) either (a) 

actually reduced to practice for their intended purpose in 

April and July 2005, prior to the critical date, or (b) diligently worked on toward constructive reduction to practice 

on May 3, 2006, the challenged patents’ effective filing

date. Id. at J.A. 34, 61–62, 71. In so doing, the Board found 

that the intended purpose of the claimed inventions was 

providing improved backup support for the guide catheter, 

rejecting Medtronic’s suggestion that the intended purpose, or additional intended purpose, was providing backup 

support necessary for accessing and crossing tough or 

chronic occlusions. Id. at J.A. 53. The Board therefore determined that Itou did not qualify as prior art to the challenged patents under pre-AIA 35 U.S.C. § 102(e), thereby 

eliminating the challenges presented in the five IPRs relevant to this appeal. The Board thus concluded that Medtronic had failed to demonstrate that the challenged claims 

were unpatentable. 

Medtronic appealed. We have jurisdiction under 

28 U.S.C. § 1295(a)(4)(A).

DISCUSSION

In considering whether or not a reference qualifies as 

prior art under pre-AIA 35 U.S.C. § 102(e), we must consider whether or not “the invention was described in . . . a 

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MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 5

patent granted on an application for patent by another filed 

in the United States before the invention by the applicant 

for patent.” A patent owner may antedate an asserted

prior art patent by showing conception of the claimed invention prior to the critical date and either actual reduction to practice prior to the critical date or “reasonably 

continuous diligence” in reducing the invention to practice 

until its effective filing date. See ATI Techs. v. Iancu, 920 

F.3d 1362, 1369 (Fed. Cir. 2019); Tyco Healthcare Grp. v. 

Ethicon Endo-Surgery, Inc., 774 F.3d 968, 975 (Fed. Cir. 

2014). Inventor declarations submitted to antedate a reference must be corroborated, and corroboration is governed 

by a “rule of reason” standard. Perfect Surgical Techs., Inc. 

v. Olympus Am., Inc., 841 F.3d 1004, 1007–09 (Fed. Cir. 

2016).

In an IPR, the petitioner bears the ultimate burden of 

persuasion on invalidity, which never shifts to the patent 

owner. Dynamic Drinkware, LLC v. Nat’l Graphics, Inc., 

800 F.3d 1375, 1378 (Fed. Cir. 2015). However, when a patent owner attempts to antedate an asserted prior art reference, the patent owner takes on a temporary burden of 

production. Id. at 1378–79. Once that burden is met, the 

burden shifts back to the petitioner. Id. at 1379.

We review the Board’s factual findings on reduction to 

practice and diligence for substantial evidence, and its legal conclusion of priority de novo. E.I. du Pont de Nemours 

& Co. v. Unifrax I LLC, 921 F.3d 1060, 1075 (Fed. Cir. 

2019). Medtronic does not challenge the Board’s findings 

of conception prior to the critical date on appeal, but challenges both the Board’s findings on actual reduction to 

practice and reasonable diligence toward constructive reduction to practice. We address each argument in turn. 

I 

To establish actual reduction to practice before the critical date, it must have been shown that “(1) [the inventors] 

constructed an embodiment or performed a process that 

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6 MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 

met all the limitations of the [claimed invention]; and (2) 

[the inventors] determined that the invention would work 

for its intended purpose.” Cooper v. Goldfarb, 154 F.3d 

1321, 1327 (Fed. Cir. 1998). Medtronic challenges the 

Board’s determinations regarding both of these elements

on three grounds. First, Medtronic argues that the Board 

erred in identifying the intended purpose of the claimed inventions. Second, Medtronic argues that, even if the 

Board’s finding of the intended purpose was correct, the 

Board erred in not requiring comparative testing to demonstrate that the invention worked for that purpose. Third, 

Medtronic argues that the Board erred in relying solely on 

uncorroborated inventor testimony as evidence of actual 

reduction to practice. We disagree for the reasons provided 

below. 

A 

Medtronic argues that the intended purpose should be 

both, as the Board found, providing increased backup support as compared with a guide catheter alone and facilitating the delivery of interventional devices through tough or 

chronic occlusions. Medtronic faults the Board for relying 

on extrinsic evidence to determine the intended purpose 

when the patents’ specifications and claims are the proper 

source of information. Medtronic further argues that had 

the Board correctly determined the intended purpose, it 

could not have found that Teleflex proved that the prototypes functioned for that purpose. Teleflex argues that 

Medtronic waived the argument that the Board erred by 

considering extrinsic evidence in determining the intended 

purpose when it repeatedly urged the Board to consider extrinsic evidence and failed to point the Board to any intrinsic evidence, and the Board’s determination of the intended 

purpose is correct. 

Similar to claim construction, a determination of an invention’s intended purposes is a legal issue, reviewed de 

novo. See z4 Techs., Inc. v. Microsoft Corp., 507 F.3d 1340, 

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MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 7

1352 (Fed. Cir. 2007) (affording no deference to district 

court’s reading of patents’ language to “define[] the ‘intended purpose’ of the invention”). Because we evaluate 

the intended purpose without deference to the Board’s determination, it is of no consequence whether the Board relied on extrinsic evidence or whether Medtronic waived the 

argument that doing so would have been in error. Regardless, although the patents themselves are the most important and, indeed, most persuasive evidence of the 

patents’ intended purpose, we find it is appropriate to consider extrinsic evidence, particularly when it does not contradict the patents themselves. Medtronic cites no case 

showing otherwise. 

We, like the Board, find Medtronic’s proposed intended 

purpose to be overly narrow. See Decision, J.A. 52–53. Although the challenged patents do mention crossing “tough” 

or “chronic” occlusions, we find that to be a specific example 

within a broader general purpose. Indeed, as the Board 

found, the challenged patent specification itself recognizes 

a broader purpose when discussing the field and background of the invention. See, e.g., ’032 patent at col. 1 ll. 8–

11 (“More particularly the present invention relates to 

methods and apparatus for increasing backup support for 

catheters inserted into the coronary arteries from the 

aorta.”), col. 2 ll. 45–49 (“Thus, the interventional cardiology art would benefit from the availability of a system that 

would be deliverable through standard guide catheters for 

providing backup support by providing the ability to effectively create deep seating in the ostium of the coronary artery.”). Although that intrinsic evidence is sufficient, a

broader purpose than that urged by Medtronic is further 

supported by both expert and inventor testimony. See Decision, J.A. 54–55 (citing J.A. 12012; J.A. 11815–16; J.A. 

11834). 

Moreover, the evidence suggests a broader intended 

purpose than the Board found may even be appropriate. 

The challenged patents are titled “Coaxial Guide Catheter 

Case: 21-2356 Document: 56 Page: 7 Filed: 05/24/2023
8 MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 

for Interventional Cardiology Procedures,” and the claims

are generally directed to a “device for use with a standard 

guide catheter.” See, e.g., ’032 patent at Title, col. 10 ll. 21; 

see also J.A. 11816 (inventor describing the intended purpose). The claims do not mandate a purpose beyond performing the functions of a guide extension catheter. This 

is not an obviousness inquiry. The very title of the patents 

themselves, “Coaxial Guide Catheter for Interventional 

Cardiology Procedures,” describes the purpose of the 

claimed inventions, and it is undisputed that the claim language does not impose a further purpose than this. We 

therefore reject Medtronic’s argument that the intended 

purpose of the claimed invention should be narrower than 

that determined by the Board. 

B 

Medtronic further argues that, even assuming the 

Board’s determined intended purpose is correct, there is no 

evidence that Teleflex’s claimed device compared favorably 

with a guide catheter alone (i.e., worked for the Board’s determined intended purpose of “providing improved backup 

support for a guide catheter”). Decision, J.A. 53 (emphasis 

added). Teleflex argues that Medtronic forfeited the argument that comparative testing was required by not raising 

it before the Board, and, regardless, testing is not required 

to confirm aspects of the invention that would have already 

been known to a person of ordinary skill in the art. 

As an initial matter, we do not find Medtronic’s argument on this point to be forfeited. Generally, a federal appellate court does not consider issues not raised before the 

lower tribunal. Singleton v. Wulff, 428 U.S. 106, 120 

(1976). The exact phrasing of the argument need not have 

been used below “so long as it can be said that the tribunal 

was ‘fairly put on notice as to the substance of the issue.’” 

Nike Inc. v. Adidas AG, 812 F.3d 1326, 1342 (Fed. Cir. 

2016) (citing Consolidation Coal Co. v. United States, 351 

F.3d 1374, 1378 (Fed. Cir. 2003) (quoting Nelson v. Adams, 

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MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 9

529 U.S. 460, 469 (2000) (“But [issue preservation] does not 

demand the incantation of particular words; rather, it requires that the lower court be fairly put on notice as to the 

substance of the issue.”))). But even if an issue was not 

presented below, there is no absolute bar to considering 

and deciding the issue on appeal, as forfeiture is a matter 

of discretion. Harris Corp. v. Ericsson Inc., 417 F.3d 1241, 

1251 (Fed. Cir. 2005) (“An appellate court retains case-bycase discretion over whether to apply waiver.”). 

Here, Medtronic argued in their Reply that “Teleflex 

cannot prove VSI performed any testing, much less testing 

to confirm intended purpose.” J.A. 24495; see also J.A. 

25042 (“The Board cannot evaluate whether Teleflex’s testing ‘evidence’ proves that VSI demonstrated that [the invention] would work for its intended purpose.”). We 

consider these assertions sufficient to preserve Medtronic’s 

argument that comparative testing was required given the 

intended purpose determined by the Board. Although 

Medtronic’s statements before the Board more generally 

addressed the insufficiency of the evidence and corroboration of testing, without a specific mention to “comparative” 

testing, they still address the same, general issue: whether 

or not the testing showed the invention worked for its intended purpose. 

Regardless, we find the testing performed to be sufficient to show that the claimed invention worked for its intended purpose as determined by the Board. Sufficiency of 

the testing required to show an invention worked for its 

intended purpose is a question of fact reviewed for substantial evidence. See z4 Techs., 507 F.3d at 1352 (“[T]he necessity and sufficiency of such testing are factual issues.”); 

Scott v. Finney, 34 F.3d 1058, 1061–62 (Fed. Cir. 1994) 

(“[T]he testing requirement depends on the particular facts 

of each case.”). Here, the Board thoroughly reviewed and 

analyzed the evidence of testing in the record, and we decline to remake or reweigh its factual findings. 

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10 MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 

Namely, we find the Board’s conclusion that the 

claimed invention was determined to work for its intended 

purpose was supported by substantial evidence. As the 

Board noted, both inventors Howard Root and Gregg Sutton testified regarding testing performed on a prototype of 

the claimed invention. Decision, J.A. 44 (citing J.A. 11815, 

11834, 11971, 11982–83). Although these tests did not specifically compare the invention prototype with a guide catheter alone, they enabled the inventors to observe the forces 

exerted on the prototype and the durability of the prototype. Id. The Board determined that these tests, although 

“more qualitative than quantitative,” were sufficient to enable the inventors to confirm that the prototype would 

work for its intended purpose—providing increased backup 

support as compared with a guide catheter alone. Id. We 

agree. The Board’s determined intended purpose did not 

mandate a 1:1 comparison or quantitative assessment to 

show an “increase” or “improvement” in function. Rather, 

it simply requires that an inventor, a skilled artisan, would 

observe the tests and understand that they indicate the 

prototype is more effective than a guide catheter alone. 

And that is the case here. See, e.g., J.A. 12010–12 (expert 

testimony that “actual reduction to practice of the GuideLiner invention would have required little if any testing,” 

and that, to the extent it did, “qualitative testing would 

have been sufficient”). 

Because we find the Board’s finding of actual reduction 

to practice under its determined intended purpose supported by substantial evidence, we find the same would be 

true for our suggested, broader, intended purpose of simply 

functioning as a guide extension catheter. Indeed, as counsel for Appellant conceded at oral argument, “[w]e may not 

need comparative testing if the Board had found a different

intended purpose.” Oral Arg. at 3:18–22. 

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MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 11

C 

Finally, Medtronic argues that Teleflex’s evidence of 

actual reduction to practice is insufficiently corroborated. 

Inventor testimony may serve as evidence of reduction to 

practice, but it must be corroborated by independent evidence. Cooper, 154 F.3d at 1330. The sufficiency of such 

corroborating evidence is evaluated under a “rule of reason,” considering all pertinent evidence. Id. Corroboration 

can come from documentary evidence, noninventor testimony, or a combination of both. Loral Fairchild Corp. v. 

Matsushita Elec. Indus. Co., 266 F.3d 1358, 1364 (Fed. Cir. 

2001) (“Under the ‘rule of reason,’ the inventor's testimony 

must be sufficiently corroborated by independent evidence, 

but not necessarily documentary evidence.”). Corroborating evidence may also be circumstantial. Cooper, 154 F.3d 

at 1330 (“In order to corroborate a reduction to practice, it 

is not necessary to produce an actual over-the-shoulder observer. Rather, sufficient circumstantial evidence of an independent nature can satisfy the corroboration 

requirement.”). Nor must every individual aspect of reduction to practice be corroborated. E.I. du Pont, 921 F.3d at

1077. Rather, the corroborative evidence simply needs to 

be sufficient to support the credibility of the inventors’ 

story. Id. 

Here, we find the inventors’ testimony of actual reduction to practice, including that the invention worked for its 

intended purpose, sufficiently corroborated. Inventors 

Root and Sutton testified regarding the building and testing of a prototype of the claimed invention. J.A. 11815, 

11834, 11971, 11982–83. As the Board found, that testimony was supported by both documentary evidence and 

noninventor testimony. Decision, J.A. 36–51. For example, 

Steven Erb, a former Research & Development Technician 

at VSI, testified that he “worked on the early GuideLiner 

prototypes,” including the “first rapid exchange GuideLiner prototypes in early 2005.” J.A. 12000. He confirmed 

that “[t]hese prototypes were then tested, including for 

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12 MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 

durability . . . and for functionality,” which informed them 

that “it would work.” J.A. 12001–02. Erb testified that he 

was both personally involved in some of the testing, and 

recalls watching the inventors perform testing on the prototypes on multiple occasions. Id. Deborah Schmalz, the 

former Vice President of Regulatory and Clinical Affairs at 

VSI, testified that she “specifically recall[ed] that a working prototype of the rapid exchange version of GuideLiner 

was created” prior to August 24, 2005. J.A. 9878–79.

Those findings are further supported by documentary 

evidence. For example, reports and invoices show that VSI 

ordered specialized “hypotubes” for prototypes of the rapid 

exchange GuideLiner in the first half of 2005. See, e.g., Decision, J.A. 37–51; J.A. 9592–97 (project spend report); J.A. 

11468 (invoice and purchase orders); J.A. 11471 (invoice 

and purchase orders). As the Board found, the dimensions 

of that hypotubing are consistent with the dimensions provided in the patents themselves and engineering drawings 

specific to the rapid exchange GuideLiner. See, e.g., Decision, 38–51; ’032 patent at col. 3 ll. 30–32, 43–46, 55–59, 

col. 7 ll. 19–25; J.A. 11592–93, 11595 (engineering drawings). Even Medtronic’s expert witness acknowledged that

it “doesn’t make a lot of sense” for VSI not to have assembled the purchased parts together once they were ordered 

and received. J.A. 13920 at 208:10–25. And Medtronic concedes that a benchtop model depicted in a July 2005 sales 

presentation could have been used to test a device like the 

rapid exchange GuideLiner. See J.A. 9725 (photograph); 

Decision, J.A. 58 (citing Medtronic, Inc. v. Teleflex Innovations S.À.R.L., IPR2020-00126, Conception and Reduction 

to Practice Reply at 17–18); see also J.A. 12011–12 (expert 

testimony regarding bench model testing). That evidence, 

taken together, is, at minimum, circumstantial evidence of 

corroboration. 

Medtronic’s main complaint is that some of the evidence in the record of corroboration is unclear as to 

whether or not it relates to the over-the-wire GuideLiner 

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MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 13

or the rapid exchange GuideLiner. That is true, and certain documents could only be connected to the rapid exchange prototype through inventor testimony, which 

carries little to no weight in the context of corroboration; 

one cannot corroborate oneself, after all. However, when 

viewing the pertinent evidence in its entirety, we still find 

the inventors’ story corroborated. Erb’s and Schmalz’ testimony, along with that of others and numerous documents, specifically mention the rapid exchange GuideLiner 

or can be connected to that version of the device in ways 

independent of the inventors’ testimony. 

For example, Teleflex asserts that a Computer Aided 

Design schematic from August 2005, J.A. 9751–52, corroborates the inventors’ testimony that they had moved beyond prototyping and testing at that point in time. 

Medtronic challenges the Board’s reliance on inventor 

Root’s testimony to connect that document to the reduction 

to practice of the rapid exchange prototype. Although 

Root’s testimony certainly enunciates that connection, his 

testimony is not required to establish the document’s corroborative value. The document is labeled “GuideLiner 

Rapid Exchange/Preliminary Design Assumptions/Rev 

X03,” indicating that the drawing is indisputably linked to 

the rapid exchange prototype, not the over-the-wire prototype, and that it is not the first, or even second, version of 

that drawing. See Decision, J.A. 42–43. The part number 

(20-0658) on the drawing is also consistent with those identified in certain purchase documents for tubing. Compare 

J.A. 9751–52 with J.A. 9749–50, J.A. 11480–84, and J.A. 

11466–71. Moreover, the “law does not impose an impossible standard of ‘independence’ on corroborative evidence by 

requiring that every point of a reduction to practice be corroborated by evidence having a source totally independent 

of the inventor; indeed, such a standard is the antithesis of 

the rule of reason.” Knorr v. Pearson, 671 F.2d 1368, 1374 

(CCPA 1982). We find the inventors’ testimony regarding 

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14 MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 

reduction to practice sufficiently corroborated under the 

rule of reason standard. 

Because we find the Board’s determination of actual reduction prior to the critical date supported by substantial 

evidence, we affirm the Board’s finding that Itou does not 

qualify as prior art to the challenged patents under 

35 U.S.C. § 102(e). Because Itou does not qualify as prior 

art, we likewise affirm the Board’s holding that Medtronic 

did not demonstrate by a preponderance of the evidence 

that the challenged claims of the challenged patents are 

unpatentable.

II

Medtronic additionally argues that the Board erred in 

finding that there was reasonably continuous diligence in 

reducing the invention to practice during the critical period. Because we agree with the Board that the claimed invention was actually reduced to practice prior to the critical 

date and affirm the Board’s finding that Itou did not qualify as prior art on that basis, there is no need to reach the 

issue of whether or not reasonable diligence was exercised. 

CONCLUSION

We have considered Medtronic’s remaining arguments 

but find them unpersuasive. For the foregoing reasons, the 

decision of the Board is affirmed. 

AFFIRMED

Case: 21-2356 Document: 56 Page: 14 Filed: 05/24/2023
United States Court of Appeals 

for the Federal Circuit ______________________ 

MEDTRONIC, INC., MEDTRONIC VASCULAR, 

INC.,

Appellants

v.

TELEFLEX INNOVATIONS S.À.R.L.,

Appellee

______________________ 

2021-2356, 2021-2358, 2021-2361, 2021-2363, 2021-2365

______________________ 

Appeals from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in Nos. IPR2020-

00126, IPR2020-00128, IPR2020-00132, IPR2020-00135, 

IPR2020-00137.

______________________ 

DYK, Circuit Judge, dissenting.

Contrary to the majority, I think that Itou1 has been 

shown to be prior art to the patents at issue2 and therefore 

could support a determination of anticipation or obviousness. This is so because, under the pre-America Invents 

1 U.S. Patent No. 7,736,355 to Itou et al. (“Itou”).

2 The challenged patents claim priority to the application that led to U.S. Patent No. 8,048,032 (“’032 patent”), 

filed on May 3, 2006.

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2 MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 

Act (“AIA”) 35 U.S.C. § 102(e), applicable to this case,3 Itou 

has an earlier filing date than that of the ’032 patent, and 

the evidence in this case fails to adequately corroborate inventor testimony that the rapid exchange (“RX”) GuideLiner invention had been reduced to practice before Itou’s 

filing date of September 23, 2005. I agree with the majority 

that the Board correctly identified the object of the invention as “providing increased backup support,”4 Panel Op. 6, 

and that the testimony and corroborating evidence support 

the Board’s finding that prototypes reflecting the invention 

were assembled before the priority date. Panel Op. 12. My 

disagreement lies with respect to the issue of testing. Specifically, the evidence does not corroborate that testing of 

the RX GuideLiner prototypes before the critical date had 

shown them to work for their intended purpose.

I 

“To show reduction to practice, [a patent owner] must 

demonstrate that the invention is ‘suitable for its intended 

3 The AIA’s first-to-file provisions do not apply to the 

challenged patents, because they apply to patents with an 

effective filing date on or after March 16, 2013. See AIA, 

Pub. L. No. 112-29, § 3(n)(1), 125 Stat. 284, 293 (2011).

4 The majority confusingly suggests the intended 

purpose of the invention may be even broader than the purpose identified by the Board and urged by Teleflex. Panel 

Op. 7–8; see also J.A. 52 (noting that Teleflex’s position was 

that the intended purpose of the invention was “to increase 

backup support” (citation omitted)). I do not understand 

the majority to rest its disposition on a purpose broader 

than that found by the Board. And reviewing the Board’s 

decision using a different standard than the Board’s own 

standard would present a problem under Securities & Exchange Commission v. Chenery Corp., 332 U.S. 194, 196 

(1947).

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MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 3

purpose.’” Scott v. Finney, 34 F.3d 1058, 1061 (Fed. Cir. 

1994) (quoting Steinberg v. Seitz, 517 F.2d 1359, 1363 

(C.C.P.A. 1975)). This case does not involve a situation 

where the invention is “so simple and [its] purpose and efficacy so obvious that [its] complete construction is sufficient to demonstrate workability.” Id. (citation omitted). 

Under such circumstances, testing is required to establish 

a reduction to practice. Id. at 1063 (citation omitted). As 

both the majority and the Board assumed, testing was required to establish a reduction to practice here. See Panel 

Op. 9–10; J.A. 57 n.22. “The issue . . . is not whether it 

might be possible to reduce the invention to practice by laboratory testing, but whether the particular tests made by 

[the inventor] were sufficient for that purpose.” Elmore v. 

Schmitt, 278 F.2d 510, 513 (C.C.P.A. 1960). The evidence 

must show that the “tests accurately reproduced the operating conditions which would be encountered in any practical use of the invention.” Id.

II

The testimony of the inventors here never describes 

(1) any specific tests showing the RX GuideLiner prototypes would work for their intended purpose of providing

increased backup support5 or (2) the results of the tests 

5 The inventors do describe in general terms tests regarding the simple delivery of cardiology devices in benchtop cardiac models, and they mention “pull tests to assess 

the durability of the prototype[s].” J.A. 11816 (Root Decl. 

¶ 18); see also J.A. 11982 (Sutton Decl. ¶ 41). The Board 

also described the “bench-top coronary models, including 

two-dimensional (“2D”) acrylic heart models and three-dimensional (“3D”) glass heart models, to simulate the native 

anatomy and environment,” in which these tests were performed. J.A. 43. On their face, these tests do not relate to 

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4 MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 

they did conduct. One inventor characterized the tests as 

“more qualitative than quantitative,” J.A. 11983 (Sutton 

Decl. ¶ 41), and both declarant inventors relied in large 

part on their own assessment that they knew that the prototypes would work. See, e.g., J.A. 11834 (Root Decl. ¶ 47)

(testifying that, before performing any tests, the inventor 

“already had confidence that the rapid exchange GuideLiner would work for its intended purpose”).

III

Even if the inventors’ testimonies were sufficient to 

show relevant testing, “[i]n order to establish an actual reduction to practice, an inventor’s testimony must be corroborated by independent evidence.” Cooper v. Goldfarb, 154 

F.3d 1321, 1330 (Fed. Cir. 1998). As with all “inventive 

facts,” an “inventor’s testimonial assertions” regarding 

testing “require corroboration by independent evidence.” 

Brown v. Barbacid, 276 F.3d 1327, 1335 (Fed. Cir. 2002).

With respect to testing, the Board barely addressed the 

issue of corroboration. At best, it relied on two items. First, 

the Board referenced a July 2005 sales presentation that 

includes a picture of an over-the-wire (“OTW”) GuideLiner 

device inserted into a benchtop cardiac model. See J.A. 43; 

J.A. 58. Second, the Board may have relied on the testimony of two non-inventor witnesses, Steven Erb (a technician and machinist at Vascular Solutions), see J.A. 58, and 

Deborah Schmalz (former Vice President of Regulatory and 

whether the prototypes provided increased backup support. On that question, the inventors testified that they 

“observed the forces involved in navigating the GuideLiner 

prototype through such a [benchtop coronary] model,” 

J.A. 11816 (Root Decl. ¶ 18); see also J.A. 11983 (Sutton 

Decl. ¶ 41), but they did not provide any explanation of 

what the testing found and how any results indicated that 

the devices provided increased backup support.

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Clinical Affairs at Vascular Solutions). See J.A. 45. Neither the 2005 sales presentation nor the non-inventor testimony is adequate corroboration.

As to the first—the 2005 sales presentation—even if 

the single picture of an OTW GuideLiner device could lend 

some support for testing of that OTW GuideLiner device, it 

shows nothing about testing the RX GuideLiner prototypes, the devices at issue here. The OTW device is quite 

different: As the majority agrees, the OTW GuideLiner 

“was more akin to the prior art guide extension catheters 

and does not practice the challenged patents,” and, as a result, “it had fewer challenges to overcome and work on it 

progressed more rapidly than for the rapid exchange device.” Panel Op. 3. Evidence that does not even correspond 

to an embodiment of the patented invention cannot corroborate that invention’s reduction to practice. See In re NPT, 

Inc., 654 F.3d 1279, 1292 (Fed. Cir. 2011).

As to the second, the non-inventor testimony also does 

not offer adequate corroboration. The Board relied on Erb’s 

testimony that he “worked on the early GuideLiner prototypes,” including the “first rapid exchange GuideLiner prototypes in early 2005,” related to prototypes allegedly made 

in January or February 2005. J.A. 12000 (Erb Decl. ¶ 8); 

J.A. 37. But the inventor testimony of reduction to practice 

is based on later prototypes, the so-called April and July 

prototypes. See J.A. 11834 (Root Decl. ¶ 48). The early 

2005 prototypes Erb worked on are not claimed to have reduced the invention to practice. See J.A. 36 n.17. Accordingly, Erb’s testimony about his work on these early 

prototypes has no corroborative value for the question of 

whether the April and July prototypes were ever tested and 

shown to work for their intended purpose, let alone that 

these later prototypes were tested and shown to work by 

the critical date. 

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6 MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 

As for the April and July prototypes, all Erb testified is 

that “[a]dditional testing . . . was performed on these subsequent prototypes” and that “[he] recall[ed] watching [inventor] Howard Root and others working in R&D test these 

subsequent prototypes, as well.” J.A. 12002 (Erb Decl. 

¶ 12). There is no specific description of what tests were 

performed or the results of the tests. Most significantly, 

there is no specific testimony of when the tests were performed and whether they were performed before the critical date.

The Board also mentioned Schmalz’s testimony that 

she “specifically recall[ed] that a working prototype of the 

rapid exchange version of GuideLiner was created” before 

August 24, 2005.” See J.A. 45 (quoting J.A. 9879 (Schmalz 

Decl. ¶ 7)). The fact a working prototype was created does 

not corroborate the inventors’ testimony of testing. 

Schmalz did not testify to witnessing any tests, much less 

testify regarding what tests were performed, when they 

were performed, or the results of the tests. We have held 

that, absent other corroborating evidence, “vague testimony” like this by non-inventors is insufficient to corroborate inventor’s testimony that an experiment 

demonstrated an invention had been reduced to practice. 

Brown, 276 F.3d at 1337.

The majority relies on additional items for corroboration not relied on by the Board to corroborate testing. The 

majority relies on documents related to the purchasing of 

parts. See Panel Op. 12 (citing J.A. 9592–97; J.A. 11468; 

J.A. 11471). This may corroborate assembly of prototypes 

but hardly corroborates testing, let alone successful testing

by the critical date. 

The majority also relies on an August 2005 Computer 

Aided Design (“CAD”) schematic of an RX GuideLiner device. See Panel Op. 13 (citing J.A. 9751–52). While this

CAD schematic may corroborate the inventors’ testimony 

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MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 7

that they had conceived of the RX GuideLiner invention before the critical date—which is not in dispute—it says nothing about testing of an RX GuideLiner device. The only

testimony connecting the CAD schematic to the question of 

testing of the RX GuideLiner is the conclusory testimony of 

the inventors. See J.A. 11835 (Root Decl. ¶ 49) (the schematic “reflects the fact that we had moved past the prototyping phase and were getting ready to begin the formal 

quality process for bringing a completed medical device to 

market”); J.A. 11981 (Sutton Decl. ¶ 39). The majority 

agrees that the testimony of the inventors “carries little to 

no weight in the context of corroboration.” Panel Op. 12–

13; see also Apator Miitors ApS v. Kamstrup A/S, 887 F.3d 

1293, 1296 (Fed. Cir. 2018).

IV

The majority suggests that finding the evidence insufficient here would impose an “impossible standard of ‘independence’ on corroborative evidence by requiring that 

every point of reduction to practice be corroborated by evidence having a source totally independent of the inventor.” 

Panel Op. 13 (quoting Knorr v. Pearson, 671 F.2d 1368, 

1374 (C.C.P.A. 1982)). That is hardly the case. Teleflex

produced essentially no internal documents corroborating 

any testing that Vascular Solutions was doing with the RX 

GuideLiner prototypes in the critical period in 2005. See

J.A. 11817–18 (Root Decl. ¶ 20). Common sense, and Teleflex’s own testimony,6 suggest that these documents would 

exist if testing had occurred. Teleflex’s theory is that the 

relevant documents did exist at one time but have since 

6 “In [Jim Kauphusman’s] role [as the primary engineer working on RX GuideLiner], he’s creating some level 

of work product every day, and, you know, it comes in the 

form of drawings, prototypes, test results, you know, and 

written reports.” J.A. 5244 (Sutton Dep. 36:23–37:2).

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8 MEDTRONIC, INC. v. TELEFLEX INNOVATIONS S.À.R.L. 

been destroyed. See J.A. 11817 (Root Decl. ¶ 20); J.A. 5197 

(Erb Dep. 29:13–19). A rule that favors the retention of 

relevant documents does not create an “impossible standard” for inventors seeking to enforce a patent for a claimed 

invention.

V 

Because the corroborating evidence that the RX GuideLiner prototypes had been tested and shown to work for 

their intended purpose was insufficient, I would reverse 

the Board’s holding that the invention had actually been 

reduced to practice before Itou’s priority date.7 I respectfully dissent.

7 The Board also found that Teleflex had demonstrated reasonable diligence between Itou’s September 23, 

2005, filing date and the filing date of the RX GuideLiner 

patent application on May 3, 2006. The majority does not 

reach the question of reasonable diligence. I note only that, 

with the exception of two law firm invoices covering work 

for a small portion of the diligence period, the corroborating 

evidence for reasonable diligence is equally lacking during 

the vast majority of the relevant period.

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