Federal Circuit IP

Medtronic, Inc. v. Teleflex Innovations S.À.R.L.

By Julia F. Kottmeier Published June 20, 2023

Case No. 21-2356, Decided May 24, 2023

Moore, Lourie (majority), and Dyk (dissenting)

Overview: Determination of whether an invention would work for its intended purpose for the purposes of actual reduction to practice to antedate art cited under §102(e) does not require 1:1 comparison or quantitative assessment, merely that an inventor would understand a test to indicate that the prototype is more effective than an existing device.


  • Medtronic filed IPRs against Teleflex’s U.S. Pat. No. 8,048,032 and related family member patents (Challenged Patents), which are directed to guide extension catheters having a tapered inner catheter that runs over a guidewire for reducing dislodgement of a guide catheter.
  • Five consolidated IPRs assert the Challenged Patents are anticipated by U.S. Pat. No. 7,736,355 to Itou, filed Sept. 23, 2005, under pre-AIA 35 U.S.C. §102(e). In response, Teleflex provided inventor testimony and corroborating evidence to antedate Itou.
  • The Board determined (1) the invention was conceived prior to Sept. 23, 2005 (no later than August 2005), and (2) inventors (a) actually reduced to practice the invention for its intended purpose in April and July 2005 or (b) diligently pursued until constructive reduction to practice through filing application on May 3, 2006, thereby antedating Itou.
  • Medtronic appealed on grounds that the Board erred in its finding of actual reduction to practice and reasonable diligence toward constructive reduction to practice – Specifically, Medtronic asserted the Board erred in (i) its identification of the intended purpose of the claimed invention, (ii) its failure to not require comparative testing to show that the invention worked for the alleged intended purpose, and (iii) its reliance solely on uncorroborated inventor testimony as evidence of actual reduction to practice.

Issues: (i) Whether the specification indicates a narrower intended purpose. (ii) Whether comparative testing is required to show that an inventor believed prototype would work for its intended purpose.  (iii) Whether inventor testimony was corroborated by independent evidence. 

Test for Actual Reduction to Practice for Antedating § 102(e) Prior Art: To establish actual reduction to practice, it must be shown that (1) the inventors constructed an embodiment or performed a process that met all the limitations of the claimed invention; and (2) the inventors determined that the invention would work for its intended purpose.  Inventor declarations submitted to antedate a reference must be corroborated by independent evidence.

CAFC Decision and Analysis: Affirmed Board’s finding regarding actual reduction to practice (therefore no need to address constructive reduction) and Itou is not prior art.

Issue (i): Is the purpose of the claimed device narrower than that identified by the Board? – NO

  • Rationale: The Board found that the intended purpose of the claimed inventions was “providing improved backup support for the guide catheter” based on field and background. Rather than being narrower and further requiring “crossing tough or chronic occlusions” (as asserted by Medtronic), the Court found the purpose of the invention based on the claims and title is even broader than that identified by the Board – finding the purpose is “performing the functions of a guide extension catheter.”  Crossing occlusions is merely an example of the broader general purpose.
  • Holding: The specification does not further limit the intended purpose of the invention.

Issue (ii): Is comparative testing required of the prototype require? – NO

  • Rationale: Inventors testified they observed forces exerted on and durability of the prototype in glass model heart – confirming it would work for intended purpose of providing increased back up support as compared to guide catheter alone.  Determination of working for intended purpose does not require 1:1 comparison or quantitative assessment, merely that an inventor would understand a test to indicate that the prototype was more effective than a guide catheter alone.
  • Holding: The testing described in the inventor testimony was sufficient to show inventors determined the prototype practicing the claimed invention worked for its intended purpose, and therefore Board’s conclusion is supported by substantial evidence.

Issue (iii): Was the inventor testimony sufficiently corroborated? – YES

  • Rationale: Inventor testimony was supported by documentary evidence (invoices for parts used in prototype in first half of 2005, model in July 2005 sales presentation, CAD schematic from Aug. 2005 corresponding to purchase orders) and non-inventor testimony (technician worked on prototypes in early 2005 including testing for durability and functionality, VP recalled a working prototype prior to Aug. 24, 2005).
  • Holding: When corroborating evidence is viewed as a whole, it is sufficient to provide circumstantial evidence to support the inventor testimony.


  • With respect to issue (ii): Testimony of inventors never describes any specific tests or results showing prototype provided increased backup support – only durability test in glass model. Inventor states “more qualitative than quantitative.”
  • With respect to issue (iii): Evidence does not corroborate that testing of the prototype before the critical date had shown it to work for its intended purpose. Purchase orders may corroborate assembly of prototypes, but does not corroborate successful testing by the critical date. Sales presentation was directed to a different (over-the-wire “OTW”) guide liner device. The non-inventor testimony is directed to prototypes developed in Jan or Feb 2005 while the inventor testimony referenced prototypes developed in April and July 2005.


  • Actual reduction to practice may be easier to meet than one might have thought!
  • Advise clients to maintain invention records, promotional materials, purchase order records, and non-inventor and inventor contact information for pre-AIA patents.
  • Be wary of asserting art under pre-AIA §102(e).