Case: 23-2153 Document: 59 Page: 1 Filed: 07/18/2025
United States Court of Appeals for the Federal Circuit ______________________
COLIBRI HEART VALVE LLC, Plaintiff-Appellee
v.
MEDTRONIC COREVALVE, LLC, Defendant-Appellant ______________________
2023-2153 ______________________
Appeal from the United States District Court for the Central District of California in No. 8:20-cv-00847-DOC- JDE, Judge David O. Carter. ______________________
Decided: July 18, 2025 ______________________
JEFFREY A. LAMKEN, MoloLamken LLP, Washington, DC, argued for plaintiff-appellee. Also represented by WALTER H. HAWES, IV, MICHAEL GREGORY PATTILLO, JR.; CATHERINE MARTINEZ, New York, NY; STEVEN DERRINGER, MEG E. FASULO, MATTHEW R. FORD, KATHERINE E. RHOADES, Bartlit Beck LLP, Chicago, IL; JOHN HUGHES, TAYLOR JAMES KELSON, Denver, CO.
GREGORY A. CASTANIAS, Jones Day, Washington, DC, argued for defendant-appellant. Also represented by JENNIFER L. SWIZE; JOSEPH FARLEY, Columbus, OH; KELLY HOLT RODRIGUEZ, New York, NY; MARK D. FOWLER, DLA Case: 23-2153 Document: 59 Page: 2 Filed: 07/18/2025
Piper LLP (US), Palo Alto, CA; STANLEY JOSEPH PANIKOWSKI, III, San Diego, CA. ______________________
Before TARANTO, HUGHES, and STOLL, Circuit Judges. TARANTO, Circuit Judge. U.S. Patent No. 8,900,294, owned by Colibri Heart Valve LLC, claims a method, for use in trying to implant an artificial heart valve to replace a defective valve, that furnishes a do-over opportunity to the installer to get the positioning right. In the claimed method, the replacement valve is only partially deployed from the delivery appa- ratus but recaptured within the delivery apparatus before full deployment if it looks like the positioning will be off. Colibri sued Medtronic CoreValve, LLC, a manufacturer of replacement heart valves, for infringement—alleging, as now relevant, that Medtronic was inducing surgeons to perform the claimed method with Medtronic’s products. See 35 U.S.C. § 271(b). The ’294 patent, at the outset of prosecution, included two independent claims reciting the opportunity-for-do- over method of partial deployment: one claimed pushing out the valve from an outer sheath of the delivery appa- ratus, and one claimed retracting the outer sheath to ex- pose the valve. During prosecution, the examiner rejected the latter claim for lack of written description, see 35 U.S.C. § 112, and Colibri cancelled it. The patent issued with an independent claim reciting partial deployment by pushing, and no claims expressly reciting partial deployment by re- tracting. In the district court, Medtronic contended that the ac- cused use of its product involved partial deployment by re- tracting, not pushing. At trial, Colibri dropped its assertion of literal infringement, relying solely on the doc- trine of equivalents to establish infringement by accused direct infringers using the accused method with Case: 23-2153 Document: 59 Page: 3 Filed: 07/18/2025
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Medtronic’s products. The jury, besides rejecting Med- tronic’s invalidity challenge, found that Medtronic had in- duced infringement and awarded more than $106 million in damages to Colibri. Before and after the verdict, Med- tronic sought judgment as a matter of law (JMOL) on the ground, among others, that Colibri’s equivalents claim was barred by prosecution history estoppel, but the district court denied the motions. On appeal, Medtronic argues, among other things, that the district court erred in denying JMOL of noninfringe- ment. We now conclude that prosecution history estoppel, based on Colibri’s cancelling of a claim to “retraction” for partial deployment of the replacement valve and Colibri’s own recognition of the close linkage of the subject matter of the cancelled and retained claims, bars application of the doctrine of equivalents. We therefore reverse the district court’s denial of JMOL of noninfringement. That is all we need decide to resolve this dispute over the now-expired pa- tent. I A The ’294 patent, which expired in January 2022 and is titled “Method of Controlled Release of a Percutaneous Re- placement Heart Valve,” relates to artificial heart valves used to replace diseased or otherwise defective heart valves. ’294 patent, title; id., col. 2, lines 52–54. Blood flows through valves in the heart from areas of relatively high pressure to areas of relatively low pressure. Id., col. 1, lines 31–33, 46–48. Each valve includes “leaflets” (some- times called “cusps”) spanning the passageway through which blood flows, with the opening and closing of the leaf- lets allowing blood to flow only in the proper direction through the circulatory system. Id., col. 1, lines 48–56; id., col. 2, lines 1–28. Case: 23-2153 Document: 59 Page: 4 Filed: 07/18/2025
The ’294 patent describes a replacement heart valve (200) formed by folding biologically compatible material to form a tubular portion (210) and a leaflet portion (220), id., col. 5, lines 1–7; id., col. 6, lines 62–64, shown in figures 1 and 5.
The leaflets (220) are formed from “a single, continuous, uncut layer” of material. Id., col. 8, lines 54–60. The tub- ular portion (210) of the valve (200) is sutured to the inte- rior of a cylindrical, self-expanding metal stent member (100), which provides a “semi-rigid” channel through the diseased valve upon implantation. Id., col. 6, lines 57–67; id., col. 7, lines 9–11, 27–29, 65–67. The patent further describes a method of making the valve and, of key importance here, a method for use in im- planting a replacement heart valve in which the valve is partially released and can be recovered if it looks like the positioning will be incorrect. Id., col. 11, lines 51–62. Fig- ure 8 depicts an implantation system used in the claimed method, with the distal end at the bottom and proximal end at the top, and with the components shown in an expanded view simply for display purposes. Id., col. 11, lines 40–51. Case: 23-2153 Document: 59 Page: 5 Filed: 07/18/2025
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A flexible, hollow catheter (400) carrying the stent (100)— to which the replacement heart valve (200), not shown, is sutured—is inserted into a blood vessel of the patient, e.g., the femoral artery, and advanced through the circulatory system to the location of the valve that is to be replaced. Id., col. 11, lines 3–7, 40–48. The catheter (400) includes a pusher member (420), and, in some embodiments, a move- able sheath (460) that covers the stent (100) and valve (shown pulled down for display purposes). Id., col. 11, lines 48–51; id., col. 12, lines 11–14.
Once the catheter is in what seems the desired posi- tion, the pusher member (420) pushes the stent (100) and valve (200) towards the distal end of the catheter (410) such that the stent (100) only partially expands. Id., col. 11, lines 51–55. At that stage, if the positioning seems incor- rect, the valve can be “recaptured” (i.e., recovered and re- turned to its original position within the catheter, with the stent re-squeezed) and re-deployed once the catheter’s Case: 23-2153 Document: 59 Page: 6 Filed: 07/18/2025
overall location is adjusted. Id., col. 11, lines 55–59. If no recapture is necessary, the catheter (400) is retracted slightly, and the pusher member (420) fully pushes out the stent (100) and valve from the catheter (400). Id., col. 11, lines 59–62. In embodiments with a moveable sheath (460), the stent (100) and valve are released by pulling the moveable sheath towards the proximal end (440) of the catheter (400), “allowing the self-expending stent to achieve its full expansion.” Id., col. 12, lines 11–14, 24–27. Claim 1 is representative and recites as follows: 1. A method of controlled release of a percutaneous replacement heart valve at a location of a native heart valve in a patient, the method comprising: obtaining a replacement heart valve device and a delivery and implantation system: the replacement heart valve device including: a stent member that is collapsible, expand- able and configured for percutaneous deliv- ery; and a valve residing entirely within an inner channel of the stent member and attached to a proximal portion of the stent member, the valve including two to four individual leaflets made of fixed pericardial tissue; the delivery and implantation system including: a pusher member and a moveable sheath, wherein the pusher member includes a guide wire lumen, and wherein the movea- ble sheath includes a lumen configured for receiving the pusher member; after the obtaining step, loading the replacement heart valve device into the lumen of the moveable sheath such that the replacement heart valve Case: 23-2153 Document: 59 Page: 7 Filed: 07/18/2025
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device is collapsed onto the pusher member to re- side in a collapsed configuration on the pusher member and is restrained in the collapsed configu- ration by the moveable sheath; after the loading step, advancing the delivery and implantation system transluminally over a guide wire within the patient to position the replacement heart valve device for deployment within the pa- tient at the location of the native heart valve; after the advancing step, partially deploying a distal portion of the replacement heart valve device within the patient by pushing out the pusher member from the moveable sheath to expose the distal portion of the re- placement heart valve device; after the partially deploying step, restraining the replacement heart valve device so that it does not pop out and is held for controlled release, with a potential that the replacement heart valve device can be recovered if there is a problem with position- ing; and after the restraining step, recovering the distal por- tion of the replacement heart valve device within the moveable sheath that was exposed in order to address a problem with the position of the replace- ment heart valve device within the patient. Id., col. 13, line 38 through col. 14, line 37 (emphasis added). B Medtronic sells replacement heart valves, broadly re- ferred to as the “Evolut” line of products. The Evolut prod- ucts include a self-expanding metal stent and a replacement heart valve with three leaflets sutured to a cy- lindrical “inner skirt.” J.A. 26579, 26676, 28875. Case: 23-2153 Document: 59 Page: 8 Filed: 07/18/2025
Importantly here, the Evolut products can be “recaptured” during implantation, if necessary. See, e.g., J.A. 26514–15 (describing recapture process). The implantation of the Evolut products involves ad- vancing a catheter containing the replacement heart valve through the patient’s circulatory system. J.A. 26580–81. The catheter includes an inner member disposed inside the replacement heart valve and stent, and a moveable sheath (also called a capsule) that covers the replacement heart valve and stent. J.A. 22866–68. It is illustrated in the rec- ord as follows (with the distal end to the left):
J.A. 27612. A deployment knob (located on a portion of the catheter outside the patient’s body) controls the position of the moveable sheath relative to the replacement heart valve and stent: Rotating the deployment knob in one di- rection retracts the moveable sheath and uncovers (i.e., partially or fully deploys) the replacement heart valve and stent, while rotating in the other direction re-covers (i.e., recaptures) the replacement heart valve and stent. J.A. 22867–68; see also J.A. 21133, line 1 through J.A. 21135, line 7 (Colibri’s witness discussing deployment mecha- nism). II A In May 2020, Colibri sued Medtronic for infringement of the ’294 patent in the United States District Court for the Central District of California. Complaint at 16–21, Case: 23-2153 Document: 59 Page: 9 Filed: 07/18/2025
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Colibri Heart Valve LLC v. Medtronic CoreValve LLC, No. 20-cv-00847 (C.D. Cal. May 4, 2020), ECF No. 1 (Com- plaint); see also First Amended Complaint at 16–22, Colibri Heart Valve LLC v. Medtronic CoreValve LLC, No. 20-cv- 00847 (C.D. Cal. June 12, 2020), ECF No. 30 (First Amended Complaint). 1 Colibri asserted direct infringe- ment (literally and under the doctrine of equivalents) un- der 35 U.S.C. § 271(a), contributory infringement under § 271(c), and inducement of infringement under § 271(b). Complaint at 18–19; First Amended Complaint at 18–19. Colibri later abandoned its allegations of direct and con- tributory infringement, proceeding only with its allega- tions of inducement of infringement. Medtronic raised affirmative defenses of invalidity and prosecution history estoppel in its answer. Answer at 10, Colibri Heart Valve LLC v. Medtronic CoreValve LLC, No. 20-cv-00847 (C.D. Cal. Apr. 13, 2021), ECF No. 114. A special master appointed by the district court, after conducting claim-construction proceedings, issued a recom- mendation to the court on February 11, 2021. Report and Recommendation on Claim Construction at 1, Colibri Heart Valve LLC v. Medtronic CoreValve LLC, No. 20-cv- 00847, 2021 WL 4437737, at *1 (C.D. Cal. Feb. 11, 2021), ECF No. 97 (Claim Construction). The parties disputed the construction of one term relevant here: “pushing out the pusher member from the moveable sheath.” Id. at *20–22. Colibri proposed that the phrase meant a “pushing force is applied to the pushing member in a direction outwards from the moveable sheath,” and Medtronic proposed the phrase meant “pressing against the pusher member with a
1 Colibri also asserted infringement of U.S. Patent No. 9,124,739. Complaint at 16–17; First Amended Com- plaint at 16–18. The district court granted summary judg- ment of noninfringement of the ’739 patent, and Colibri did not cross-appeal. Case: 23-2153 Document: 59 Page: 10 Filed: 07/18/2025
force that moves the pusher member out of the moveable sheath.” Id. at *20. The special master recommended that the district court adopt Medtronic’s proposed construction, reasoning that the claimed “pushing out” limitation is not just a matter of the force’s direction but “requires move- ment of the pusher member such that the replacement heart valve moves outward from the sheath to at least some degree.” Id. at *26. The district court adopted the recom- mended claim construction. Order at 1, Colibri Heart Valve LLC v. Medtronic CoreValve LLC, No. 20-cv-00847, 2021 WL 4439091, at *1–2 (C.D. Cal. May 19, 2021), ECF No. 119. B After claim construction, both parties moved for sum- mary judgment: Colibri for partial summary judgment of no invalidity, and Medtronic for summary judgment of in- validity and noninfringement. Medtronic argued, among other things, that Colibri’s assertion of infringement of claim 1 under the doctrine of equivalents was barred by prosecution history estoppel. In particular, it argued that Colibri’s cancelling during prosecution of then-claim 39— while retaining then-claim 34 (which issued as claim 1)— “precludes Colibri from asserting that, under the [doctrine of equivalents], partial deployment and recovery of the valve is performed by retracting the sheath.” J.A. 3164 (emphasis added). Cancelled claim 39 recited: A method of controlled release of a percutaneous replacement heart valve in a patient where a bio- prosthetic heart valve is indicated, comprising: providing a replacement heart valve device and a delivery and implantation system; the replacement heart valve device including: a stent member that is collapsible, expand- able and configured for percutaneous deliv- ery; and Case: 23-2153 Document: 59 Page: 11 Filed: 07/18/2025
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a valve attached to the stent member. the valve including two to four individual leaf- lets; the delivery and implantation system including: a pusher member and a moveable sheath, wherein the pusher member includes a lu- men for receiving a guide wire, wherein the moveable sheath includes a lumen config- ured for receiving the pusher member, and wherein the replacement heart valve de- vice is collapsed onto the pusher member to reside in a collapsed configuration on the pusher member and is restrained in a col- lapsed configuration by the moveable sheath; after the providing step, advancing the delivery and implantation system over the guide wire within the patient to position the replacement heart valve device for deployment within the pa- tient; after the advancing step, partially deploying the replacement heart valve device within the patient by retracting the moveable sheath to expose a portion of the replacement heart valve device; and after the partially deploying step, recovering the portion of the replacement heart valve device within the moveable sheath that was exposed in or- der to address a problem with the position of the replacement heart valve device within the patient. J.A. 23140–41 (emphasis added). The special master recommended that the court reject Medtronic’s prosecution-history-estoppel argument. Re- port and Recommendation on Summary Judgment at 33– Case: 23-2153 Document: 59 Page: 12 Filed: 07/18/2025
38, Colibri Heart Valve LLC v. Medtronic CoreValve LLC, No. 20-cv-00847 (C.D. Cal. July 26, 2021), ECF No. 202; see also Redacted Report and Recommendation at 33–38, Colibri Heart Valve LLC v. Medtronic CoreValve LLC, No. 20-cv-00847 (C.D. Cal. Aug. 10, 2021), ECF No. 220-1 (Summary Judgment Recommendation). The special mas- ter reasoned that cancelled claim 39 “was an independent claim separate from” retained claim 34 (issued claim 1) and Medtronic “d[id] not show that . . . [Colibri] cancelled claim 39 in favor of purs[u]ing a limitation that already appeared in [claim 1] . . . or that [Colibri] added or amended any claims directed to this limitation.” Summary Judgment Recommendation at 37. In other words, cancelled claim 39 and retained claim 34 (issued claim 1) were clearly differ- ent, i.e., separate and distinct. The special master also dis- tinguished Colibri’s “asserted equivalent” as “not merely retraction” but instead a combination of pushing and re- tracting, so “[t]he asserted equivalent . . . differs from what was set forth in the cancelled claim.” Id. at 37–38. The district court adopted the special master’s recommendation regarding the “pushing out” limitation and denied sum- mary judgment. Order at 12–13, Colibri Heart Valve LLC v. Medtronic CoreValve LLC, No. 20-cv-00847 (C.D. Cal. Nov. 15, 2021), ECF No. 275. C A jury trial on the issues of invalidity and infringement began on January 31, 2023. Mid-trial, Colibri abandoned its theory that Medtronic literally infringed the ’294 pa- tent, arguing instead that, under the doctrine of equiva- lents, Medtronic’s partial-deployment method (applying a force to hold the stent in place while retracting the movea- ble sheath) is equivalent to the claimed partial-deployment method (applying a force to push the stent out of the move- able sheath). During the jury trial, Medtronic filed two mo- tions for JMOL, see Fed. R. Civ. Pro. 50(a), seeking, among other things, judgment of no equivalents infringement on Case: 23-2153 Document: 59 Page: 13 Filed: 07/18/2025
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the ground of prosecution history estoppel. The district court did not rule on the Rule 50(a) motions. The jury found that Medtronic induced infringement of claims 1–3 of the ’294 patent and that Medtronic had not proven that those claims were invalid, and it awarded more than $106 million in damages to Colibri. J.A. 20–23. After the jury issued its verdict, Medtronic filed a renewed mo- tion for judgment as a matter of law under Fed. R. Civ. P. 50(b) and a motion for new trial under Fed. R. Civ. P. 59. The district court denied the motions on June 8, 2023, re- jecting Medtronic’s prosecution history estoppel argument “for the same reasons set forth by the Court during sum- mary judgment proceedings.” J.A. 4. The district court entered final judgment on June 16, 2023, J.A. 16–17, and Medtronic timely appealed, J.A. 205. We have jurisdiction under 28 U.S.C. § 1295(a)(1). III Medtronic challenges four rulings of the district court: (1) the denial of JMOL of invalidity, Medtronic Opening Br. at 30–40; (2) the denial of JMOL of noninfringement, id. at 41–53; (3) the denial of JMOL of no active inducement, id. at 53–58; and (4) the denial of Medtronic’s motion for a new trial on damages, id. at 59–71. It is undisputed that, if we reverse the denial of JMOL of noninfringement, we need not reach Medtronic’s other challenges, including the inva- lidity challenge to this expired patent. Oral Arg. at 2:23– 2:45, https://oralarguments.cafc.uscourts.gov/default.aspx ?fl=23-2153_05052025.mp3. We follow the Ninth Circuit’s de novo standard for re- view of the district court’s JMOL decision. See TEK Global, S.R.L. v Sealant Systems International, Inc., 920 F.3d 777, 783 (Fed. Cir. 2019) (citing Wechsler v. Macke International Trade, Inc., 486 F.3d 1286, 1290 (Fed. Cir. 2007)). The JMOL standard itself, regarding fact issues, requires def- erence to the factfinder: JMOL is not to be granted unless Case: 23-2153 Document: 59 Page: 14 Filed: 07/18/2025
“the evidence, construed in the light most favorable to the nonmoving party, permits only one reasonable conclusion, and that conclusion is contrary to the jury’s verdict.” TVIIM, LLC v. McAfee, Inc., 851 F.3d 1356, 1362 (Fed. Cir. 2017) (quoting Harper v. City of Los Angeles, 533 F.3d 1010, 1021 (9th Cir. 2008)). Prosecution history estoppel, how- ever, is a matter of law, not of fact, and it is decided de novo on appeal under our own circuit’s law on this patent-law issue. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 344 F.3d 1359, 1367–68 (Fed. Cir. 2003) (en banc). Although Medtronic challenged the district court’s de- nial of JMOL of noninfringement on several grounds, we address and decide only on one of those grounds—prosecu- tion history estoppel. We conclude that Colibri’s cancella- tion during prosecution of claim 39, which recited “retracting the moveable sheath,” bars Colibri from assert- ing infringement under the doctrine of equivalents under the theory that a combination of applying a pushing force to the pusher member while retracting the moveable sheath (what Medtronic’s device does) is equivalent to, i.e., not substantially different from, “pressing against the pusher member with a force that moves the pusher mem- ber outward from the moveable sheath” (what claim 1 re- quires). Medtronic Opening Br. at 46–51; see Claim Construction at *26; see also Colibri Response Br. at 47 (discussing equivalence theory). That conclusion suffices for reversal. A As an initial matter, we reject Colibri’s assertion that we should not consider Medtronic’s prosecution-history-es- toppel argument because Medtronic waived it before the district court. Colibri Response Br. at 45. Colibri’s waiver argument rests on Medtronic’s statement in a pre-trial memorandum filed on January 3, 2022, under the heading “Abandonment of Issues,” that “Medtronic is not pursuing the Fifth Affirmative Defense of Prosecution History Case: 23-2153 Document: 59 Page: 15 Filed: 07/18/2025
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Estoppel.” J.A. 13659. Medtronic filed this pre-trial mem- orandum in accordance with Local Rule 16-4.6 of the Cen- tral District of California, which requires that the parties “identify any pleaded claims or affirmative defenses which have been abandoned.” In the circumstances of this case, we do not deem Medtronic to have waived the JMOL argu- ment based on prosecution history estoppel, an argument the district court itself reached on the merits in denying JMOL without suggesting that there was a waiver. First, Medtronic’s statement, though poorly worded, can reasonably be understood to be saying only what it was not pursuing at trial, i.e., that Medtronic would not repeat its prosecution-history-estoppel argument before the jury, as this argument had already been rejected at summary judgment and involved a question of law on which no facts needed to be proved at trial. Indeed, Medtronic in the same pre-trial memorandum disclaimed waiver, stating: “The [c]ontentions below are based on Medtronic’s current un- derstanding of the parties’ claims in light of the Technical Special Master’s Reports and Recommendations on Sum- mary Judgment . . . . Medtronic’s inclusion of the [c]onten- tions below does not constitute a waiver or concession of any aspect of Medtronic’s objections or arguments made in connection with those orders, not does it constitute a waiver of Medtronic’s right to appeal the same.” J.A. 13637. Medtronic made a similar disclaimer in its trial brief. J.A. 18581–82. Second, when Medtronic later made a Rule 50(a) mo- tion for JMOL during trial, Medtronic explicitly made its prosecution-history-estoppel argument. J.A. 18727. And Colibri, responding, did not assert that Medtronic had abandoned the argument, instead urging the court to reject the argument solely on the merits. J.A. 18751. That re- sponse by Colibri comes within the principle that a waiver argument may be forfeited “by addressing the claim on the merits without also making a waiver argument.” Norwood v. Vance, 591 F.3d 1062, 1068 (9th Cir. 2010). Case: 23-2153 Document: 59 Page: 16 Filed: 07/18/2025
Third, Colibri asserted waiver for the first time in its opposition to Medtronic’s Rule 50(b) motion, even though it had the opportunity to do so when responding to Med- tronic’s Rule 50(a) motions. Colibri’s Opposition to Med- tronic’s Renewed Motion for Judgment as a Matter of Law at 8, Colibri Heart Valve LLC v. Medtronic CoreValve LLC, No. 20-cv-00847 (C.D. Cal. May 11, 2023), ECF No. 479 (“The Court should hold Medtronic to its voluntary aban- donment of its prosecution history estoppel defense and find this issue waived.”). But even then, Colibri did not establish any prejudice from the pretrial statement fol- lowed by the raising of this issue of law in seeking JMOL. And the district court, in then ruling on the Rule 50(b) mo- tion, did not agree with Colibri’s waiver contention. In- stead, it directly addressed the merits, with no suggestion that the estoppel argument had been waived. See J.A. 4. Whether that course reflected the district court’s reading of the pre-trial statement, reliance on Colibri’s failure to raise waiver in opposing the Rule 50(a) motion, or exercise of any available discretion to reach the merits in the ab- sence of any prejudice in these circumstances, we see no justification for us now to reject Medtronic’s prosecution- history-estoppel argument as waived by its pre-trial state- ment. B On the merits of prosecution history estoppel, Med- tronic argues that the district court erred by concluding that Colibri’s asserted equivalent is quite distinct and sep- arate from what was recited in cancelled claim 39 and that Colibri’s cancellation of claim 39 was not a narrowing amendment. Medtronic Opening Br. at 47–48. We agree with Medtronic on those two related points, relying on Colibri’s own recognition, in its affirmative case for finding equivalents, of the substantive linkage between the can- celled and retained claims. And because Colibri makes no argument against prosecution history estoppel except that the presumption of estoppel is inapplicable at the Case: 23-2153 Document: 59 Page: 17 Filed: 07/18/2025
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threshold, i.e., it makes no argument that this case comes within an exception when the presumption of estoppel ap- plies or that the scope of particular narrowing does not jus- tify estoppel, we hold that estoppel bars equivalents infringement here. 1 We begin with the district court’s conclusion that the asserted equivalent (i.e., the implantation method of Med- tronic’s Evolut system) differs distinctly from what was re- cited in cancelled claim 39. Colibri asserts that claim 39 did not require pushing the inner member—only retracting the moveable sheath—whereas Medtronic’s Evolut devices require both pushing and retracting. Colibri Response Br. at 47; see also id. at 47–48 (“Pushing while retracting is not ‘precisely what was recited in claim 39.’ Pushing appears nowhere in claim 39.”). The district court agreed with Colibri that, because Colibri’s “asserted equivalent is not merely retraction,” the “asserted equivalent . . . differs from what was set forth in the cancelled claim.” Summary Judg- ment Recommendation at 37–38 (emphasis added). Colibri’s own affirmative theory of equivalence, how- ever, hinges on what Colibri calls “simple physics,” Colibri Response Br. at 11, 38, and “basic physics,” id. at 56, re- quiring that opposing forces (i.e., pushing and retracting) be applied to deploy the valve and stent from the moveable sheath. Colibri repeatedly asserted, before both this court and the district court, that the relevant artisan would un- derstand that pushing necessarily accompanies retracting: “[B]ecause of the radial force the stent exerts on the inside of the sheath, there’s ‘[a]bsolutely’ no way to deploy the re- placement heart valve without ‘applying opposing forces.’” 2
2 We do not rely on Medtronic’s argument based on the “comprising” language of cancelled claim 39. See Med- tronic Opening Br. at 47–48. Case: 23-2153 Document: 59 Page: 18 Filed: 07/18/2025
Id. at 59 (second alteration in original) (quoting J.A. 21292, lines 20–24); see also J.A. 21077, lines 3–18 (Colibri’s wit- ness explaining that, because the stent is self-expanding, “we have to have something that’s going to contact and take hold of that stent so that we can move it”). Claim language present in both retained claim 34 (is- sued claim 1) and cancelled claim 39 further indicates that the relevant artisan would know that pushing necessarily accompanies retraction—that, in Colibri’s words, “basic physics require pushing.” See Colibri Response Br. at 56. Both claims recite that “the replacement heart valve device . . . is restrained in the collapsed configuration by the moveable sheath.” ’294 patent, col. 14, lines 12–15 (claim 1); J.A. 23140 (claim 39). This language indicates that the stent is held in place by the moveable sheath and will move with the moveable sheath in the absence of a pushing force on the stent (or something holding the stent, like the pusher member). We conclude, accordingly, that the district court and special master were incorrect that Colibri’s asserted equiv- alent distinctly “differs from what was set forth in” claim 39 such that the substance dropped when cancelling claim 39 is quite separate from the substance of retained claim 34 (issued claim 1). Summary Judgment Recommendation at 38. Colibri’s assertions before this court and the district court, coupled with the surrounding claim language, make clear that pure retraction of the moveable sheath would re- sult in retraction of the stent and valve as well—the only way to deploy (i.e., separate) the stent and valve from the moveable sheath is to simultaneously exert a pushing force on the inner member holding the stent and valve. A coun- tervailing pushing force is therefore necessary to both Colibri’s asserted equivalent and the deployment method described by claim 39. Case: 23-2153 Document: 59 Page: 19 Filed: 07/18/2025
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2 We similarly agree with Medtronic’s second argument, which is closely related to the first—that Colibri’s cancel- ling of claim 39 in favor of pursuing limitations that al- ready appeared in retained claim 34 (issued claim 1) was a narrowing amendment giving rise to prosecution history estoppel. Medtronic Opening Br. at 47–48. Narrowing is a prerequisite to prosecution history estoppel: “If the amendment was not narrowing, then prosecution history estoppel does not apply.” Festo, 344 F.3d at 1366. But the required narrowing is not a purely formal matter of alter- ing a single claim’s terms; it can exist, and we conclude here does exist, as a substantive matter based on cancelling a closely related claim involving such intertwined termi- nology that cancelling one claim necessarily communicated that the scope of the other claim had narrowed. As just explained, Colibri cancelled claim 39, which re- cited partial deployment by retracting and necessarily in- volved applying a pushing force to the inner member in order to achieve that retraction. That cancellation bears on what can be covered under the doctrine of equivalents by claim 1 because a relevant artisan would understand the close basic-physics relationship of the cancelled and re- tained claims. The portions of the two claims that recite the partial-deployment step in question are substantially similar—both recite exposing the valve, the only difference is that then-claim 34 (issued claim 1) recites doing so by “pushing” while claim 39 recites “retracting”: after the advancing step, partially deploying a dis- tal portion of the replacement heart valve device within the patient by pushing out the pusher member from the moveable sheath to expose the distal portion of the replacement heart valve device ’294 patent, col. 14, lines 21–25 (emphasis added) (claim 1); see J.A. 23140 (then-claim 34). Case: 23-2153 Document: 59 Page: 20 Filed: 07/18/2025
after the advancing step, partially deploying the re- placement heart valve device within the patient by retracting the moveable sheath to expose a por- tion of the replacement heart valve device; J.A. 23141 (emphasis added) (claim 39). The district court’s reasons for rejecting such a rela- tionship between the cancelled subject matter and claim 1 rely on formalities: that then-claim 34 (issued claim 1) and then-claim 39 were separate independent claims, and that Colibri did not “add[] or amend[] any claims directed to” the pushing limitation. Summary Judgment Recommendation at 37. That rationale, however, makes an entirely formal point, requiring a formal claim relationship between the cancelled and allowed claims (e.g., independent and de- pendent). If formalities are not determinative, however, the rationale does not justify denying estoppel here. As al- ready indicated, the relevant artisan would understand that claim 1 (reciting only pushing) and claim 39 (reciting only retracting) are not unrelated to each other but, in fact, are closely related as a substantive matter, so giving up one communicates a narrowing message about the one re- tained. Governing law precludes making formalities determi- native, to the exclusion of substantive relationships that would be understood by relevant readers. “Estoppel is a ‘rule of patent construction’ that ensures that claims are interpreted by reference to those ‘that have been cancelled or rejected.’” Festo Corp. v. Shoketsu Kinzoku Kogyo Ka- bushiki Co., 535 U.S. 722, 733 (2002) (quoting Schriber- Schroth Co. v. Cleveland Trust Co., 311 U.S. 211, 220–21 (1940)). That principle by its terms does not limit estoppel to situations in which the issued, asserted claim itself was amended, though the claim in Festo itself had been amended. See Festo, 344 F.3d at 1371–72 (discussing pa- tentee’s narrowing by adding limitations). And the Court in Festo used additional language not strictly limiting Case: 23-2153 Document: 59 Page: 21 Filed: 07/18/2025
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estoppel to the amendment of a particular claim, but in- stead tailoring the inquiry to the scope of the claims of the patent as a whole, pre- and post-amendment. See, e.g., Festo, 535 U.S. at 736 (“Estoppel arises when an amend- ment is made to secure the patent and the amendment nar- rows the patent’s scope.” (emphasis added)); id. at 740 (“Where the original application once embraced the pur- ported equivalent but the patentee narrowed his claims to obtain the patent or to protect its validity, the patentee cannot assert that he lacked the words to describe the sub- ject matter in question.” (emphasis added)). 3
3 The Supreme Court in Festo relied on the reasoning of Schriber-Schroth, which explained the underlying ra- tionale of prosecution history estoppel in a validity context not directly involving that doctrine. For example, the Court in Schriber-Schroth said: “Where the patentee in the course of his application in the patent office has, by amend- ment, cancelled or surrendered claims, those which are al- lowed are to be read in the light of those abandoned and an abandoned claim cannot be revived and restored to the pa- tent by reading it by construction into the claims which are allowed.” 311 U.S. at 218; see also id. at 220–21 (“It is a rule of patent construction consistently observed that a claim in a patent as allowed must be read and interpreted with reference to claims that have been cancelled or re- jected and the claims allowed cannot by construction be read to cover what was thus eliminated from the patent.” (citation omitted)). In Schriber-Schroth, the patentee had cancelled claims reciting a “flexible web” feature and sub- sequently argued that claims not reciting the feature should be construed to include it (to escape invalidation by prior art). Id. at 219–20. The Supreme Court rejected the patentee’s argument and explained that “the patentee, having acquiesced in the[] rejection [of claims reciting the Case: 23-2153 Document: 59 Page: 22 Filed: 07/18/2025
We rejected a formalistic approach to the narrowing in- quiry in Honeywell International Inc. v. Hamilton Sundstrand Corp., 370 F.3d 1131, 1141–44 (Fed. Cir. 2004) (en banc). In that case, following the patent office’s rejec- tion of the original independent claims for obviousness, the patentee cancelled those independent claims and simply rewrote two dependent claims into independent form. Id. at 1141. The rewritten claims were subsequently allowed. Id. at 1137–38, 1141. Honeywell later asserted infringe- ment under the doctrine of equivalents of the rewritten claims. Id. at 1138. Honeywell argued that rewriting a dependent claim into independent form does not give rise to the presump- tion of prosecution history estoppel “because the scope of the rewritten claims themselves has not been narrowed.” Id. at 1141. After all, the original dependent claims, by statutory directive, already contained all the independent claims’ elements, 35 U.S.C. § 112(d) (“A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.”); the rewritten claims simply made the incorporation express, changing nothing of substance. But we rejected that argument, rea- soning that the Supreme Court had already rejected it in Festo. Id. at 1141–42. In particular, we observed that the Supreme Court had explained in Festo that this type of ar- gument “conflates the patentee’s reason for making the amendment with the impact the amendment has on the subject matter.” Id. at 1141–42 & n.7 (citing Festo, 535 U.S. at 736–37). “[T]he fact that the scope of the rewritten claim has remained unchanged will not preclude the appli- cation of prosecution history estoppel if, by canceling the original independent claim and rewriting the dependent
flexible web feature], is no longer free to gain the supposed advantage of the rejected claims by a construction of the allowed claims as equivalent to them.” Id. at 221–22. Case: 23-2153 Document: 59 Page: 23 Filed: 07/18/2025
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claims into independent form, the scope of subject matter claimed in the independent claim has been narrowed to se- cure the patent.” Id. at 1142. The focus in Honeywell on the scope of what was aban- doned, even when a particular claim was not altered in scope, is reflected in other decisions of this court as well. See Glaxo Wellcome, Inc. v. Impax Laboratories, Inc., 356 F.3d 1348, 1356 (Fed. Cir. 2004) (“[S]ubject matter surren- dered via claim amendments during prosecution is also re- linquished for other claims containing the same limitation.” (emphasis added)); Deering Precision Instruments, L.L.C. v. Vector Distribution System, Inc., 347 F.3d 1314, 1325–26 (Fed. Cir. 2003) (applying presumption of prosecution his- tory estoppel to “all claims containing the [cancelled limi- tation], regardless of whether the claim was, or was not, amended during prosecution”). In our non-precedential de- cision in Mycogen Plant Science, Inc. v. Monsanto Co., we summarized a key aspect of governing law: “Among the rules from the original Festo en banc decision that were un- changed by the Supreme Court and reaffirmed by this court . . . was our holding that cancellation of claims for reasons related to patentability in favor of claims with a narrower literal scope has the same presumptive effect on claim limitations as amending the claims directly.” 91 F. Appx. 666, 668 (Fed. Cir. 2004) (non-precedential) (refer- ring to Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558 (Fed. Cir. 2000) (en banc), which was va- cated in Festo, 535 U.S. 722 (2002), which in turn was fol- lowed by Festo, 344 F.3d 1359 (Fed. Cir. 2003) (en banc))). When evaluating prosecution history estoppel, we do not address each claim in isolation, considering only whether that asserted claim was amended. If that were the proper approach, this court in Honeywell, for example, would have rejected the application of prosecution history estoppel when dependent claims were amended to be put in independent form, because the scope of those particular claims did not change by amendment. Instead, this court Case: 23-2153 Document: 59 Page: 24 Filed: 07/18/2025
concluded that the cancellation of a prior, broader inde- pendent claim may give rise to prosecution history estoppel in relation to a narrower claim, depending on the relation- ship between the scopes of those claims. Honeywell, 370 F.3d at 1144. This court in Honeywell also cited favorably to Keith v. Charles E. Hires Co., 116 F.2d 46 (2d Cir. 1940), in which the Second Circuit held that prosecution history estoppel applied where, as with the claims at issue here, the pa- tentee filed two independent claims and cancelled one after its rejection. Honeywell, 370 F.3d at 1142 n.8 (discussing Keith, 116 F.2d at 48). The Second Circuit rejected the proposition that, for estoppel to apply, the patentee must have amended the claim that ultimately issued. Keith, 116 F.2d at 47–48. Because the patentee “ha[d] already filed a claim which contains the necessary differentia” from the rejected subject matter, maintaining that claim while can- celling another, broader claim abandoned coverage of “the element by which that claim differs from the cancelled claim.” Id. at 48. For those reasons, we reject Colibri’s contention that claim 1 itself had to be amended for prosecution history es- toppel to apply. The close substantive relationship be- tween the cancelled and retained claims, by Colibri’s own basic-physics logic for its affirmative assertion of equiva- lence, is enough to cross the estoppel threshold. A skilled artisan reading the prosecution history would understand that some narrowing had occurred through cancelling claim 39. In that situation, in the absence of further argu- ments about the scope of narrowing or exceptions to the presumption of estoppel, the doctrine of equivalents be- came unavailable to Colibri for the issued claim 1. If Colibri wished to capture territory involving retraction that was outside the literal scope of claim 1, it could have filed a continuation application (and there sought to show written-description support). Within the confines of the ’294 patent, the public-notice function of prosecution Case: 23-2153 Document: 59 Page: 25 Filed: 07/18/2025
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history estoppel is served by barring infringement under the doctrine of equivalents. IV Having determined that Medtronic was entitled to judgment as a matter of law of noninfringement of the ’294 patent, we reverse the district court’s denial of such a judg- ment. That reversal moots the remaining aspects of Med- tronic’s appeal (i.e., those relating to invalidity, the remaining noninfringement arguments, and damages). The parties shall bear their own costs. REVERSED