IP Law Daily, PATENT—D. Mass.: Covidien’s surgical instrument patents are valid, but not infringed by Ethicon’s products, (Apr 27, 2020)

By Joseph Arshawsky, J.D.

Trial evidence showed that Ethicon’s Enseal X1 Large Jaw vessel sealer did not infringe two Covidien patents and both asserted patents are not invalid as obvious or anticipated.

Following a bench trial, the federal district court in Boston has decided that Ethicon Endo-Surgery did not infringe the asserted claims of two patents directed to bipolar surgical instruments and owned by Covidien. Ethicon’s Enseal X1 Large Jaw vessel sealer device failed to satisfy several claim limitations. Ethicon failed establish that any of the asserted claims were invalid for obviousness or anticipation (Ethicon Endo-Surgery, Inc. v. Covidien LP, April 24, 2020, Sorokin, L.).

Ethicon Endo-Surgery, Inc. and Ethicon Endo-Surgery, LLC (collectively, "Ethicon") filed a declaratory judgment action against Covidien LP, Covidien Sales LLC, and Covidien AG (collectively, "Covidien"), seeking a declaration that Ethicon’s Enseal X1 Large Jaw vessel sealer does not infringe certain Covidien patents and that the patents are invalid. Covidien counterclaimed for infringement. The parties stipulated to the dismissal of all but two patents, the U.S. Patent No. 9,241,759 (the ’759 patent), entitled "Vessel Sealer and Divider for Use with Small Trocars and Cannulas," and U.S. Patent No. 8,323,310 (the ’310 patent), entitled "Vessel Sealing Jaw with Offset Sealing Surface." Both patents relate to features of advanced bipolar surgical instruments used to seal and cut tissue or blood vessels. The devices permit surgeons to grasp a vessel or tissue between two opposing jaws at the distal end of the instrument, apply energy to the vessel or tissue to form a seal—thereby stopping the blood flowing through it—and then cut the sealed tissue using a knife that moves along the length of the opposing jaws.

Infringement of the ’759 patent. The parties disputed whether the preamble of claim 1, which recites "[an] endoscopic bipolar forceps" is limiting and, if it is not, whether the Enseal X1 nevertheless infringes by practicing three claim limitations pertaining to the claimed "movable handle": (a) it has a finger loop, (b) it has a drive flange, and (c) it is "of unitary construction." Here, the term "endoscopic bipolar forceps" is recited only in the preambles of asserted ’759 patent claims; it does not appear in the body of any claim. Reading the claim body on its own, it is apparent that the preamble at issue merely describes a purpose or intended use for the invention, and that the claim body describes a structurally complete invention, the court noted. That said, the specification does not limit the invention to instruments used endoscopically. The deletion of the preamble from the claims of the ’759 patent, or its substitution with a generic term like "apparatus" or "device," does not affect the structure of the claimed invention because the term "endoscopic" does not provide any additional structure to the apparatus claims of the ’759 patent. Nor do the asserted claims recite or suggest an overall size limitation on the patented device—e.g., that it be small or narrow enough to be used only in endoscopic procedures. The court therefore concluded that the preamble at issue is not limiting.

The "finger loop" limitation. The claimed "finger loop" consists of a closed curved structure that surrounds the back and front of the inserted fingers, enabling the user to pull the movable handle to close the jaws of the device and to push the handle to open the jaws. Covidien did not show by a preponderance of the evidence that the accused shepherd’s hook practices the finger loop claim limitation under either articulation of the test for equivalence. There are meaningful differences between the finger loop and the shepherd’s hook handle, which are grasped and released differently, and which "receive" the user’s fingers differently. The shepherd’s hook handle does not "contain" the user’s fingers in the same way as the claimed invention. The court concluded that the shepherd’s hook design does not perform substantially the same function, in substantially the same way, with substantially the same result as the finger loop, and that it is not insubstantially different from the shepherd’s hook design. The court therefore concluded that Covidien has not shown by a preponderance of the evidence that the shepherd’s hook design of the Enseal X1 satisfies the "finger loop" limitation.

The "of unitary construction" and "drive flange" limitations. The remaining two disputed claim limitations of the ’759 patent—"a movable handle of unitary construction having a finger loop positioned towards a first end thereof, [and] a drive flange positioned towards a second end thereof…"—are of a piece. By its own terms, claim 1 of the ’759 patent requires that the "unitary construction" of the movable handle include "a drive flange." The court construed "of unitary construction" to mean "constructed as a single unit." The court construed the term "drive flange" to mean "a force-actuating and projecting rib or rim."

The parties disputed the proper interpretation of both parts of the court’s claim construction—that is, they disagreed over what constitutes a "rib" and over what "force-actuating and projecting" means. After reviewing the evidence and arguments, the court determined that a "rib" is "material added to strengthen or reinforce a part." The court agreed with Covidien that for present purposes, the term "rib" is not limited to "thin strips," as Ethicon contended. In construing the claim term "a drive flange," the court determined that "the phrase ‘projecting rib or rim’ appears to aptly describe all of the other components which the ’759 patent also calls ‘flanges.’" The court therefore rejectedEthicon’s proposed requirement that "ribs" be limited to "thin, protruding strips" and interprets the term to mean "material added to strengthen or reinforce a part." On this basis, the court concluded that the raised structures on the movable handle of the Enseal X1 are "ribs" under the court’s claim construction.

The only remaining question, then, was whether the ribs on the movable handle of the Enseal X1 are "force-actuating and projecting." The court concluded that the claim limitation at issue requires that the claimed drive flanges are the only components that transmit the force exerted by the user’s hand on the movable handle to the drive sleeve. The court found—as Covidien urged—that the Enseal X1, as sold and used, has ribs that are operably coupled to the drive sleeve, and that these ribs strengthen and reinforce the edge of the pinhole with which they, and the part of the handle on which they sit, come into contact. The court therefore concluded that Covidien failed to show that the ribs on the movable handle of the Enseal X1 device are "force-actuating and projecting," and, therefore, has not shown that the movable handle of the Enseal X1 device contains the claimed "drive flanges." And, because the movable handle of the Enseal X1 device does not contain the claimed "drive flanges," the accused device also does not meet the limitation that the movable handle be "of unitary construction."

Invalidity of the ’759 patent. Ethicon argued the asserted claims of the ’759 patent are obvious in light of U.S. Patent No. 6,419,675 ("Gallo") in view of one or more of: WO 02/080795 ("Dycus ’795"), WO 02/080799 ("Dycus ’799") and WO 02/058544 ("Witt"). Ethicon’s primary reference, Gallo, does not teach several of the limitations recited in independent claim 1 of the ’759 patent. First, Gallo does not teach the claimed movable and fixed jaw member configuration, disclosing instead a design with four pliable jaw members. Second, the four pliable jaw members in Gallo are moved from the open to the closed positions by a tubular sheath mechanism, not by a drive sleeve mechanism as claimed in the ’759 patent. Third, Gallo does not disclose a finger loop handle but instead discloses a straight lever handle, which does not enable the user to push forward on a surrounding structure to open the jaw members. Fourth, Gallo does not disclose a locking flange positioned on a movable handle of unitary construction in the way recited by independent claim 1 of the ’759 patent—that is, disposed between the finger loop and the drive flange.

The issue before the Court was whether Ethicon showed by clear and convincing evidence that a person of ordinary skill in the art would have been motivated to modify Gallo in such a way as to produce the device claimed in the ’759 patent. Modifying the device disclosed in Gallo to arrive at the ’759 patent device would have required a substantial re-design of the Gallo device, including re-designing at least the jaw members, shaft and shaft assembly, the mechanism used to close the jaw members, and the movable handle, the court observed. The court was not persuaded that a person of ordinary skill in the art at the time of the invention would have been motivated to modify Gallo’s four pliable jaw member configuration and tubular sheath mechanism to arrive at the configuration of one movable and one fixed jaw member actuated by a drive sleeve mechanism as claimed in the ’759 patent. The court therefore concluded that Ethicon failed to meet its burden to show, by clear and convincing evidence, that the asserted claims of the ’759 patent are obvious over any of the prior art references.

Claim construction of the ’310 patent. Claim 1 of the ’310 patent recites that "when the jaw members are disposed in the second [i.e. closed or "clamped"] position, a plane is formed between the opposing sealing surfaces." It also recites that the plane is offset from the longitudinal axis in a direction opposite to that of the pivot pin. During claim construction proceedings, Ethicon argued that because a gap exists between the claimed opposing jaw members when they are closed, and because basic geometry dictates that an unlimited number of planes exist within such a three-dimensional space, the "plane" limitation renders the claim indefinite. After reviewing the evidence submitted at trial and the parties’ arguments, the court concluded that the "plane" term is not indefinite, and that a person of ordinary skill in the art would understand the claimed plane to be the mid-plane between the sealing surfaces when the jaws are in the closed position. The court construed the "plane" term as "the plane that bisects the gap between the sealing surfaces when the jaw members are in the closed position," and rejected Ethicon’s reading of the "plane" limitation as requiring that the sealing surfaces touch when the jaw members are in the closed position.

Infringement of ’310 patent. For purposes of the infringement inquiry, the only issue was whether Covidien established that the plane that bisects the gap between the sealing surfaces of the jaw members when they are in the closed position is below the longitudinal axis. The court concluded that Covidien failed to meet its burden of proving that the Enseal X1 practices the "plane" limitation, and therefore failed to prove that the Enseal X1 infringes the asserted claims of the ’310 patent. The court also considered the totality of the separate pieces of evidence Covidien submitted, but in this case the sum of the parts was not greater than the individual constituent pieces. The court concluded that Covidien did not show by a preponderance of the evidence that the Enseal X1 practices the claimed plane limitation and that Covidien therefore failed to prove that the Enseal X1 infringes any of the asserted claims of the ’310 patent.

Invalidity of ‘310 patent. The parties stipulated that the cited prior art references—U.S. Patent Application Publication No. 2003/0229344 ("Dycus ’344"), U.S. Patent No. 6,056,735 ("Okada"), and WO2008/040485 ("Geiselhart")—disclose all but the claimed "plane" limitation at issue in the asserted independent claims of the ’310 patent. All three prior art references are directed to surgical devices. None of them claim or describe the offset configuration claimed in the ’310 patent—i.e., a pivot pin offset in one direction from the longitudinal axis and a plane formed between the opposing sealing surfaces of the jaw members when they are in the closed position offset in a different direction from the longitudinal axis, according to the court. Nor do any of the cited prior art references discuss the problem addressed by the ’310 patent—to improve the mechanical advantage and uniform pressure distribution across the jaw members to enable better tissue sealing. The court concluded that Ethicon failed to meet its burden of showing by clear and convincing evidence that the cited figures (or the prior art references more generally) anticipate the claimed "plane" limitation or render it obvious. The court concluded that the figures in the cited prior art references do not constitute clear and convincing evidence of anticipation or obviousness of the plane limitation in the asserted claims of the ’310 patent, and that Ethicon has therefore failed to prove that the asserted claims of the ’310 patent are invalid.

The court concluded that Ethicon failed to establish invalidity and that Covidien failed to establish infringement.

This case is No. 1:16-cv-12556-LTS.

Attorneys: Abhishek Bapna (Patterson Belknap Webb & Tyler LLP) and Alexander K. Parachini (Donnelly, Conroy & Gelhaar, LLP) for Ethicon Endo-Surgery, Inc. and Ethicon Endo-Surgery, LLC. Drew Wintringham (DLA Piper LLP) and David J. Apfel (Goodwin Procter, LLP) for Covidien LP, Covidien Sales LLC and Covidien AG.

Companies: Ethicon Endo-Surgery, Inc.; Ethicon Endo-Surgery, LLC; Covidien LP; Covidien Sales LLC; Covidien AG

Cases: Patent GCNNews MassachusettsNews