Ethiсon Endo-Surgery, Inc. (Ethicon) appeals a decision of the District Court for the Southern District of Ohio granting summary judgment of noninfringement to United States Surgical Corp. (U.S. Surgical) with respect to claims 6 and 24 of U.S. Reissue Patent No. 34,519 (’519). Ethicon Endo-Surgery v. United States Surgical Corp.,
Linear cutter staplers (staplers) are surgical instruments used to cut internal body-tissue while simultaneously placing rows of staples along both sides of the incision in order to prevent excessive bleeding. It is important, therefore, that the stapler not be used when its staple cartridge is empty. The ’519 patent discloses a “lockout mechanism” for ensuring that once the staple cаrtridge is emptied, the stapler cannot be used again before the spent staple cartridge is replaced. The ’519 patent is a reissue of U.S. Patent No. 4,892,244 (’244).
The reissue patent discloses several embodiments which work similarly. Illustratively, Fig. 1 of the reissue patent, reproduced below, depicts a stapler 10
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Also reproduced below is Fig. 2 of the reissue patent which is an elevation view of the lockout mechanism during firing of the stapler. As shown in Fig. 2, lockout mechanism 90 comprises a strip 92, a barrier lock 96 biased to enter slots 33, and a restraining member 98 to inhibit barrier lock 96 from entering slots 33. As the stapler is fired, pusher bars 32 slide forward until they reach and engage the front end 94 of strip 92, thus sliding strip 92 forward. As a result, re
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William D. Fox et al., assignors to Ethicon, applied for and received the ’244 patent, which issued on January 9, 1990. Claim 6 of that patent, the only claim from the original patent which is at issue in this case, recites:
In a staple cartridge insertable within a surgical stapler and containing staples and comprising an elongated body including one or more longitudinal slots for slidably receiving one or more longitudinal pusher bars comprising a firing mechanism of said surgical stapler, and a рlurality of drivers engageable by said pusher bars for ejecting the staples from the cartridge, said staple cartridge releasably fastened to a said surgical stapler,
the improvement comprising a lockout mechanism connected to said longitudinal slots for preventing said pusher bars from passing more than one time through said longitudinal slots.
(emphasis added).
Subsequently, Ethicon became concerned that this claim might not read on several lockout mechanisms employed by its competitor U.S. Surgical. As is illustratively shown in the trial exhibit drawings reproduced below, the lockout mechanism on U.S. Surgical’s open staplers functions by impeding the cam bar retainеr, rather than the pusher bars.
Seeking to broaden its claims to cover U.S. Surgical’s product, Ethicon put its patent into reissue. One of these broader claims, claim 24, is asserted by Ethicon against U.S. Surgical in this case. Claim 24 recites:
A surgical stapler comprising a frame,
a cartridge filled with staples and positionаble in operative association with said frame and having one or more slots,
a firing assemblage including a pusher assembly moveable relative to said frame, said pusher assembly comprising one or more pusher bars respectively extending through said slots to fire said staples,
a member operatively connected to said pusher assembly for moving the pusher assembly in a firing direction down a path to fire the staples, and in a direction opposite to said firing direction to a retracted position after at least a portion of the staples have been fired,
a lockout mechanism for preventing fir.ing movement of the pusher assembly in the firing direction after the pusher assembly has been moved to the retracted position, said lockout mechanism including a barrier assemblage for preventing movement of the pusher assembly from said retracted position, said barrier assemblage comprising a resilient projecting member normally biased toward a position to engage said pusher assembly to prevent movement of said pusher assembly relative to said resilient projecting member after said pusher assembly has been moved to said retracted position, and
a restraining structure separate from said pusher bar for blocking said barrier assеmblage to maintain said resilient projecting member out of the path of the pusher assembly during staple firing, said restraining structure being moveable by said pusher assembly during movement of the pusher assembly in the firing position whereby the barrier assemblage is released to allow the resilient projecting member to move into the path of the pusher assembly to prevent firing movement of said pusher assembly after movement thereof to said retracted position.
(emphasis added).
Facially, the primary distinction between claims 6 and 24 is that claim 6 seems to tie the location of the lockout mechanism to the slots through which the pusher bars pass,
One week after its patent was reissued on January 25,1994, Ethieon sued U.S. Surgical for infringement asserting that several of U.S. Surgical’s staplers infringed claims 6 and 24 of the ’519 patent. Discovery was conducted and the case was set for jury trial on April 10,1994. On the eve of trial, however, we issued our in báñe decision in Markman v. Westview Instruments, Inc.,
A five day hearing was held, at the close of which the district court interpreted the claims. On the basis of the claim language and the prosecution history, the district court concluded that both claims 6 and 24 must be read narrowly as requiring the lockout mechanism to engage the pusher bars rather than any other portion of the firing assembly. Since U.S. Surgical’s lockout barriers do not engage the pusher bars, but instead engage the cam bar retainer or other portions of the firing assembly, the district court proceeded to hold, as a matter of law, that U.S. Surgical’s staplers do not literally infringe claims 6 or 24 of the ’519 patent. In addition, the district court seems to have determined as a matter of law that U.S. Surgical’s staplers do not infringe under the doctrine of equivalents since the judgment from the district court dismisses Ethieon’s suit with prejudice. The district court, however, presented no findings to explain its doctrine of equivalents holding.
Ethieon appeals from the district court’s judgment. With respect to literal infringement, Ethieon contends that the district court read claims 6 and 24 too narrowly and that those claims are broad enough to cover devices in which the lockout barrier engages portions of the firing assembly other than the pusher bars. Additionally, Ethieon asserts that it was inappropriate for the Court to grant judgment as a matter of law on the doctrine of equivalents at the close of the Markman hearing. Ethieon believes that disputed issues of fact remain with respect to' infringement by equivalents and that .it is entitled to a jury trial on those issues. We have jurisdiction to review the district court’s judgment under 28 U.S.C. § 1295(a)(1) (1994).
II
Claim construction is a matter of law which we review de novo. See Vitronics Corp. v. Conceptronic, Inc.,
We agree with the district court’s interpretation of claim 6. Initially, we note that claim 6 is a Jepson claim. See Ex parte Jepson,
Several considerations support this conclusion. Looking first at the claim itself, we note that the functional language at the end of the claim recites that the purpose of the lockout is to prevent the pusher bars from passing again through the longitudinal slots, rather than describing in more general terms that the function is to prevent refiring of the stapler. This is sоme indication that what is being described is an operative relationship between the lockout barrier and the longitudinal slots.
In addition, as the district court noted, the claim’s preamble places the lockout mechanism “in a staple cartridge.” “Staple cartridge” is a term used in the ’519 specifi
On this point, Ethieon argues that the term “staple cartridge” should not be defined with reference to the specification, but rather should be understood broadly to include any portion of the surgical stapler which is “in-sertable within and releasably fastened to” the stapler. Citing Electro Medical Systems, S.A. v. Cooper Life Sciences, Inc.,
Ethieon’s reliance on Electro Medical, however, is misplaced. Here, the district court did not import an additional limitation into the claim; instead, it looked to the specification to aid its interpretation of a term already in the claim, an entirely appropriate practice. See Autogiro Co. of America v. United States,
Ethieon also challenges the district court’s claim interpretation on the ground that the term “connected to” in the phrase “connected to the slots” should be read broadly to include two distant elements which are “connected” by intervening elements. Thus, Ethieon argues, even if, as in the accused devices, the lockout mechanism is located in another portion of the surgical stapler, it is still indirectly “connected tо” the longitudinal slots, and thus Ethicon’s claim 6 literally reads on it.
We acknowledge that the term “connected to” could, in other contexts, be broadly construed. Nevertheless, in the context of this claim, the district court correctly concluded that the entire phrase “connected to said longitudinal slots” must be read narrowly. First, in what meaningful sense is it possible to “connect” the restraining member, which is a physical item, with the longitudinal slots, which are hollow passageways, unless “connected to” is understood to mean that the restraining member operatively interacts with the longitudinal slots by blocking them? Second, Ethicon’s argument proves too much. If, as Ethieon argues, “connected to” should be read broadly to include elements which are connected directly or indirectly, then this language would read on a lockout mechanism located anywhere in the surgical stapler, and the “connected to” limitation would be meaninglessly empty.
We have also considered Ethicon’s additional arguments based on the prosecution history which allegedly shows that the examiner viewed claim 6 as including a lockout mechanism located in other portions of the surgical stapler. They are insufficient, however, to overcome our strong sense that claim 6 is directed to a lockout mechanism which functions by blocking the longitudinal slots in the staple cartridge so as to inhibit the pusher bars from passing through the longitudinal slots once the staples in the cartridge have been fired. We therefore affirm the district court’s interpretation of claim 6. Since there are no genuine issues of material fact with respect to the structure of U.S. Surgical’s staplers, we also affirm the district court’s holding that claim 6 is not literally infringed.
Ill
Turning to claim 24, we agree with Ethieon that the claim reads on a lockout mechanism
Here, the dispute between the parties centers around the term “pusher assembly.” According to Ethicon, the “pusher assembly” encompasses not only the pusher bars recited in the claim, but additionally includes the cam bar retainer which holds the pusher bars. Although not separately described in the ’519 specification, the cam bar retainer constitutes one element of the firing means 30 in Fig. 1 of the ’519 patent; it is the far left element of the firing means. As a result, Ethicon asserts that those of U.S. Surgical’s lockouts which engage the cam bar retainer literally infringe this claim.' U.S. Surgical, on the other hand, contends that “pusher assembly” is merely a synonym for “pusher bars,” and that claim 24, like claim 6, is limited to a lockout which engages the pusher bars.
The district court began its analysis by noting that the claim itself does not define the makeup of the “pusher assembly” beyond stating that it “compris[es] one or more pusher bars.” Furthermore, the term “pusher assembly” is not used or defined anywhere in the ’519 specification, so the specification provides minimal guidance as to the meaning of this claim term. The district court also noted that neither party’s proposed claim interpretation was necessarily inconsistent with other portions of claim 24, or with the rest of the patent document as a whole. Cf. Markman, — U.S. at -,
Faced with what it considered an ambiguous term, the district court adopted U.S. Surgical’s narrow claim interpretation over Ethicon’s broader proposal, stating: “we return to the view that since Ethicon sought reissue for the specific purpose of extending Fox’s invention to cover U.S. Surgical’s lockout, some unambiguous disclosure of that coverage should be found in Claim 24.” Since reissue claim 24 did not, in the district court’s opinion, unambiguously сover the allegedly infringing staplers, the district court adopted a claim interpretation under which the staplers do not infringe. The district court additionally bolstered its claim interpretation with two pieces of prosecution history which it believed supported its interpretation of the claim. Accordingly, it held that “pusher assembly” means the same as “pusher bars,” and determined as a matter of law that U.S. Surgical’s staplers do not infringe claim 24 since U.S. Surgical’s lockout does not engage the pusher bars.
We need not pass on the district court’s reasoning that reissue claims sought for the purpose of covering a specific competitor’s product must unambiguously read on the allegedly infringing product, because we conclude that claim 24 is not, with respect to whether the pusher assembly comprises the cam bar retainer, ambiguous. Like the district court, we begin with the language of the claim itself. Admittedly, the claim says little about the structure of the “pusher assembly.” It does clearly imply, however, that whatever “pusher assembly” means, it is not a synonym for “pusher bar.” For example, the claim recites:
a restraining structure separate from said pusher bar for blocking said barrier assemblage to maintain said resilient projecting member out of the path of the pusher assembly during staplе firing.
(emphasis added). If the terms “pusher assembly” and “pusher bar” described a single element, one would expect the claim to consistently refer to this element as either a “pusher bar” or a “pusher assembly,” but not both, especially not within the same clause. Therefore, in our view, the plain meaning of the claim will not bear a reading that “pusher assembly” and “pusher bar” are synonyms.
The question remains, though, what is the meaning of the term “pusher assembly”? The answer to that question lies in the ’519’s
In support of its request for an interference, Ethicon copied claim 1 of Tompkins and submitted a chart to the U.S. Patent Office in which it asserted that Fox disclosed each element of the claim. In relevant part, that chart stated:
[Tompkins’ claim] [Ethicon’s comments]
A surgical fastening Applicants [i.e., Fox] apparatus comprising: disclose a surgical stapler 10
a pusher assembly slid-ably mounted on said cartridge frame ..., said pusher assembly having at lеast one cam bar longitudinally movable through said cartridge [to engage staple drivers]; Applicants disclose a pusher bar 32 that is mounted between the upper jaw 20 and lower jaw 40 that form the cartridge frame. The bar 32 slidably moves within longitudinal slot 33 of the cartridge to sequentially engage the drivers 52 ....
and a cam bar retainer for mounting said at least one cam bar; and Applicants disclose a firing means 30 whereon a cam bar 32 is retained.
locking mechanism means engageable with said cam bar retainer for preventing reactuation of the surgical stapling apparatus. Applicants disclose a locking mechanism including a barrier lock 96 that engages with the cam bar 32 to prevent reactuation of the stapler. The aforementioned teaching is the same since to engage the cam bar is no different that engaging a retainer that holds the cam bar.
As this chart demonstrates, the term “pusher assembly” in Tompkins’ claim is not used as a synonym for “pusher bar.” Instead, it describes an “assembly”
In response, U.S. Surgical argues that Ethicon cannot rely on Tompkins’ disclosure to define the term “pusher assembly” since claim 24 demonstrably uses the term differently than Tompkins’ specification. Specifically, Tompkins’ specificаtion defines the “pusher assembly” as including the firing knob, while claim 24 describes the firing knob as a distinct element separate from the “pusher assembly.” This argument is not without some merit. In our view, however, the prosecution history as a whole would
In view of our holding in Athletic Alternatives, Inc. v. Prince Manufacturing, Inc.,
Here, too, we have exрended significant effort endeavoring to ascertain the proper construction of the term “pusher assembly” in claim 24. As has already been noted, the ’519 specification provides minimal guidance on this question. Similarly, as U.S. Surgical points out, the Tompkins’ specification which originated the term is of little, if any, help. Without more explicit alternatives, we have been forced to spend a significant quantity of time carefully sifting through each piece of the reissue prosecution history made part of the appellate record in an effort to discover the term’s proper meaning. As noted above, that reading convincеs us that the “pusher assembly” unambiguously includes the cam bar retainer in addition to the pusher bars expressly recited in the claim.
More than that, however, we cannot say. On the one hand, an argument could be made that Ethicon intended the term “pusher assembly” essentially as a synonym for its firing means 30. Compare Joint Appendix at 3044 (“the original claims did not specify, as broadly as applicants had a right to claim ... a lockout mechanism that ... blocks- the firing means and prevents refiring of the stapler” (emphasis added)) with Joint Appendix at 3127 (“The essence of applicants’ invention is the provision of a lockout mechanism in a surgical stapler that is actuated during initiаl longitudinal movement of a firing means such as a pusher assembly.” (emphasis added)) and Joint Appendix at 3134 (“the essence of applicants’ invention ... provides that when the pusher assembly is retracted after longitudinal movement, a locking mechanism will be activated to prevent subsequent longitudinal movement.” (emphasis added)). On the other hand, in many of the reissue claims, Ethicon implied that they are not synonyms by employing both terms in the same claim and reciting that the firing means “includes” the pusher assembly. See, e.g., Joint Appendix at 3417 (claim 17 of the ’519 patent which recites “a firing means including a pusher assembly”). Consequently, we conclude that the term “pusher assembly” unambiguously describes only the pusher bars and the cam bar retainer, but does not unambiguously cover any other portions of the ’519 patent’s firing means.
Our task, however, is not over. We must affirm the decision of the district court if it is supported by any ground properly preserved on appeal. See Datascope Corp. v. SMEC, Inc.,
In response, Ethicon argues that other portions of the claim as well as the prosecution history make it clear that “it is irrelevant whether the [barrier is still restrained] as the staples are actually being ejected” and that successful operation of the lockout requires only that the barrier be restrained long enough for the firing assembly to begin movement in the firing direction. Ethicon’s argument simply does not address the fact that U.S. Surgical’s barrier is in the path of the pusher assembly before any staples are fired. Ethicon’s reliance on other claim language to overcome this fact invites us to read its “during staple firing” limitation out of the claim. This we cannot do. See Exxon Chemical Patents, Inc. v. Lubrizol Corp.,
The claim recites that the barrier is maintained out of the path of the pusher assembly “during staple firing.” The plain meaning of this limitation requires that the barrier re
IV
At the conclusion of its opinion, the district court dismissed Ethicon’s complaint with prejudice. From this it would appear that the district court granted summary judgment to U.S. Surgical with respect to both literal infringement and infringement under the doctrine of equivalents. On this appeal, the parties dispute whether the posture of the case at the close of the Markman hearing permitted the grant of summary judgment on the issue of infringement by equivalents. Ethicon contends that the Markman hearing established only the literal meaning of the claims, but that genuine issues of material fact may remain with respect to infringement by equivalents. According to Ethicon, the district court never decided whether such issues of fact exist, and therefore could not, at this stage in the proceedings, grant summary judgment on this issue. U.S. Surgical, in contrast, contends that the question of infringement by equivalents was litigated as part of the Markman hearing and that, on this record, summary judgment in their favor with respect to infringement by equivalents is warranted.
Infringement under the doctrine of equivalents frequently turns on questions of fact, such as whether the allegedly infringing device performs substantially the same function in substantially the same way to achieve substantially the same result as the claimed invention. See Hilton Davis Chemical Co. v. Warner-Jenkinson Co., Inc.,
V
For the reasons described above, the judgment of the district court is
AFFIRMED-IN-PART, VACATED-IN-PART, and REMANDED. No costs.
. Two types of staplers are at issue in this case. The first are called "open” staplers and are used in conventional surgery. The second are called “endoscopic” staplers and are used in endoscopic surgery. The stapler shown in the '519 patent is an open stapler.
. The cam bar retainer holds the pusher bars and is located behind the pusher bars in the stapler’s firing assembly.
. In its opinion denying Ethicon’s motion for a preliminary injunction, the district court pointed out that Ethicon and U.S. Surgical are, for practical purposes, the only two manufacturers of the type of surgical staplers involved in this suit. Ethicon Endo-Surgery v. United States Surgical Corp.,
. Although not necessary to resolve this case because of the clear prosecution history, we note in passing that the word "assembly” itself implies a multi-component apparatus. The McGraw Hill Dictionary of Scientific and Technical Terms 133 (4th ed.1989), for example, defines "assembly” as: "A unit containing the component parts of a mechanism, machine, or similar device."
. On similar grounds we reject Ethicon's argument that U.S. Surgical’s endoscopic lockout literally meets claim 24's limitation requiring "movement [of the pusher assembly] to [a] retracted position." As noted above, the tеrm "pusher assembly” includes only the pusher bars and the cam bar retainer. U.S. Surgical’s endoscopic staplers, however, do not appear to contain a cam bar retainer and the pusher bars are not retracted after firing but rather are left in the forward position.
. The district court also misinteipreted the second piece of prosecution history which it cited in support of its interpretation. During the reissue proceedings, the examiner rejected claim 1 of the original '244 patent which recited a lockout mechanism located "on the stapler” saying: "there is no support in the [Fox] specification for а lockout mechanism that is mounted to the stapler.... The disclosed mechanism is mounted to the cartridge;” and "[c]laim 1 implies that the lockout mechanism is not part of the cartridge.” From these statements, the district court erroneously inferred that the examiner considered all of the claims to be limited to a lockout mechanism located on the staple cartridge. In doing so, the district court confused a claim not supported by the specification, which is not allowable, with a broad claim, which is.
Claim 1 was properly rejected because it recited an element not supported by Fox’s disclosure, i.e., a lockout "on the stapler.” It does not follow, however, that Fox’s disclosure сould not support claims sufficiently broad to read on a lockout off of the cartridge. See, e.g., In re Vickers,