Opinion
CAUSE NO. IP 96-1718-C H/G
June 14, 2001
ENTRY ON DEFENDANTS' MOTION FOR SUMMARY JUDGMENT ON PROSECUTION HISTORY ESTOPPEL AS A BAR TO THE DOCTRINE OF EQUIVALENTS
Plaintiffs Cardiac Pacemakers, Inc. ("CPI"), Guidant Sales Corporation, and Eli Lilly and Company allege that defendants St. Jude Medical, Inc., Pacesetter, Inc., and Ventritex, Inc. have infringed two patents for medical devices and methods used to evaluate and treat abnormal conditions in a patient's heart. The two patents in suit are United States Patent No. 4,316,472 (issued Feb. 23, 1982), and United States Patent No. 4,407,288 (issued Oct. 4, 1983). Both patents address implantable cardiac stimulators that deliver electrical shocks to a patient's heart in order to correct various arrhythmias. Plaintiffs contend that defendants' devices infringe various claims of the patents in suit either literally or under the doctrine of equivalents.
On November 29, 2000, the Federal Circuit issued an en banc decision holding that when a patent applicant amends and narrows a claim limitation in an application for a substantial reason related to patentability, the amendment gives rise to prosecution history estoppel and completely bars application of the doctrine of equivalents with respect to the amended limitation. Festo Corp. v. Shoketsu Kinzoku Kogyo Kabushiki Co., 234 F.3d 558, 574 (Fed. Cir. 2000). The Federal Circuit explained that making prosecution history estoppel act as a "complete bar" serves to enforce the disclaimer effect of narrowing claim amendments, thereby preserving the notice function of the claims and lending certainty to the process of determining the scope of protection afforded by a patent. See id. at 567, 575-77.
Defendants contend that the rule applied in Festo applies in this case. According to the defendants, the patent applicants amended several limitations of the '472 and '288 patents that are alleged to be met by equivalents. Defendants' motion for summary judgment seeks a ruling that plaintiffs may prove only literal infringement as to any claim limitations that fall under the so-called Festo rule. As explained below, defendants' motion is granted in part and denied in part. The motion is denied to the extent that the court finds that several of the limitations at issue are means-plus-function limitations entitled to the full range of statutory equivalents under 35 U.S.C. § 112 ¶ 6.
The record on defendants' motion consists of Docket Nos. 454, 455, 456, 495, 496, 497, 543, 544, 566, 570, 584, 639, 640, and 651. Oral argument on the motion was held on May 10, 2001. The motion for summary judgment did not address whether the trial would go forward. It was focused on the instructions the court will give the jury relating to infringement in general and the doctrine of equivalents in particular. The court therefore has not tried to resolve the issue before the trial in this case, which began on June 11, 2001.
Discussion
I. Claim 1 and Claim 10 of the '288 PatentPlaintiffs allege that defendants' devices infringe Claim 1 and Claim 10 of the '288 patent both literally and under the doctrine of equivalents. During prosecution, however, the applicants amended the "selecting" step of Claim 1 and the "selecting means" of Claim 10. These amendments are the foundation for defendants' summary judgment motion. The relevant portions of the allowed claims, as amended, are reproduced below. As to the "selecting" limitation in each claim ( i.e., the only limitations defendants address in their motion), language unchanged by amendment appears in normal text, language added by amendment appears in italics, and original language deleted by amendment appears in brackets:
1. A method of heart stimulation . . . comprising the steps of:
(a) determining a condition of the heart from among a plurality of conditions of the heart;
(b) selecting at least one mode of operation of the implantable heart stimulator which operation includes a unique sequence of events corresponding to [for treating] said determined condition; and
(c) executing said at least one mode of operation of said implantable heart stimulator thereby to treat said determined heart condition.
See '288 Patent, col. 21, ll. 9-23; Mixdorf Decl., Ex. B at 48 (reproducing the original, unamended application claims).
10. An implantable heart stimulator capable of monitoring and detecting a plurality of arrhythmias, and capable of being programmed to undergo a single or multi-mode of operation corresponding to a respective arrhythmia to treat automatically the detected arrhythmia, said stimulator comprising:
determining means for determining the occurrence of one of a plurality of conditions of the heart; selecting means responsive to said determining means for selecting at least one mode of operation of said implantable heart stimulator corresponding to a respective one of said plurality of conditions for automatically treating said determined condition s; and executing means for executing a sequence of events defined by said at least one mode of operation, whereby to treat said determined condition.
See '288 Patent, col. 22, ll. 10-26; Mixdorf Decl., Ex. B at 50. The terms and phrases used in the "selecting" step of Claim 1 and the "selecting means" of Claim 10 obviously overlap. Claim 1 is the method that corresponds to the Claim 10 apparatus.
Whether prosecution history estoppel applies to a given claim limitation is a question of law. Festo, 234 F.3d at 585. A court should find that an amendment to a claim limitation gives rise to prosecution history estoppel only if the amendment narrowed the literal scope of the claim and was made for a reason related to patentability. Id. at 586-87. The patent holder bears the burden of establishing that an amendment was made for purposes unrelated to patentability, and any argument concerning the reason for the amendment must be based solely upon the public record of the patent's prosection. Id.
In this case, plaintiffs properly concede that the amendments to the "selecting" limitations in Claim 1 and Claim 10 of the '288 patent were narrowing amendments made to render the claims patentable over a prior art reference that had caused the examiner to reject the original application claims. As a result, prosecution history estoppel applies to the amended "selecting" limitations appearing in Claim 1 and Claim 10 of the '288 patent.
Because prosecution history estoppel applies to the claims, defendants contend that a straightforward application of Festo completely bars plaintiffs from using the doctrine of equivalents to prove infringement as to either "selecting" limitation. Plaintiffs, however, have raised two arguments that would mitigate the effect of Festo as applied to the "selecting" step of Claim 1 and the "selecting means" of Claim 10.
Plaintiffs first contend that the two "selecting" limitations as a whole were not affected by the amendments and that any unamended claim language is irrelevant to a Festo analysis. In other words, plaintiffs argue, the patent holder may assert infringement under the doctrine of equivalents as to any portion of a phrase or clause that was unaffected by the narrowing amendment. See Pl. Br. at 6-7.
Under plaintiffs' view of Festo as applied to the '288 claims, the court would be required to parse each amended "selecting" clause to determine whether there are any discrete portions of the clause that were essentially unaffected by the amendments. If the court successfully identified any such unaffected portions, then those portions would be spared from Festo's "complete bar" — presumably because it would be clear to everyone that the applicant did not "surrender" anything as to those portions of the claim unaffected by the amendments.
Plaintiffs' approach to defining the scope of prosection history estoppel (and the reach of Festo's "complete bar") is not persuasive. At least as applied to the amended "selecting" limitations at issue in Claim 1 and Claim 10 of the '288 patent, plaintiffs' invitation to parse the claim language into affected portions and unaffected portions is simply another version of the "flexible bar" expressly repudiated by the Federal Circuit in Festo as "unworkable."
Under the "flexible bar" approach to prosecution history estoppel, courts determined the scope of the estoppel by determining " the exact `subject matter the patentee actually surrendered.'" Festo, 234 F.3d at 574 (emphasis added), quoting Hughes Aircraft Co. v. United States, 140 F.3d 1470, 1476-77 (Fed. Cir. 1998). This approach generated great uncertainty as to the extent of the surrender. It was "virtually impossible to predict before the decision on appeal where the line of surrender [would be] drawn. The patentee would draw the line just at or slightly short of the prior art, leaving a wide range of equivalents untouched by prosecution history estoppel. The accused infringer, however, would draw the line close to the literal terms of the claims, leaving little or no range of equivalents." Festo, 234 F.3d at 575.
The "complete bar" approach, on the other hand, tends to reduce the public's need to speculate as to the subject matter surrendered. As the term "complete bar" suggests, it affords no scope of equivalents to a claim limitation that was narrowed because of patentability concerns. Id. at 576. "With a complete bar, both the public and the patentee know that once an element of a claim is narrowed by amendment for a reason related to patentability, that element's scope of coverage will not extend beyond its literal terms." Id. at 577.
In Festo, the Federal Circuit used the term "element" as a substitute for the term "limitation" in order to maintain consistency with the questions presented for en banc review. The court noted that it is preferable to use the term "limitation" when referring to claim language. See 234 F.3d at 563 n. 1.
The express language of Festo indicates that the "complete bar" applies to the entire claim limitation (element) that was narrowed by amendment. A recent Federal Circuit case applies Festo and also runs counter to plaintiffs' argument that courts should carve out unaffected portions of an amended claim limitation and save those unaffected portions from the "complete bar." See Lockheed Martin Corp. v. Space Systems/Loral, Inc., ___ F.3d ___, ___, 2001 WL 436028, at *10-*11 (Fed. Cir. Apr. 30, 2001) (holding that the plaintiff's attempt to distinguish between portions of a limitation that were narrowed by amendment and portions that were not affected by the amendment was an improper attempt to apply the "flexible bar" approach). With the possible exception of a case where the court finds that a narrowing amendment adds a new and completely separate limitation to the patent claim (and thus that other language was "unaffected" because it appears in a separate limitation), Festo and Lockheed Martin preclude the court from parsing amended limitations in the manner plaintiffs propose.
Plaintiffs cite ACLARA Biosciences, Inc. v. Caliper Technologies Corp., 125 F. Supp.2d 391 (N.D.Cal. 2000), in support of their argument that the doctrine of equivalents may still be applied to any claim language unaffected by the narrowing amendment. See Pl. Br. at 7. The amended phrase at issue in ACLARA read (with common language in normal text, old language in brackets, and new language italicized):
a plurality of electrodes positioned to be [operatively connected to] in electrical contact with a medium when present in said trenches [for moving said charged particles in said trenches].125 F. Supp.2d at 393.
The district court in ACLARA divided this single phrase into three separate "components": (1) the number of electrodes component; (2) the non-insulation component; and (3) the electrode configuration component. The district court then held that each "component" was a separate "limitation" for purposes of the Festo analysis. Id. at 402-03. The court reasoned: "Adopting a rule that any amendment to any portion of a clause in a claim creates prosecution history estoppel as to the entire clause and not just the portion of the clause that was amended would do little to promote the purposes of the complete bar approach." Id. at 402 (referring to the Federal Circuit's concerns about fostering innovation, reducing litigation, and minimizing the uncertainty facing the public). In particular, because the applicant in ACLARA never amended the claim to alter what the patent taught about the placement of electrodes, "no potential competitor was left wondering what range of equivalents a fact finder might apply in deciding whether some other electrode configuration was substantially similar." Id. at 401. The narrowing amendment had simply required that the electrodes be non-insulated so that they would be in "electrical contact with a medium." Thus, the complete bar applied only to the non-insulation component of the claim.
ACLARA was issued several months before the Federal Circuit's decision in Lockheed Martin. In this court's view, Lockheed Martin and ACLARA are not necessarily inconsistent, although there is a tension between the two decisions. As the district court noted in ACLARA, the question becomes one of the definition of a "limitation."
On one hand, ACLARA might be distinguished from Lockheed Martin on the basis that Lockheed Martin casts doubt only on intra-limitation parsing of the claim language. Under this view, Lockheed Martin leaves open the possibility that, if a court can identify distinct "components" of the claim that an applicant can manipulate independently ( i.e., narrow and/or broaden), then the court may properly treat those components as separate "limitations" for purposes of the Festo analysis. The result reached in ACLARA arguably demonstrates that a court need not apply the "flexible bar" ( i.e., a court need not define the exact subject matter the patentee actually surrendered) in order to identify separate claim limitations.
In Lockheed Martin, the Federal Circuit expressly noted that the narrowing amendment at issue in that case had not added a "completely separate limitation" to the claim. Instead, the amendment was closely related to the claim language that the plaintiff argued should be excluded from the reach of Festo's complete bar. See 2001 WL 436028, at *11. This distinction suggests that in appropriate cases there is room for the type of analysis conducted in ACLARA. Other portions of the Lockheed Martin decision also appear to leave open the possibility that a single means-plus-function clause may contain multiple limitations. See id. at *8.
On the other hand lies the tension between Lockheed Martin and ACLARA. Defining independent limitations that were "unaffected" by a narrowing amendment will often involve questions of degree. There is a danger that the "flexible bar" approach will reassert itself in the process of parsing clauses into separate limitations. In short, it is difficult to separate entirely the process of defining independent limitations from the process of defining the scope of what the applicant actually surrendered under a narrowing amendment.
Wherever the proper balance between Lockheed Martin and ACLARA may ultimately lie, the narrowing amendments to the "selecting" step of Claim 1 and to the "selecting means" of Claim 10 did not add a completely separate limitation to those claims. Nor are there any independent limitations in the "selecting" step or in the "selecting means" that were unaffected by the narrowing amendments. Accordingly, the "complete bar" to proving infringement under the doctrine of equivalents applies to the entirety of the "selecting" step in Claim 1 and the "selecting means" in Claim 10.
Plaintiffs' second argument for limiting the effect of Festo as applied to the claims of the '288 patent relies on the distinction between the "doctrine of equivalents" and the statutory range of "equivalents" for claim limitations drafted under 35 U.S.C. § 112 ¶ 6, which provides:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
(Emphasis added.) As explained in the Markman claims construction entry in this case, claim limitations phrased in the § 112 ¶ 6 format are called "means- plus-function" or "step-plus-function" limitations. In operation, § 112 ¶ 6 allows a patentee to state claim limitations in broad, general language by reciting the "functions" of the invention, rather than by repeating the detailed structures or materials (in apparatus claims) or detailed acts (in method claims) that perform the claimed functions.
For purposes of the Festo analysis, the most significant characteristic of a claim limitation drafted under § 112 ¶ 6 is the unique test for infringement that applies to such clauses. A means-plus-function limitation, for example, is literally infringed if the relevant structure in the accused device (1) performs the identical function recited in the claim, and (2) is identical or equivalent to the corresponding structure disclosed in the patent specification. See Lockheed Martin, 2001 WL 436028, at *9. An accused device that does not literally infringe a means-plus-function limitation may alternatively infringe under the doctrine of equivalents if the relevant structure in the accused device "performs substantially the same function, in substantially the same way, to achieve substantially the same result." Id. at *10.
Where an applicant has narrowed a means-plus-function clause by amendment for reasons related to patentability, a subtle issue arises, especially for purposes of jury instructions. Festo's "complete bar" to the judicial doctrine of equivalents must be applied to a claim limitation which, by statute, can be literally infringed by an identical or equivalent structure. As the court understands the problem, one question is how the "complete bar" applies to equivalents of the function recited in the claim. A separate question is how the "complete bar" applies to equivalents of the structures disclosed in the specification.
Where an applicant narrows a means-plus-function claim limitation for reasons related to patentability, Festo's "complete bar" forecloses any argument that the accused device infringes the limitation by performing an equivalent of the function recited in the claim. In other words, the patent holder must show that the relevant structure in the accused device performs the identical function recited in the claim. This rule was applied in Lockheed Martin. See 2001 WL 436028, at *9-*11 (finding no infringement where Festo applied to a means-plus-function limitation and the patent owner conceded that the limitation was not literally infringed because the relevant structure in the accused device did not perform the identical function recited in the limitation). In addition, at least one district court has applied a similar rule in a case decided prior to Lockheed Martin. See TM Patents, LLP v. International Business Machines Corp., 136 F. Supp.2d 209, 219-20 (S.D.N.Y. 2001). Cf. Jackson v. Casio PhoneMate, Inc., No. 98 C 6250, 2001 WL 395182, at *3 n. 4 (N.D.Ill. Apr. 17, 2001) (granting summary judgment of non-infringement; after previously finding that the means- plus-function limitation at issue was not literally infringed, the court held that Festo applied to the limitation and, as a result, that plaintiff was also barred from proving infringement under the doctrine of equivalents).
Where an applicant narrows a means-plus-function claim limitation for reasons related to patentability, Festo's "complete bar" does not affect the statutory test for literal infringement under § 112 ¶ 6, which includes structures equivalent to those disclosed in the patent specification. In other words, even if a narrowing amendment gives rise to prosecution history estoppel as to the function performed by the relevant structure, a patent holder may still prove literal infringement under § 112 ¶ 6 by showing that the relevant structure in the accused device is identical or equivalent to the structure disclosed in the patent specification. See TM Patents, 136 F. Supp.2d at 222 ("even after Festo, the structural element of a means-plus-function limitation may be satisfied by either an identical or an equivalent structure").
In summary, the statutory test for literal infringement of a means-plus-function limitation is unchanged even when prosection history estoppel applies to that limitation. Patent holders may prove literal infringement of a means-plus-function limitation just as they would have in the absence of any amendment to the claim language.
The court does not mean to imply that positions taken in the patent prosecution have no effect on the position a patentee may take on claim construction under § 112 ¶ 6. See Wenger Mfg., Inc. v. Coating Machinery Systems, Inc., 239 F.3d 1225, 1239 (Fed. Cir. 2001) (stating that "assertions made in support of patentability . . . may affect the range of equivalents under § 112, ¶ 6."), quoting Cybor Corp. v. FAS Technologies, Inc., 138 F.3d 1448, 1457 (Fed. Cir. 1998).
Defendants also contend that, in applying Festo to a means-plus-function claim limitation, only structures known at the time the patent issued can be equivalents for purposes of literal infringement under § 112 ¶ 6. See Def. Reply Br. at 4-5, citing Chiuminatta Concrete Concepts, Inc. v. Cardinal Industries, Inc., 145 F.3d 1303, 1310-11 (Fed. Cir. 1998). (In contrast, the judicial "doctrine of equivalents" is broad enough to encompass technology developed after the date the patent was issued.) Accordingly, as to any means-plus-function limitation that is subject to prosecution history estoppel and the Festo rule, defendants contend that the jury should be instructed that pre-existing equivalent structures can literally infringe under § 112 ¶ 6 but that later-developed technology cannot be a statutory equivalent, so that Festo completely bars such later technology from further consideration as a non-statutory equivalent.
The court agrees with defendants that there is a distinction between technologies known at the time the patent issued and later-developed technologies. As the Federal Circuit has explained:
One important difference between § 112, ¶ 6 and the doctrine of equivalents involves the timing of the separate analyses for an "insubstantial change." As this court has recently clarified, a structural equivalent under § 112 must have been available at the time of the issuance of the claim. An equivalent structure or act under § 112 cannot embrace technology developed after the issuance of the patent because the literal meaning of a claim is fixed upon its issuance. An "after arising equivalent" infringes, if at all, under the doctrine of equivalents. Thus, the temporal difference between patent issuance and infringement distinguish an equivalent under § 112 from an equivalent under the doctrine of equivalents. In other words, an equivalent structure or act under § 112 for literal infringement must have been available at the time of patent issuance while an equivalent under the doctrine of equivalents may arise after patent issuance and before the time of infringement. An "after-arising" technology could thus infringe under the doctrine of equivalents without infringing literally as a § 112, ¶ 6 equivalent.Al-Site Corp. v. VSI Int'l, Inc., 174 F.3d 1308, 1320 (Fed. Cir. 1999) (emphasis added; citations and footnote omitted).
This court assumes that Festo's complete bar is intended by the Federal Circuit to be in fact complete. As a result, for means-plus-function claim limitations that are subject to prosecution history estoppel and Festo's "complete bar," and if the evidence supports such an instruction, the court intends to instruct the jury that it may not find infringement unless the relevant structure in the accused device (1) performs the identical function recited in the claim, (2) was known at the time the patent was issued, and (3) is identical or equivalent to the corresponding structure(s) disclosed in the patent specification. This approach allows plaintiffs the full range of statutory equivalents under § 112 ¶ 6, but does not allow any expanded coverage of the claims under the judicial doctrine of equivalents.
All that remains for purposes of defendants' motion on the '288 patent is to determine whether the two claim limitations at issue are subject to § 112 ¶ 6. The court finds that the "selecting" step recited in Claim 1 is not a step-plus-function limitation. The "selecting" step, as defined by the court, is a sufficiently discrete action in the claimed method. The "selecting means" recited in Claim 10, however, is a means-plus-function limitation subject to § 112 ¶ 6. The limitation includes the presumptive "means for" language and recites no definite structure that performs the stated function. The court intends to apply Festo to the "selecting means" limitation in a manner that preserves the full range of statutory equivalents.
During the Markman stage of this case, the court construed the language of the "selecting" step in Claim 1 as follows:
The step of "selecting at least one mode of operation of the implantable heart stimulator which operation includes a unique sequence of events corresponding to said determined condition" involves matching the currently determined heart condition to the unique set of instructions that have been programmed to treat the detected condition. The treatment operation selected by the device is determined exclusively by the currently determined condition of the heart.Cardiac Pacemakers, Inc. v. St. Jude Medical, Inc., No. IP 96-1718-C-H/G, 2000 WL 1765358, at *36 (S.D.Ind. Nov. 29, 2000). However, in resolving the parties' specific dispute over the proper construction of the "selecting" step, it was unnecessary to determine whether the "selecting" step had been drafted as a "step-plus-function" limitation under 35 U.S.C. § 112 ¶ 6. Similarly, the court had no need at the Markman stage to address whether the "selecting means" limitation in Claim 10 had been drafted in "means-plus-function" form.
II. The '472 Patent
The '472 patent stems from application number 65,228 (the '228 application), which was a continuation of the earlier-filed and abandoned application number 641,381 (the '381 application). The '381 application itself was a continuation of the still earlier-filed 464,180 application (the '180 application) that ultimately issued as United States Patent No. 3,952,750. Defendants contend that Festo's complete bar applies to several amended limitations in Claim 1 and Claim 18 of the '472 patent.
A. Claim 1 of the '472 Patent
Claim 1 of the '472 patent is an apparatus claim. To show the evolution of Claim 1 into its current form, it is clearest to begin with Claim 34 of the '381 application:
34. An implantable non-automatic atrial cardioverting device whose operation is controlled from external to the skin of the wearer, the device comprising:
storage means for storing energy to convert an abnormal supra-ventricular cardiac rhythm to normal sinus rhythm; delivery electrode means associating said storage means with the atrium of the wearer and for discharging the stored energy into the atrium;
switch means for controlling the discharge of the stored energy into the atrium;
charging means for delivering to said storage means said energy to convert such abnormal supra-ventricular cardiac rhythm;
means for determining when the stored energy has reached a predetermined magnitude for converting such supra-ventricular cardiac rhythm;
and means for initiating the discharge of cardioverting energy into the atrium of the wearer after the stored energy has reached said predetermined magnitude.
Mixdorf Decl., Ex. F at 1-2 (clauses separated for readability). As indicated above, the entire '381 application — including Claim 34 — was abandoned after the Patent and Trademark Office rejected the pending claims as obvious in light of several references.
The '228 continuation application was filed on August 9, 1979. The application claim that would eventually issue as Claim 1 of the '472 patent was originally submitted as a new Claim 34 via a "preliminary amendment" to the '228 application. As explained in the applicants' submissions to the PTO:
This Preliminary Amendment presents claims corresponding to claims (in the parent application) which were the subject of an appeal to the Patent and Trademark Office Board of Appeals. However, the present claims are narrower than the previously appealed claims by virtue of the recitation of "means for selecting a predetermined magnitude, from among a plurality of selectable magnitudes, of stored energy for converting said abnormal cardiac rhythm." Accordingly, the claims of the present application are distinguishable from the prior art cited by the Examiner in the parent application.
Mixdorf Decl., Ex. G at 10 (emphasis added).
As suggested by the submissions that accompanied the preliminary amendment to the '228 application, new Claim 34 was very similar to rejected Claim 34 of the abandoned parent application. Although the applicants stressed the addition of a "means for selecting" limitation as the significant change from the rejected Claim 34, there were additional differences. For example, rejected Claim 34 expressly recited a "non-automatic atrial cardioverting device," while the new Claim 34 dropped all express references to "atrial" cardioversion, the "atrium" of the heart, and "supra-ventricular" conditions. In its entirety, new Claim 34 of the '228 application read as follows:
34. An implantable non-automatic converting device whose operation is controlled from external to the skin of the wearer, the device comprising:
storage means for storing energy to convert an abnormal cardiac rhythm to normal sinus rhythm;
delivery electrode means associating said storage means with the heart of the wearer and for discharging the stored energy into the heart of the wearer;
switch means for controlling the discharge of the stored energy into the heart of the wearer;
charging means for delivering to said storage means said energy to convert such abnormal cardiac rhythm;
means for selecting a predetermined magnitude, from among a plurality of selectable magnitudes, of stored energy for converting said abnormal cardiac rhythm;
means for determining when the stored energy has reached said selected predetermined magnitude for converting such abnormal cardiac rhythm;
and means for initiating the discharge of converting energy into the heart of the wearer after the stored energy has reached said predetermined magnitude.
Mixdorf Decl., Ex. G at 3 (clauses separated for readability; including minor corrections made as part of a second preliminary amendment).
Despite the differences between new Claim 34 of the '228 application and rejected Claim 34 of the abandoned parent application, the PTO rejected new Claim 34, along with other pending claims in the '228 application, as obvious based on a Schuder reference in combination with other patents. See Mixdorf Decl., Ex. I. In response, the applicants amended the "means for initiating" limitation in new Claim 34 to recite "means for initiating the discharge of cardioverting energy into the heart of the wearer after the stored energy has reached said selected predetermined magnitude." Def. Br., Statement of Material Facts ¶ 12 (amended language appears in italicized text). The applicants argued that new Claim 34, as amended, should be distinguished from the cited references because it included "means for selecting a predetermined magnitude" of stored energy and because it taught "controlled build-up" of the energy required for cardioversion. Mixdorf Decl., Ex. K at 13, 16. In spite of these arguments, the PTO again rejected new Claim 34 in light of prior patents. Mixdorf Decl., Ex. L.
The effect of this amendment, which appears to have merely clarified rather than narrowed the "means for initiating" limitation, is not material. As shown below, the applicants' later amendments to Claim 34 did not preserve this change to the claim language. In the issued patent, the "initiating" limitation does not include the word "selected."
After the second rejection of new Claim 34, the patent examiner held an interview with the applicants. The examiner's notes from the interview indicate that he and the applicants discussed Claim 34, Claim 38, and Claim 49 of the pending application. The notes further state that "adding command means and making the selecting means responsive to the commands avoids prior art." Mixdorf Decl., Ex. M.
After the interview with the examiner, the applicants submitted further amendments to the limitations recited in new Claim 34. The amendments deleted the "means for selecting" limitation as it had appeared in the original application, but also added several completely new limitations (including a modified version of the "means for selecting" limitation). See Mixdorf Decl., Ex. N at 1-3. The PTO approved this amended version of new Claim 34 and issued it as Claim 1 of the '472 patent. In its final form, Claim 1 reads:
1. In a cardioverting device comprising:
storage means for storing energy to convert an abnormal cardiac rhythm to normal sinus rhythm, delivery electrode means for discharging the stored energy into the heart of a wearer of the device, and switch means for controlling the discharge of the stored energy into the heart of the wearer;
said device further comprising:
charging means for delivering to said storage means said energy to convert said abnormal cardiac rhythm, determining means for determining when the stored energy has reached a predetermined magnitude for converting said abnormal cardiac rhythm, and initiating means for initiating the discharge of converting energy into the heart of the wearer after the stored energy has reached said predetermined magnitude; the improvement wherein said device is an implantable externally programmable cardioverting device, and includes receiving means for receiving commands from external to the skin of the wearer of the device, said programming commands designating a predetermined magnitude of stored energy for converting said abnormal cardiac rhythm,
said device also including selecting means responsive to said programming commands received by said receiving means for selecting said predetermined magnitude, from among a plurality of selectable magnitudes, of stored energy, for converting said abnormal cardiac rhythm.
'472 Patent, col. 8, l. 64 to col. 9, l. 26 (limitations added by the amendment immediately preceding issuance appear in italicized text and have been separated for readability).
The new limitations added to application Claim 34 were both narrowing and made for substantial reasons related to patentability. The new limitations addressed the PTO's reasons for rejecting application Claim 34 and effectively replaced the broader "means for selecting" limitation that had appeared in the original '228 application. The new limitations require that the implanted device contain means for receiving externally generated programming commands. The programming commands designate a particular energy level for cardioversion. The implanted device must also have some structure ( i.e., the amended "selecting means" limitation) that is responsive to the programming commands so that the device will actually conduct cardioversion at the designated energy level.
Plaintiffs contend that prosecution history estoppel should not arise from the final amendments to Claim 1 of the '472 patent because the amendments were not "narrowing." In support of this argument, plaintiffs rely on the general rule that the court should consider the entire prosecution history of the claim limitation at issue in order to determine whether estoppel applies. See Pl. Br. at 8, citing Southwall Technologies, Inc. v. Cardinal IG Co., 54 F.3d 1570, 1582 (Fed. Cir. 1995), and Biovail Corp. Int'l v. Andrx Pharmaceuticals, Inc., 239 F.3d 1297, 1301-04 (Fed. Cir. 2001) (examining prosecution history of grandparent application and applying that prosecution history to the claims filed in a continuation application; holding that prosecution history estoppel arising in connection with grandparent application applied to claims in the continuation application).
In this case, plaintiffs contend that the court should look beyond the '228 continuation application (which issued as the '472 patent) and beyond the '381 "parent" application (which was abandoned), all the way back to the so-called "grandparent" '180 application. Original Claim 7 of the '180 application, plaintiffs argue, included the subject matter that is at issue in the amended language of Claim 1 of the '472 patent. In other words, plaintiffs contend that each of the limitations added by the final amendment to Claim 1 of the '472 patent can be traced back to Claim 7 of the '180 application. See Pl. Br. at 10-11. Given that the limitations at issue in Claim 1 of the '472 patent correspond to limitations that appeared in Claim 7 of the grandparent application, plaintiffs argue, the limitations at issue are neither "new" nor "narrowing."
As noted above, the '180 application ultimately issued as the '750 patent.
Plaintiffs stop short of comparing each limitation in Claim 1 of the '472 patent to a potentially corresponding limitation in Claim 7 of the '180 application. Such an exercise would put them on dangerous ground with respect to the defendants' double patenting defense.
The logic of plaintiffs' argument is that the limitations at issue first appeared as part of a narrow claim, disappeared for a time in applications with broader claims, and then reappeared when the broader claims were re-narrowed in the face of rejection by the PTO. In other words, the entire prosecution history shows narrow claims, followed by a broadening, followed by a re-narrowing. Given that the final step was a "re-narrowing," plaintiffs contend that the limitations at issue do not give rise to prosecution history estoppel.
In terms of the patent applications, plaintiffs' approach assumes that the original narrow claim was Claim 7 of the "grandparent" '180 application. The broadening began with Claim 34 of the abandoned '381 application. The re-narrowing was completed by the amendment that resulted in the final language that issued as Claim 1 of the '472 patent.
Even assuming that plaintiffs are correct that the limitations added by amendment to Claim 1 of the '472 patent were simply recycled from a claim that appeared in the grandparent application, the court is not persuaded that the applicants successfully avoided prosecution history estoppel. If plaintiffs' theory were correct, the outcome in Festo itself seems highly unlikely.
In Festo, the Stoll patent application presented a main independent Claim 1 and several dependent claims. After rejection of all of the original claims, the applicant canceled some claims and amended others. Most significantly, independent application Claim 1 was replaced with a new independent Claim 1 that contained additional limitations. The two limitations added to new Claim 1 that were at issue in the case corresponded to limitations that had appeared in two of the canceled dependent claims. In other words, the limitations added to Claim 1 had made a previous appearance in the prosecution history. Nonetheless, the Federal Circuit held that Claim 1 had been narrowed by the addition of the limitations. See Festo, 234 F.3d at 580-83, 587-89; see also Pioneer Magnetics, Inc. v. Micro Linear Corp., 238 F.3d 1341, 1344 (Fed. Cir. 2001) (holding that a "switching analog multiplier" limitation added by amendment to the only independent claim in the application was a narrowing amendment even though a substantially similar "switching" limitation had previously appeared in a dependent application claim).
Compare Festo and Pioneer Magnetics with Honeywell Int'l Inc. v. Hamilton Sundstrand Corp., No. Civ. A. 99-309, 2001 WL 66348, at *5-*6 (D.Del. Jan. 8, 2001), in which the district court held that the mere re-writing of a dependent claim into independent form after rejection of the original independent claim was not a narrowing amendment.
In this court's view, Festo's holding that a claim can be narrowed by limitations that appeared in canceled dependent claims in the same application forecloses plaintiffs' argument that amending a claim with limitations that appeared in the claims of a grandparent application will avoid prosecution history estoppel. As a result, prosecution history estoppel and Festo's complete bar to the doctrine of equivalents apply to the limitations added by amendment to Claim 1 of the '472 patent. That is, plaintiffs may prove only literal infringement of all the limitations following the phrase "the improvement wherein . . ."
The parties dispute whether any of the limitations added by amendment to Claim 1 of the '472 patent have been written in means-plus-function form. Upon examination of the claim language and the relevant intrinsic evidence, the court finds that both the "receiving means" limitation and the "selecting means" limitation, as amended, are means-plus-function limitations under § 112 ¶ 6. Under the reasoning expressed above in the discussion of the '288 patent, the "receiving means" and the "selecting means" are entitled to the full range of statutory equivalents under § 112 ¶ 6.
B. Claim 18 of the '472 Patent
Claim 18 of the '472 patent defines a method for electrically cardioverting a patient's heart. The patentees added Claim 18 to the application (as application Claim 56) at the same time that they amended application Claim 34 to include the several narrowing limitations at issue in Section II-A of this entry. That is, the patentee added Claim 18 to the application after the PTO rejected all of the pending application claims based on prior art. Claim 18 reads:
18. A method for electrically cardioverting a heart, the method comprising the steps of:
implanting an electronic package beneath the skin of a wearer, said electronic package including a storage element for storing electrical energy to convert an abnormal cardiac rhythm to normal sinus rhythm, delivery electrodes for discharging said stored energy into the heart of the wearer, a receiver for receiving control information from external to the skin of the wearer, said control information designating a selected magnitude of energy to be discharged through said delivery electrodes into the heart of the wearer, and charge control means responsive to said control information for storing said selected magnitude of stored energy in said storage element; sensing an abnormal cardiac rhythm, wherein cardioversion is required; delivering said control information through the skin of the wearer to cause the storage element to store said selected magnitude of energy; and electrically cardioverting the heart by discharging said selected magnitude of stored energy through said delivery electrodes into the heart of the wearer.
'472 Patent, col. 10, l. 62 to col. 12, l. 8.
The "implanting" step of the method contains several structural limitations in the description of the "electronic package" to be implanted beneath the skin of the wearer. Several of the limitations recited in the steps of the method are very similar to the narrowing limitations that were added by the final amendment to Claim 1 of the '472 patent. Defendants contend that each limitation in Claim 18 that corresponds to one of the narrowing limitations added to Claim 1 is subject to prosecution history estoppel and Festo's complete bar. As explained by defendants:
While claim 18 was not amended, per se, it is clear from a review of the relevant portions of the prosecution history that the Festo decision also applies to bar CPI from now asserting infringement of the claim under the doctrine of equivalents. . . . [The amendment which added claim 18 to the application] was the result of a prior personal interview with the examiner, in which the applicants and the examiner agreed that the applicants would need to add particular language to their claims in order to overcome the rejection based on prior art. When they added claim 18, the applicants made sure to include this same language by providing a "receiver," specifying the use of certain "control information" and making other elements responsive to such control information.
Def. Br. at 12 (citations omitted). Defendants' major premise in support of their Claim 18 argument is that limitations subject to prosecution history estoppel in Claim 1 should be likewise limited in Claim 18. See Def. Reply Br. at 9, citing Pall Corp. v. Hemasure, Inc., 181 F.3d 1305, 1312 (Fed. Cir. 1999) ("When a claim limitation is added in order to overcome a specific cited reference, estoppel as to that limitation is generated whether the limitation is added by amendment to pending claims, or by the submission of new claims containing the limitation."), and Molten Metal Equipment Innovations, Inc. v. Metaullics Systems Co., 130 F. Supp.2d 917, 921-23 (N.D.Ohio. 2001) (holding that a narrowing amendment that added a limitation to a non-asserted claim barred application of the doctrine of equivalents to all asserted, but unamended claims in which the same limitation appeared).
In response to the defendants' contention that several limitations in Claim 18 are subject to prosecution history estoppel by virtue of their similarity to the narrowing limitations of Claim 1, the plaintiffs refer the court to the "re-narrowing" argument they raised in their effort to protect the Claim 1 limitations. See Pl. Br. at 12-13. As explained above, the court rejects the "re-narrowing" theory. The final pre-issuance amendments to Claim 1 of the '472 patent narrowed the literal scope of that claim, and Festo applies to the limitations changed or added by the amendments to that claim.
By arguing that the subject matter recited in Claim 7 of the '180 application also saves the limitations recited in Claim 18 from Festo's complete bar, plaintiffs implicitly accept defendants' premise that the limitations at issue in Claim 18 are, for these purposes, identical to the narrowing limitations added by amendment to Claim 1.
Because the prosecution history that applies to the limitations in Claim 1 also applies to the same narrowing language as used in other claims, the court finds that the following limitations in Claim 18 are subject to prosecution history estoppel and Festo's complete bar:
(1) a receiver for receiving control information from external to the skin of the wearer,
(2) said control information designating a selected magnitude of energy to be discharged through said delivery electrodes into the heart of the wearer;
(3) charge control means responsive to said control information for storing said selected magnitude of stored energy in said storage element; and
(4) delivering said control information through the skin of the wearer to cause the storage element to store said selected magnitude of energy.
Jointly, these limitations in Claim 18 cover the same subject matter that was added to Claim 1 by the narrowing amendment discussed above. The parties dispute whether the Claim 18 limitations at issue fall under § 112 ¶ 6.
The "receiver" limitation in Claim 18 of the '472 patent corresponds to the "receiving means" limitation is Claim 1. The difference between the two limitations is that the "receiver" recited in Claim 18 lacks the "means for" language. Although the failure to use the word "means" creates a presumption that § 112 ¶ 6 does not apply, see Personalized Media Communications, LLC v. International Trade Comm'n, 161 F.3d 696, 703-04 (Fed. Cir. 1998), here there is a reason to depart from the presumption. The two nearly identical receiving limitations in Claim 1 and Claim 18 should be treated the same. Thus, like the "receiving means" limitation in Claim 1, the "receiver" limitation in Claim 18 is a means-plus-function limitation. The full range of statutory equivalents under § 112 ¶ 6 will be available for this limitation.
The court has already ruled that the "charge control means" limitation in Claim 18 of the '472 patent is a means-plus-function limitation. The court intends to adhere to the construction of this limitation as stated in the claims construction entry. As explained in the claims construction entry, the "charge control means" in Claim 18 is a blend of limitations from Claim 1, including the requirement found in the "selecting means" of Claim 1 that the associated structure be "responsive" to the control information. Because the "charge control means" limitation in Claim 18 corresponds, in part, to the narrowed "selecting means" limitation in Claim 1, Festo applies to the "charge control means" limitation. Although plaintiffs may not prove infringement of the "charge control means" limitation under the doctrine of equivalents, the jury will be permitted to consider the full range of statutory equivalents under § 112 ¶ 6.
Reading the claim as a whole, the court finds that the step of "delivering said control information through the skin of the wearer . . ." is a sufficiently discrete act in the claimed method such that it is not a step-plus-function limitation. No range of statutory equivalents applies to the "delivering" step.
Defendants' motion for summary judgment is granted in part and denied in part as stated above, and the court expects to instruct the jury accordingly.
So ordered.