Biodex Corporation (“Biodex”) appeals the judgment of the U.S. District Court for the Eastern District of California entered on a jury verdict that found U.S. Patent *852 No. 4,691,694 (“694 patent”) invalid and U.S. Patent No. 4,628,910 (“910 patent”) not infringed by devices manufactured by defendants, Loredan Biomedical, Inc., and its chief executive, Malcolm Bond (collectively, “Loredan”). Biodex Corp. v. Loredan Biomedical, Inc., Civ-S-87-1132 (E.D.Ca. Oct. 2, 1990). We affirm.
I
Biodex is the assignee of both patents in suit which claim certain muscle exercise and rehabilitation devices. The 910 patent issued December 16, 1986. After notice of allowance, Biodex had filed a continuation-in-part application on September 15, 1986, which later matured into the 694 patent upon issuance on September 9, 1987. Bio-dex filed suit asserting that devices manufactured by Loredan infringed various claims of the patents.
At trial before a jury, Loredan contended, inter alia, that the 694 patent was invalid under 35 U.S.C. § 102(b) because the subject matter of the claimed invention had been offered for sale in the spring and summer of 1985, more than one year before the filing date. Biodex argued that the invention claimed in the 694 patent had not been satisfactorily tested so as to be safe for human use until after the critical date of September 15, 1985, and, therefore, could not have been on sale. On the 910 patent, Loredan argued that two terms in the asserted claims, written in means-plus-function language, did not read on the alleged devices because the corresponding structures found in the Loredan devices were not equivalent to the structures disclosed in the specification. Loredan contended that the inventor had expressly conceded this fact before the U.S. Patent and Trademark Office (“PTO”). Biodex responded, first, that the jury need only consider the plain language of the terms in question which read on the Loredan devices; second, that Loredan misconstrued the inventor’s concession during prosecution; and, third, that the structures in the accused devices were equivalents.
In its appellate briefs, Biodex recognizes that resolution of these issues required the jury to decide questions of fact. For instance, in its opening brief, Biodex contests that “the jury verdict of non-infringement of the ’910 patent was supported by substantial evidence.” In its reply brief, Biodex argues that the special verdict of invalidity of the 694 patent was not “supported by the evidence.” We read both references to evidentiary, support to concede that the verdicts were based upon factual determinations made by the jury. In any event, while we agree with Biodex’s initial contention that an ultimate conclusion as to an on-sale bar is a question of law,
Barmag Barmer Masckinenfabrik AG v. Murata Mach., Ltd.,
As permitted by Fed.R.Civ.P. 51, both parties requested and submitted various jury instructions. The district court, however, drafted its own instructions. Preserving its plain language argument, Bio-dex objected to the instructions on identifying equivalent structures to a claimed means expressed in functional language and on using the doctrine of prosecution history estoppel in determining the scope of protection under the doctrine of equivalents. Biodex contended that literal claim construction should be no different for a claim drafted under 35 U.S.C. § 112 ¶ 6 because the statute makes no “distinction” whether a claim uses “means-plus-function” language or not. Biodex requested but did not receive an additional instruction on application of the doctrine of prosecution history estoppel, which read, in pertinent part:
However, you should note that the doctrine of prosecution history estoppel has no applicability whatsoever if the plain language of the claims reads on an accused device for then infringement exists.
At the conclusion of testimony, Biodex orally moved for a directed verdict. Review of a transcript of that motion does not reveal a specific allegation that Loredan’s evidence in support of the contested validity or infringement issues was insufficient although judgment was requested on those issues as a matter of law. The district court never ruled upon the motion. The case was submitted to the jury with multiple special verdicts forms. In the verdicts, the jury found that all the asserted claims of the 694 patent were proved invalid and that none of the claims of the 910 patent were infringed by Loredan. The district court entered judgment on the jury verdicts. Biodex made no post-verdict motions either by renewing its motion for a directed verdict, moving for a new trial, or by moving for judgment non obstante veredicto (“JNOV”).
II
On appeal, Biodex contends that the failure to give the requested jury instruction was prejudicial error. Furthermore, Bio-dex contends that neither special verdict, of invalidity of the one patent nor of non-infringement of the other, was supported by substantial evidence. Loredan answers that the suggested jury instruction, while perhaps technically accurate, was misleading in the context of its defense that, “means-plus-function” language must be carefully construed. Nor, Loredan contends, were the jury instructions, read in their entirety, incorrect, unclear, or less than comprehensive. On the special verdicts, Loredan argues that, while there was sufficient evidentiary support, Biodex did not preserve the issues for appellate review by filing a post-verdict motion in the district court.
III
We must first determine the standard of review to be applied to the issues before us and whether we should apply regional circuit law or our own. There is no dispute among the circuits, nor in our own jurisprudence, that a judgment should be altered “because of a mistake in jury instructions only if the error was prejudicial” and that we must “look to the entire jury charge ... to determine whether the instructions fairly stated the legal principles to be applied by the jury.”
1
Under
*854
this standard, jury instructions must be both legally correct and sufficiently comprehensive to address factual issues for which there is disputed evidence of record. A party has no vested right in its own carefully couched form of words in an instruction, because “the court is not required to give instructions in the language and form requested.”
Oliveras v. U.S. Lines Co.,
IV
The extent to which we may review the special verdicts is not so readily apparent. Quite clearly, the only available remedy upon finding error in a judgment entered on a jury verdict where there has been no motion for JNOV is limited to a remand for a new trial.
2
Whatever the remedy, however, we must first respond to the contention of Loredan and determine whether there is any limitation on our review for error in these circumstances,
i.e.,
whether and to what degree a jury verdict on a factual issue is reviewable on appeal. When no motion challenging the legal sufficiency of the evidence has been made at any stage in the district court, the law is uniform in all circuits that review is limited to plain error.
3
In this case, Biodex did make an oral motion for directed verdict at the conclusion of the evidence, although this motion was not resubmitted or renewed in any form after the verdict. Our case law does not address whether jury verdicts, in such circumstances, may lack reviewability for sufficiency of the evidence.
4
Furthermore, our case law has not been clear on whether we should or must defer to the law of the regional circuit on
*855
this kind of issue.
5
An added difficulty, as noted by both parties, is that the law of the U.S. Court of Appeals for the Ninth Circuit, whence this case originates, on this point is not clearly discernable. In
Kopczynski v. The Jacqueline,
V
We first address whether deference to regional circuit law is appropriate in deciding if a post-verdict motion is a prerequisite to appellate review of the sufficiency of the evidence underlying a jury verdict. In general, our initial inquiry in determining whether deference to regional circuit law is due has been to decide whether the law that must be applied, whether procedural or substantive, is one “... over which this
*856
court does not have exclusive appellate jurisdiction.”
Cicena Ltd. v. Columbia Telecommunications Group,
Our inquiry into this question will benefit from an examination of the origins of our rule of deference. In
Atari, Inc. v. JS & A Group, Inc.,
We, therefore, rule, as a matter of policy, that the Federal Circuit shall review procedural matters, that are not unique to patent issues, under the law of the particular regional circuit court where appeals from the district court would normally lie. This policy is within the intent and spirit of not only our enabling statute but also the general desire of the federal judicial system to minimize confusion and conflicts. Since our mandate is to eliminate conflicts and uncertainties in the area of patent law, we must not, in doing so, create unnecessary conflicts and confusion in procedural matters.
Panduit,
In the very next sentence, with prescience, the Court recognized that the relationship between the particular issue at hand and the exercise of our exclusive statutory jurisdiction could not then be expressed in fixed language, by stating that “[t]he exact parameters of this ruling will not be clear until such procedural matters are presented to this court for resolution.”
Id.
The
Panduit
Court itself further phrased the relevant line of demarcation in fluid language, noting that the resolution of the issue of deference in particular cases would depend on whether the procedural matter should “pertain to” or be “related to patent issues, [such that] they have a direct bearing on the outcome.”
Id.
at n. 14 (citing
Barmag Banner Maschinenfabrik AG v. Murata Machinery, Ltd.,
In sum, Panduit did not engrave a fixed meaning to the terms “unique to,” “related to,” or “pertainpng] to,” our exclusive statutory subject matter jurisdiction, but instead recognized that each case must be decided by reference to the core policy of not creating unnecessary conflicts and confusion in procedural matters. Moreover, Panduit expressly directs us to a review of our subsequent cases, in which deference has been applied, to clarify the parameters of the rule.
In reviewing our subsequent cases, we note that our practice has been to defer to regional circuit law when the precise issue involves an interpretation of the Federal Rules of Civil Procedure or the local rules of the district court. 10 Resolution of such *858 issues manifestly implicates the consistency of future trial management. Similarly, with regard to substantive legal issues not within our exclusive subject matter jurisdiction, our practice has been to defer to regional circuit law when reviewing cases arising under the patent laws. 11
However, we have not deferred in the resolution of all procedural issues merely because that issue might separately arise in a case having nothing to do with the patent laws. Such an application of the rule in
Panduit
would be too expansive. For instance, in
Chrysler Motors Corp. v. Auto Body Panels of Ohio, Inc.,
Furthermore, in
Sun-Tek Indus., Inc. v. Kennedy Sky Lites, Inc.,
Where there is an essential relationship between our exclusive statutory mandate or our functions as an appellate court and the relevant procedural issue, that relationship provides an additional reason why resolution of the procedural issue may be committed to our jurisprudence. No offense would be taken were we to apply the law of our circuit, with due regard for established regional circuit law, to other issues that are essential to our statutory function such as the interpretation of the Federal Rules of Appellate Procedure or the promulgation of our Rules of Practice.
VI
The precise issue before us, not jurisdictional but closely related to the exercise of our mandate, is the reviewability on appeal of fact findings made by a jury in a patent trial absent any post-verdict motions. Determination of the prerequisites to appellate review of legal issues, here sufficiency of the evidence, is committed to this Court by statute, which expressly includes all “appeal[s] from a final decision of a district court ... if the jurisdiction of that court” arose under an Act of Congress relating to patents. 28 U.S.C. §§ 1295(a)(1), 1338 (1988). The issue at hand, albeit procedural, bears an essential relationship to matters committed to our *859 exclusive control by statute, the appellate review of patent trials.
Uniformity in the review of patent trials is enhanced, rather than hindered, by our adoption of a single position, rather than applying varying regional law to the issue before us. Indeed, an opposite rule would be confusing, as the same patent, asserted in different district court jurisdictions, might have the same dispositive factual finding reviewed or not depending upon which of differing regional circuit laws was applicable. Moreover, concern that district courts not be required to apply two sets of substantive or procedural laws during trial, depending on the appellate path ultimately taken, is not at issue. The extent to which the underlying factual findings of a judgment on a verdict are reviewed on appeal, absent a motion for JNOV, is an issue that can only arise after all the evidence is submitted and the verdict rendered. A district court would not, therefore, be required to have “served two masters” since the availability of appellate review is irrelevant to the conduct of the trial or to any decision on substantive legal issues that may arise during trial. Furthermore, our national jurisdiction provides a good position from which to establish uniform rules for the reviewability of factual issues in civil litigation under federal question jurisdiction in the absence of a post-verdict motion. Finally, predictability in the later application of the law in a circuit or other circuits is improved by the adoption of a single nationwide standard for preserving the reviewability of sufficiency of the evidence in a case arising under the patent laws. Thus, applying Pcmduit, in considering the application of the longstanding policies of promoting uniformity and minimizing confusion and recognizing the essential relationship of the issue before us to the exercise of our statutory authority, we conclude that deference to regional circuit law is not appropriate in this case.
VII
In order to state the law of this circuit on the issue, we turn first to the meaning of substantial evidence in the context of appellate review of sufficiency of the evidence. “Substantial evidence is more than a mere scintilla. It means such relevant evidence as a reasonable mind might accept as adequate to support a conclusion.”
Consolidated Edison Co. v. NLRB,
In that light, a requirement for an express post-verdict motion by the potential appellant assists appellate review in several ways. First, in the preferred and best of circumstances, the district court will produce a thorough written or oral opinion on the motion for JNOV.
Senmed, Inc. v. Richard-Allan Medical Indus., Inc.,
Second, the jury may have been persuaded by many considerations beyond just the credibility of a witness that are not
*860
always adequately reproduced in a transcript. The district court “has the same opportunity that jurors have for seeing the witnesses [and] for noting all those matters in a trial not capable of record.”
Patton v. Texas & Pacific Ry. Co.,
Third, a rule requiring presentation before the district court of a party’s contention that a judgment lacks sufficient evidence promotes fair and equitable jurisprudence. The district court may take corrective action when confronted with error before an appeal is taken. “By failing to move for JNOV, the trial judge was denied the chance to correct any error by the jury.”
Coffman v. Trickey,
*861
Fourth, a rule requiring formal post-verdict presentation of contested issues is not burdensome. For instance, local rules in district courts may similarly require early and explicit formulation and substantiation of contentions that have been made in con-clusory fashion in pleadings.
See James-bury Corp. v. Litton Indus. Prods., Inc.,
Adoption of such a rule would not deny an appellant its right to appeal. The law has long been that appellate review is not available for issues not preserved at trial.
Farley Transp. Co. v. Sante Fe Trail Transp. Co.,
The rule, furthermore, stands in harmony with Rule 50 of the Federal Rules of Civil Procedure. Rule 50(b) states that “[wjhenever a motion for a directed verdict ... is denied or for any reason not granted, the [district] court is deemed to have submitted the action to the jury subject to a later determination of the legal questions raised by the motion.” Although a later determination of the legal question of sufficiency of the evidence by this Court would be predicated upon the filing of the post-verdict motion which renewed the contention, that predicate would not interfere with interpretation of Rule 50(b) by the district court in accordance with the procedural law of its regional circuit. The precise methodology of the district court’s treatment of a previous directed verdict motion after the verdict is not a matter for us to decide. The district court remains free to defer action upon a motion for directed verdict until after the jury’s deliberations. A district court may choose not to rule on a directed verdict motion made at the close of the evidence, and may, instead, under Rule 50(b), make a later determination of the legal question raised by the motion without first receiving a motion for JNOV. In such circumstances, the ruling by the district court on the deferred motion, whether by grant or denial, will have the legal consequence on appellate review of a similar ruling by the district court on a motion for JNOV, because the court’s deferred consideration effectively converts the motion into a post-verdict motion. *862 Thus, a requirement for a post-verdict motion does not affect the manner in which a district court chooses to determine legal questions raised on motions.
In sum, we conclude that we cannot review the sufficiency of the evidence after a jury verdict absent some post-verdict disposition, either by a deferred ruling or upon a post-verdict motion. Biodex’s failure to present the district court with a post-verdict motion precludes appellate review of sufficiency of the evidence. Our resolution of the standard for establishing reviewability of the sufficiency of evidence in a patent ease by requiring a post-verdict motion is, therefore, dispositive of that portion of the appeal directed to whether there was substantial evidence to support the special verdicts.
VIII
In order to prevail on the jury instruction issue in this case, Biodex must demonstrate both that the jury instructions actually given were fatally flawed and that the requested instruction was proper and could have corrected the flaw. We conclude that Biodex has failed in both tasks. We have reviewed the instructions given by the judge and find no reversible error in the instructions governing the issues at trial in this case. We note that both parties consented to a trial in which the jury responses would require resolution of mixed questions of fact and law. In response to Biodex’s contention that the jury instructions were incomplete because they lacked a “plain language” instruction for determining the permissible scope of the “means-plus-function” term en route to making a finding on literal infringement, we note that the district court did instruct the jury, that “[t]o determine whether a machine ‘literally’ has each element of a claim, you must first look to the language” and “[i]n deciding the meaning of the words
[e.g.,
terms] used in a claim, you should refer to the text and drawing in the patent, as well as the ‘prosecution history.’ ” Thus, in the circumstances of this case, we do not find reversible error in the instructions on resolving the contested factual question underlying the verdict of infringement. Furthermore, Biodex’s suggestion that lay jurors would be able to determine the scope of the terms in the 910 patent from their “plain” meaning ignores the language of the disputed terms and the fact that claims are drafted to be read by those skilled in the art, rather than lay persons. Thus, the claim terms in question, such as “servo motor” or “closed loop velocity servo feedback,” can only be understood by the lay juror with assistance from the ancillary aids to interpretation such as the expert testimony of the inventor or of those skilled in the art, and review of the specification, the prosecution history, and the relevant prior art.
Moeller v. Ionetics, Inc.,
Assuming,
arguendo,
that one could quibble with the instructions as given, Bio-dex also fails in its other task of demonstrating that its rejected instruction could have corrected the flaw. In the context of the defense in this case, the proposed jury instruction would have been misleading. There is a clear line of distinction between using the contents of the prosecution history to reach an understanding about disputed claim language,
Standard Oil Co. v. American Cyanamid Co.,
Finally, this Court has specifically cautioned against reading means-plus-function limitations to cover all possible means that perform the recited function.
Johnston v. IVAC Corp.,
IX
Since we conclude that we may not review for sufficiency of the evidence, and since there was no prejudicial legal error, we must affirm the judgment as a whole. In so doing, we also reject Loredan’s argument that the appeal is frivolous. In the penultimate paragraph of its brief, Loredan contends, in conclusory fashion, that the “appeal is sufficiently frivolous to support an award of sanctions” without citation to the opening brief or argument on the factual basis for the allegation of frivolity. Fed. R.App.P. 38 provides that, “[i]f a court of appeals shall determine that an appeal is frivolous, it may award just damages and single or double costs to the appellee.” While a court of appeals is not precluded, by the plain language, from making such a determination
sua sponte, see Romala Corp. v. United States,
After this Court first made clear its intention to impose sanctions for frivolous appeals,
Asberry v. United States Postal Serv.,
As we have repeatedly noted, “[a]n appeal having a small chance for success is not for that reason alone frivolous” and thus deserving of sanctions.
Id.
at 1578, 17 USPQ2d at 1918 (citing
Connell v. Sears, Roebuck & Co.,
AFFIRMED.
Notes
.
Smiddy
v.
Varney,
.
Johnson v. New York, N.H. & H.R.R.,
.
Jurgens v. McKasy,
.Biodex, in response to Loredan’s contention, cites
Sun Studs, Inc. v. ATA Equip. Leasing, Inc.,
. Because this case does not involve a post-verdict motion, we need not resolve an apparent conflict in this circuit as to whose law applies to review of such motions.
Compare Sjolund v. Musland,
.
Compare Woods v. National Life & Accident Ins. Co.,
.Railroad Dynamics, Inc. v. A. Stucki Co.,
.
See Fonar Corp. v. Johnson & Johnson,
. We recognized in
Atasi Corp. v. Seagate Technology,
.
See Badalamenti v. Dunham’s, Inc.,
.
See U.S. Philips Corp. v. Windmere Corp.,
. That proposition was also forcefully stated by this Court, in banc, in
Woodard v. Sage Products, Inc.,
[Djeference is inappropriate on issues of our own appellate jurisdiction. This court has the duty to determine its jurisdiction and to satisfy itself that an appeal is properly before it.
