United States: Claim Drafting In The Light Of Recent Federal Circuit Decisions

It is clear from recent decisions of the United States Court of Appeals for the Federal Circuit that courts are now taking a much tougher line on how to draft specifications and how to draft claims than has previously been the case. The Court of Appeals for the Federal Circuit was created over 20 years ago. Its first decade was really focused on pointing out that the patent statute means what it says when it says that a patent shall be presumed valid. The second decade was focused on the doctrine of equivalents and what the true scope of what that was. In the third decade the court has returned to the principle of something meaning what it says and saying what it means but this time is looking at the language of the specification and the language of the claims and the drafters of patent applications are being held to a higher standard than used to be the case.

An early indication of what was to come is found in 1997 in the Sage Products¹ case. In that case the Federal Circuit was actually dealing with a doctrine of equivalents issue but it emphasized that as between the patentee who had a clear opportunity to negotiate with the PTO and the public at large, it is the patentee who must bear the cost of failure to claim the invention properly. The court went on to make specific comments that it is recognized:

Today the court seems to be applying this approach to any claim where one might be able to argue for more than one possible interpretation of its scope.

Since then, the Federal Circuit has effectively raised the standards by increasing the emphasis on precision of claim drafting and the written description required to support the claim while at the same time there has been a diminution in the importance of the doctrine of equivalents following the Warner Jenkinson² and Festo³ cases.

Paragraph 1 of 35 USC 112 requires a written description of:

1. the invention; and
2. the manner and process of making and using the invention "in such full, clear, concise and exact terms as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and use" the invention, and that the specification
3. describes the best mode "contemplated" by the inventor for carrying out the invention.

Additionally the claims must point out and distinctly claim the subject matter that the applicant regards as his or her invention to comply with paragraph 2 of the same section.

In Phillips v AWH⁴ in 2005 the Federal Circuit attempted to pull together its case law on how to construe patent claims and many have taken the view that this was really an exercise to try to reduce the scope of patent claims. From the uncontroversial position that what one needs to look at is the ordinary and customary meaning of a claim term to one skilled in the art at the date of filing the application, the court went on to say that a person skilled in the art is deemed to read the claim term not only in the context of the particular claim in which the disputed term occurs but in the context of the entire patent including the specification. The court proceeded to list a number of a number of places to look to try to determine what a claim term means. The first place to look is the claims themselves. One should look at the specification then one looks at the prosecution history, mainly from the point of view of looking to see whether the patentee was attempting to use the term as a "nose of wax" as one famous nineteenth century case, White v Dunbar⁵ said. One cannot construe a claim one way in prosecution and another way in litigation. Finally one can look at extrinsic information including dictionaries, testimony of experts and so on. The impact of this was to switch emphasis away from a trend which had been looking at dictionaries as being the primary source of information as to the meaning of patent claims and return to focusing on the specification as the primary source to use in claim interpretation.

We shall now turn to particular examples of the way in which the Federal Circuit’s toughened standards have added to the patentee’s burdens.

The first case to look at in this context is Warner Lambert v Teva⁶. This is a case where the claim related to a pharmaceutical composition containing a drug component susceptible to cyclization, hydrolysis and discoloration, a suitable amount of an alkali or alkaline earth metal carbonate to inhibit cyclization and discoloration of that compound and a suitable amount of saccharide to inhibit hydrolysis. None of the claims set out specific amounts of any of the components that were to be present. The Federal Circuit held that the evidence which was put forward had shown that the defendants had included amounts of alkali or alkaline earth carbonates to inhibit cyclization and a suitable amount of saccharides to inhibit hydrolysis. However, there was no evidence to show that the amount of magnesium carbonate employed similarly prevented discoloration and the Court held that evidence that was required.

Moral: inclusion of specific amounts in the claim (although sometimes it is difficult to determine these amounts) can avoid the risk of needing additional expensive efforts to prove the nexus between the cause and the stated effect that may be required when defining quantities functionally.⁷

Chef America v. Lamb-Weston⁸ involved a claim for making a dough product which was intended to be able to be quick-frozen. One of the steps required heating a batter-covered piece of dough to a temperature of about 400^oF to about 850^oF for a particular period of time. The specification referred to the baking step as taking place in a suitable oven, preferably a convection oven in which air is circulated this results in first setting the batter and melting shortening flakes which are on the piece of dough quickly heating to a temperature of about 400^oF to 850^oF. The examples referred to heating at a particular temperature and did not make it particularly clear whether that temperature was that of the oven or the dough. The Federal Circuit took the view that the clear and unambiguous language of the claim, the temperature-limitation language of which had been added during prosecution, required heating the dough "to" a temperature of 400 to 850^oF rather than heating it "at" a temperature of 400 to 850^oF. The court thought that had the term "at" been used, this would have indicated the temperature of the oven. Use of the word "to", however and the fact that the claim contained no mention of an oven meant that the dough itself had to be heated to that temperature. It was accepted that this was a nonsense interpretation because if a piece of dough was heated up to this temperature of 850^oF.it would have turned to charcoal - but that did not matter. If the unambiguous language of the claim leads to a nonsensical result then the claim is invalid - end of story. To quote:

Obviously thinking more carefully about the actual language being used would have avoided this problem. Make sure you understand what the invention is and make sure you get the language right.

In Standard Oil v. American Cyanamid.⁹ (An older case than most of those we a re considering) the claim related to a process for hydrolyzing a nitrile in the presence of a copper ion and the claim required that the copper ion be at least partially soluble in water. The inventor had in other patents used the words "slightly soluble". The court was persuaded that the words slightly soluble had a generally accepted meaning as such.¹⁰ The court was not persuaded that anybody knew what the term "partially soluble" might mean and as a result of that the court concluded that the claim was bad for not defining clearly the scope of the claimed protection.

Moral: do not invent new terms to describe something without giving a proper definition of what is meant.

That one can be one's own lexicographer is a well-established feature of U.S. Patent Law. The Vitronics¹¹ case, which is one of the more significant cases in terms of the evolution of the law on the claim construction, clearly states that the patentee can act as its own lexicographer as long as he clearly states any special definitions of the claim terms in patent specification or in the file history. Even though a definition is not provided in a specific definitional format the specification may define claims by implication (and this is where many of the more recent problems have occurred) such that the meaning may be found in or ascertained by reason of the patent document. The issue in the Vitronics case was the meaning of the term "solder reflow temperature". The invention related to a method for reflow soldering of surface-mounted devices in a printed circuit board and the evidence produced by the defendant was that the terms "reflow" and "solidus" temperatures were quite often viewed by those skilled in the art as being interchangeable. The patent in question, however, clearly distinguished between the solidus temperature and a reflow temperature and the court on appeal took the view, contrary to that of the trial court that one could not therefore equate the solidus temperature and reflow temperature. The Court did, however, make it clear that if one uses terms to mean something other than their normal meaning, this must be made clear in the specification. In this case, however, by using the two words to have different meanings in the specification, the patentee had done this.

It is therefore highly desirable that to think very carefully about what needs to be defined in applications as they are being drafted should they be sued on years later. It is also desirable when incorporating text written by a third party (such as the inventor) to check carefully that terms are being used consistently and that the same term is used for the same concept throughout. Otherwise inadvertent discrepancies may creep into the specification and cause problems later.

A case which also deals with how the language in the specification can impact on the meaning of the claim and lead to a narrower interpretation than one might otherwise expect is Bell Atlantic v. Covad.¹² The case related to DSL technology and a claim directed to a transmission system for variably transmitting information data in a plurality of different modes over a network. The question was whether there was infringement where one transmitted information data not in different modes but at different rates. It was accepted by the court that the term "mode" was often used in a way that included situations in which data is transmitted at different rates and it was argued by the plaintiffs that a plurality of different "modes" as required by the claim simply required multiple operational states as distinguished by their up stream and down stream transmission rates whether the differences are achieved by altering bandwidth or by other familiar methods of altering transmission rates. Unfortunately for Bell Atlantic, the specification had consistently distinguished between "modes" and "rates". Thus it was stated:

and another object of the invention was

At another point the specification stated:

Such statements effectively precluded the plaintiffs from being able to argue that "mode" is a generic term including "rate" because the two terms had been used to have distinct meanings throughout the specification. Thus the court took the view that even though on the natural meaning of the word "mode" it could perhaps have included different rates, such a meaning did not apply in this particular circumstance.

Moral: if a term may have generic and specific meanings, do not use it as a specific term in the specification if it is desired to have it read as a generic term in the claims.

Alza Corporation v. Mylan Laboratories¹³ is an interesting case in that the claim is quite simple.

The alleged infringers had a transdermal system that used fentanyl citrate.

The court construed the claims to read on "a fentanyl compound other than fentanyl citrate". It did this because of certain statements in the specification, such as

Based on this, the district court in its instructions to the jury said that the claim covers any fentanyl compound except for fentanyl citrate because of this. The Federal Circuit on appeal upheld that claim construction.

In Honeywell International Inc. v. ITT Industries Inc.¹⁴, similar reasoning to that in the Alza case was used to conclude that the term "electrically conductive fibers" did not include carbon fibers. The specification included statements that stainless steel fibers had desirable properties not possessed by carbon. The court concluded that these statements specifically taught that "carbon fibers would not be suitable".

In both cases, by looking at specific embodiments that were said in the specification not to work, the courts have construed the claim to make sure that such embodiments are excluded from the claim even though they fell within the literal language of the claim.

Moral: do not say that something does not work unless this is absolutely certain.¹⁵

In Multiform Desiccants v. Medzam¹⁶, the issue was the meaning of the term "degradable". The claim which is directed to a packet for treatment of a liquid comprising a degradable envelope containing an absorbent material and a treating material. The claim reads as follows;

The dictionary definition of "degradable" included a number of different ways in which something could be degraded. The specification talks only about dissolution. The alleged infringement worked by swelling of the contents of the packet thus causing it to burst. The Federal Circuit took the view that this was therefore not an infringement. It said

The court stressed that the description of the envelope stated that it was made of "degradable starch paper", "degradable in water and other liquids" "able to dissolve", and "practically entirely disintegrated" in finding that the function of releasing the envelope contents must be performed by an envelope that disintegrates by dissolution.

So again if one wishes to avoid an excessively narrow interpretation of a claim, it is highly desirable to have mentioned some alternatives which achieve the same results in the specification and not to rely on the often-stated, but seemingly rarely applied principle, that a claim should not be construed simply to cover the embodiments described. If it has more than one embodiment described then one avoids this problem. In the chemical arts, it is very common to have more than one embodiment described. In the mechanical and electrical arts, it may be more difficult to have more embodiments described but if one can this is desirable to avoid the risk that the courts will hold only one thing is described so that must have been what was meant.

In Bicon v Straumann¹⁷, the issue was to what extent was a statement of external features in the preamble of a claim a limitation of the claim. Prior to this case most practitioners would have been very surprised if such a statement had any such effect. However, this is what happened.

The preamble in question read:

The alleged infringement had something that was the same as the cuff that was used in connection with an abutment, but the basal surface of abutment was not frusto-spherical. The court held that this statement in the preamble that the abutment had to be frusto-spherical was a limitation on the scope claim and therefore there was no infringement. Firstly the court looked at what was the significance of the preamble.

Preambles in the United States have traditionally been looked at as not being particularly important but they have become much more important over the last few years and a number of recent decisions give significant weight to the preamble, although there are others that give little weight to it.¹⁸ This often makes it difficult to advise clients exactly what is the significance of the preamble. In this case, however, the Federal Circuit had no problem. Although there was no reference in the body of the claim to the abutment having a frusto-spherical basal portion because the cuff member itself does not relate to that portion of the abutment, reference to the abutment having a conical surface was important to the definition of the cuff member. In particular it was important to understanding what was meant by a requirement in the body of the claim that the cuff member had a conical surface. From this the Federal Circuit concluded that the preamble was important. Once this was established, one had to look at the entirety of the preamble. This included the requirement for a frusto-spherical basal portion for the abutment. Consequently since the alleged infringement lacked a frusto-spherical basal portion in its abutment it did not infringe.

Morals: Do not include unnecessary language in the claims. Avoid reference to external factors that have really nothing to do with the invention being claimed and make sure that the specification makes it clear that there are alternatives to any such external feature as another way to try to avoid having a claim read with unnecessary limitations.

Schoenhaus v Genesco¹⁹ shows the importance of the first point noted in the Phillips v AWH case, namely looking at the claims as a whole to try to determine what any particular claim means. Claim 1 was to an orthotic device for preventing hyperpronation of a human foot comprising a number of different elements. Claim 2 was to a footwear product having as an element an orthotic device as claimed in claim 1. The specification stated that either the shoe itself could constitute this orthotic device or there could be a removable insert which constituted the orthotic device. The alleged infringement was something in which some of the features of the orthotic device occurred in the shoe and some in a removable insert so that it was important to determine exactly what the scope of claim 1 was. The Federal Circuit held that claim 1 could not be construed as covering a shoe having all the listed features in itself because if it did then claim 2 would have no meaning. Claim 2 would simply become "A shoe having a shoe" Therefore claim 1 had to be limited to being an insertable removable insert. That being the case, all of the features required had to be present in the insert and so there was no infringement.

This may be a situation where it is desirable to think very carefully about whether multiple independent claims should be used. There is this tendency world-wide unfortunately to push applicants to having only one independent claim in a category. This case shows that there are good reasons to fight against this trend. This is a case where clearly there was a single inventive concept. However, use of multiple independent claims was the most effective and clear way to secure protection for that concept. There are reasons in the United States, of course, why multiple independent claims are used which go beyond this type of situation. Litigators like to have different possible ways of explaining an invention to a jury and having multiple independent claims is one way of doing that. However, as this case shows there are also reasons why in some cases proper protection of an invention is best secured by the use of multiple independent claims, irrespective of any question about how to present a case to the jury.

Further examples of how one claim can impact the interpretation of another are found in Curtiss-Wright Flow Control Corp v Velan²⁰ where it was noted that "reading an additional limitation from a dependent claim into an independent claim would not only make the additional limitation superfluous, it might render the dependent claim invalid" and Pfizer v. Ranbaxy²¹ which focused on the requirements of 35 USC 112 paragraph 4.²² In this case Claim 6 was directed to the hemicalcium salt of the compound of claim 2. Claim 2 depended on claim 1 was directed to a specific acid. Claim 1 included the compound of claim 2 or pharmaceutically acceptable salts thereof. Claim 6 was held invalid for not being a further limitation of claim 2 (which did not cover salts).

Morals: There is a reason why one should use multiple independent claims – to avoid this type of problem. Furthermore, do not refer to a previous claim unless it is intended to have all of its limitations read into the claim in which that reference is made.

Abbott Laboratories v. Baxter²³ deals with the use of Markush language. A certain sloppiness that has crept in over the year in using Markush language in thinking that if one has language claiming a material "selected from the group consisting of A, B and C" this will cover something in which both A and B are present. Abbott Laboratories emphasizes that this is not the law. The court held:

namely A or B or C. There is no "and/or" implied there. Of course if one uses "comprising" language to introduce the Markush group, an interesting situation arises because one can then argue that the comprising language in the introduction to the Markush group itself permits the presence of additional components, but sometimes during prosecution one gets forced out of an initial claim form using comprising language into a more restricting transitional phrase Once one has done this one may be in trouble unless the Markush language itself provides for mixtures as in "selected from the group consisting of A, B, C and mixtures of two or more thereof".

A case where comprising language did save the day, although not strictly speaking a case relating to Markush groups was Gillette v. Energizer²⁴ where four razor blades were in present in a mounting in the alleged infringement as opposed to three that were recited in Gillette's claim as "first, second and third." But the claim did use comprising language and the court held that putting in the fourth blade did not avoid infringement in that particular case.

The plaintiffs were very unlucky in Nystrom v. Trex.²⁵ The claim related to the shape of boards used for making a deck. The Federal Circuit before the Phillips case had used dictionaries to come to the conclusion that the word "board" was a broad term and did not require that the board was made out of wood. There was nothing explicit in the specification to state that the board had to be made out of wood. There were some implications that the board would be made out of wood. For example there was a statement that if one did not have this particular shape one would have problems with standing water which would damage the deck and there was reference to the tree rings of a log being relevant to the shape that the surface of the board should take. But there was nothing explicit saying that the board had to be made out of wood. After the Phillips case, however, the court went back and reconsidered its decision and decided that it had been wrong to accept a dictionary definition of "board" as it had done the first time round and that it had to look at the body of the specification. Once it did this, it came to the conclusion that the specification was really talking about wooden boards and therefore the claim should be construed as being limited to such boards.

Moral: to make sure that something that is totally extraneous but which happens to run as a theme through the specification is not picked up and used by the courts as being an essential requirement of the claim, it is important to emphasize that the invention is not dependent on this feature in the body of the specification.

Again, if one has multiple embodiments, then make sure that they are mentioned and try hard to think of multiple embodiments that you can use.

Another example of a case where the Federal Circuit limited the claim in view of the description of something extraneous to the core of the invention based on statements in the specification is On Demand Machine Corp v. Ingram²⁶. In this case, the invention was a method of printing single copies of books to order. The specification talks about the information that is given to the person who wants to order the copy as including "sales information". The alleged infringement just gave an ISBN number or a title so that one could just select the book wanted from the ISBN number or the title and nothing beyond that. The Federal Circuit construed the "sales information" requirement of the claim to mean that that term had to have some sort of promotional aspect to it. One of the reasons for this was that the object clause of the specification talked about one of the objects being to assist the person who was ordering the copy to select the book that they wanted. This being the case, the sales information had, according to the Federal Circuit, to include promotional information as well as the title and the ISBN number.

Moral: Object clauses can be dangerous. It is worth noting that the U.S. Manual of Patent Examining Procedure in the passage that lays out what one should have in a patent application used to include specific reference to object clauses. That reference has been dropped for the last ten years or so - although large numbers of U.S. patents still include object clauses.

Inpro II Licensing SARL v. T-Mobile.²⁷ This is a case where is the invention relates to a pda and the question was whether the term "host interface" which occurred in the claim was something that had a broad meaning or had a narrow one. Again the Federal Circuit looked closely at the specification which stated that the use of a direct parallel bus interface was "a very important feature" of the invention and construed the claim as requiring that the host interface had to be a direct parallel bus.

So again, do not say something is very important, if it is not very important.

The final type of claim to consider is "means plus function" claims. These have caused much confusion over the years. The statute itself specifically says that means plus function language can be used in combination claims. The history of this is that back in the late 1930's the Supreme Court held that any functionality at the point of novelty was bad effectively because such a claim was covetous.²⁸ Then there was another Supreme Court case which held that any functional claiming anywhere in the claim rendered it indistinct.²⁹ It was generally felt that this went too far. The 1952 statute adopted a compromise position that if one needed to have functional language, this was permitted as long as it was in a combination claim so that there was more than one element in the claim and that the claim was to be construed as covering only what is described in the specification or the equivalents of what is described in the specification. This construction is a matter of literal infringement not an application of the doctrine of equivalents so that one is looking at the claim as literally including the equivalents of what is described in the specification. One consequence of this is under this test only equivalents that exist at the time when the patent is filed are covered. It is of course possible that a means plus function case itself can be construed under the doctrine of equivalents to cover something broader. When one has a means plus function claim, the courts have held that there is a two step analysis to be carried out.³⁰ First discern what is the claimed function (it is only that claimed function that is covered by the claim) and secondly identify the corresponding structure in the specification that performs that function.

In Budde v. Harley-Davidson³¹, it was held that the lack of any description of a structure in the specification to carry out the stated function made a means plus function claim totally indefinite and therefore invalid.

In Cardiac Pacemakers v. St Jude³², where the only means described for carrying out the function was a physician, there was no way to determine what a corresponding structure was and again the claim was invalid for lack of clarity.

The following conclusions seem justified by the recent case law:

1. Object clauses can be dangerous.
2. There is an advantage in having multiple independent claims.
3. Where possible it is desirable to include a description of more than one embodiment in the specification.
4. Think about whether it is desirable to claim sub-combinations. A sub-combination can be claimed in the United States if it is useful. Such claims might have avoided some of the problems that confronted some of the claim drafters who produced claims that we have looked at in this paper.
5. When using means plus function claims, make sure that the specification describes structures that work to perform the stated function.
6. Include definitions of anything that needs to be defined. Do not rely on what the court might come up with. Try to make sure that there is a very clear definition wherever possible.
7. Try to avoid linking cause and effect any more than is necessary.
8. Finally check that there is no suggestion that something is essential when it is not or that something does not work when it does.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.