Preamble held not limiting because body of claim sets forth complete inventionSeptember 20, 2010

In a recent decision, the Federal Circuit reversed a decision of the United States District Court for the District of Massachusetts. The district court had granted summary judgment of noninfringement to the defendant finding that the defendant's accused device did not perform a function found only in the preambles of the asserted claims.The Federal Circuit held that the disputed preamble term did not limit the asserted claims, and therefore, reversed and remanded the case for further findings. Specifically, the court noted there was no suggestion in the prosecution history that the preamble was limiting, the preamble did not provide any antecedent basis for terms in the body of the claim (even though one element used "the" in the body of the claim), and the preamble did not define an essential component of the invention, such that the body of the claim defined the complete invention. Based on these factors, the preamble was not a limitation of the claim, and the summary judgment of noninfringement was reversed.

Judge Dyk dissented, and invited the court to take the issue of preambles en banc to create a bright-line rule that preambles are always limiting, rather than relying on the context of each patent.

More concerning Am. Med. Sys., Inc. v. Biolitec, Inc. after the jump.The method and apparatus disclosed in U.S. Patent No. 6,986,764 ("the '764 patent") can be used to treat Benign Prostatic Hyperplasia ("BPH"), in which growth of the prostate gland restricts the passage of urine out of the bladder and through the urethra. Vaporization, or ablation, of some of the prostate tissue reduces the size of the prostate and can relieve bladder outlet obstructions. The '764 patent describes the process as inserting a cytoscope into the urethra, providing an irrigant such as sterile water, and applying a high-intensity laser radiation to the target tissue. The specification of the '764 patent discloses that ideally the radiation has a wavelength between 250-600 nanometers (nm). The patent also includes various methods and devices for achieving a high volumetric power density by manipulating variables such as wavelength, output power, beam quality, irrigant composition, and distance between the optical fiber and the tissue.Claim 31, a representative of the method claims, discloses (the apparatus claims are generally similar, except that they also recite a laser and an endoscope):

31. A method for photoselective vaporization of tissue, comprising: delivering laser radiation to a treatment area on the tissue, the laser radiation having a wavelength and having irradiance in the treatment area sufficient to cause vaporization of a substantially greater volume of tissue than a volume of residual coagulated tissue caused by the laser radiation, wherein the delivered laser radiation has an average irradiance in the treatment area greater than 10 kiloWatts/cm2 in a spot size at least 0.05 mm2.

American Medical Systems sued Biolitec, alleging that the defendant's Evolve™ laser system and method of use infringed a number of claims of the '764 patent. The system is a laser-powered tissue ablation system that uses radiation having a wavelength of 980 nm. During a Markman hearing, the district court ruled that repeated use of the phrase "photoselective vaporization" in the specification and claims indicated that the phrase is a "fundamental characteristic" of the invention, and thus the preamble was a limitation of the claims. The district court then construed the preamble term "photoselective vaporization" to mean "using a wavelength that is highly absorptive in the tissue, while being absorbed only to a negligible degree by water or other irrigant." Based on this claim construction, and an assertion that the Evolve™ laser system operated at a wavelength at which the energy is absorbed to more than a negligible degree by water or other irrigant, the district court granted the defendant's motion for summary judgment for noninfringement.The Federal Circuit reversed the district court's decision. The court held that the preamble phrase "photoselective vaporization of tissue" does not limit the claims of the '764 patent. Because the district court predicated its entire decision on finding that the plaintiff did not violate the preamble phrase, the court remanded the case for further proceedings.After reviewing case law regarding whether a preamble should be treated as a claim limitation, noting that it should be "determined on the facts of each case in light of the claim as a whole and the invention described in the patent," the court concluded that the preamble language of the '764 patent did not constitute a limitation of the claims. First, the court held that there was no suggestion in the prosecution history of the '764 patent that the inventors added the phrase of the preamble in order to distinguish over prior art. Second, the court held that the language in question of the preamble did not provide antecedent basis for terms in the claim body. Finally, the court held that "photoselective" did not embody an essential component of the invention, noting the invention was fully set forth in the body of the claims.Regarding the defendant's argument that their laser operates at a wavelength greater than the range given as preferred in the specification, the court used the doctrine of claim differentiation. The court noted that not all of the independent claims had dependent claims that included the use of wavelengths "from about 200 nm to about 650 nm." Therefore, the dependent claims give rise to a presumption that the broader independent claims are not confined to that range. Thus, the Federal Circuit concluded that, read as a whole, the '764 patent disclosed methods and devices for increasing power density that may be achieved in ways that do not require a specific wavelength range. Therefore, the preamble did not constitute a claim limitation, and the finding of summary judgment for noninfringement was reversed and the action was remanded to the district court for further proceedings.Judge Dyk dissented, and argued for a uniform rule stating that all claim preambles are limiting. He took issue with the lack of a uniform test regarding claim preambles, and noted having one standard would make cases such as this one easier. As such, he suggests the court take up the issue en banc to set forth such a rule. In addition, Judge Dyk thought that, even under the existing precedent, the preamble term should have been construed as a claim limitation. Judge Dyk noted that the '764 patent was a continuation-in-part of U.S. Patent No. 6,554,824 ("the '824 patent"). The '824 patent did not include the use of the phrase "photoselective vaporization" in the claims or in the specification. Accordingly, the judge thought that by adding the terminology during prosecution of the '764 patent, the patentee conceded that the term gave life, meaning, and vitality to the claims, and therefore, the phrase should be construed to limit the claims.To read the full decision in Am. Med. Sys., Inc. v. Biolitec, Inc., click here.

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