American Medical Systems, Inc. v. Biolitec, Inc.

American Medical Systems, Inc., and Laserscope (plaintiffs) held United States Patent No. 6,986,764 (the 764 patent), which was continued in part from United States Patent No. 6,554,824 (the 824 patent). Neither the claims nor the specification of the 824 patent contained the term “photoselective vaporization.” However, the preamble of the 764 patent claims referred to methods and apparatuses for “photoselective vaporization of tissue,” and the patent specification described and defined the term. The patents covered laser-radiation methods and devices aimed at removing obstructive tissue caused by an enlarged prostate. Part of the 764 specification stated that the proper range of wavelengths to operate the “present invention” was 200 to 650 nanometers (nm) because wavelengths in that range were minimally absorbed by an irrigant, the defining characteristic of photoselective vaporization. Some claims included a similar wavelength limitation of 200 to 650 nm. Other claims and parts of the specification referred to wavelengths up to 1,000 nm or did not include a wavelength limitation at all. The body of the claims completely described both the structure and process of practicing the invention. The recitation of the invention was framed in terms of its function of vaporizing tissue, not on the use of particular wavelengths, and indicated that tissue could be vaporized at various wavelengths. Biolitec, Inc. (defendant) was sued in federal court for infringing the 764 patent. The district court held a Markman hearing and construed “photoselective vaporization” as a claim limitation. Biolitec moved for summary judgment of noninfringement. The district court granted the motion, and American Medical Systems and Laserscope appealed.