Candela Laser Corp. v. Cynosure, Inc., Civ. A. No. 92-12640-Z.

862 F. Supp. 632

CANDELA LASER CORPORATION and Gaelis Corporation v. CYNOSURE, INC.

Civ. A. No. 92-12640-Z.

United States District Court, D. Massachusetts.

July 28, 1994.

Steven M. Bauer, Testa, Hurwitz & Thibeault, Boston, MA, and Richard B. Smith, Tewksbury, MA, for Candela Laser Corp.

Sandra E. Lundy, Steven M. Bauer, and Eric A. Deutsch, Testa, Hurwitz & Thibeault, Boston, MA, for Gaelis Corp.

Wayne L. Stoner, Gary A. Walpert, Diane C. Freniere, William F. Lee, and S. Tara Miller, Hale & Dorr, Boston, MA, for Cynosure, Inc.

Wayne L. Stoner, Gary A. Walpert, William F. Lee, and S. Tara Miller, Hale & Dorr, Boston, MA, for Horace W. Furumoto.

William F. Lee, Hale & Dorr, Boston, MA, for Harry L. Ceccon and Thomas Lovett.

MEMORANDUM OF DECISION

ZOBEL, District Judge.

Candela Laser Corporation ("Candela"), the holder of several patents in the field of laser technology, brought this action against Cynosure, Inc. ("Cynosure") and others for patent infringement, breach of contract, trade secret misappropriation and unfair competition.¹ On defendant's motion, I ordered that the issue of liability be tried separately from that of damages. The parties subsequently narrowed the trial to infringement of U.S. Patent Nos. 5,066,293 (the '293 patent) and 5,109,387 (the '387 patent) and a counterclaim of invalidity as to the '387. This memorandum shall constitute my findings of fact and conclusions of law on those issues.

I. BACKGROUND

"Laser" is an acronym for Light Amplification by the Stimulated Emission of Radiation. All conventional lasers have certain basic components in common. A quantity of material, called the excitation medium, is exposed to an energy source that causes the medium's molecules to emit photons, or light. The light resonates throughout the medium, usually by means of reflection off a combination of lenses and mirrors, called the "optics," becomes amplified as it travels back and forth and stimulates additional molecules. When the light reaches a critical level of intensity, it leaves the medium in the form of a laser beam.

In a dye laser, the excitation medium consists of dye molecules suspended in a liquid. A flashing light, the flashlamp, serves as the energy source, exciting the dye molecules and causing them to emit photons. A "dye cell" holds the dye solution in proximity to the optics. The amplified light finally passes through a specially coated mirror as a useful laser beam.

In a conventional dye laser most of the amplified light is designed to travel back and forth through the dye cell in precise, coherent paths, or "modes." Light travelling through the cell in a straight line is said to be travelling "coaxially." The medium does not produce exclusively coaxial light rays, however, because the flashlamp energy creates certain thermal distortions that change the course of the photons, directing them out of their coherent paths. In a conventional dye laser, some of the light traveling non-coaxially is not reflected back into the cell, but out of the cell at various angles. As a result, the non-coaxial light loses energy relative to the coaxial rays which further gain energy by being reflected off the mirrors at each end of the dye cell.

The patents at issue relate to the use of lasers for selective photothermolysis of biological tissue. In this technique, targeted tissue, such as a port wine birthmark on human skin, is heated by the laser light. The color of the light, duration of the laser pulse and intensity of the laser beam must all be carefully regulated in order to damage the tissue causing the skin's dark pigment, but leave other tissue unaffected. Dye lasers are well suited to selective photothermolysis because the choice of dye can determine the wavelength of the light and because dye lasers can provide high output energy with controlled pulse duration. Conventional dye laser technology, however, created a laser pulse lasting only a few microseconds, whereas optimal photothermolysis requires nearly a millisecond pulse. The '293 patent addresses the problem of pulse duration and wavelength. The '387 patent pertains to a second problem, the creation of byproducts in the dye solution and its consequent dilution.

II. U.S. Patent No. 5,066,293

While employed at Candela Laser, Dr. Horace Furumoto developed a dye laser with a pulse duration approaching one millisecond. He realized that light amplification could in fact be achieved with the rays of light reflected off the cell walls. He did so by means of a dye cell with apertures at either end. Optics at each end of the cell image each aperture on itself, thus capturing the light coming from the aperture and returning it to the cell for amplification. In this manner, light is available for amplification whether it travelled coaxially within the cell, or was reflected off the cell walls. Dr. Furumoto patented his method in 1991. He assigned the patent to Candela which marketed an embodiment of the claimed method as the "SPTL-1," a dye laser used for selective photothermolysis.

Dr. Furumoto and Harry Ceccon had founded Candela in 1970. At that time it primarily developed lasers for scientific purposes. In the 1980s, however, Candela began developing lasers for medical applications. Dr. Furumoto led the company until 1991, when he was terminated. He then purchased the assets of Candela's scientific laser business and founded a new company, Cynosure, Inc. The parties agreed that Cynosure would not compete with Candela in the medical laser business before April 15, 1992, but that it would be permitted to engage in medical laser research and development during that time. When the noncompetition agreement expired, Cynosure introduced the PhotoGenica V laser, which is now accused of infringing the '293 patent.

The PhotoGenica V is a flashlamp-excited dye laser with a 24-inch dye cell. Approximately 2.5 centimeters from each end of the dye cell is a flat mirror, one of which is coated to allow the laser beam to exit the cell. According to Dr. Furumoto, the PhotoGenica V, unlike the patented method, uses coaxial light in its lasing process. It takes advantage of improvements in the dye medium and flashlamp technology to create the longer pulses formerly impossible in conventional dye lasers.

A. Claim Interpretation

Plaintiff alleges that the PhotoGenica V laser nevertheless infringes on Claims 1 and 5 of the '293 patent. Claim 1 is for:

A method of phothermolysis sic of biological tissue comprising:

energizing a liquid dye medium in a dye cell including an aperture at each end thereof to an energy level at which the medium has net optical gain thereby producing an output beam from said dye cell;

from each end of the cell returning into the cell substantially all light other than the output beam, within a wavelength band emanating from the cell, such that the light traverses the cell with internal reflections off cell walls and the cell amplifies the light, the light being returned including other than spatially coherent light traveling coaxially in the cell, the output beam being of at least one hundred microsecond duration and at least one-tenth joule; and

illuminating the biological tissue with the output beam from the cell. (Emphasis added.)

Claim 5 substitutes "subcutaneous vascular lesions" for "biological tissue" but is identical in all other respects.

The parties do not dispute that the PhotoGenica V laser embodies a method of photothermolysis of biological tissue or subcutaneous vascular lesions in which a liquid dye medium is energized in a dye cell with an aperture at each end thereby producing an output beam. The controversy centers around the meaning and application of the claims' second paragraph. Specifically, the parties differ regarding the meaning of "the light" in the second and third of the three steps delineated above.

Plaintiff contends that "substantially all the light" refers to the type of light, i.e., both coaxial and noncoaxial light, rather than some quantity of light. Thus, both coaxial and noncoaxial light from each end returns into the cell, but only some of that light reflects off cell walls to become amplified. Plaintiff claims that the PhotoGenica V returns both coaxial and noncoaxial light to the cell and uses some of each in its lasing process. It does not claim that the PhotoGenica V reflects and amplifies "substantially all" the returned light.

Defendant reads this section to describe a method in which "substantially all light" returns into the cell and reflects off cell walls and is amplified for use as a laser. It maintains that the PhotoGenica V does not infringe because most of the light it amplifies is coaxial, i.e., it resonates back and forth in a straight line within the cell; only a very small proportion traverses the cell with internal reflections off cell walls.

A determination of patent infringement involves a two-step analysis; the court first interprets the language of the claim and then compares the claims to the accused device. Standard Oil Co. v. American Cyanamid Co., 774 F.2d 448, 452 (Fed.Cir.1985). When the meaning of key terms is disputed, courts may consider extrinsic evidence, including testimony of witnesses, as well as reference to the specification, the prosecution history and prior art. Tandon Corp. v. I.T.C., 831 F.2d 1017, 1021 (Fed.Cir.1987). The claims, not the specification or the embodiments, define the invention. Uniroyal, Inc. v. Rudkin-Wiley Corp., 837 F.2d 1044, 1053 (Fed.Cir.1988) (citing Loctite Corp. v. Ultraseal Ltd., 781 F.2d 861, 870 (Fed.Cir. 1985)).

The claims' clear meaning is that substantially all the light from each end of the dye cell is returned to the cell and substantially all the light is amplified by travelling through the dye cell with reflections off the cell walls. This interpretation comports with credible witness testimony, the specification, the prosecution history and the prior art. Plaintiff's own witness, Dr. Ralph...