Varian Medical Systems, Inc. v. ViewRay, Inc.

Background

Varian Medical Systems, Inc. sued ViewRay, Inc. and ViewRay Technologies, Inc. for allegedly infringing U.S. Patent Nos. 8,637,841 and 9,082,520. The patents concern multilevel multileaf collimators—devices used in radiotherapy to shape radiation beams while reducing leakage and improving beam-shaping resolution. The court held a claim-construction hearing on July 7, 2020. Claim construction is the court’s interpretation of the words and limitations in patent claims.

The parties identified eight disputed terms. Varian generally proposed the terms’ plain and ordinary meanings, while ViewRay proposed narrower interpretations for several terms and argued that one term was indefinite.

Rulings on the Disputed Terms

1. “Substantially same” and “different” cross-sections

The court found indefinite the term in claims 12-19 of the ’841 patent requiring each leaf in one set to have a “substantially same” cross-section, each leaf in another set to have a “substantially same” cross-section, and the first cross-section to be “different” from the second.

Under 35 U.S.C. § 112, a claim is indefinite when, read in light of the patent’s specification and prosecution history, it does not inform a skilled person with reasonable certainty about the scope of the invention. The court concluded that neither the claim language nor the specification supplied objective boundaries for deciding when cross-sections were “substantially same” or “different.” The figures and examples showed some widths described as substantially the same and different, but did not explain how to treat intermediate differences or variations in shape, angles, and position. The court therefore found the term indefinite.

2. First set of beam-blocking leaves

For the ’841 patent claims 1 and 12 and the ’520 patent claims 1 and 6, the court construed the disputed term to mean a first set of adjacent pairs of beam-blocking leaves whose leaves oppose each other and move lengthwise relative to one another in a first direction, with the clarification that “the first set may be above or below the second set.”

The court added that parenthetical because the claims place the two sets in different planes or levels and the clarification would assist the jury.

3. “Direction” or “directions”

For the identified claims of both patents, the court adopted Varian’s construction: “direction” includes the opposite direction, multiple directions parallel to it, and both straight-line and curved paths. The court rejected ViewRay’s proposal to define “opposite” as perpendicular because ViewRay identified no supporting evidence, and the patent specification supported Varian’s construction.

4. Inner and outer sections with first and second cross-sections

For claim 1 of the ’841 patent, the court applied the plain and ordinary meaning of the term describing an inner first section and an outer second section with first and second cross-sections. The court rejected ViewRay’s proposed requirement that the two cross-sections necessarily be different in width or shape. The claim language and specification established that two cross-sections exist but did not require them to differ.

5. Leaf pairs on each side of the inner section

For claim 1 of the ’841 patent, the court construed the term to require that each of the first and second sets include at least two pairs of leaves on one side of the inner first section and at least two pairs on the other side. The court rejected Varian’s proposed plain-meaning construction because the parties disputed whether the claimed plurality of pairs could be shared between the two sides. The court said ViewRay’s additional parenthetical was unnecessary.

6. Main portion and projections

For claim 19 of the ’841 patent, the court construed the term to mean that the end portion—defined as the leading edge of a leaf inserted into a radiation field—has one or two projections extending beyond the height of the main portion. The court rejected ViewRay’s additional limitations concerning abutting an opposing leaf and the height of the leaf’s side surface.

7. Upward or downward extended portion

For claim 14 of the ’520 patent, the court similarly construed “an end portion having an upward and/or downward extended portion” to refer to the leading edge of a leaf inserted into a radiation field. The court did not include ViewRay’s proposed additional limitations concerning abutting an opposing leaf or extending beyond the side surface’s height.

8. Locations offset from a beam’s point of view

For claim 20 of the ’841 patent, the court construed the term to require that a pair of leaves in the first set close at a first location and a corresponding pair in the second set close at a second location, with the locations offset from the beam’s point of view in the direction of leaf movement. The court defined the beam’s point of view as the view from the radiation source toward the leaves in the direction of the radiation beam.

The court concluded that a lateral offset or another offset not in the leaf-movement direction would not address the patent’s stated concern about leakage between abutting leaves. The specification also described the offset as being in the direction of leaf travel.

Disposition

Judge Susan Illston adopted the claim constructions stated in the order. The court found the disputed cross-section term in claims 12-19 of the ’841 patent indefinite and construed the remaining seven disputed terms as described above. The order did not decide whether ViewRay infringed the patents.