Scimed Life Systems, Inc. v. Advanced Cardiovascular Systems, Inc.
2001 U.S. App. LEXIS 3864, 58 U.S.P.Q. 2d (BNA) 1059, 242 F.3d 1337 (2001)
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Rule of Law:
When a patent's specification repeatedly describes the invention as having a particular feature, characterizes that feature as essential to all embodiments of the invention, and criticizes prior art for lacking that feature, the patent's claims are limited to that feature, and the patentee is barred from asserting infringement against the disclaimed subject matter under the doctrine of equivalents.
Facts:
- SciMed Life Systems, Inc. (SciMed) owned patents for balloon dilatation catheters used in coronary angioplasty.
- The catheters require two internal passageways (lumens): a guide-wire lumen and an inflation lumen.
- Two primary configurations for these lumens exist in the art: a coaxial configuration (one lumen inside the other) and a dual lumen configuration (lumens are side-by-side).
- SciMed's patent specifications consistently described the invention as having a coaxial lumen structure, with an 'annular inflation lumen.'
- The specifications also explicitly stated that this coaxial structure 'is the basic sleeve structure for all embodiments of the present invention contemplated and disclosed herein.'
- In discussing prior art, SciMed's specifications criticized the dual lumen configuration as suffering from disadvantages, such as being stiffer and having larger shaft sizes.
- Advanced Cardiovascular Systems, Inc. (ACS) manufactured and sold catheters that exclusively used the dual lumen configuration.
Procedural Posture:
- SciMed Life Systems, Inc. sued Advanced Cardiovascular Systems, Inc. in the U.S. District Court for the Northern District of California, alleging infringement of three patents.
- ACS moved for summary judgment of non-infringement.
- The district court (trial court) granted summary judgment in favor of ACS.
- The district court first construed the patent claims to be limited to catheters with a coaxial lumen structure, which meant there was no literal infringement.
- The district court then ruled that ACS's devices did not infringe under the doctrine of equivalents.
- SciMed (as appellant) appealed the district court's summary judgment ruling to the U.S. Court of Appeals for the Federal Circuit.
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Issue:
Does a patent's written specification, which consistently describes an invention as having a coaxial lumen configuration, identifies that structure as the basis for 'all embodiments of the present invention,' and distinguishes prior art with a dual lumen configuration, thereby limit the patent's claims to only the coaxial configuration and preclude an infringement claim under the doctrine of equivalents against a device with a dual lumen configuration?
Opinions:
Majority - Circuit Judge Bryson
Yes. A patent's claims are limited to the coaxial configuration because the specification acts as a clear and explicit disclaimer of the dual lumen configuration. The court reasoned that this was not a case of improperly reading a limitation from the specification into the claims, but rather using the specification to correctly interpret the claims. The specification repeatedly described the 'present invention' as having a coaxial structure, criticized the dual lumen alternative found in prior art, and unequivocally stated the coaxial design was the 'basic sleeve structure for all embodiments.' Having explicitly disclaimed the dual lumen structure in the specification, SciMed cannot now recapture that subject matter through the doctrine of equivalents, as this would vitiate a claim limitation and undermine the public notice function of the patent.
Concurring - Circuit Judge Dyk
Yes. While agreeing with the majority's conclusion in this specific case, the concurrence expresses concern that the court's broader jurisprudence provides inadequate guidance on when it is appropriate to use the specification to narrow the scope of patent claims. This lack of a clear framework can lead to confusion for lower courts and litigants trying to understand the boundaries of claim construction.
Analysis:
This decision significantly reinforces the concept of disclaimer through the patent specification, holding that a patentee can limit claim scope through their own descriptive words, not just through actions during prosecution. It serves the critical public notice function of patents, allowing competitors to rely on an inventor's clear disavowal of certain designs when creating their own products. The case cautions patent drafters against using limiting language like 'the present invention is' or 'all embodiments have' when describing a particular feature, as this may inadvertently surrender broader claim scope. It establishes that a patentee who distinguishes their invention from a known alternative cannot later claim that alternative is equivalent to their invention.
