Appeal No. 2006-2826 Page 3
Application No. 09/993,907
1. An implantable or insertable medical device comprising:
(a) a substrate;
(b) a hydrogel polymer coating at least a portion of the surface of the
substrate, wherein said hydrogel polymer is adapted by cross-linking said
hydrogel polymer to a degree sufficient to render said medical device visible
under magnetic resonance imaging upon insertion or implantation of said medical
device into a patient, and wherein visibility of detectable species associated with
said hydrogel polymer to magnetic resonance imaging is modified by varying the
degree of said cross-linking.
We begin with claim construction because that is necessary to determine the
scope and meaning of the claims. For this purpose, we will focus on claim 1 as
representative. The claim is directed to a medical device which has a surface
(“substrate”) coated with a hydrogel. The hydrogel polymer which coats the substrate is
required to be “adapted by cross-linking said hydrogel polymer to a degree sufficient to
render” the device visible to MRI imaging. There is no definition in the specification of
what is meant by “cross-linking.” Accordingly, we adopt its ordinary and conventional
meaning1 that chains of atoms in the hydrogel polymer are joined together by bonds,
atoms, or chemical groups.
The specification explains that cross-linking (“adapted by cross-linking”) the
hydrogel modifies its magnetic environment in comparison to the magnetic environment
surrounding the coated device. Specification, ¶ 33. Coating a device with the cross-
linked hydrogel facilitates the visibility of the device because “detectable species”
associated with the hydrogel will behave differently than “detectable species” in the
surroundings. Id., ¶¶ 24-26, 29. Claim 1’s subsequent “wherein” clause indicates that
the “detectable species” are “associated with” the hydrogel, and that their visibility “is
1 Crosslink: “1. a bond, atom, or group linking the chains of atoms in a polymer, protein, or other complex
organic molecule.” The Random House College Dictionary, 319 (Rev. ed. 1982).
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