Indefiniteness Under 35 U.S.C. §112

AlertNautilus, Inc. v. Biosig Instruments, Inc.
By Colin W. Turner

Issue: What standard should apply in evaluating the indefiniteness of a patent claim, and, how much imprecision does 35 U.S.C. §112 tolerate in doing so?

Case History: Biosig held a patent directed to a heart monitor device commonly utilized on exercise equipment such as treadmills, which consists of a cylindrical bar with electrodes on each end that are gripped by both of the user's hands. Biosig filed a patent infringement suit against Nautilus alleging that it used Biosig's patented device on products without obtaining a license.

Claim 1 of the patent at issue describes a "heart monitor for use by a user in association with exercise apparatus and/or exercise procedures." The electrodes of the device are "in spaced relationship with each other." (emphasis added).

The District Court held a Markman hearing in order to construe the claims. In doing so, it construed the term "spaced relationship" to mean "there is a defined relationship between the [electrodes] on one side of the cylindrical bar and the same or a different defined relationship between the [electrodes] on the other side of the cylindrical bar" without any reference to the width of the electrodes.

35 U.S.C. §112, second paragraph, requires that a patent application conclude with "one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention." The Court held that the term "spaced relationship" was indefinite under 35 U.S.C. §112, second paragraph, as it did not put anyone, including the court, on notice as to what precisely the space should be, much less provide any parameters for ascertaining the
correct spacing.

The Federal Circuit reversed, holding that a claim was indefinite only when it is "not amenable to construction" or when it is "insolubly ambiguous."

Supreme Court Holding: A unanimous Court vacated and remanded the Federal Court's decision, holding that the Federal Circuit's standard as articulated does not satisfy the statute's definiteness requirement as it tolerates "some ambiguous claims but not others."

The Court adopted a new standard for ascertaining definiteness of a claim:

A patent is invalid for indefiniteness if its claims, read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.

The claims must be clear, but need not be absolutely precise. Claim construction requires "sophisticated analysis" of the entire patent application "and may turn on evaluations of expert testimony."

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