US Supreme Court Tightens the Standard for Definiteness of Patent Claims

US Supreme Court Tightens the Standard for Definiteness of Patent Claims

Nautilus Inc v Biosig Instruments Inc, No 13-369, 572 US ____ (2014)

This case, involving a heart-rate monitor used with exercise equipment, concerned the proper reading of the patent statute’s requirement that a patent specification “conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as [the] invention.” 35 U.S.C. §112, ¶2.

Federal Circuit jurisprudence had held that a patent claim passes the §112, ¶2 threshold so long as the claim is “amenable to construction,” and the claim, as construed, is not “insolubly ambiguous.”

In place of the “insolubly ambiguous” standard, the Supreme Court held that 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 patent at issue was US 5,337,753. The lengthy claim 1 reads:

1. A heart rate monitor for use by a user in association with exercise apparatus and/or exercise procedures, comprising;

an elongate member;

electronic circuitry including a difference amplifier having a first input terminal of a first polarity and a second input terminal of a second polarity opposite to said first polarity;

said elongate member comprising a first half and a second half;

a first live electrode and a first common electrode mounted on said first half in spaced relationship with each other;

a second live electrode and a second common electrode mounted on said second half in spaced relationship with each other;

said first and second common electrodes being connected to each other and to a point of common potential;

said first live electrode being connected to said first terminal of said difference amplifier and said second live electrode being connected to said second terminal of said difference amplifier;

a display device disposed on said elongate member;

wherein, said elongate member is held by said user with one hand of the user on said first half contacting said first live electrode and said first common electrode, and with the other hand of the user on said second half contacting said second live electrode and said second common electrode;

whereby, a first electromyogram signal will be detected between said first live electrode and said first common electrode, and a second electromyogram signal, of substantially equal magnitude and phase to said first electromyogram signal will be detected between said second live electrode and said second common electrode;

so that, when said first electromyogram signal is applied to said first terminal and said second electromyogram signal is applied to said second terminal, the first and second electromyogram signals will be subtracted from each other to produce a substantially zero electromyogram signal at the output of said difference amplifier;

and whereby a first electrocardiograph signal will be detected between said first live electrode and said first common electrode and a second electrocardiograph signal, of substantially equal magnitude but of opposite phase to said first electrocardiograph signal will be detected between said second live electrode and said second common electrode;

so that, when said first electrocardiograph signal is applied to said first terminal and said second electrocardiograph signal is applied to said second terminal, the first and second electrocardiograph signals will be added to each other to produce a non-zero electrocardiograph signal at the output of said difference amplifier;

means for measuring time intervals between heart pulses on detected electrocardiograph signal;

means for calculating the heart rate of said user using said measure time intervals;

said means for calculating being connected to said display device;

whereby, the heart rate of said user is displayed on said display device. (emphasis added)

The ‘753 patent was upheld upon re-examination by the USPTO.

In a Markman hearing the District Court considered the claim language “in spaced relationship with each other.” According to the patentee, Biosig, the phrase “spaced relationship” referred to the distance between the live electrode and the common electrode in each electrode pair. Nautilus, seizing on Biosig’s submissions to the PTO during the re-examination, maintained that the “spaced relationship” must be a distance “greater than the width of each electrode.” The District Court held that “spaced relationship” was indefinite, but the Federal Circuit reversed on the basis, inter alia, that the functional language in the claim aided in clarifying the meaning of “spaced relationship”.

The Supreme Court stated that “[t]o tolerate imprecision just short of that rendering a claim ‘insolubly ambiguous’ would diminish the definiteness requirement’s public-notice function and foster the innovation-discouraging ‘zone of uncertainty’”. Instead the Court held that a patent is invalid for indefiniteness if its claims, read in light of the specification and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.

However, the Court, mindful of its role as a court of review rather than a court of first view, declined to apply the new indefiniteness standard to the claim at issue, and remanded the case back to the Federal Circuit.