Claim language employing terms of degree is not indefinite when its bounds can be inferred from inherent parameters related to proper operation. Here, for example, a “spaced relationship” between two electrodes was found to be sufficiently definite because the spacing is inherently bounded by “the width of a user’s hands” and an “infinitesimally small” distance for maintaining separation, outside of which the invention would not operate properly. “Claim language employing terms of degree has long been found definite where it provides enough certainty to one of skill in the art when read in the context of the invention.” This would be a good case to consult and cite in response to an indefiniteness rejection for a claim term whose logical bounds are made clear by the operation of the invention.
Background / Facts: The patent on remand here is directed to a heart rate monitor that purports to improve upon the prior art by effectively eliminating noise signals during the process of detecting a user’s heart rate. According to the patent, prior art monitors did not eliminate signals given off by skeletal muscles (“electromyogram” or “EMG” signals), which are brought about when users move their arms or squeeze the monitor with their fingers. Because EMG signals are of the same frequency range as electrical signals generated by the heart (“electrocardiograph” or “ECG” signals), EMG signals can mask ECG signals rendering heart rate determination while exercising difficult. To address this problem, the patent describes a difference amplifier for substantially removing EMG signals between a live electrode and a common electrode, which claimed as being in “spaced relationship” with each other.
Issue(s): Whether the claimed “spaced relationship” referring to the spacing between the common and live electrodes is indefinite.
Holding(s): No. Employing the “reasonable certainty” indefiniteness standard prescribed by the Supreme Court above, the Federal Circuit here found that “a skilled artisan would understand the inherent parameters of the invention as provided in the intrinsic evidence. The term ‘spaced relationship’ does not run afoul of ‘the innovation-discouraging ‘zone of uncertainty’ against which [the Supreme Court] has warned,’ and to the contrary, informs a skilled artisan with reasonable certainty of the scope of the claim.” Reiterating its previous findings, the court again stated that, although “the specification of the [] patent does not specifically define ‘spaced relationship’ with actual parameters, e.g., that the space between the live and common electrodes is one inch,” the “claim language, specification, and the figures illustrating the ‘spaced relationship’ between the live and common electrodes are telling and provide sufficient clarity to skilled artisans as to the bounds of this disputed term. For example, on the one hand, the distance between the live electrode and the common electrode cannot be greater than the width of a user’s hands because claim 1 requires the live and common electrodes to independently detect electrical signals at two distinct points of a hand. On the other hand, it is not feasible that the distance between the live and common electrodes be infinitesimally small, effectively merging the live and common electrodes into a single electrode with one detection point.”