The discussion of indefiniteness case law in this opinion is quite comprehensive and worth consulting if you ever need general guidance on the topic. Here, the court focused on the idea that the claims provide “inherent” parameters of the claimed “spaced relationship.” Because simple tests could be carried out to determine the appropriate values for these inherent parameters for any given application, they need not be spelled out with specificity in the claims themselves. “These parameters constitute the metes and bounds of ‘spaced relationship’ as articulated in the ’753 patent. Nothing more rigorous is required under § 112, ¶ 2.”
Background / Facts: The patent 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. “[T]the district court is correct that the specification of the ’753 patent does not specifically define ‘spaced relationship’ with actual parameters, e.g., that the space between the live and common electrodes is one inch. Nevertheless, the ’753 patent’s 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. See ’753 patent col. 3 ll. 26–31 (describing how each hand is placed over the live and common electrodes so that they are ‘in physical and electrical contact with both electrodes.’). Thus, the ’753 patent discloses certain inherent parameters of the claimed apparatus, which to a skilled artisan may be sufficient to understand the metes and bounds of ‘spaced relationship.’ … In addition, a skilled artisan could apply a test and determine the ‘spaced relationship’ as pertaining to the function of substantially removing EMG signals.”