<i>Biosig Instruments, Inc. v. Nautilus, Inc.</i>

Claim 1 is representative and recites the following:

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; '
(emphasis added)

Biosig first sued Nautilus, Inc. (“Nautilus”) for patent infringement in 2004, alleging that Nautilus' exercise equipment included the patented heart monitor device covered by the product claims of the '753 patent. Following two re-examination attempts and a claim construction ruling, Nautilus countered with a motion for summary judgment that the '753 patent was invalid on the grounds that “spaced relationship” rendered those product claims indefinite. The district court agreed and granted Nautilus' motion, holding the '753 patent indefinite under 35 U.S.C. ' 112 as a matter of law.

The Federal Circuit Decision

On appeal, the Federal Circuit reversed, ruling that it was perfectly acceptable to include terms having functional implications in product claims, without the need to employ “means-plus-function” terminology. The Federal Circuit noted that when a claim limitation is defined in functional terms, determining whether the limitation is sufficiently definite depends on the disclosure in the specification and the knowledge of a person of ordinary skill in the art.

The Federal Circuit held that the term “spaced relationship” was not indefinite because those of ordinary skill in the art, having read the patent specification, would understand the boundaries of this term. The Federal Circuit acknowledged that the district court was correct that the specification of the '753 patent did not specifically define “spaced relationship” with the distance between the live and common electrodes. Nevertheless, the Federal Circuit reasoned that the '753 patent's claim language, specification, and the figures illustrating the spaced relationship between the live and common electrodes provided sufficient clarity with respect to its boundaries to those of ordinary skill in the art.

For example, claim 1 required the live and common electrodes to independently detect electrical signals at two distinct points of the hand. Therefore, the distance between the live electrode and the common electrode could not be greater than the width of a user's hand. Also, the electrodes could not be so close that independent signals could not be detected. Thus, the Federal Circuit reasoned, the '753 patent disclosed ” certain inherent parameters of the claimed apparatus, which to a skilled artisan may be sufficient to understand the metes and bounds of 'spaced relationship.'” (emphasis added)

The Federal Circuit also considered the functionality of the claimed heart rate monitor, as recited in claim 1, to support the definiteness of the meaning of “spaced relationship.” For example, claim 1 recites the function of substantially removing EMG signals using the structure of the claimed elongate member, the live electrode, and the common electrode. The Federal Circuit considered it significant that the Patent Office Examiner found the function to be “crucial” as a reason for overcoming the prior art and confirming the patentability of the asserted claims upon re-examination. “Thus, the recitation of this function in claim 1 is highly relevant in ascertaining the proper bounds of the “spaced relationship” between the live and common electrodes.” (emphasis added).

Accordingly, the Federal Circuit concluded that the claim provided sufficient parameters for one of ordinary skill to determine the metes and bounds of the spaced relationship limitation, even if some experimentation was needed:

In summary, the claims provide inherent parameters sufficient for a skilled artisan to understand the 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. Indeed, the test would have included a standard oscilloscope connected to both the inputs and outputs of the differential amplifier to view the signal wave forms and to measure signal characteristics. With this test, configurations could have been determined by analyzing the differential amplifier input and output signals for detecting EMG and ECG signals and observing the substantial removal of EMG signals from ECG signals while simulating an exercise. These parameters constitute the metes and bounds of “spaced relationship” as articulated in the '753 patent. Nothing more rigorous is required under ' 112, ' 2. (emphasis added)

The Federal Circuit also noted that the fact that some experimentation may be necessary to determine the scope of a claim, does not render the claims indefinite, as long as the experimentation is not “undue.”

In addition, the court held that objections based on the premise that the '753 patent did not include disclosure sufficiently commensurate with the scope of the claims were not relevant to indefiniteness considerations. For example, when ruling on the definiteness issue, the Federal Circuit was not concerned that different users might have differently sized hands:

inquiries as to the size of the users' hands, placement of fingers, and the “composition of the handle” may be relevant, if at all, to issues that relate to enablement under ' 112, ' 1, not indefiniteness under ' 112, ' 2, because they are directed to the operability of varying embodiments of the claimed heart rate monitor, not to the precision of the claims at issue.

Although Nautilus argued that the specification failed to disclose how a skilled artisan would have determined the parameters for determining the correct spaced relationship, the Federal Circuit disagreed:

Here, the claimed apparatus has inherent parameters where the “spaced relationship” cannot be larger than the width of a user's hand. Additionally, it has been shown that skilled artisans can readily ascertain the bounds of the “spaced relationship” through tests using standard equipment. (emphasis added)

The Federal Circuit explained that the record showed that the variables, including the spacing, size, shape, and material affecting the “spaced relationship” between the electrodes, could be determined by those skilled in the art.

The Federal Circuit also remarked that there is no prohibition on “drafting or defining [product] claims in relation to their functions. ' Indeed, functional language in a means-plus-function format is explicitly authorized by statute. 35 U.S.C. ' 112, ' 6. Functional language may also be used to limit the claims without having the means-plus-function format.”

Nautilus also argued that the claims were indefinite because they claimed both an apparatus and a method of use simultaneously. Nautilus asserted that the claims recited a heart rate monitor, but also recited the step that a user hold the monitor. According to Nautilus, the claims were indefinite because it was unclear whether infringement occurred when the heart rate monitor having the recited structural elements was made, or whether infringement occurred when the user held the handle and contacted the electrodes.

The Federal Circuit was not persuaded and explained that product claims could include functional limitations:

The '753 patent recites apparatus claims with functional limitations that describe the capability of substantially removing EMG signals. Indeed, claim 1 of the '753 patent is clearly limited to a heart rate monitor possessing the recited structure that is capable of substantially removing EMG signals. It is not indefinite. (emphasis added)

Therefore, the Federal Circuit reversed the district court's invalidity determination and held the claims were not indefinite.

Matthew Siegal and Irah Donner are partners in the Intellectual Property Practice Group of Stroock & Stroock & Lavan LLP. Siegal is a member of this newsletter's Board of Editors.

In Biosig Instruments, Inc. v. Nautilus, Inc. , __ F.3d __, 106 USPQ2d 1554, 2013 WL 1776745 (Fed. Cir. 2013), the Federal Circuit held that the functional claim language of “spaced relationship” was definite in view of the inherent parameters of the claimed apparatus, notwithstanding the lack of any specific quantification of exactly how wide the spacing should be. In addition, the Federal Circuit held that functional language may be used to limit patent claims without resorting to the means-plus-function format and that it was acceptable to define “spaced relationship” in terms of the function the spacing was intended to provide.

Biosig Instruments, Inc. (“Biosig”) is the assignee of U.S. Patent No. 5,337,753 (“the '753 patent”), which relates to grip activated heart rate monitors associated with exercise equipment, which are now ubiquitous on treadmills, step climbers and excercycles. The invention purportedly eliminates noise signals that interfere with the process of detecting a user's heart rate. Prior art monitors allegedly did not eliminate signals given off by skeletal muscles (“electromyogram” or “EMG” signals), which are caused 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 interfere with ECG signals, making it difficult to determine heart rate during exercise.

The '753 patent discloses a heart rate monitor mounted on exercise equipment. A user's left and right hands each contact both a live electrode and a common electrode on a cylindrical member. The distance between the live electrode and the common electrode is not quantified in terms of a range of distances. Rather, the claims merely require that the two electrodes be in a “spaced relationship”:

Claim 1 is representative and recites the following:

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; '
(emphasis added)

Biosig first sued Nautilus, Inc. (“Nautilus”) for patent infringement in 2004, alleging that Nautilus' exercise equipment included the patented heart monitor device covered by the product claims of the '753 patent. Following two re-examination attempts and a claim construction ruling, Nautilus countered with a motion for summary judgment that the '753 patent was invalid on the grounds that “spaced relationship” rendered those product claims indefinite. The district court agreed and granted Nautilus' motion, holding the '753 patent indefinite under 35 U.S.C. ' 112 as a matter of law.

The Federal Circuit Decision

On appeal, the Federal Circuit reversed, ruling that it was perfectly acceptable to include terms having functional implications in product claims, without the need to employ “means-plus-function” terminology. The Federal Circuit noted that when a claim limitation is defined in functional terms, determining whether the limitation is sufficiently definite depends on the disclosure in the specification and the knowledge of a person of ordinary skill in the art.

The Federal Circuit held that the term “spaced relationship” was not indefinite because those of ordinary skill in the art, having read the patent specification, would understand the boundaries of this term. The Federal Circuit acknowledged that the district court was correct that the specification of the '753 patent did not specifically define “spaced relationship” with the distance between the live and common electrodes. Nevertheless, the Federal Circuit reasoned that the '753 patent's claim language, specification, and the figures illustrating the spaced relationship between the live and common electrodes provided sufficient clarity with respect to its boundaries to those of ordinary skill in the art.

For example, claim 1 required the live and common electrodes to independently detect electrical signals at two distinct points of the hand. Therefore, the distance between the live electrode and the common electrode could not be greater than the width of a user's hand. Also, the electrodes could not be so close that independent signals could not be detected. Thus, the Federal Circuit reasoned, the '753 patent disclosed ” certain inherent parameters of the claimed apparatus, which to a skilled artisan may be sufficient to understand the metes and bounds of 'spaced relationship.'” (emphasis added)

The Federal Circuit also considered the functionality of the claimed heart rate monitor, as recited in claim 1, to support the definiteness of the meaning of “spaced relationship.” For example, claim 1 recites the function of substantially removing EMG signals using the structure of the claimed elongate member, the live electrode, and the common electrode. The Federal Circuit considered it significant that the Patent Office Examiner found the function to be “crucial” as a reason for overcoming the prior art and confirming the patentability of the asserted claims upon re-examination. “Thus, the recitation of this function in claim 1 is highly relevant in ascertaining the proper bounds of the “spaced relationship” between the live and common electrodes.” (emphasis added).

Accordingly, the Federal Circuit concluded that the claim provided sufficient parameters for one of ordinary skill to determine the metes and bounds of the spaced relationship limitation, even if some experimentation was needed:

In summary, the claims provide inherent parameters sufficient for a skilled artisan to understand the 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. Indeed, the test would have included a standard oscilloscope connected to both the inputs and outputs of the differential amplifier to view the signal wave forms and to measure signal characteristics. With this test, configurations could have been determined by analyzing the differential amplifier input and output signals for detecting EMG and ECG signals and observing the substantial removal of EMG signals from ECG signals while simulating an exercise. These parameters constitute the metes and bounds of “spaced relationship” as articulated in the '753 patent. Nothing more rigorous is required under ' 112, ' 2. (emphasis added)

The Federal Circuit also noted that the fact that some experimentation may be necessary to determine the scope of a claim, does not render the claims indefinite, as long as the experimentation is not “undue.”

In addition, the court held that objections based on the premise that the '753 patent did not include disclosure sufficiently commensurate with the scope of the claims were not relevant to indefiniteness considerations. For example, when ruling on the definiteness issue, the Federal Circuit was not concerned that different users might have differently sized hands:

inquiries as to the size of the users' hands, placement of fingers, and the “composition of the handle” may be relevant, if at all, to issues that relate to enablement under ' 112, ' 1, not indefiniteness under ' 112, ' 2, because they are directed to the operability of varying embodiments of the claimed heart rate monitor, not to the precision of the claims at issue.

Although Nautilus argued that the specification failed to disclose how a skilled artisan would have determined the parameters for determining the correct spaced relationship, the Federal Circuit disagreed:

Here, the claimed apparatus has inherent parameters where the “spaced relationship” cannot be larger than the width of a user's hand. Additionally, it has been shown that skilled artisans can readily ascertain the bounds of the “spaced relationship” through tests using standard equipment. (emphasis added)

The Federal Circuit explained that the record showed that the variables, including the spacing, size, shape, and material affecting the “spaced relationship” between the electrodes, could be determined by those skilled in the art.

The Federal Circuit also remarked that there is no prohibition on “drafting or defining [product] claims in relation to their functions. ' Indeed, functional language in a means-plus-function format is explicitly authorized by statute. 35 U.S.C. ' 112, ' 6. Functional language may also be used to limit the claims without having the means-plus-function format.”

Nautilus also argued that the claims were indefinite because they claimed both an apparatus and a method of use simultaneously. Nautilus asserted that the claims recited a heart rate monitor, but also recited the step that a user hold the monitor. According to Nautilus, the claims were indefinite because it was unclear whether infringement occurred when the heart rate monitor having the recited structural elements was made, or whether infringement occurred when the user held the handle and contacted the electrodes.

The Federal Circuit was not persuaded and explained that product claims could include functional limitations:

The '753 patent recites apparatus claims with functional limitations that describe the capability of substantially removing EMG signals. Indeed, claim 1 of the '753 patent is clearly limited to a heart rate monitor possessing the recited structure that is capable of substantially removing EMG signals. It is not indefinite. (emphasis added)

Therefore, the Federal Circuit reversed the district court's invalidity determination and held the claims were not indefinite.

Matthew Siegal and Irah Donner are partners in the Intellectual Property Practice Group of Stroock & Stroock & Lavan LLP. Siegal is a member of this newsletter's Board of Editors.