NOTE: This disposition is nonprecedential.

 

United States Court of Appeals 

for the Federal Circuit ______________________ 

MASIMO CORPORATION,

Appellant

v.

SOTERA WIRELESS, INC.,

Appellee

______________________ 

2022-1393

______________________ 

Appeal from the United States Patent and Trademark 

Office, Patent Trial and Appeal Board in No. IPR2020-

00967.

______________________ 

Decided: October 24, 2023

______________________ 

JEREMIAH HELM, Knobbe, Martens, Olson & Bear, LLP, 

Washington, DC, argued for appellant. Also represented 

by JAROM D. KESLER, STEPHEN W. LARSON, Irvine, CA. 

 RUDOLPH A. TELSCHER, JR., Husch Blackwell LLP, St. 

Louis, MO, argued for appellee. Also represented by 

JENNIFER E. HOEKEL, DAISY MANNING. 

 ______________________ 

Case: 22-1393 Document: 42 Page: 1 Filed: 10/24/2023
2 MASIMO CORPORATION v. SOTERA WIRELESS, INC. 

Before PROST, WALLACH, and CHEN, Circuit Judges.

PROST, Circuit Judge. 

Masimo Corporation (“Masimo”) appeals from an inter 

partes review final written decision determining all claims 

of U.S. Patent No. RE47,244 (“the ’244 patent”) are unpatentable. Sotera Wireless, Inc. v. Masimo Corp., No. 

IPR2020-00967, 2021 WL 6338280 (P.T.A.B. Nov. 19, 2021)

(“Board Decision”). For the following reasons, we affirm.

BACKGROUND

The ’244 patent, titled “Alarm Suspend System,” is assigned to Masimo. It relates to an alarm suspension system for medical alarms where the duration of an alarm 

delay or suspension is responsive to the specific physiological parameter measured. ’244 patent col. 2 l. 18–col. 4. l. 

8. The ’244 patent delays or suspends these alarms “so as 

to prevent unnecessary disturbance to the patient and distraction of the caregiver.” Id. at col. 2 ll. 34–36.

Claims 1, 13, and 18 are independent. Claim 13 is illustrative and states:

A method of electronically delaying or suspending an alarm while an electronically calculated 

measurement of a physiological parameter satisfies an alarm activation threshold, the measurement of the physiological parameter 

responsive to a signal from a noninvasive sensor positioned at a monitored patient, the 

method comprising:

electronically processing a signal from a noninvasive sensor; 

responsive to processing the signal, electronically determining a first measurement of a first 

physiological parameter and a second measurement of a second physiological parameter using 

a patient monitoring device, the patient 

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MASIMO CORPORATION v. SOTERA WIRELESS, INC. 3

monitoring device including a processor and a 

memory device;

electronically storing, using the patient monitoring device, a first parameter-specific alarm 

delay or suspension period of time corresponding to the first physiological parameter and a 

second parameter-specific alarm delay or suspension period of time corresponding to the second physiological parameter, the first 

parameter-specific alarm delay or suspension 

period of time being different from the second 

parameter-specific alarm delay or suspension 

period of time; 

electronically determining, using the patient 

monitoring device, that the first measurement 

of the first physiological parameter satisfies a 

first alarm activation threshold;

electronically initiating, using the patient monitoring device, the first parameter-specific 

alarm delay or suspension period of time; and

electronically activating, using the patient 

monitoring device, a first alarm for the first 

physiological parameter in response to expiration of a first amount of delay or suspension associated with the first parameter-specific alarm 

delay or suspension period of time. 

’244 patent claim 13 (emphasis added).

 Sotera Wireless, Inc. (“Sotera”) petitioned for inter 

partes review of all claims of the ’244 patent. Sotera argued obviousness on four grounds using U.S. Patent No. 

5,865,736 (“Baker”) as a reference and on two grounds using U.S. Patent Publication No. 2005/0038332 (“Saidara”)

as a reference. The Board determined all claims are unpatentable on the Saidara grounds. Masimo timely 

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4 MASIMO CORPORATION v. SOTERA WIRELESS, INC. 

appealed, and we have jurisdiction under 28 U.S.C. 

§ 1295(a)(4)(A). 

DISCUSSION

Masimo argues that the Board erred by incorrectly construing several claims and by improperly concluding that 

the prior art rendered the claims of the ’244 patent obvious. 

Specifically, Masimo argues: (1) that claims 1 and 13 require the noninvasive measurement of two physiological 

parameters; (2) that the Board erred by not giving claim 18 

a means-plus-function construction; and (3) that the Board 

erred by construing the “parameter-specific alarm delay or 

suspension period of time” limitation to encompass only 

pre-alarm delays. Masimo also independently argues that

the Board’s obviousness determinations cannot stand because several of its factual findings are unsupported by 

substantial evidence. We address each argument in turn.

I 

We review the Board’s ultimate claim construction and 

any determinations based on intrinsic evidence de novo 

and review subsidiary factual findings involving extrinsic 

evidence for substantial evidence. Personalized Media 

Commc’ns, LLC v. Apple Inc., 952 F.3d 1336, 1339 (Fed. 

Cir. 2020). We address Masimo’s claim construction arguments in the order discussed above.

A 

Regarding the first claim-construction dispute, 

Masimo argues that the Board erred by determining all 

claims were obvious over Sotera’s proposed combination 

consisting of one physiological parameter measured from a 

noninvasive sensor and another physiological parameter 

measured from an invasive sensor. Claim 13 recites “electronically processing a signal from a noninvasive sensor” 

and “responsive to processing the signal, electronically determining a first measurement of a first physiological parameter and a second measurement of a second 

Case: 22-1393 Document: 42 Page: 4 Filed: 10/24/2023
MASIMO CORPORATION v. SOTERA WIRELESS, INC. 5

physiological parameter.” ’244 patent claim 13. Claim 1 

similarly recites a “noninvasive physiological sensor” configured to output a signal, where “responsive to processing 

the signal,” the system “determine[s] a measurement of a 

physiological parameter based at least in part upon the signal.” Id. at claim 1. Claim 1 also recites “at least one other 

physiological parameter for which the one or more processors are configured to determine at least one measurement.” Id. Claim 8, which depends from claim 1, further 

recites “determin[ing] a measurement of a second physiological parameter based at least in part upon the signal.” 

Id. at claim 8.

Relying on this language, Masimo argues that claims 1 

and 13 require the noninvasive measurement of two different physiological parameters. Appellant’s Br. 23–28. Sotera responds that Masimo did not present this issue as a 

claim-construction dispute before the Board. We agree 

with Sotera. None of Masimo’s arguments before the Board 

presented or implicated a construction for claims 1 or 13 

requiring the noninvasive measurement of two physiological parameters. We therefore conclude that Masimo forfeited this argument.

In its petition, Sotera stated that “Saidara discloses a 

noninvasive sensor.” J.A. 236 (claim 1); see also J.A. 248 

(claim 13). In its preliminary response, Masimo presented 

proposed constructions for several terms, but it did not assert how many parameters must be measured noninvasively in claims 1 and 13. J.A. 303–07. And in its postinstitution patent owner response, Masimo merely stated 

that “Saidara focuses on invasive sensors,” J.A. 549, and 

that Sotera’s expert “admitted Saidara does not teach a 

[skilled artisan] how to monitor blood glucose noninvasively,” J.A. 562 n.7. Thus, the parties’ initial dispute concerned the nature of Saidara’s disclosure—not how many 

parameters must be measured noninvasively.

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6 MASIMO CORPORATION v. SOTERA WIRELESS, INC. 

In the petitioner’s reply, Sotera stated that “Masimo 

does not dispute Saidara discloses noninvasive sensors.” 

J.A. 618 n.7. In the patent owner sur-reply, Masimo noted 

that “[c]laims 1 and 13 require noninvasive sensors,” e.g., 

J.A. 678, and argued that Saidara discloses only invasive 

sensors and monitors, J.A. 676, 678–79. Masimo’s arguments thus again concerned the contents of the prior art 

(namely, whether Saidara disclosed noninvasive sensors)—not how many parameters must be measured noninvasively. 

The Board “recognize[d] [Masimo’s] argument that 

claim 1 recites a noninvasive sensor,” Board Decision, 2021 

WL 6338280, at *25, but concluded that Sotera demonstrated a skilled artisan would have used a noninvasive 

sensor, as described in Sotera’s proposed combination, id.

Masimo’s argument on appeal—that two parameters 

must be measured noninvasively—does not reflect the arguments Masimo made before the Board. Masimo limited 

its arguments before the Board to the disclosures of Sotera’s prior-art combination. Under these circumstances, 

we conclude that Masimo did not make this claim-construction argument before the Board. Masimo has thus forfeited 

this argument. See In re Google Tech. Holdings LLC, 980 

F.3d 858, 864 (Fed. Cir. 2020) (“Even under the most generous of readings, Google’s arguments below did not suggest any definition of ‘network penalty,’ let alone the highly 

particularized definition it presents on appeal.”).

B 

Masimo’s second claim construction argument presents 

an issue about whether Sotera complied with 37 C.F.R. 

§ 42.104(b). We review decisions related to compliance 

with the Board’s procedural requirements for abuse of discretion. Ericsson Inc. v. Intell. Ventures I LLC, 901 F.3d 

1374, 1379 (Fed. Cir. 2018).

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Masimo argues that Sotera’s failure to present a 

means-plus-function construction for the limitation “a 

physiological measurement system comprising: a physiological sensor means . . . .” requires reversing the Board’s 

unpatentability determination for claim 18. We disagree.

Masimo argues that the presence of “means” in claim 

18 necessitates a means-plus-function construction. According to Masimo, Sotera’s failure to present a meansplus-function construction for claim 18 signifies that Sotera’s petition did not comply with 37 C.F.R. § 42.104(b)(3), 

thus prohibiting the Board from determining claim 18 is 

unpatentable. 

Claim 18 does not warrant a means-plus-function construction. Under our precedent, the use of “means” in a 

claim does not require a means-plus-function construction 

where the claim itself provides a sufficiently definite structure. Williamson v. Citrix Online, LLC, 792 F.3d 1339, 

1348–49 (Fed. Cir. 2015) (en banc). Claim 18 recites “a 

physiological sensor means,” while claim 1 recites “a noninvasive physiological sensor.” ’244 patent claims 1, 18. 

Masimo, understandably, does not argue that claim 1 lacks 

a sufficiently definite structure or that the use of “physiological sensor” renders claim 1 indefinite. See Oral Arg. at 

12:22–35, No. 22-1393, https://oralarguments. 

cafc.uscourts.gov/default.aspx?fl=22-1393_08092023.mp3

(agreeing that “physiological sensor” should not be understood as a means-plus-function limitation and that “physiological sensor” does not render claim 1 indefinite). The 

use of “physiological sensor” in claim 1, combined with 

Masimo’s failure to dispute that claim 1 recites adequate 

structure, suggests that a skilled artisan would understand the structure of a physiological sensor from the 

words “physiological sensor” alone. We have determined 

means-plus-function construction is not appropriate in 

similar situations where the limitation preceding “means” 

provides a sufficiently definite structure to a skilled artisan. Lighting Ballast Control LLC v. Philips Elecs. N. Am. 

Case: 22-1393 Document: 42 Page: 7 Filed: 10/24/2023
8 MASIMO CORPORATION v. SOTERA WIRELESS, INC. 

Corp., 790 F.3d 1329, 1338–39 (Fed. Cir. 2015) (concluding 

that a “voltage source means” provides sufficient structure 

where a skilled artisan would understand that the voltage 

source is a class of structures providing direct current voltage); TecSec, Inc. v. Int’l Bus. Machs. Corp., 731 F.3d 1336, 

1347–48 (Fed. Cir. 2013) (concluding that a “system 

memory means” provides sufficient structure for the function of storing data).

We now address the Board’s determination that Sotera 

complied with 37 C.F.R. § 42.104(b)(3) in light of our conclusion that claim 18 does not warrant a means-plus-function construction. Section 42.104(b)(3) states: “Where the 

claim to be construed contains a means-plus-function or 

step-plus-function limitation as permitted by 35 U.S.C. 

§ 112(f), the construction of the claim must identify the specific portions of the specification that describe the structure, material, or acts corresponding to each claimed 

function.” This regulation applies only where the limitation at issue necessitates a mean-plus-function construction. Since we have concluded that claim 18 does not, the 

Board did not abuse its discretion in determining that Sotera complied with this regulation.

C 

Masimo next argues that the Board’s construction of 

the “parameter-specific alarm delay or suspension period 

of time” limitation in claims 1, 13, and 18 was “gratuitous” 

and incorrect. See Appellant’s Br. 50, 59.

Masimo’s argument that the Board gratuitously construed “parameter-specific alarm delay or suspension period of time” is meritless. Sotera petitioned for inter partes 

review on six grounds—four grounds using Baker as a reference and two grounds using Saidara as a reference. Sotera explained in its petition that it was presenting 

alternative grounds for alternative constructions of “parameter-specific alarm delay or suspension period of time.” 

The Baker grounds address obviousness under a 

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MASIMO CORPORATION v. SOTERA WIRELESS, INC. 9

construction where the alarm delay term covers pre-alarm 

delays, while the Saidara grounds address obviousness under a construction where the alarm delay term covers only 

post-alarm delays. J.A. 187 (“Grounds 1–4 [Baker] of this 

Petition are directed to a construction encompassing delays 

before an alarm is activated (i.e., pre-alarm delays), and 

Grounds 5–6 [Saidara] are directed to temporary suspension of active alarms (i.e., post-alarm suspensions).”). The 

Board did not err by construing the “parameter-specific 

alarm delay or suspension period of time” limitation that 

governed which grounds it would analyze in evaluating obviousness.

The Board also correctly construed “parameter-specific 

alarm delay or suspension period of time” to cover only 

post-alarm delays or suspensions. We interpret patent 

claims by looking to the claim language, the specification, 

the prosecution history, and, where relevant, extrinsic evidence. Phillips v. AWH Corp., 415 F.3d 1303, 1314 (Fed. 

Cir. 2005) (en banc). This interpretation is done “in the 

context of the entire patent, including the specification.” 

Id. at 1313.

Here, the claim language itself is not particularly informative. Claims 1, 13, and 18 contain no language elucidating whether the “parameter-specific alarm delay or 

suspension period of time” limitation covers pre-alarm delays or only post-alarm delays, nor do the dependent 

claims. The specification, however, provides significant information regarding the scope of this limitation. The specification is uniform in its description of the alarm delay and 

suspensions as post-alarm delays and suspensions. It refers throughout to the silencing or suspending of audible or 

active alarms and the reactivation of alarms. E.g., ’244 patent Abstract, Fig. 4, col. 2 ll. 33–38, col. 2 ll. 55–57, col. 2 

ll. 61–63, col. 3 ll. 1–6, col. 3 ll. 31–32, col. 3 ll. 34–36, col. 3 

ll. 43–47, col. 3 ll. 58–60, col. 3 l. 65–col. 4 l. 1, col. 4 ll. 46–

48, col. 4 ll. 58–60, col. 5 l. 42, col. 5 ll. 52–65, col. 6 ll. 1–

12. This uniformity of description leads us to conclude that 

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10 MASIMO CORPORATION v. SOTERA WIRELESS, INC. 

the ’244 patent uses “parameter-specific alarm delay or 

suspension period of time” to mean a post-alarm delay or 

suspension. See Trs. of Columbia Univ. v. Symantec Corp., 

811 F.3d 1359, 1368 (Fed. Cir. 2016) (construing “probabilistic model of normal computer system usage” in line with 

the specification’s consistent disclosures). 

We thus affirm the Board’s construction of “parameterspecific alarm delay or suspension period of time.”

II 

We turn now to Masimo’s obviousness arguments. We 

review the Board’s legal conclusion of obviousness de novo 

and review its subsidiary fact findings, including the scope 

and content of the prior art and the presence or absence of 

a motivation to combine, for substantial evidence. Intelligent Bio-Sys., Inc. v. Illumina Cambridge Ltd., 821 F.3d 

1359, 1366 (Fed. Cir. 2016); Randall Mfg. v. Rea, 733 F.3d 

1355, 1362 (Fed. Cir. 2013). 

Masimo first argues that the Board lacked substantial 

evidence to conclude that a skilled artisan would modify 

Saidara by adding a noninvasive pulse oximeter that 

measures blood oxygen levels to Saidara’s sensor set, both 

as to the existence of a motivation to combine and the disclosure of a noninvasive sensor. We disagree. Substantial 

evidence supports the Board’s findings that a skilled artisan would modify Saidara to noninvasively measure blood 

oxygen levels by adding a noninvasive pulse oximeter to 

Saidara’s sensor set. See J.A. 1644 ¶ [0076] (Saidara disclosing the monitoring of multiple physiological parameters); J.A. 1496 ¶ 168 (Sotera’s expert explaining why a 

skilled artisan would make the proposed combination); J.A. 

3936 at 23:2–11 (Masimo’s expert agreeing a skilled artisan would use a noninvasive pulse oximeter to measure 

blood oxygen levels). 

Masimo also argues that the prior art does not disclose 

multiple alarm delay or suspension periods of time for 

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different parameters, as required by the independent 

claims. We disagree and conclude that substantial evidence supports the Board’s findings that the prior art discloses multiple alarm delay or suspension periods of time 

for different parameters. J.A. 1644 ¶ [0073] (Saidara disclosing the use of multiple sensors and multiple measurements); J.A. 1651 ¶ [0133] (Saidara disclosing a multiple 

alarm function for blood sugar levels); J.A. 1498–99, 1501–

02 ¶¶ 174, 178 (Sotera’s expert explaining why a skilled artisan would modify Saidara to use multiple alarm timings); 

J.A. 4237 at 324:3–17 (Masimo’s expert admitting that Saidara discloses multiple sensors measuring multiple physiological characteristics).

CONCLUSION

We have considered Masimo’s remaining arguments 

and find them unpersuasive. For the foregoing reasons, we 

affirm.

AFFIRMED

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