Centrak, Inc. v. Sonitor Technologies, Inc. , 915 F.3d 1360 ( 2019 )


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  •   United States Court of Appeals
    for the Federal Circuit
    ______________________
    CENTRAK, INC.,
    Plaintiff-Appellant
    v.
    SONITOR TECHNOLOGIES, INC.,
    Defendant-Appellee
    ______________________
    2017-2510
    ______________________
    Appeal from the United States District Court for the
    District of Delaware in No. 1:14-cv-00183-RGA, Judge
    Richard G. Andrews.
    ______________________
    Decided: February 14, 2019
    ______________________
    JEFFREY I. KAPLAN, Kaplan, Breyer, Schwarz, LLP,
    Matawan, NJ, argued for plaintiff-appellant. Also repre-
    sented by JOSEPH W. BAIN, Shutts & Bowen LLP, West
    Palm Beach, FL.
    JACK B. BLUMENFELD, Morris, Nichols, Arsht & Tun-
    nell LLP, Wilmington, DE, argued for defendant-appellee.
    Also represented by JENNIFER YING.
    ______________________
    Before REYNA, TARANTO, and CHEN, Circuit Judges.
    2                CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.
    CHEN, Circuit Judge.
    CenTrak, Inc. sued Sonitor Technologies, Inc. for al-
    leged infringement of 
    U.S. Patent No. 8,604,909
     (’909 pa-
    tent), which claims systems for locating and identifying
    portable devices using ultrasonic base stations. The dis-
    trict court granted Sonitor’s motions for summary judg-
    ment that claims 1, 7, 8, 16, 18, 21, 22, and 26 are invalid
    for lack of written description and that claims 1, 7, 8, 16,
    18, 21, and 22 are not infringed. Because the district court
    erred in determining that there were no genuine disputes
    of material fact on both issues, we reverse and remand for
    further proceedings.
    BACKGROUND
    A. Asserted Patent
    The ’909 patent is entitled “Methods and Systems for
    Synchronized Ultrasonic Real Time Location.” The ’909
    patent relates to systems for real-time location (RTL),
    which allow users to locate and identify portable devices in
    a facility. ’909 patent col. 1 ll. 16–19, 23–24. Hospitals, for
    example, might use RTL systems to track equipment and
    patients. The asserted claims generally recite the follow-
    ing components: (1) ultrasonic (US) base stations; (2) port-
    able devices (i.e., tags); (3) a server; (4) radio frequency (RF)
    base stations; and (5) a backbone network that connects the
    server with the RF base stations. See, e.g., 
    id.
     claim 1. The
    ultrasonic base stations can be mounted in various fixed
    locations in a facility, see 
    id.
     col. 4 ll. 37–45, such as rooms
    in a hospital, and the portable devices can be attached to
    people or assets that move between rooms, see 
    id.
     col. 4 ll.
    60–65. Each portable device is configured to detect the ul-
    trasonic location codes from the nearby ultrasonic base sta-
    tions and “transmit an output signal including a portable
    device ID representative of the portable device and the de-
    tected ultrasonic location code.” 
    Id.,
     Abstract. While the
    portable devices receive location codes from ultrasonic base
    stations via ultrasound, they might transmit location and
    CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.                3
    device information via RF to an RF base station. 
    Id.
     col. 2
    ll. 59–62. The RF base station then transmits the location
    and device ID information obtained from the portable de-
    vices to the server. See 
    id.
     col. 2 ll. 56–66.
    To save power, the ultrasonic base stations and porta-
    ble devices do not transmit or receive location information
    constantly; instead, they transmit and receive at predeter-
    mined times. 
    Id.
     col. 3 ll. 56–61. To ensure that the com-
    ponents remain synchronized, the RF base station can
    periodically transmit “timing synchronization information
    (TSI) that may provide a unified time of origin to all nodes
    in the system.” 
    Id.
     col. 3 ll. 51–56.
    Claim 1 is illustrative:
    1. A system for determining a location and an iden-
    tity of a portable device, the system comprising:
    means for transmitting timing synchroni-
    zation information including a plurality of
    RF transceivers coupled to a backbone net-
    work and a time server generating the tim-
    ing synchronization information;
    wherein each of the plurality of RF trans-
    ceivers periodically transmits a request to
    the time server to receive the timing syn-
    chronization information;
    a plurality of stationary ultrasonic base
    stations, each ultrasonic base station con-
    figured to receive the timing synchroniza-
    tion information and to transmit a
    corresponding ultrasonic location code in a
    time period based on the received timing
    synchronization information, each ultra-
    sonic location code representative of a loca-
    tion of the respective ultrasonic base
    station; and
    4                 CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.
    a plurality of portable devices, each porta-
    ble device configured to 1) receive the tim-
    ing synchronization information, 2) detect
    the ultrasonic location codes from the ul-
    trasonic base stations and 3) transmit an
    output signal including a portable device
    ID representative of the portable device
    and the detected location code,
    wherein each portable device is synchro-
    nized to detect the ultrasonic location code
    in the time period based on the received
    timing synchronization information.
    
    Id.
     col. 14 ll. 25–49.
    Notably, while all claims of the ’909 patent recite “ul-
    trasonic” components, the vast majority of the specification
    focuses on infrared (IR) or RF components. See, e.g., 
    id.
     fig.
    1 (depicting infrared base stations labeled “IR-BS”). The
    ’909 patent is a divisional of an application that became
    
    U.S. Patent No. 8,139,945,
     which contains claims that are
    similar to the ones in the ’909 patent but that recite IR
    technology instead of ultrasonic technology for communica-
    tions from the base stations to nearby portable devices.
    Only two sentences of the ’909 patent’s specification dis-
    cuss ultrasonic technology:
    Although IR base stations 106 are described, it
    is contemplated that the base stations 106 may also
    be configured to transmit a corresponding BS-ID by
    an ultrasonic signal, such that base stations 106
    may represent ultrasonic base stations. Accord-
    ingly, portable devices 108 may be configured to in-
    clude an ultrasonic receiver to receive the BS-ID
    from an ultrasonic base station.
    
    Id.
     col. 5 ll. 5–11.
    CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.                 5
    B. Accused Products
    The accused Sonitor Sense system includes three
    pieces of hardware sold by Sonitor: RF “gateways,” ultra-
    sonic location transmitters, and portable locator tags. See
    J.A. 642. Sonitor also provides software for installation on
    a customer’s server hardware. J.A. 491 at 25:8–11. When
    these components are integrated with a customer’s existing
    network and server hardware, CenTrak argues that the re-
    sulting system infringes the ’909 patent.
    The parties dispute whether Sonitor personnel or third
    parties (who might or might not be hired by Sonitor) phys-
    ically install the Sonitor hardware in client hospitals.
    Sonitor’s vice president testified that after the hardware is
    installed, Sonitor personnel go on site and “configure” the
    system. See J.A. 2130 at 27:8–13. CenTrak argues that
    the configuration entails bringing location transmitters
    online as part of a facility’s existing network. Appellant
    Br. 12–13 (citing J.A. 476 at 42:2–14). According to Soni-
    tor’s vice president, Sonitor personnel also perform “data
    entry” in the server to map the locations of various ultra-
    sonic transmitters to their physical locations in a building.
    Appellant Br. 14; J.A. 2745 at 29:5–23.
    C. Procedural History
    CenTrak accuses Sonitor of infringing claims 1, 7, 8, 16,
    18, 21, 22, and 26 of the ’909 patent. CenTrak, Inc. v. Soni-
    tor Techs., Inc., No. CV 14-183-RGA, 
    2017 WL 3730617
    , at
    *1 (D. Del. Aug. 30, 2017). Sonitor does not sell all of the
    hardware necessary to practice the asserted claims, so
    while CenTrak asserted various theories of infringement
    before the district court, on appeal, CenTrak has only pur-
    sued a theory under 
    35 U.S.C. § 271
    (a) that Sonitor
    “makes” infringing systems when it installs and configures
    the Sonitor Sense system. See Appellant Br. 1, 23. Cen-
    Trak asserts only direct infringement. J.A. 2823 at 47:3–
    5.
    6               CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.
    Sonitor filed motions for summary judgment of non-in-
    fringement, J.A. 89, and invalidity for lack of written de-
    scription and enablement, J.A. 3831. 1
    Sonitor’s main non-infringement argument was that
    Sonitor does not make, use, or sell certain elements recited
    in the claims, including the required backbone network,
    Wi-Fi access points, or server hardware. J.A. 95. CenTrak
    responded that the party assembling components into the
    claimed assembly “makes” the patented invention, even
    when someone else supplies most of the components.
    J.A. 129. The district court ordered supplemental briefing
    so that CenTrak could identify evidence in support of its
    “final assembler” theory. See J.A. 2826–27 at 61:21–62:9.
    Regarding written description, Sonitor argued that the
    two sentences in the specification dedicated to ultrasound,
    quoted above, did not show that the inventors had posses-
    sion of an ultrasound-based RTL system. See J.A. 3839–
    49.
    The district court granted summary judgment of non-
    infringement. It held that a defendant must be the actor
    who assembles the entire claimed system to be liable for
    direct infringement, and CenTrak had not submitted proof
    that Sonitor personnel had made an infringing assembly.
    CenTrak, 
    2017 WL 3730617
    , at *6. The district court also
    ruled that CenTrak’s infringement theory based on Sonitor
    allegedly undertaking the final act that completes assem-
    bly by “assigning location codes” was “entirely new.” 
    Id.
     at
    *5 n.3. The district court ruled that even if it were to con-
    sider this theory, “[s]imply entering the data into a server
    does not constitute making the physical system claimed in
    the ’909 patent.” 
    Id.
    1   Sonitor moved for summary judgment of non-in-
    fringement on all asserted claims except claim 26. It di-
    rected its invalidity motion to all asserted claims.
    CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.                   7
    Regarding invalidity, the district court ruled that while
    the specification “contemplated” ultrasound, “[m]ere con-
    templation . . . is not sufficient to meet the written descrip-
    tion requirement.” 
    Id. at *8
    . The district court reasoned
    that “electromagnetic radiation and sound waves are not
    simply two species of the same genus; rather these are two
    completely different types of phenomena” and that “one
    could not simply drop [an ultrasonic] transmitter into the
    system as disclosed in the specification and have a func-
    tioning [ultrasonic] system.” 
    Id.
     Accordingly, it granted
    summary judgment that CenTrak’s claims did not satisfy
    the written description requirement. 
    Id. at *9
    . The district
    court did not rule on the issue of enablement, 
    id.
     at *7 n.4,
    and denied other pending motions as moot. 
    Id. at *9
    .
    Sonitor appeals. We have jurisdiction under 
    28 U.S.C. § 1295
    (a)(1).
    DISCUSSION
    A district court’s grant of summary judgment is re-
    viewed under the law of the regional circuit. Profectus
    Tech. LLC v. Huawei Techs. Co., 
    823 F.3d 1375
    , 1379 (Fed.
    Cir. 2016). “The Third Circuit reviews grants and denials
    of motions for summary judgment de novo, applying the
    same standard of review as the district court.” Mo-
    bileMedia Ideas LLC v. Apple Inc., 
    780 F.3d 1159
    , 1164
    (Fed. Cir. 2015) (citing Gonzalez v. Sec’y of Dep’t of Home-
    land Sec., 
    678 F.3d 254
    , 257 (3d Cir. 2012)). When review-
    ing a grant of summary judgment, we view the facts in the
    light most favorable to the nonmoving party and draw all
    inferences in that party’s favor. Gonzalez, 678 F.3d at 257.
    A. Written Description
    We have held that “the test for sufficiency” of a patent’s
    written description “is whether the disclosure of the appli-
    cation relied upon reasonably conveys to those skilled in
    the art that the inventor had possession of the claimed sub-
    ject matter as of the filing date.” Ariad Pharm., Inc. v. Eli
    8                CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.
    Lilly & Co., 
    598 F.3d 1336
    , 1351 (Fed. Cir. 2010) (en banc).
    “[T]he test requires an objective inquiry into the four cor-
    ners of the specification from the perspective of a person of
    ordinary skill in the art. Based on that inquiry, the speci-
    fication must describe an invention understandable to that
    skilled artisan and show that the inventor actually in-
    vented the invention claimed.” 
    Id.
     A “mere wish or plan”
    for obtaining the claimed invention does not satisfy the
    written description requirement. Regents of the Univ. of
    Cal. v. Eli Lilly & Co., 
    119 F.3d 1559
    , 1566 (Fed. Cir. 1997).
    The issue of whether a claimed invention satisfies the writ-
    ten description requirement is a question of fact. Ariad,
    
    598 F.3d at 1351
    .
    The district court determined that the ’909 patent
    lacked adequate written description support for an RTL
    system that relied on ultrasound-based communication
    from the base stations to the portable devices. The district
    court found that IR and ultrasound are “fundamentally dif-
    ferent” technologies, in part because IR radiation travels at
    approximately 300 million meters per second, while ultra-
    sonic sound waves propagate at approximately 340 meters
    per second in air. CenTrak, 
    2017 WL 3730617
    , at *8. Be-
    cause “[t]iming is critical to the technology disclosed in the
    ’909 patent,” the district court found, these speed differ-
    ences “would necessarily require a significantly different
    solution if implemented using IR than if [ultrasound] were
    used.” 
    Id. at *9
    . The district court also cited inventor tes-
    timony that interference from reflection and echoes is dif-
    ferent in IR and ultrasonic systems. 
    Id.
     (citing J.A. 442).
    The district court reasoned that because the ’909 patent’s
    written description does not discuss how to address propa-
    gation delays or interference in ultrasonic systems, the pa-
    tent does not show that the inventors had possession of the
    claimed invention as of the filing date. 
    Id.
    CenTrak argues that the district court’s written de-
    scription ruling erred by effectively requiring the specifica-
    tion to disclose basic, routine implementation details for
    CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.                   9
    how a portable device can receive location and timing syn-
    chronization information from a neighboring base station
    using an ultrasound signal. In CenTrak’s view, a skilled
    artisan reading the ’909 patent’s specification, with an un-
    derstanding of the basics of IR and ultrasonic signals,
    would understand that the inventors had possession of
    RTL systems that could use either IR or ultrasound, and
    not merely an unformed wish or plan for an ultrasonic al-
    ternative. CenTrak further contends that the district
    court’s invalidity analysis falls more in line with an enable-
    ment theory, which CenTrak believes its claims also sat-
    isfy. 2
    As CenTrak correctly points out, a patented invention
    must satisfy separate written description and enablement
    requirements. Ariad, 
    598 F.3d at 1351
    . The governing
    statute states, in relevant part: “The specification shall
    contain a written description of the invention, and of the
    manner and process of making and using it, in such full,
    clear, concise, and exact terms as to enable any person
    skilled in the art . . . to make and use the same . . . .” 
    35 U.S.C. § 112
    , ¶ 1 (2006). 3 One purpose of this statutory
    provision is to require an inventor to provide sufficient de-
    tail in a patent’s specification to enable a person of ordinary
    skill in the art to make and use the invention. But a sepa-
    rate purpose of this text “is to ‘ensure that the scope of the
    right to exclude, as set forth in the claims, does not over-
    reach the scope of the inventor’s contribution to the field of
    2    As noted above, the district court declined to reach
    the parties’ enablement arguments on summary judgment.
    3    Because the application resulting in the ’909 pa-
    tent was filed before September 16, 2012, the effective date
    of the amendments to 
    35 U.S.C. § 112
     enacted in the
    Leahy–Smith America Invents Act (AIA), Pub. L. No. 112–
    29, § 4(c), (e), 
    125 Stat. 284
    , 296, 297 (2011) we refer to the
    pre-AIA version of § 112.
    10               CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.
    art as described in the patent specification.’” Univ. of Roch-
    ester v. G.D. Searle & Co., 
    358 F.3d 916
    , 920 (Fed. Cir.
    2004) (quoting Reiffin v. Microsoft Corp., 
    214 F.3d 1342
    ,
    1345 (Fed. Cir. 2000)). Thus, we have explained, “written
    description is about whether the skilled reader of the pa-
    tent disclosure can recognize that what was claimed corre-
    sponds to what was described; it is not about whether the
    patentee has proven to the skilled reader that the inven-
    tion works, or how to make it work, which is an enablement
    issue.” Alcon Research Ltd. v. Barr Labs., Inc., 
    745 F.3d 1180
    , 1191 (Fed. Cir. 2014).
    In this case, genuine issues of material fact remain as
    to whether disclosure of the implementation details that
    the district court identified is necessary to satisfy the writ-
    ten description requirement. The considerations relied on
    by the district court and Sonitor do not compel summary
    judgment for lack of written description. As an initial mat-
    ter, the district court leaned heavily on the fact that the
    specification devoted relatively less attention to the ultra-
    sonic embodiment compared to the infrared embodiment.
    But in ScriptPro LLC v. Innovation Associates, Inc., 
    833 F.3d 1336
    , 1341 (Fed. Cir. 2016), we explained that “a spec-
    ification’s focus on one particular embodiment or purpose
    cannot limit the described invention where that specifica-
    tion expressly contemplates other embodiments or pur-
    poses.”
    Here, as in ScriptPro, the fact that the bulk of the spec-
    ification discusses a system with infrared components does
    not necessarily mean that the inventors did not also con-
    structively reduce to practice a system with ultrasonic com-
    ponents. Sonitor attempts to distinguish ScriptPro on the
    basis that the specification at issue disclosed multiple prob-
    lems and multiple, exemplary solutions, but “the written
    description requirement does not demand either examples
    or an actual reduction to practice; a constructive reduction
    to practice” may be sufficient if it “identifies the claimed
    CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.                11
    invention” and does so “in a definite way.” Ariad, 
    598 F.3d at 1352
    .
    Sonitor’s citation to cases finding inadequate written
    description to support summary judgment here is unper-
    suasive. The ’909 patent’s disclosure of an ultrasonic em-
    bodiment, albeit brief, distinguishes the instant case from
    Rivera v. International Trade Commission, 
    857 F.3d 1315
    ,
    1322 (Fed. Cir. 2017), in which we affirmed an invalidity
    finding because the specification at issue did not make any
    mention of the later-claimed container with an integrated
    filter and thus did not provide written description for such
    a container.
    The ’909 patent’s express disclosure also distinguishes
    this case from Lockwood v. American Airlines, Inc., 
    107 F.3d 1565
     (Fed. Cir. 1997), on which Sonitor relies. In
    Lockwood, we affirmed a summary judgment ruling that a
    patent was not entitled to an earlier priority date because
    its parent applications did not make any reference to an
    “individual merchandising apparatus that contained video
    disk players or other equivalent storage means,” which was
    a claimed limitation. 
    Id. at 1572
    . We found that testimony
    by Lockwood’s expert arguing that such a feature “would
    have been apparent to one skilled in the art” was insuffi-
    cient to “raise a genuine issue of material fact” because it
    was undisputed that one of the intervening applications
    did not disclose the claimed feature. 
    Id.
     Here, in contrast,
    the specification at least mentions base stations and receiv-
    ers that use ultrasound, which makes this case distinguish-
    able from Lockwood. 4
    4   Sonitor also argues that the patentee’s original dis-
    closure fails to describe other claimed features such as the
    “ultrasonic detector” recited in claim 7 or “concurrently”
    transmitting ultrasonic location codes as required by claim
    8. Appellee Br. 54. Because the district court did not base
    12               CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.
    Sonitor argues that although the ’909 patent’s specifi-
    cation mentions ultrasonic communication between base
    stations and portable devices, the disclosure is insufficient,
    because, according to Ariad, “generic claim language ap-
    pearing in ipsis verbis in the original specification does not
    satisfy the written description requirement if it fails to sup-
    port the scope of the genus claimed.” 
    598 F.3d at 1350
    .
    While it is true that a specification’s passing reference to
    generic claim language, without more, may not adequately
    support claims to a broad genus, we do not believe that
    CenTrak’s claims to an ultrasonic RTL embodiment are
    akin to claiming a vast genus based on a limited disclosure
    of a species. The district court’s analysis ignores the fact
    that at least some components recited in the claims, such
    as the “RF transceivers” and “backbone network” recited in
    claim 1, do not depend on IR or ultrasound. The question
    here is the level of detail the ’909 patent’s specification
    must contain, beyond disclosing that ultrasonic signals can
    be used, to adequately convey to a skilled artisan that the
    inventors possessed an ultrasonic embodiment. As we ex-
    plained in Ariad, “the level of detail required to satisfy the
    written description requirement varies depending on the
    nature and scope of the claims and on the complexity and
    predictability of the relevant technology.” 
    Id. at 1351
    .
    In this case, the parties disputed the complexity and
    predictability of ultrasonic RTL systems, and the district
    court erred at the summary judgment stage by not suffi-
    ciently crediting testimony from CenTrak’s expert that the
    differences between IR and ultrasound, when used to
    transmit small amounts of data over short distances, are
    incidental to carrying out the claimed invention. Cen-
    Trak’s expert opined that “[a] 2 byte location code would
    allow identification of up to 65,000 different locations” and
    its decision on these limitations, we do not address them in
    the first instance on appeal.
    CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.                  13
    that “transmitting 2 bytes of ultrasonic data, regardless of
    the transmission speed, would certainly pose no obstacle
    and require no special instructions for a POSITA [person
    of ordinary skill in the art] using a standard ultrasonic
    transmitter at the time of the invention.” J.A. 882. He also
    opined that “[t]iming synchronization can be derived from
    . . . almost any amount of information ranging from a sin-
    gle start bit up to several bytes of date/time or timing offset
    data” and that “receiving several bytes of data from an ul-
    trasonic signal would pose no obstacle . . . using a standard
    [u]ltrasonic receiver.” J.A. 883. In the context of the ’909
    patent, the expert characterized IR and ultrasonic technol-
    ogies as “interchangeable.” J.A. 901. Indeed, CenTrak
    points out that many features of the claimed system, such
    as the backbone network, time server, and RF transmitters
    do not depend on whether the base stations in each room
    communicate with portable tags using IR or ultrasound.
    On the other hand, Sonitor’s expert opined that the speed
    of ultrasonic signals “is roughly a million times slower than
    light,” J.A. 1414, and that “ultrasound would take hun-
    dreds of times longer than infrared to transmit the same
    amount of data,” J.A. 1416. Moreover, Sonitor argues that
    “[t]he specification is entirely silent about the structure of
    ultrasonic base stations or receivers.” Appellee Br. 50. But
    the testimony from CenTrak’s expert cited above suggests
    that those details were not particularly complex or unpre-
    dictable, and Sonitor does not explain why a person of or-
    dinary skill in the art would need to see such details in the
    specification to find that the named inventors actually in-
    vented the claimed system. This, at the very least, pre-
    sents a material factual issue still in dispute.
    Putting aside the testimony of CenTrak’s expert, Soni-
    tor argues that the named inventors actually admitted that
    the ’909 patent’s specification does not disclose certain ul-
    trasonic limitations. For example, one of the inventors, Dr.
    Amir, testified as follows:
    14                CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.
    Q. But there’s no ultrasonic portable device that is
    actually described in the ’909 patent; right?
    A. This is correct, yeah.
    Q. And there’s no ultrasonic base station that is ac-
    tually described in the ’909 patent; correct?
    A. Yes. It’s not explicitly, correct.
    J.A. 447 at 166:24–167:5. In another exchange, however,
    Dr. Amir suggested that it would be simple for a person of
    ordinary skill to adjust for the differences between IR and
    ultrasound:
    Q. And nothing in the ’909 patent teaches a person
    specifically how to create or develop an RTLS sys-
    tem using ultrasonic signals; correct?
    THE WITNESS: I disagree with you because I
    think it’s almost like -- I can think about some ex-
    ample, but I can’t think of it right now. The teach-
    ing -- once you have the teaching of the concept, the
    reduction to practice is immediate. I don’t explain
    how to really even do the IR to this extent.[5] The
    only thing that’s missing is understanding the rel-
    ative ratios and understanding how ultrasound
    propagates to make it work. You have to under-
    stand how to drive an ultrasonic transmitter, how
    to receive an ultrasonic signal, and how to process
    them. But this is known art to people who are
    knowing ultrasound.
    Q. But none of that knowledge of ultrasound is in
    your ’909 patent; correct?
    5   Sonitor disputes Dr. Amir’s suggestion that the
    level of detail in ’909 patent regarding IR and ultrasound
    is similar. See Appellee Br. 31; ’909 patent col. 13 l. 20–
    col. 14 l. 16.
    CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.                 15
    A. Correct.
    J.A. 447 at 167:6–168:1 (objection omitted).
    Although Sonitor seems to treat this testimony as con-
    clusive proof that the inventors did not “possess” an ultra-
    sonic RTL system, we do not read this testimony as an
    admission, as a matter of law, that the specification does
    not adequately describe an ultrasonic embodiment. In con-
    text, a reasonable fact finder could interpret Dr. Amir’s tes-
    timony not as a legal conclusion regarding written
    description, but as an acknowledgement that the specifica-
    tion did not literally detail the inner workings of ultrasonic
    devices or identify particular examples of such devices be-
    cause such details were known to skilled artisans and not
    part of the inventors’ inventive contribution. As explained
    above, however, it is not clear to us that a person of ordi-
    nary skill in the art would require disclosure of such details
    to find that the named inventors actually invented an ul-
    trasonic embodiment.
    Based on the evidence of record, there is a material dis-
    pute of fact as to whether the named inventors actually
    possessed an ultrasonic RTL system at the time they filed
    their patent application or whether they were “leaving it to
    the . . . industry to complete an unfinished invention.” No-
    vozymes A/S v. DuPont Nutrition Biosciences APS, 
    723 F.3d 1336
    , 1350 (Fed. Cir. 2013) (quoting Ariad, 
    598 F.3d at 1353
    ). Thus, the district court erred in granting sum-
    mary judgment.
    B. Enablement
    Sonitor argues that if we reverse the district court on
    written description, we should nevertheless rule that the
    asserted claims are invalid for lack of enablement. The dis-
    trict court concluded that it need not consider enablement
    because of its written description ruling. CenTrak, 
    2017 WL 3730617
    , at *7 n.4. Although an “appellee may, with-
    out taking a cross-appeal, urge in support of a decree any
    16              CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.
    matter appearing in the record,” United States v. Am. Ry.
    Express Co., 
    265 U.S. 425
    , 435 (1924), in this case we de-
    cline to reach the question of enablement for the first time
    on appeal, see TypeRight Keyboard Corp. v. Microsoft
    Corp., 
    374 F.3d 1151
    , 1160 (Fed. Cir. 2004) (reversing sum-
    mary judgment of obviousness and declining to reach issue
    of non-infringement that district court had not addressed).
    C. Infringement
    CenTrak argues that the district court applied an in-
    correct legal standard to the infringement question and
    that Sonitor makes a system covered by the claims when it
    completes the installation of the Sonitor Sense system in a
    hospital. 6 Sonitor responds that we should reject Cen-
    Trak’s “final assembly” theory as untimely, that the dis-
    trict court applied the correct legal standard, and that
    CenTrak failed to present sufficient evidence to prove in-
    fringement. We address each of these issues in turn.
    1. Timeliness
    Sonitor argues that we should not consider CenTrak’s
    “final assembly” theory—the main infringement theory
    that CenTrak presents on appeal—because CenTrak did
    not timely present it to the district court. As explained be-
    low, we find Sonitor’s argument unpersuasive.
    On appeal, CenTrak presents a range of arguments for
    how Sonitor infringes the claimed system. First, CenTrak
    argues that the conduct of Sonitor’s customers in installing
    the claimed backbone network, RF transceivers (wireless
    access points), and other hardware is attributable to Soni-
    tor. Second, CenTrak argues that Sonitor personnel
    6  CenTrak also asserted an infringement theory be-
    fore the district court based on “using” the claimed system,
    but CenTrak’s appellate briefs only pursue a theory based
    on Sonitor “making” an infringing system.
    CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.                 17
    configure ultrasonic location transmitters to work with
    customers’ networks. Third, CenTrak argues that Sonitor
    personnel enter into the Sonitor server a system of location
    codes and corresponding physical locations at which each
    ultrasonic location transmitter was installed.
    Sonitor concedes that CenTrak presented its first argu-
    ment regarding installation-as-infringement in its opposi-
    tion brief to Sonitor’s summary judgment motion, see
    Appellee Br. 38; J.A. 130, but Sonitor argues that CenTrak
    did not present its second or third arguments regarding
    configuration and entering location codes during summary
    judgment briefing. We disagree with Sonitor and find that
    CenTrak’s arguments were adequately preserved. Cen-
    Trak’s district court opposition brief argues that the instal-
    lation process for an accused system involves, among other
    things, “installing the software to make the Sonitor server”
    and “integrating the entire system into the customer’s net-
    work.” J.A. 127–28. This argument, while briefly pre-
    sented, is substantially the same as CenTrak’s
    “configuration” argument on appeal. See Appellant Br. 26
    (citing testimony that Sonitor’s vice president “assists the
    Sonitor support team if they are doing an installation and
    have trouble getting the installed devices to come on line
    on the [customers] network.” (emphasis and internal quo-
    tation marks omitted)). CenTrak also argued, with cita-
    tions to deposition testimony, that Sonitor “personnel also
    enter the location data on the virtual server . . . where the
    Sonitor software was installed during installation.” Cen-
    Trak, 
    2017 WL 3730617
    , at *5 (quoting J.A. 128); J.A. 2745
    at 29:2–23. CenTrak further argued that “the party assem-
    bling components into the claimed operable assembly is the
    direct infringer making the patented invention, even when
    most or all of those components are supplied by other par-
    ties.” J.A. 129 (citing Cross Med. Prods., Inc. v. Medtronic
    Sofamor Danek, Inc., 
    424 F.3d 1293
    , 1311 (Fed. Cir. 2005)).
    In context, CenTrak’s opposition brief was arguing that
    Sonitor performed the final setup to create a completed,
    18              CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.
    infringing system. Thus, we disagree with Sonitor’s con-
    tention that CenTrak’s configuration and location code ar-
    guments did not appear in CenTrak’s summary judgment
    briefs. 7
    We are also unpersuaded by Sonitor’s argument that
    CenTrak failed to present its infringement theories based
    on “making” during discovery. CenTrak’s First Amended
    Complaint accuses Sonitor of infringing by “making, using,
    marketing, testing, selling, installing, supporting or im-
    porting . . . the Sonitor Sense™ RTLS.” J.A. 56 ¶ 30.
    While mere allegations in an unverified complaint gener-
    ally cannot defeat summary judgment, CenTrak’s expert
    also supported CenTrak’s position, opining that
    “SONITOR either provides or configures every component
    of the SONITOR Sense system” and that all ultrasonic lo-
    cation transmitters “are provided and configured by
    SONITOR.” J.A. 797. He further opined that “each of the
    components of the SONITOR Sense portion of the backbone
    is configured by SONITOR.” J.A. 798. We are troubled by
    CenTrak’s incomplete response to Sonitor’s interrogatory
    seeking CenTrak’s infringement contentions, which does
    not specify “the supplier, vendor, or other entity that pro-
    vides such product, service, software, function, or [accused]
    instrumentality,” as Sonitor requested. J.A. 1742–43; see
    J.A. 2133–81. However, it does not appear that Sonitor
    moved to compel a more complete response or argued that
    the district court should disregard portions of CenTrak’s
    summary judgment opposition brief that went beyond the
    scope of its interrogatory response. Under these circum-
    stances, we cannot say that CenTrak failed to preserve its
    infringement arguments for appeal.
    7  Additionally, the district court was mistaken when
    it characterized CenTrak’s location code argument as “an
    entirely new theory of infringement.” CenTrak, 
    2017 WL 3730617
    , at *5 n.3.
    CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.                19
    2. Infringement by Final Assembly
    “Infringement is a question of fact.” Medgraph, Inc. v.
    Medtronic, Inc., 
    843 F.3d 942
    , 949 (Fed. Cir. 2016). Direct
    infringement can be found when a defendant makes a prod-
    uct containing “each and every limitation set forth in a
    claim.” Cross Med., 
    424 F.3d at 1310
    .
    The district court found that CenTrak did not present
    sufficient evidence to raise a triable issue of fact as to
    whether Sonitor makes infringing systems. It is undis-
    puted that Sonitor does not provide certain claimed ele-
    ments in the accused systems, such as a backbone network,
    Wi-Fi access points, or server hardware. Moreover, the dis-
    trict court analyzed the evidence CenTrak offered and con-
    cluded that no reasonable jury could find that Sonitor
    “made” the claimed invention by performing installations.
    See CenTrak, 
    2017 WL 3730617
    , at *4–6.
    The district court and Sonitor relied on Centillion Data
    Systems, LLC v. Qwest Communications International,
    Inc., 
    631 F.3d 1279
     (Fed. Cir. 2011) for the proposition that
    to “make” a system, a single entity must assemble the en-
    tire system itself. CenTrak, 
    2017 WL 3730617
    , at *6. In
    Centillion, we held that Qwest, which provided software to
    customers, did not “make” a patented phone billing system
    requiring a “back-end” system maintained by a service pro-
    vider and a “front-end” system maintained by an end user.
    631 F.3d at 1288. We explained that “to ‘make’ the system
    under § 271(a), Qwest would need to combine all of the
    claim elements” but that “[t]he customer, not Qwest, com-
    pletes the system by providing the ‘personal computer data
    processing means’ and installing the client software.” Id.
    Sonitor argues that like Qwest, it does not directly infringe
    because it makes only part of a claimed system.
    Sonitor and the district court misunderstand Cen-
    Trak’s argument. CenTrak’s infringement theory is com-
    paring Sonitor not to the software maker Qwest, but to
    Qwest’s customers, who completed the claimed system by
    20              CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.
    installing Qwest’s software onto their own hardware.
    Qwest’s customers were not named defendants in Centil-
    lion, 8 and thus, according to CenTrak, Centillion does not
    rule out CenTrak’s infringement theory. In this case, Cen-
    Trak argues that the final, missing elements are the con-
    figuration that allows the location transmitters to work
    with the network and the location codes that are entered
    into the Sonitor server. According to CenTrak, admissible
    evidence that Sonitor is the “final assembler” raises a tria-
    ble issue of fact on infringement even though Sonitor does
    not “make” each of the claimed components of the accused
    systems.
    CenTrak primarily relies on two cases in support of its
    argument that Sonitor infringes when it performs an act
    that completes an infringing assembly. In Cross Medical,
    we analyzed claims to surgical implants that would in-
    fringe when brought in contact with a patient’s bone. We
    held that Medtronic, the manufacturer of the accused de-
    vice, did not infringe because it “does not itself make an
    apparatus with the ‘interface’ portion in contact with
    bone.” 
    424 F.3d at 1311
    . Instead, we explained, “if anyone
    makes the claimed apparatus, it is the surgeons” who in-
    stalled the devices. 
    Id.
    Sonitor argues that, like Medtronic, it does not make
    the entire system alleged to infringe. But Sonitor’s argu-
    ment misses the mark again because CenTrak is arguing
    that Sonitor stands in the shoes of the surgeons, who acted
    as potentially infringing final assemblers in Cross Medical,
    and not in the position of the medical device maker.
    8  We also held in Centillion that Qwest was not vi-
    cariously liable for its customers’ conduct. 631 F.3d at
    1288. CenTrak’s “final assembly” theory focuses solely on
    Sonitor’s actions, not those of its customers or others.
    CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.                 21
    CenTrak also cites Lifetime Industries, Inc. v. Trim-
    Lok, Inc., 
    869 F.3d 1372
     (Fed. Cir. 2017), in which we ana-
    lyzed claims to a two-part seal used on a recreational vehi-
    cle with a slide-out room. The defendant made only the
    seal, not the RV, but we held that an allegation that the
    defendant installed the seal on an RV was sufficient to
    state a claim for direct infringement:
    Although Lifetime did not allege that Trim-Lok
    made the RV onto which it installed the seal, Life-
    time did allege that Trim-Lok installed the seal
    onto the RV; that is, Lifetime alleged that Trim-
    Lok made an infringing seal-RV combination. Be-
    cause Lifetime alleged that an agent of Trim-Lok
    installed the seal onto the RV, and that the result-
    ing seal-RV combination infringed the ’590 patent,
    it alleged that Trim-Lok directly infringed in a
    manner consistent with our precedents holding
    that assembling the components of an invention is
    an infringing act of making the invention.
    
    Id. at 1378
     (citation omitted).
    Sonitor responds that Lifetime involved a motion to dis-
    miss rather than summary judgment and that CenTrak
    has provided insufficient proof of infringement. But Soni-
    tor does not challenge the core holding of Lifetime that as
    long as a defendant adds the final limitations to complete
    a claimed combination, the defendant infringes. Under
    Lifetime and Cross Medical, a final assembler can be liable
    for making an infringing combination—assuming the evi-
    dence supports such a finding—even if it does not make
    each individual component element.
    3. CenTrak’s Infringement Evidence
    With the above framework in mind, we find that Cen-
    Trak’s cited evidence raises a triable issue of fact regarding
    infringement.
    22              CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.
    On the question of whether Sonitor or its agents phys-
    ically install components of the accused systems, a Sonitor
    employee testified that Sonitor employees “aren’t the main
    installers typically.” J.A. 2775 at 77:16–22 (emphasis
    added). But the witness noted that Sonitor’s vice president
    of technical and customer support “oversees the installa-
    tion.” J.A. 2770 at 25:4–9, 18–24. Sonitor’s VP testified
    that “resellers or a subcontractor” perform the installation.
    Appellee Br. 43 (quoting J.A. 2130 at 27:22–23). The dis-
    trict court noted testimony that Sonitor has “integration
    agreement[s]” with third parties. CenTrak, 
    2017 WL 3730617
    , at *5 (citing J.A. 2772–73 at 62:24–63:8). The
    district court found this evidence insufficient to create a
    material issue of fact, but we disagree. Part of CenTrak’s
    infringement theory is that Sonitor “integrat[es] the entire
    system into the customer’s network.” J.A. 128. An “inte-
    gration agreement” could constitute circumstantial evi-
    dence that Sonitor hired a contractor to build at least part
    of an infringing system.
    But even if a third party who does not work for Sonitor
    installed all claimed hardware, CenTrak argues that Soni-
    tor would still infringe by configuring the Sonitor ultra-
    sonic location transmitters to integrate with the customer’s
    network and by entering location codes into the Sonitor
    server software to associate location transmitters with lo-
    cations in the facility. CenTrak notes that claim 1 contains
    a limitation requiring the base stations to be “configured to
    . . . transmit a corresponding ultrasonic location code . . .
    each ultrasonic location code representative of a location of
    the respective ultrasonic base station.” According to Cen-
    Trak, the accused system is not an operable assembly until
    it is configured.
    CenTrak cites testimony from Sonitor’s VP that Soni-
    tor employees “go on site and configure our system.”
    J.A. 2130 at 27:8–11. The VP further testified that before
    a system “goes live,” Sonitor employees will take drawings
    prepared by an “installation company . . . illustrating what
    CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.                  23
    devices were put into which locations” and that Sonitor will
    then “take that data and create a system with it, that sys-
    tem is then put into the server on site.” Appellant Br. 27
    (quoting J.A. 2745 at 29:5–23). He further testified that
    Sonitor personnel “are the ones who do the data entry for
    that system and then they go out and tune the system to
    ensure it functions normally.” 
    Id.
     Based on this testimony,
    a reasonable jury could find that before an accused Sonitor
    system goes online, Sonitor personnel complete at least a
    portion of the final system configuration and software
    setup necessary to make the system work—in other words,
    that Sonitor makes a combination of hardware and soft-
    ware that is “configured” to infringe.
    CenTrak argues that based on Sonitor’s failure to dis-
    pute CenTrak’s configuration and data entry evidence, the
    district court should have granted summary judgment of
    infringement in favor of CenTrak. This argument does not
    address the fact that the district court declined to analyze
    all of Sonitor’s non-infringement defenses in light of its rul-
    ing regarding “making.” CenTrak, 
    2017 WL 3730617
    , at *4
    n.2. Moreover, the record before us does not conclusively
    show who installs each claimed element or who, if anyone,
    completes an infringing combination. Thus, we decline
    CenTrak’s request for an order that the district court grant
    partial summary judgment of infringement. Moreover, we
    need not decide whether CenTrak’s request for summary
    judgment, which CenTrak made in its opposition brief to
    Sonitor’s motion for summary judgment and not in a sepa-
    rate filing, was procedurally proper. CenTrak’s motion to
    consider additional authority (ECF No. 72) is denied as
    moot.
    Based on the record before us, the district court erred
    in ruling that there were no genuine issues of material fact
    and that Sonitor was entitled to summary judgment on the
    24               CENTRAK, INC. v. SONITOR TECHNOLOGIES, INC.
    issue of “making.” 9 We therefore reverse and remand for
    further proceedings.
    REVERSED AND REMANDED
    COSTS
    Costs to Appellant.
    9   CenTrak argues that on remand, it should be al-
    lowed to take additional discovery to address an argument
    it claims Sonitor made for the first time after summary
    judgment briefing was complete, namely, that Sonitor per-
    sonnel do not install any accused hardware. We do not
    agree that this argument was untimely. The record shows
    that Sonitor served an interrogatory response during dis-
    covery stating: “Sonitor has not infringed any of the As-
    serted Claims because certain claimed limitations such as
    the ‘backbone network’ are not provided by Sonitor.”
    J.A. 1266. To the extent that CenTrak wanted additional
    detail into which specific elements Sonitor contended were
    provided by others, CenTrak has not explained why the dis-
    trict court’s discovery schedule was insufficient to seek
    such information. Accordingly, we ultimately leave the de-
    cision of whether to reopen discovery to the discretion of
    the district court, but we decline to order the district court
    to reopen discovery on remand.