US 11156557

I'll verify this patent against live sources, including checking for any CAFC/litigation activity.

Let me pin down the exact claim set and check for any litigation/PTAB activity.

US 11,156,557 B2 — Verified Summary

Search scope / confidence note: I verified the bibliographic data and text via Google Patents, the USPTO-derived PDF (patentimages), and a USPTO Patent Grants record (EDS/CNU library record). I could not directly query USPTO PatentCenter or the CAFC docket system from this session; my litigation search was general web search. I found no CAFC 2026 docket, no IPR/PTAB proceeding, and no district-court case involving U.S. Patent No. 11,156,557. If a case exists, it did not surface — treat that as "not found," not as proof of none.

Bibliographic data

Note: the assignment record lists the assignors in the order Takao, Fukushima, Hashiguchi, Hoshino, Yanata (Ricoh Company, Ltd., recorded Mar. 16, 2018).

Abstract (verbatim)

A chemiluminescence analyzer includes a reactor to cause waste liquid discharged from a blood purification apparatus to react with a reagent solution, a photodetector to measure an intensity of chemiluminescence arising in the reactor, a first liquid conveyor to convey the waste liquid from a waste liquid passage of the blood purification apparatus to the reactor, and a second liquid conveyor to convey the reagent solution to the reactor. The chemiluminescence analyzer further includes a liquid mixture passage extending from the reactor to convey a liquid mixture including the waste liquid and the reagent solution after reaction, a joint to couple the liquid mixture passage to the waste liquid passage of the blood purification apparatus, and an electric interface for connection with an external device.

Plain-language overview of the independent claims

The patent has 14 claims (confirmed: the EDS record quotes "Claim 14. A blood purification system comprising: a blood purification apparatus; and the chemiluminescence analyzer according to claim 11…"). There appear to be two independent apparatus claims (1 and 11) plus a system-type claim and an apparatus claim at the end. Because I could not retrieve the literal text of every claim, the mapping below is inferred from the specification's "Aspect A"–"Aspect M" summary, which mirrors the claim set; I flag it as inference rather than verbatim claim language.

• Claim 1 — the chemiluminescence analyzer (Aspect A). A urea-measuring chemiluminescence analyzer that (a) has a reactor mixing blood-purification waste liquid with a chemiluminescent reagent, (b) has a photodetector measuring the resulting light, (c) has a first pump/conveyor moving waste liquid from the dialyzer's waste passage into the reactor and a second conveyor moving reagent in, (d) routes the post-reaction liquid mixture out through a joint that ties back into the blood purification apparatus's own waste passage, and (e) has an electrical interface for hooking the analyzer to an external device. The point of the joint is that spent reagent rejoins the dialyzer's drain line, so no separate drain plumbing is needed.

• Claim 11 — the "standalone" analyzer (Aspect B, and the claim 14 depends on it). Same core hardware as claim 1, but expressly adds a controller that drives the photodetector and both liquid conveyors, and a communicator for talking to an external device (PC/server, smartphone). This is the configuration that lets the analyzer run and report results on its own, without being slaved to the host dialyzer's control system.

• Claim 13 — blood purification apparatus (Aspect L). A blood purification apparatus (e.g., a dialyzer) that incorporates the analyzer as its measuring instrument for a target component (urea) concentration in the waste liquid.

• Claim 14 — blood purification system (Aspect M). A system comprising (1) a blood purification apparatus and (2) the chemiluminescence analyzer of claim 11, to measure a target-component concentration in the waste liquid discharged from the blood purification apparatus.

Dependent claims add the secondary features that the specification dwells on: an internal tank to buffer variable waste flow; thermometers (tank liquid thermometer 115a, reagent thermometer 120) and flowmeters (waste liquid flowmeter 117, liquid mixture flowmeter 119) whose readings the controller uses to correct the photodetector signal; upstream/downstream internal passages with a waste liquid port 125 and exit port 128 for quick-connect plumbing; a reagent port 127 for a detachable reagent cartridge; a cleaning and calibration port 126 on the tank; and a non-return valve 124 between tank and joint to stop reacted mixture backflowing into the tank.

Technical problem and stated objects

The specification frames the invention around two problems: (1) conventional chemiluminescence analyzers need per-device power/signal lines, drivers, amplifiers, and a dedicated controller, making them bulky and hard to retrofit into an existing dialyzer; and (2) built-in analyzers produce non-comparable output depending on manufacturer/model. The two stated objects are an easily installable analyzer and unified measurement data regardless of the host dialyzer brand/model. The independent claims mirror this by pairing the analyzer with an electric interface (claim 1) and a controller + communicator (claim 11).

Two drafting artifacts worth flagging

These are in the authoritative text, so I report rather than correct them:

1. The Detailed Description opens with: "particularly to FIG. 1, an image forming apparatus according to an embodiment of this disclosure is described." — an apparent copy-paste leftover from a Ricoh image-forming-apparatus template; the patent is not about an image forming apparatus.
2. The case description reads: "the case … is divided into two cases of the control and communication unit 102 and the control and communication unit 102" — evidently intended to read "the conveyance and reaction unit 101 and the control and communication unit 102."

Prior art of record

Cited references include WO 2012/133394 (also cited in the specification as JP-5637300-B for reactor configurations, alongside JP-4855854-B / JP-2008-014910-A). Prosecution-related documents noted in the record: European Search Report (EP App. 18161057.7, June 5, 2018), Chinese Office Action (CN 201810204161.0, Apr. 21, 2020), and Japanese Office Action (JP 2017-249296, July 13, 2021).

Uncertainty statement: Inventor list, dates, assignee, abstract, and the existence of claims 1/11/13/14 are corroborated across sources. The exact wording of each independent claim beyond what is quoted here is inferred from the "Aspects" summary and should be confirmed against the USPTO PatentCenter full-text claims before being relied on for any legal purpose.

I'll search for litigation involving US patent 11156557 across patent litigation databases.

Let me run more targeted searches on litigation-specific databases.

Let me try a few more litigation-specific sources.

Litigation Search Report — U.S. Patent No. 11,156,557

Bottom line

No litigation involving U.S. Patent No. 11,156,557 was found in any of the sources searched.

I searched for the exact number (11156557, 11,156,557, US11156557B2) across patent-litigation-oriented queries and databases, including the Unified Patents litigation-oriented results surfaced in search, Docket Alarm/Docket Navigator-indexed materials, Justia Dockets, CourtListener RECAP, and general district-court/PTAB coverage. Every "near-miss" hit was for a different patent number or an unrelated matter — full details below so you can see the exact-match discipline applied.

Verification of the patent identity (to confirm the number I searched is the one you mean)

Source: https://patents.google.com/patent/[US11156557B2](/patent/US11156557B2)

Searches performed and what they returned

• US patent 11156557 litigation / 11156557 patent infringement lawsuit — no case citing this patent. The only patent-litigation records returned were for unrelated numbers (e.g., Salix v. Mylan, 1:25-cv-00024, asserting U.S. Pat. Nos. 11,564,912 / 11,779,571 / 8,193,196 etc. — not 11,156,557).
• "11156557" Unified Patents litigation — returned unrelated PTAB/IPR materials (VLSI v. Intel, Dolby v. Unified Patents, ACQIS, etc.); none referenced 11,156,557.
• Ricoh patent 11156557 chemiluminescence analyzer lawsuit defendant — surfaced only Ricoh patent holdings/portfolios and older Ricoh disputes involving other patents (e.g., Round Rock Research v. Ricoh, D. Del. 1:2015-cv-00157; Ricoh v. Oki Data, D. Del. 1:2009-cv-00694; In re Ricoh Patent Litigation, N.D. Cal. 5:03-cv-02289). None assert or reference 11,156,557.
• "11,156,557" ... district court and CourtListener queries — no matching docket.

None of the near-miss results should be read as hits. The recurring "557" references in search output (e.g., Optis/U.S. 8,411,557; Voxer/Meta; SK Hynix/Advanced Memory Technologies, U.S. 7,777,557; ACQIS) are different patents and must not be auto-associated with 11,156,557.

Case list

Scope, limitations, and caveats

1. Negative findings are provisional. If a suit were filed recently and not yet indexable, or if it were filed in a forum with poor public docketing, it could be missed. This is a good-faith negative result, not a guarantee.
2. Unified Patents portal access. I could not directly load the Unified Patents litigation case-list portal (https://portal.unifiedpatents.com/litigation/caselist); the searches returned third-party/PTAB materials referencing Unified rather than portal pages. The absence of a hit there is therefore not dispositive.
3. PTAB/IPR. My searches also did not surface any IPR, PGR, or reexamination against 11,156,557. (Recorded foreign prosecution references — a European Search Report, a Chinese Office Action on CN 201810204161.0, and a Japanese Office Action on JP 2017-249296 — are prosecution documents, not litigation.)
4. To confirm with authoritative dockets, the definitive lookups would be PACER (via the court's CM/ECF), CourtListener/RECAP (https://www.courtlistener.com), Docket Navigator, and the Unified Patents litigation caselist. If you need, I can draft the exact search strings/party queries to run there (e.g., assignee "Ricoh" as plaintiff, and "11,156,557" / "11156557" as asserted patent).

Conclusion: Based on the searches available here, no known litigation (district court, ITC, or PTAB) involves U.S. Patent No. 11,156,557. I recommend an authoritative PACER/Docket Navigator confirmation before relying on this for any filing or clearance opinion.

Proceedings overview

Total AIA trial proceedings on US 11,156,557: 0. The USPTO Open Data Portal returns no IPR, PGR, or CBM for this patent, and my web searches surfaced no petition, institution decision, Final Written Decision, or Federal Circuit appeal naming 11,156,557 — breakdown: 0 active, 0 claims invalidated, 0 claims sustained, 0 settled, 0 institution denials. Bottom line for a defendant: there is no PTAB record to work with. This patent has never been tested at the Board, so every claim is UNTESTED, and you cannot buy a validity defense off the shelf — you would be filing the first petition, on a clean § 315(e) estoppel slate, against a Ricoh-owned patent that (per the structured legal-status data, as an assumption not a legal conclusion) has lapsed for failure to pay maintenance fees.

No proceedings to report

There is no IPR####-##### / PGR####-##### / CBM####-##### number to populate the per-proceeding template with. Manufacturing one would violate the constraint against inventing proceeding numbers, so I am leaving the template empty.

Near-misses I checked and excluded (do not cite these as this patent's history):

• IPR2021-00661, Satco Products, Inc. v. The Regents of the University of California — a different patent, U.S. 10,658,557 B1 ("Transparent light emitting device with light emitting diodes"). Petition filed 2021-04-09; institution denied 2021-11-08 (Paper 14), post-institution fees refunded 2022-01-18. See https://ipverse.greyb.com/ptab-web/cases/case-details/IPR2021-00661 and https://www.docketalarm.com/cases/PTAB/IPR2021-00661/. A search hit for "the '557 patent" refers to this LED patent, not Ricoh's analyzer patent.
• IPR2024-00886 (patent 11,019,557 B2), IPR2019-00611 (patent 8,831,557 B2, Apple), and several district-court "’557 Patent" references (e.g., Optis v. ZTE, the Fadell/Apple line) are all unrelated patents whose last three digits coincide.

Sourcing: the structured "PTAB proceedings on file" block from USPTO ODP supplied to me states no AIA trial proceedings are indexed for this patent as of the most recent ingest; web searches for petitions naming 11156557 returned nothing to contradict it.

Strategic summary

Claim status — everything is untested. No claim of 11,156,557 has been canceled, confirmed, or even construed by the Board. There is no FWD to quote, no claim-level disposition, and therefore no "claims 1–5 are dead" argument available to you. Note that the patent is not short and not narrow: the EDS record shows at least claims 11 and 14 (claim 14 being a blood purification system claim depending from claim 11), and the specification carries a long Aspect A–L list of alternative configurations (tank, thermometers, flowmeters, non-return valve, waste-liquid/exit/reagent ports, cleaning-and-calibration port). That breadth is a real risk factor for a defendant — but also, because nothing has been litigated at the Board, every one of those limitations is an open § 102/§ 103/§ 112 target.

Estoppel landscape — completely clean. Because no petition has ever been filed, § 315(e)(2) estoppel has never attached to anyone. You are not limited by any prior petitioner's grounds, and no "reasonably could have raised" bar constrains your art selection. Conversely, the patent owner has no IPR-tested claim construction to leverage against you — you would go first, which means you also carry first-mover risk (an adverse institution denial does not estop you, but it is public and your § 315(b) one-year clock from service of a complaint is what governs timing).

Pattern signals — none. No repeat petitioner (no party has filed even once), no patent-owner PTAB appeal history, and no evidence of a defensive aggregator (Unified Patents, RPX, etc.) challenging this patent. Ricoh Company, Ltd. is the original and current assignee — a large operating company, not a troll — which is consistent with the absence of IPRs: operating companies with a modest medical-device-side portfolio (this family also has JP 7017077B2 and a US publication US20180266963A1) tend not to attract validity challenges unless they assert.

One flag worth verifying immediately: Google Patents records the legal status as "Expired - Fee Related" with an adjusted expiration of 2040-02-23 (source: https://patents.google.com/patent/US11156557/en). If that reflects a genuine failure to pay a maintenance fee, the patent may already be unenforceable-by-lapse regardless of validity, which would dwarf any IPR analysis. This is expressly a status assumption on Google's part and not a legal conclusion — confirm it in USPTO Patent Center / the maintenance-fee record for application 15/923,526 before advising a client.

Recommended next steps

• There is no PTAB activity to build on. Say that plainly in any opinion letter: the absence of AIA proceedings means no claim of 11,156,557 has been invalidated and no ground is foreclosed — but it is also a signal. Well-asserted patents eventually attract IPRs; this one has never been asserted (no district-court suit naming 11,156,557 surfaced in my searches), which is consistent with a low-profile portfolio patent rather than a litigation weapon.
• Check the maintenance-fee status first. If the "Expired - Fee Related" record is confirmed, the practical defense is lapse/unenforceability, not invalidity, and no IPR petition is needed. Do this against USPTO Patent Center (application 15/923,526) and the fee-history records.
• If you do file, you would be the first petitioner. With no institution decision, no FWD, and no appeal, there are no trial-stage milestones to track and no statutory deadlines running (the § 316(a)(11) one-year clock begins only at institution). Budget for a full petition cycle: POPR, institution decision within ~6 months of the filing date per § 314(b), then FWD within 12 months of institution. Check § 315(b) — the one-year bar runs from service of a complaint alleging infringement of 11,156,557 — and confirm on PTAB E2E (https://ptacts.uspto.gov/) and CourtListener (https://www.courtlistener.com/) whether any complaint, ITC complaint, or CAFC appeal has been filed since ODP's last ingest; those are the filings most likely to appear before ODP indexes them.
• Do not cite IPR2021-00661 in a brief about this patent. It concerns U.S. 10,658,557 (Satco v. Regents of the University of California) and is institution-denied; treating it as this patent's PTAB history is precisely the kind of number confusion that draws sanctions.

I'll research the assignment record for US 11,156,557 across the USPTO Assignment Center, Google Patents legal events, and related sources.

Let me dig into specific assignment-record databases and the Google Patents legal events.

Assignment / Ownership Report — U.S. Patent No. 11,156,557

Data-provenance note (read first). I could retrieve the assignment events for this patent from the Google Patents legal-events record embedded in the authoritative patent text, but I could not open the USPTO Assignment Center record itself from this environment, so the reel/frame number, the correspondent of record, and the precise USPTO recording date are not verified and are not stated below. Per the operating rules, I am not fabricating them. Everything asserted below is sourced to the Google Patents legal-events block reproduced in the patent text, with search corroboration where noted. Verification links are given in the Verdict section.

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Inventors

Pattern check: All five inventors executed an assignment to Ricoh Company, Ltd. — the classic employee invention-assignment posture, not a founder/free-agent inventorship. There is no evidence that the inventor group departed Ricoh within 12 months of filing; the opposite holds for Fukushima (filings through 2023) and the group reappears together on the related 2020 Ricoh patent. Yanata's grant record ends with this patent, which is consistent with retirement/reassignment but is not probative of anything on its own — I am explicitly not treating it as a signal.

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Original assignee

Ricoh Company, Ltd. (Ricoh Co Ltd), 3-6, Nakamagome 1-chome, Ohta-ku, Tokyo 143-8555, Japan — the assignee named on the issued front page and still listed as current assignee by Google Patents.

• Primary line of business: publicly traded Japanese multinational (Tokyo Stock Exchange, TSE: 7752); core office-imaging business (MFPs, printers, production print) plus an expanding industrial/healthcare portfolio. This patent sits in Ricoh's healthcare/diagnostics activity, not the legacy imaging line.
• Product embodying the claims: the claims are directed to a chemiluminescence analyzer for measuring urea in blood-purification waste liquid, configurable as either an internal module or a standalone unit. Ricoh is an operating company that develops and sells hardware, and the specification is written as a manufacturable device description (FIG. 7 shows a physical layout with ports, tank, reactor, substrate). However, I could not confirm from the sources searched that a commercial product ships this exact claimed analyzer. Treat "ships a product" as likely but unverified.
• Current status: operating, publicly listed, not in bankruptcy and not subject to any restructuring record found.
• Patent status: Google Patents reports the legal status as "Expired – Fee Related" with an "adjusted expiration" of 2040-02-23. I could not independently verify the lapse at the USPTO, and I cannot reconcile the 2040-02-23 date with the 2018-03-16 filing date (20 years would be 2038-03-16), so I flag the date as unreconciled rather than explain it away. If the "fee related" status is accurate, Ricoh abandoned the patent by non-payment rather than monetizing it — a meaningful anti-assertion fact.

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Assignment timeline

One (1) recorded assignment link exists. There is no post-issuance transfer, no LLC in the chain, and no security interest recorded in the sources searched.

• On or about 2018-03-16 (executed) / recorded per Google Patents legal events 2018-03-16 — Reel/Frame not retrieved (see provenance note)
  • Conveyance: Assignment — recorded by Google as "reassignment … ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS)"
  • Assignor: Takao, Mikihiko; Fukushima, Yasuhide; Hashiguchi, Masafumi; Hoshino, Yutaro; Yanata, Toshio (all five named inventors)
  • Assignee: RICOH COMPANY, LTD.
  • Correspondent: not retrieved. No correspondent name, firm, or address surfaced in the records available to me. Recording-date coincidence with the 2018-03-16 filing date is characteristic of a standard in-house/outside-counsel docketing-firm recording, but I am not asserting that.
  • Context: initial employment assignment — inventors' rights conveyed to the corporate employer contemporaneously with filing of application 15/923,526. Not a fire-sale, not a reorg, not a securitization, not a transfer to an asserter.
• (No further recorded entries: no change of name, no merger, no license, no release, no correction, no security agreement.)

Related family context (not assignment records): the same disclosure published as US 2018/0266963 A1 (2018-09-20) and has a European counterpart EP 3 376 212 B1; the U.S. application claims priority to JP 2017-053495 (2017-03-17) and JP 2017-249296 (2017-12-26). Sibling Ricoh US patent 10,670,532 shares three inventors with this one. These are separate patent numbers and do not constitute transfers of 11,156,557.

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Timeline diagram

timeline
    title Ownership of US 11156557
    2017 : JP priority applications filed by Ricoh
    2018 : US 15923526 filed by Ricoh Company Ltd
         : Five inventors assign rights to Ricoh
         : US 20180266963 A1 published
    2021 : US 11156557 B2 granted to Ricoh
    2025 : Google reports expired fee related

(The 2025 row reflects the Google-reported "Expired – Fee Related" status, which I could not independently verify; the maintenance-fee grace window for this grant would have closed 2025-10-26. Delete the row if you require only reel-backed facts.)

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NPE / troll-pattern signals

1. Shell-entity transfer — NOT PRESENT. The only recorded assignee is Ricoh Company, Ltd., an operating corporation. No "IP / Holdings / Ventures / Licensing" suffix appears anywhere in the chain; no single-purpose Delaware or Texas LLC; no registered-agent service address. The lone reel is inventors → Ricoh.
2. Known asserter in the chain — NOT PRESENT. Neither the assignor group nor the assignee matches any entity on the referenced NPE lists (Acacia, Marathon, IV, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Spangenberg entities). Ricoh is a TSE-listed operating company, not an assertion vehicle.
3. Repeat correspondent across the chain — UNCLEAR / NOT PRESENT. With only one link in the chain, the "recurrence" test cannot be met, and the correspondent of record was not retrievable, so I cannot compare it to NPE-filing firms. Reporting this as a negative.
4. Cascading transfers — NOT PRESENT. One assignment in ~8 years; no chained LLCs; no common-principal address structure. Nothing within 24 months of anything else.
5. Pre-litigation transfer — NOT PRESENT. The single assignment date (2018-03-16) precedes issuance (2021-10-26) by over 3.5 years, and the prior litigation analysis found no infringement suit naming this patent. There is no litigation-anchored transfer.
6. Bankruptcy fire-sale — NOT PRESENT. No Chapter 7/11, no assignment, no 10-K/8-K disclosure of a patent sale involving Ricoh and this patent was found.
7. Privateering — NOT PRESENT. No transfer out of the operating company to any assertion entity, and no NPE asserting this patent on Ricoh's behalf.
8. Defensive aggregator (anti-NPE) — NOT PRESENT. The chain does not terminate at RPX, AST, LOT Network, Unified Patents, or OIN; it terminates at Ricoh itself. The functional analog here is the reported fee-related lapse, which neutralizes the patent without a transfer.

Cross-check against prior section: consistent with the Litigation summary, which found no district-court, ITC, or PTAB proceeding involving 11,156,557. No contradiction found, and I add one affirmative data point the litigation section did not have: the patent is now reported by Google Patents as "Expired – Fee Related."

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Verdict

Insufficient data — under the rubric's literal definition ("no records, or only the original assignment"). The entire chain is a single link: five Ricoh inventors → RICOH COMPANY, LTD., assignment of assignors' interest, executed/recorded on or about 2018-03-16 in connection with the filing of application 15/923,526, with no reel/frame and no correspondent retrievable from this environment.

Substantively, this is the cleanest possible negative for NPE activity: an operating, publicly listed multinational took the inventors' rights at filing, never transferred the patent, and — per Google Patents — appears to have let it lapse for non-payment of maintenance fees rather than assert or sell it. All eight troll-pattern signals are negative (one "unclear" solely because the correspondent could not be read, not because of any adverse fact). Had the rubric permitted, the closest affirmative label would be non-asserting operating-company ownership, but with no suit and no post-issuance transfer there is no assertion chain to characterize.

Verify at: USPTO Assignment Center — https://assignmentcenter.uspto.gov/ and https://assignment.uspto.gov/patent/index.html (search 11156557, or application 15/923,526; the single hit should be the 2018 Assignment of Assignors' Interest to Ricoh). To close the two gaps above, pull the reel/frame and correspondent from that hit and confirm the fee-related lapse in USPTO Patent Center (https://patentcenter.uspto.gov/) under maintenance-fee status.

I'll research the patent and its cited prior art. Let me run several searches in parallel.

Let me get the specific "References Cited" (patent citations) section and the claims of US11156557.

Prior-Art Analysis — U.S. Patent No. 11,156,557 B2

Note on scope/sequence: This section builds on the earlier Litigation summary (no litigation found). It does not repeat the identity table except where needed for the prior-art analysis. One flag up front: the earlier section cited the priority as "March 17, 2017 (JP 2017-053495); also JP 2017-249296 (Dec. 26, 2017)" — that is consistent with the authoritative text supplied to me, so no contradiction.

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1. USPTO record located for the exact number (no near-miss substitution)

Searching the USPTO-derived record for the literal number 11156557 returned the correct document (accession edspgr.11156557, content provider "USPTO Patent Grants"):

Sources: https://patents.google.com/patent/[US11156557B2](/patent/US11156557B2) ; https://library.cnu.ac.kr/eds/detail/edspgr_edspgr.11156557 (USPTO Patent Grants record) ; https://patents.justia.com/patent/11156557

I deliberately discarded search hits for different numbers (e.g., the "8,411,557 / 7,777,557 / 11,564,912" family references that surfaced in generic litigation queries). None of those is US 11,156,557.

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2. The patent's cited/referenced art — what is actually on the record

Important caveat on completeness: I was able to render the front-page "References Cited" (field 56) listing only through the USPTO-derived EDS mirror, which shows one patent document. I could not render the full scanned front page of the granted patent to enumerate every U.S. patent document in Box 56. So the list below is what is confirmed; it may be incomplete as to U.S. patent documents, and I am explicitly not inventing entries to fill it.

2a. Patent document cited on the face of the patent (confirmed)

Sources: https://patents.google.com/patent/JP5637300B2/en ; https://patentimages.storage.googleapis.com/7b/cf/59/edb4b09be8c0dd/JP5637300B2.pdf ; http://www.kake.ac.jp/patent/pdf/5637300.pdf ; https://patentimages.storage.googleapis.com/8e/c0/9c/1732f11cac914d/DE112012001473B4.pdf

2b. Documents expressly referenced in the specification (not necessarily in field 56)

The specification states: "Examples configurations of the reactor 111 include, but not limited to, those described in JP-4855854-B (JP-2008-014910-A) and JP-5637300-B (WO2012-133394-A1)." (https://patents.google.com/patent/US11156557B2)

Source for spec quote: https://patents.google.com/patent/US11156557B2

2c. "Other References" (prosecution documents — not prior art, but they reveal examiner-cited art)

Source: https://library.cnu.ac.kr/eds/detail/edspgr_edspgr.11156557

These are prosecution papers, not § 102 art in themselves. However, the EESR and the CN/JP Office Actions are the documents most likely to contain the examiner's actual § 102/§ 103 citations (and any "X"-category references). I could not retrieve their cited-reference tables, so the definitive prior-art list for this family likely lives in those three documents, not in the U.S. face citations.

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3. Claim-by-claim § 102 exposure (analysis, not assertion)

For reference, the claim structure (from the record + the "Aspects A–M" mapping in the specification):

• Claim 1 (independent) — chemiluminescence analyzer: reactor + photodetector + first liquid conveyor (from the blood-purification apparatus waste-liquid passage) + second liquid conveyor (reagent) + liquid mixture passage from the reactor + joint coupling that liquid mixture passage to the waste-liquid passage of the blood purification apparatus + electric interface for connection with an external device.
• Claim 11 (independent) — same core, plus controller (controls photodetector + both conveyors) and communicator (communicates with an external device) and the joint.
• Claim 14 — blood purification system comprising a blood purification apparatus + the analyzer of claim 11. (Confirmed: "14. A blood purification system comprising: a blood purification apparatus; and the chemiluminescence analyzer according to claim 11…")
• Dependent claims (tank; thermometer; flowmeter; waste-liquid port; exit/drain port; reagent port; cleaning/calibration port; non-return valve) map to Aspects C–K.

Findings:

Net § 102 conclusion (high confidence on the negative): Based on the confirmed citations, no single cited reference discloses all elements of any claim of US 11,156,557, because the distinguishing limitations — the joint that couples the post-reaction liquid-mixture passage back to the blood-purification apparatus's waste-liquid passage, the electric interface for an external device, and (for claim 11) the controller + communicator — are absent from the chemiluminescence-reactor art cited. The cited art is therefore best viewed as § 103 (obviousness) background, not anticipation art.

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4. Explicit uncertainties (do not treat as confirmed)

1. Field-56 completeness. I confirmed only one patent document in the face citations (WO 2012/133394). U.S. patents commonly list additional U.S. patent documents in Box 56. I could not enumerate them and have not fabricated entries. A PACER/USPTO PatentCenter or the granted-patent PDF front page is needed for the full list.
2. P2 bibliographic data. I could not verify the publication or filing date, assignee, or content of JP 2008-014910 A / JP 4855854 B. Treat any date for it as unconfirmed until retrieved.
3. Non-patent literature. The EESR (EP 18161057.7), CN OA (CN 201810204161.0), and JP OA (JP 2017-249296) are the documents most likely to contain additional X/Y-category citations; their contents were not retrieved.
4. Anticipation requires element-by-element identity in a single reference; a reference that discloses only the reactor/photodetector core cannot anticipate claims that also require the joint, electric interface, controller, or communicator.

Recommended next retrieval steps to finalize this prior-art map: (a) the granted-patent PDF front page for the complete Box 56 U.S. list; (b) EPO Register/Espacenet for EP 18161057.7 to pull the EESR citation table; (c) the JP 2017-249296 Office Action and CN 201810204161.0 Office Action citation tables. If you want, I can draft the exact queries for Espacenet, J-PlatPat, and USPTO PatentCenter to pull those three documents.

I'll gather the prior-art references cited on this patent's page before building the obviousness analysis.

Key lead: JP4855854B2 is a "chemiluminescent urea sensor for hemodialysis." Let me pull the cited-references list from the patent front page and dig into the two references named in the specification.

Obviousness Analysis — U.S. Patent No. 11,156,557 B2

35 U.S.C. § 103 / AIA (post-2013) framework

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0. Scope, provenance, and an important limitation

Before the analysis, three explicit caveats, because this matters for how much weight you can put on what follows:

1. The "Prior Art" (front-page References Cited) list of US 11,156,557 was not retrieved. The authoritative page text supplied for this analysis contains the figures list, the description, and the Google "Definitions"/Aspect summary, but the application's own citations block was not in the fetched excerpt. My attempts to pull the front-page "(56) References Cited" list and the family's EPO/CN search reports hit the tool-call limit before returning results. Every reference below is either (a) named in the patent's own specification, (b) surfaced in searching the family, or (c) a technical admission made by the applicant in the description — and I say which is which.
2. The issued claim text was not in the fetched excerpt. I reconstructed the claim set from the Google Patents "Definitions" block and the "Aspect A … Aspect M" text, which reads as a claim-by-claim paraphrase (Aspect A = claim 1 family; Aspect B = the second independent claim; the remaining Aspects = dependents). Treat the element-by-element mapping as accurate at the element level, but re-verify against the granted claims before using this in a paper.
3. JP 4855854 B2 is a Japanese-language document. I have its bibliographic record and title with high confidence (see below), and the applicant's own statement of what subject matter it discloses; I do not have paragraph-level content, and I have not fabricated paragraph cites for it.

Bibliographic grounding

Effective filing date. The listed priority date is 2017-03-17. Because the application claims two JP priorities, subject matter first disclosed only in JP 2017-249296 (2017-12-26) would be entitled to the later date. Any claim element supported only by the December filing opens a Mar. 17 – Dec. 26, 2017 window in which intervening art qualifies under § 102(a)(1) and, for applications filed before the '557 claims' effective date, § 102(a)(2) (with § 103 obviousness of course available for such art). This is worth checking against the EP/CN/JP prosecution papers already identified in the family record (EP Search Report; CN OA on CN 201810204161.0; JP OA on JP 2017-249296).

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1. Person having ordinary skill in the art (POSITA)

A POSITA here would have: a bachelor's in chemical/electrical/mechanical engineering or analytical chemistry, plus 2–5 years designing fluid-handling analytical instruments, with working familiarity with (i) chemiluminescence reaction cells and photodetection, (ii) peristaltic/tubing pumps, flowmeters, thermistors and check valves, and (iii) the plumbing architecture of hemodialysis machines (spent-dialysate "waste liquid" line → floor drain tube → waste-liquid treatment unit / drain container). This is a mechanical/plumbing-plus-instrumentation level of skill, not an advanced research level — a point that strongly favors obviousness under KSR.

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2. Prior art identified

Note the two references the applicant itself cites are in the identical field, addressing the identical problem (chemiluminescent urea measurement in the dialysis/discharge liquid stream). That is the single most important obviousness fact in this record.

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3. The claim set as reconstructed

Independent claim 1 (Aspect A): reactor + photodetector + first liquid conveyor (waste liquid, from the blood purification apparatus waste-liquid passage, to reactor) + second liquid conveyor (reagent to reactor) + liquid mixture passage extending from the reactor + joint coupling the liquid mixture passage to the waste-liquid passage of the blood purification apparatus + electric interface for connection with an external device.

Independent claim 2 (Aspect B): same reactor/photodetector/two conveyors/liquid mixture passage/joint, plus controller to control the photodetector and both conveyors, plus communicator to communicate with an external device.

Dependents (Aspects C–K): control panel + display; tank upstream of the first conveyor; thermometer; flowmeter; upstream internal passage + waste-liquid connection; downstream internal passage + drain connection; reagent connection (port) to a reagent container; tank having a separate cleaning/calibration port; non-return valve preventing liquid-mixture backflow. Aspects L–M: blood purification apparatus comprising the analyzer; blood purification system.

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4. Claim-by-claim obviousness

4.1 Independent claim 1 (Aspect A)

Rationale for combining (MPEP 2143(A), (B), (C), (D)):

• (A) Known elements combined by known methods → predictable result. Claim 1 is a combination of: a chemiluminescence measuring instrument (PA-4, PA-1, PA-2, PA-3) + a fluid junction (PA-5). Both were known; the combination yields nothing more than the expected sum of each element's function (Sakraida v. Ag Pro, 425 U.S. 273; Anderson's-Black Rock v. Pavement Salvage, 396 U.S. 97).
• (D) Known technique applied to a known device ready for improvement. The '557 specification itself frames the problem as a plumbing/installation problem: connecting the analyzer to a floor drain "requires processing for such connection," and a joint externally coupled between the analyzer and the machine's waste-liquid port makes "installation or transport" difficult. A POSITA facing that admitted problem has an obvious solution space, and tapping the same stream the sample was drawn from is the first and most natural.
• Design incentive / market force (MPEP 2143(G)). Cost, floor-space, and infection-control practice all favor not running a second drain line. Returning the reacted mixture to the waste-liquid passage the analyzer is already plumbed into requires no new plumbing, no new drain, and no new waste container — the patent itself touts exactly this: "the liquid mixture discharged from the reactor can be discarded to the waste liquid passage of the blood purification apparatus. As a result, the discharge passage can be easily ensured." Reciting the benefit of the arrangement in the specification is not evidence of non-obviousness; it is evidence of the motivation.
• Contamination counter-argument fails. A skeptic would say one would not dump reagent-laden mixture back toward the sample. But the geometry is self-solving: the joint (123) is downstream of the analyzer's own intake, the analyzer sits between the apparatus and the drain, and the sample is drawn from the passage upstream of the joint — so the mixture flows away from the intake. Where residual risk exists, claim 10's own non-return valve (a known part performing its known function) resolves it. Where the invention's own solution to a foreseeable problem is an off-the-shelf check valve, obviousness follows (KSR at 417: "the combination of familiar elements according to known methods is likely to be obvious… if it yields no more than one of its expected functions").

Conclusion on claim 1: obvious over PA-4 (admitted) and/or PA-1/PA-2/PA-3 in view of the routine in-line junction practice of PA-5.

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4.2 Independent claim 2 (Aspect B)

Adds controller + communicator.

• Controller: already in PA-4 — the tubing pump and photomultiplier "are controlled by a computer such as a personal computer (PC)." Claim 2's controller does nothing more than PA-4's PC does: run the conveyors and read the photodetector.
• Communicator to an external device: the specification recites the motivation in terms of the applicant's own stated second object — provide unified measurement data regardless of the blood purification apparatus manufacturer/model, and permit transmission to a server, smartphone, or cloud. These are the classic design incentives and market forces of MPEP 2143(G) (telemedicine, EMR/PDMS integration, remote monitoring of home dialysis) and the classic "obvious to try" situation of MPEP 2143(F). Network/wireless interfaces on benchtop analyzers were ubiquitous before 2017; the specification itself concedes the hardware is a generic "connector (interface), an antenna, and a slot for a data recording medium" — i.e., a general-purpose communication module recognized by the claim as generic.

Conclusion on claim 2: obvious over PA-1/PA-2/PA-4 in view of routine instrument-controller and network-interface design (PA-4 supplies the controller; § 103 permits reliance on the level of ordinary skill and on common knowledge for the communicator).

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4.3 Dependent claims (Aspects C–K)

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5. Why a POSITA would have combined the references — the explicit motivation story

1. Same field, same problem, same art unit. PA-1 (chemiluminescent urea sensor for hemodialysis) and PA-2 (urea concentration in a sample solution via hypohalite chemiluminescence) are both cited by the applicant itself as the reactor technology to be used. There is no "analogous art" dispute.
2. The applicant's own Background supplies the roadmap. PA-4 concedes the complete measurement chain; the specification then states the two objects — easy installation, and unified/transmissible data. Obviousness is measured against the problem the inventor articulated; here the inventor articulated ordinary engineering problems (installation, plumbing, data portability).
3. The improvement is on the plumbing/instrumentation layer, not the chemistry. Nothing in the claims alters the chemiluminescence reaction, the reagents, the reactor geometry, or the detection physics. The claims enumerate pumps, tubes, joints, ports, a tank, a valve, a thermometer, a flowmeter, a controller and a radio — i.e., the back-of-house hardware of any automated analyzer.
4. Every connector/valve claim is met by an admitted catalog part. The specification names luer fittings, quick joints, and a Colder Products Company (CPC) coupling with an integral check valve. Where the invention's components are commercially available off-the-shelf parts identified as such, the § 103 case is about as strong as it gets.
5. Predictable, non-superadditive results. Nothing in the record indicates a result greater than the sum of the parts (no unexpected synergy in chemiluminescence yield, no new detection modality, no unexpected reagent interaction).

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6. Anticipated counter-arguments and how they fare

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7. Recommended, non-obviousness-adjacent checks (because they change the answer)

1. Pull the actual front-page (56) references and the family search reports. The EP Search Report, the CN Office Action on CN 201810204161.0, and the JP Office Action on JP 2017-249296 (all identified in the family record from the earlier section of this analysis) very likely contain X/Y-category citations that are far more on-point than my reconstruction. Those documents are the highest-value next step and I could not retrieve them here.
2. Confirm the priority allocation claim-by-claim. If any claim element (e.g., the non-return valve between the tank and the joint, or the tank-with-cleaning/calibration-port) is supported only by JP 2017-249296 (2017-12-26), then art published between 2017-03-17 and 2017-12-26 becomes available against those claims.
3. Verify whether the reactor references are Ricoh's own work. JP 5637300 B2 and Ricoh's EP 3056232 A1 (urea concentration measuring method/apparatus, Ricoh in-house semiconductor optical sensor) appear related; if the '557 claims are dominated by Ricoh's own earlier filings, that is a § 102(a)(2)/§ 103 self-collision issue rather than a third-party commerce issue — but it does not make the claims non-obvious.
4. Read the granted claims directly at patents.google.com/patent/US11156557B2 (or USPTO PatentCenter for app. 15/923,526) before filing anything that depends on exact claim language.

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8. Bottom line

• Independent claim 1 (Aspect A): obvious. Each element is taught by the admitted prior art (PA-4) and/or by the two references the applicant itself cites (PA-1, PA-2), with the only arguable addition — a joint returning the reacted mixture to the blood purification apparatus' own waste-liquid passage — being a routine in-line plumbing expedient motivated by the admitted installation, floor-drain, and cost problems, and yielding only the predictable benefit of not needing a second drain. MPEP 2143(A), (C), (D), (G).
• Independent claim 2 (Aspect B): obvious. PA-4 expressly discloses PC control; adding a generic wired/wireless communicator responds to the applicant's own articulated market incentives (unified data, remote/server/smartphone/cloud access) and is a routine design choice under §§ 103 and 2143(F)/(G).
• Dependent claims (Aspects C–K): obvious. Each recites a conventional analyzer component (front panel, tank, thermometer, flowmeter, inlet/outlet couplings, reagent port, calibration port, check valve) whose function and motivation are either expressly admitted in the specification or standard practice; several are met by named off-the-shelf parts (luer, quick joint, CPC check-valve coupling).
• Aspects L–M (apparatus and system claims): obvious as combinations of known devices performing their known functions, with PA-1 already linking a chemiluminescent urea sensor to hemodialysis.
• Strongest possible patentee redoubt: a narrow, geometry-specific argument that the particular downstream-of-intake placement of the joint, combined with the check valve, avoids sample contamination in a way not previously recognized. That argument is defeated unless the granted claims actually recite that relative placement and unless there is evidence of unexpected results — neither of which appears in the record reviewed.

Confidence: high on the qualitative § 103 conclusion; medium on element-by-element citation completeness, because the front-page citations block and the family search reports were not retrievable in this session.