US 11402328

I'll verify the patent's current status and check for any litigation or CAFC docket activity.

US Patent 11,402,328 B2 — Summary

Verification note: I searched for this specific number (US 11,402,328 / application 15/763,935). I found no district court litigation and no CAFC (Federal Circuit) docket activity in 2026 or any other year involving this patent. Hamamatsu Photonics' publicly reported patent enforcement activity concerns unrelated patents (e.g., JP Patent Nos. 3867108 and 4601965 against Tokyo Seimitsu, decided in the Tokyo District Court in December 2022 — not this patent). Treat "no dockets found" as a negative search result, not as proof that no proceeding exists.

Bibliographic data

Family: JP 6832283 B2 (granted 2021-02-24); WO 2017/056905 A1. A US divisional, 17/858,183 (US 2022/0357276 A1), was filed 2022-07-06 and is listed as abandoned. Note: only method claims issued in this US patent despite the "device" and "program" language in the title.

Abstract (as granted)

A method for detecting an amyloid β oligomer in which a test sample and thioflavin T are contacted, fluorescence of the thioflavin T is measured to obtain time-resolved fluorescence spectra, the time-resolved fluorescence spectrum of time period t1 to t2 and that of time period t3 to t4 are respectively normalized to obtain normalized spectra (t1<t2≤t3<t4), and determination of the presence or absence of an amyloid β oligomer in the test sample is made based on the two normalized spectra, wherein shifting of the normalized spectrum of time period t3 to t4 toward the low wavelength side relative to the normalized spectrum of time period t1 to t2 indicates the presence of an amyloid β oligomer.

Plain-language overview of claim 1 (the only independent claim)

A four-step fluorescence method:

1. Contact — mix the test sample (e.g., brain slice, cerebrospinal fluid, blood, mucous membrane) with thioflavin T (ThT), a standard amyloid stain.
2. Measure — measure ThT fluorescence in a time-resolved manner to obtain time-resolved fluorescence spectra (specification: 405 nm excitation, emission scanned 420–620 nm, time-correlated single-photon counting; background-subtracted).
3. Normalize — take the spectrum for an early time window t1–t2 and a later time window t3–t4 (with t1<t2≤t3<t4) and normalize each so its maximum intensity equals 1.
4. Determine — conclude Aβ oligomer is present when the later spectrum (t3–t4) is shifted to shorter wavelengths relative to the earlier spectrum (t1–t2).

The underlying asserted discovery is that ThT-stained Aβ oligomer (protofibril) shows a time-dependent blue-shift in its time-resolved emission spectrum, whereas Aβ fibril does not — making the assay a low-cost alternative to gel electrophoresis/chromatography (Patent Literature 2) or antibody-based detection (Patent Literatures 3/4).

Dependent claims (all narrow claim 1 to a specific determination metric)

• Claim 2 — Compute ratio s1 = (normalized intensity at λ1 for t3–t4)/(same at λ1 for t1–t2), where λ1 is more than 480 nm (specification example: 500 nm). s1 < 1 ⇒ oligomer present; s1 ≥ 1 ⇒ absent.
• Claim 3 — Compute ratio s2 = (normalized intensity at λ2 for t3–t4)/(same at λ2 for t1–t2), where λ2 is less than 480 nm (specification example: 460 nm). s2 > 1 ⇒ oligomer present; s2 ≤ 1 ⇒ absent.
• Claim 4 — Compare peak-top wavelengths of the two normalized spectra: shorter peak top in t3–t4 than in t1–t2 ⇒ oligomer present; same or longer ⇒ absent.

Working examples (evidence in the specification)

• Example 1: Aβ1-42 oligomer (24 h, 4 °C) vs. Aβ42 fibril (24 h, 37 °C). s (500 nm) ≥ 1 for fibril, < 1 for oligomer.
• Example 2: Aβ40 fibril (10 days, 37 °C) tested against Aβ42 oligomer; fibril s ≥ 1, showing robustness to fibril type.
• Example 3: Aβ40 oligomer (1 day, 37 °C) vs. Aβ40 fibril (7 days, 37 °C); oligomer s < 1, fibril s ≥ 1.

A notable practical teaching: the inventors recommend using ThT purified of fluorescent photoreaction-product impurities (liquid–liquid extraction with hexane from an aqueous ThT solution, repeated ~10×, monitored as loss of ~440 nm emission under 350 nm excitation) to improve oligomer detection sensitivity.

Cited prior art of record (7–9 references)

WO 2008/012101 A1 (Vista Ventures); WO 2010/119704 A1 and JP 2012-524023 A (Immunas Pharma); JP 2010-168385 A (Abbott GmbH); JP 2009-544954 A (Vista Ventures); JP 2010-120942 A (Academia Sinica); JP 2014-122846 A (Hamamatsu); JP 2015-166749 A (Cognoptix); WO 2015/060333 A1 (Kobe University). Non-patent literature: Lindberg et al., Biochem. Biophys. Res. Commun. 458 (2015) 418–423 (steady-state and time-resolved ThT fluorescence reporting morphological differences in Aβ(1-40)/Aβ(1-42) fibrils); Stine et al., J. Biol. Chem. 278(13) (2003) 11612–11622.

Points of uncertainty

• Current ownership/encumbrances: the assignment record shows an assignment to Hamamatsu Photonics K.K. (recorded 2018-03-28, Reel/Frame 045371/0517). I have no authoritative data on any subsequent reassignment, license, or security interest.
• Legal status: "Active" and the 2038-07-25 adjusted expiration derive from Google Patents' aggregation, which expressly disclaims legal accuracy. Patent term adjustment and any terminal disclaimer should be confirmed in USPTO PatentCenter (application 15/763,935).
• Litigation: as noted above, no US litigation or CAFC appeal involving 11,402,328 was found. This is not an affirmative clearance; IPR/PGR and district court dockets should be checked directly if that matters.
• Claim scope limit: because only method claims issued, the apparatus ("device") and "program" subject matter described in the specification is not claimed in this patent, and the attempted divisional (17/858,183) is abandoned — so no US claims appear to cover a device or software product per se.

I'll search litigation databases for US patent 11,402,328.

Let me search more targeted litigation sources.

Bottom line

Based on the searches I was able to run, I found no litigation involving U.S. Patent No. 11,402,328 ("the '328 patent") — no district court complaints, no ITC investigations, no CAFC appeals, and no PTAB proceedings (IPR/PGR) naming it. I am reporting this as a negative finding rather than a confirmed "clean" record, because my searches did not return a comprehensive litigation database entry for this patent number, and I note the limitations below.

The patent I searched for (verified against the patent record)

Claims 1–4 are directed to a method of detecting an Aβ oligomer using thioflavin T time-resolved fluorescence spectra (claim 1), plus the fluorescence-ratio s1 (λ1 > 480 nm), fluorescence-ratio s2 (λ2 < 480 nm), and peak-top-wavelength comparison variants. Note the claims as granted are method claims only — the device and program aspects recited in the title/abstract were not carried into the granted claim set.

Sources searched and what they returned

• Google Patents page for US11402328B2 — the "Cited By," "Families Citing," "Patent Citations," and "Non-Patent Citations" tables are present, but there is no litigation or PTAB section populated. The only downstream-citing document is US20220404280A1 → US12259321B2, both Hamamatsu Photonics ("Method for removing background of fluorescence lifetime measurement…"), which are same-owner publications rather than adverse proceedings.
• Unified Patents litigation/PTAB portal (portal.unifiedpatents.com) — no case list entry surfaced for 11402328 in the search results returned.
• General web searches on the patent number, Hamamatsu Photonics litigation, Docket Alarm, and CourtListener/RECAP — results did not include any complaint, docket, or order asserting or challenging US 11,402,328.
• CAFC / Federal Circuit — no opinion or appeal referencing this patent appeared.

Important: apparent false positives to disregard

Several search hits look superficially relevant but are different patents and must not be attributed to US 11,402,328:

• Sonos, Inc. v. D&M Holdings / Linkplay references to a "'023 Patent" (Sonos playback-device patent) — different number, different owner, different technology.
• Alcon / LenSx declaratory-judgment counterclaims referencing an "'023 patent" (ophthalmic laser scanner) — different patent.
• Genelabs / Illumina and Genentech decisions referencing "the '023 patent" — different patents.
• An ANDA/pharma complaint referring to "the '328 patent" (a drug patent, plaintiff vs. Mylan) — different patent number.
• Carucel, Bradium, MCOM IP, MasterObjects, etc. — unrelated patents.

In each of these the "'023"/"'328" shorthand refers to a patent whose actual number is not 11,402,328. Consistent with your instruction not to auto-correct identifiers, I have not merged any of these into the '328 record.

Litigation-adjacent facts worth noting

• Family enforcement posture: the sibling Japanese patent JP6832283B2 and the PCT publication WO2017056905A1 are the only other family members. A separate but related Hamamatsu family member, JP6971535B2, covers "a method for purifying pure thioflavin T… and a method for detecting amyloid" (priority 2015-09-29) — indicating Hamamatsu built a small thioflavin-T purification/detection portfolio around this work, but I found no assertion activity on it either.
• No post-grant challenges: the '328 patent's legal-events history shows only ordinary prosecution events (non-final actions, responses, allowance, grant) and maintenance-fee payments. No IPR, PGR, or reexamination appears in the file history or search results.
• Abandoned continuation: US 17/858,183 (a divisional of the '328 case) went abandoned — this is a prosecution event, not litigation.

Caveats and recommended verification

I cannot certify a complete negative. Search coverage of PACER, Docket Navigator, Lex Machina, and the Unified Patents caselist for the exact string "11402328" / "11,402,328" was incomplete, and a recently filed complaint (or one where the patent is identified only as an exhibit or by its application number 15/763,935) could exist without surfacing. To confirm, I would recommend:

1. CourtListener/RECAP full-text search for "11,402,328" and "15/763,935" (RECAP often indexes complaints by patent number).
2. PACER docket search in districts where Hamamatsu or its licensees would likely sue (D. Del., C.D. Cal., E.D. Tex., W.D. Tex., N.D. Cal.).
3. Unified Patents caselist and PTAB API (PTABE2E / USPTO Open Data) filtered on patent number 11402328.
4. USPTO Patent Center "Litigation" / assignment records to see whether the patent has been assigned or exclusively licensed to an entity that might assert it (an assignment change often precedes litigation).

If you'd like, I can run those specific queries next and report back with case numbers and dockets.

Proceedings overview

Total AIA trial proceedings on US 11,402,328: 0. The structured USPTO Open Data Portal block in the prompt reports no AIA trial proceedings, and independent web searching surfaced no IPR, PGR, or CBM naming this patent as the challenged patent — no institution decision, no FWD, no settlement, no Federal Circuit appeal. The defensive posture for a defendant today is therefore the honest but unhelpful one: the patent is completely untested at the PTAB, and none of its four claims have been canceled, narrowed, or even construed by the Board. Absence of PTAB activity is not evidence the claims are strong — it more likely reflects that the patent issued only on 2022-08-02 and has yet to be asserted in a way that has drawn a well-funded challenger.

⚠️ False-positive warning before you rely on any hit. Search results for "the '328 patent" in PTAB papers often refer to Unrelated patents — e.g., an IPR petition in Facet Tech. Corp. v. Mobileye Glob., Inc., No. 2:24-cv-00058 (E.D. Tex.), challenges a " '328 Patent" having claims at least through claim 22, with statutory disclaimers of claims 17–22. US 11,402,328 has only four claims and no claim 17. Any IPR brief citing "claim 9," "claims 15–16," or "claims 19 and 21–22" of a '328 patent is not this patent. Do not import those outcomes here.

No proceedings to report

There is no {PROCEEDING_NUMBER} to list. For completeness, the following was checked and came up empty:

• PTAB structured data (USPTO ODP) — zero AIA trial proceedings (canonical, per prompt).
• PTAB E2E / PTAB Decisions — no trial numbered against Patent No. 11,402,328 located via web search; PTAB petition documents retrieved in searching referenced unrelated patents solely by coincidental " '328" shorthand.
• Federal Circuit / CourtListener — no appeal from any FWD on this patent (there is no FWD to appeal). Note that SiOnyx v. Hamamatsu Photonics (Fed. Cir. 19-2359) is a patent-ownership/duty-of-disclosure dispute over Hamamatsu's silicon photonics patents — unrelated to 11,402,328, but relevant background if you are assessing this assignee's litigation history.
• Reissue / reexamination / supplemental examination — none surfaced.
• Statutory disclaimer — none surfaced for this patent (unlike the unrelated '328 discussed above).

Patent family / administrative context (not a PTAB proceeding, but relevant):

• The Japanese sibling JP6832283B2 is the national-phase counterpart of this same application (PCT/JP2016/076469, WO2017056905A1, priority 2015-09-29).
• Hamamatsu filed a separate but related application, JP7007132B2, "Amyloid aggregate detection method, amyloid aggregate detection device, and amyloid aggregate detection program" (priority 2017-08-09), plus US20220404280A1 / US12,259,321B2 on "Method for removing background of fluorescence lifetime measurement and method for quantifying target substance" (priority 2021-06-22). This shows a continuing prosecution/R&D effort in the same detection space — a family to watch for new, likely broader, patents.
• A divisional of this very application was filed as US 17/858,183 (published US20220357276A1, 2022-11-10) and is now Abandoned. Its abandonment is a routine prosecution event, not an adverse validity ruling — but it does mean there is no pending continuation of 11,402,328 on file to produce new claims.

Strategic summary

Claim status of US 11,402,328. All four claims — claim 1 (independent), claim 2 (λ1 > 480 nm, s1 < 1), claim 3 (λ2 < 480 nm, s2 > 1), and claim 4 (peak-top-wavelength comparison) — are UNTESTED and SUSTAINED by default. No claim has been canceled or amended by any post-grant process. The patent as it issued on 2022-08-02 is the patent a defendant faces today. Claims 2–4 are all dependent on claim 1, so claim 1 is the whole ballgame: knock out claim 1 and the entire patent falls; survive on claim 1 and you get claims 2–4 essentially for free.

Estoppel landscape. There is no § 315(e)(2) estoppel against anyone, because no petitioner has ever obtained a final written decision on this patent. Every ground a defendant could raise — § 102 anticipation, § 103 obviousness, and, because this is an IPR-eligible patent, § 112 grounds only if you go the district-court or PGR route — remains fully available. Concretely, the two references cited on the face of the patent during examination that are the most natural starting points are:

• Lindberg et al., "Steady-state and time-resolved Thioflavin-T fluorescence can report on morphological differences in amyloid fibrils formed by Aβ(1-40) and Aβ(1-42)," Biochem. Biophys. Res. Commun. 458 (2015) 418–423 — cited on the face of the patent as a non-patent citation. This is important: it is time-resolved ThT fluorescence on Aβ(1-40)/Aβ(1-42) aggregates, published before the 2015-09-29 priority date, and a challenger would want to argue it discloses or renders obvious the very time-resolved spectrum behavior claimed. Because it was cited to and considered by the Examiner, a § 325(d) discretionary-denial risk exists if you lead with it — so build your petition around uncited art and use Lindberg only to show the Examiner's error.
• W. Blaine Stine, Jr. et al., "In Vitro Characterization of Conditions for Amyloid-β Peptide Oligomerization and Fibrillogenesis," J. Biol. Chem. 278(13), 11612–11622 (2003) — the patent admits this is the source of its own oligomer/fibril preparation protocols (Examples 1–3). That admission is a gift for an obviousness or written-description/enablement attack.

Pattern signals. No petitioner has ever filed on this patent, so there is no serial-filing or General Plastic story. There is no defensive aggregator (Unified Patents or similar) in the chain. Hamamatsu Photonics is a large, well-resourced, practicing Japanese optics/photonics manufacturer — not an NPE — and it litigates (see SiOnyx, where it was found to infringe willfully and to have taken confidential information). The prior-art citations on the face of the patent are predominantly Aβ-biology references and Hamamatsu's own JP2014122846A, not PTAB-style prior art; this is a prosecution-light, post-grant-untested patent.

Recommended next steps

1. Treat the patent as fully intact, not hardened. There is no FWD to link to and no disposition to quote. Do not tell a client the claims are "hardened by prior IPRs" — that would be false — and do not cite any '328 PTAB paper without first confirming the patent number at the top of the document, given the false-positive risk described above.

2. Pre-suit / early defense, if you're a defendant:

   • Run a § 102/§ 103 search targeted at pre-2015-09-29 time-resolved (TCSPC) ThT fluorescence on Aβ aggregates. The patent's own cited art (Lindberg 2015; Stine 2003) shows the field was already using time-resolved ThT spectroscopy on Aβ(1-40)/Aβ(1-42) at the priority date, and the patent's central assertion — that low-wavelength shifting "is specific to an Aβ oligomer, and it is not observed from Aβ fibril" — is a biological-empiricism claim that is highly vulnerable to competing experimental evidence. The claim-1 limitation is essentially a result ("shifting ... indicates the presence of an amyloid β oligomer"), which invites both § 103 and § 112(a)/(b) attacks on the ground that the specification provides no guidance on how to select t1–t4 or λ1/λ2 in a way that reliably discriminates oligomer from fibril across samples.
   • Note the claim-construction pressure points: claim 1 requires only t1<t2≤t3<t4 with no numerical bounds (the specification's 0–2 ns / 10–18 ns windows are expressly only exemplary), and claims 2/3 fix only λ1 > 480 nm and λ2 < 480 nm. A narrow construction or an indefiniteness finding on "shifting ... towards a low wavelength side" could substantially neutralize the patent.

3. If an IPR is filed later, the milestone clock is statutory. If the Director institutes under 35 U.S.C. § 314(a), the Board must issue the FWD not later than 1 year after the notice of institution (§ 316(a)(11)), with the ~3-month PO Preliminary Response window and a ~3-month patent-owner-response/reply/oral-hearing sequence in between. Watch https://ptacts.uspto.gov/ptabweb (PTAB E2E) and https://developer.uspto.gov/ds-api (ODP) for a new trial number; the ODP "PTAB proceedings on file" field in this prompt is currently authoritative at zero.

4. Monitor the family. JP7007132B2 ("Amyloid aggregate detection method...") and US20220404280A1 / US12,259,321B2 (background removal for fluorescence lifetime measurement) indicate Hamamatsu is still prosecuting in this space. Newer, broader claims in that family could create fresh exposure even though US 17/858,183 was abandoned.

5. If you need to confirm status yourself, the two primary sources are:

   • PTAB E2E: https://ptacts.uspto.gov/ptabweb/#/patent
   • PTAB Decisions (final written decisions): https://www.uspto.gov/patents/ptab/decisions
   • CourtListener (for any CAFC appeal, should one ever arise): https://www.courtlistener.com/?q=%22Hamamatsu%22&type=o

Bottom line: no PTAB proceedings exist on US 11,402,328 as of 2026-09-29. All four claims are live and untested. The upside for a defendant is that no IPR estoppel has attached and no prior petitioner has burned the best art; the downside is that you have no Board precedent, no FWD claim constructions, and no invalidity roadmap to borrow — you would be the first challenger, which means you would also be the one paying to develop the record.

I'll verify the assignment record for this patent before writing up the analysis.

Assignment & Ownership Analysis — US 11,402,328 B2

Sourcing caveat (read first). I could not open a live, authenticated query against the USPTO Assignment Center in this session; the Assignment Center and the legacy assignment.uspto.gov index were not directly reachable, and targeted web queries returned no assignment records beyond what Google Patents' legal-events aggregation of the same USPTO assignment data exposes. Everything below is therefore drawn from (a) the full patent text supplied in the task (which embeds the recorded legal events, including the reel/frame citation), and (b) cross-check searches. The correspondent-of-record field — normally the richest tell — is not exposed in that aggregated data, and I have not fabricated one. Confirming/refuting "no further recordings" requires a manual query at https://assignmentcenter.uspto.gov/ (search property 11,402,328 or application 15/763,935).

Inventors

Pattern assessment — no departure signal. The tell the task asks about (all inventors leaving the original assignee within 12 months of filing) is not present. The contrary evidence is affirmative: Satozono (16 US patents) and Takata (6 US patents at Hamamatsu) both show sustained, continuing prosecution output at the same company, which is the profile of long-tenured corporate R&D staff rather than founders about to exit. The inventors are also co-assignors of record on the same day as the national-stage entry (see below), and Hamamatsu continues to file in this technical neighborhood — e.g., the citing Hamamatsu applications US 2022/0404280 A1 (2021-06-22 priority) and US 12,259,321 B2, on background removal in fluorescence-lifetime measurement. This is an internal corporate inventorship team, not a spun-out group.

Related sibling filings by the same inventor group / same priority family (from the patent's "Families Citing this family"):

• JP 6971535 B2 — "A method for purifying pure thioflavin T, a method for producing pure thioflavin T, a composition containing thioflavin T, and a method for detecting amyloid" (Hamamatsu, priority 2015-09-29 — same priority date).
• JP 7007132 B2 — "Amyloid aggregate detection method, amyloid aggregate detection device, and amyloid aggregate detection program" (Hamamatsu, priority 2017-08-09).

The same-priority JP 6971535 filing on ThT purification is notable: it is the separate patent protection for the practical teaching embedded in this specification (hexane extraction of fluorescent impurities). That is complementary internal filing, not an assignment event, but it matters for freedom-to-operate analysis of anyone practicing Example 1 without a purificaton step.

Original assignee

Hamamatsu Photonics K.K., 325-6, Sunayama-cho, Naka-ku, Hamamatsu-shi, Shizuoka 430-8587, Japan (the specification's Quantaurus-Tau product line is a Hamamatsu instrument; corporate registration data returned in search lists 1126-1 Ichino-cho, Higashi-ku, Hamamatsu-shi, Shizuoka 435-8558 and Sunayama-cho addresses).

• Status: Operating, publicly listed (Tokyo Stock Exchange; fiscal year ends 30 September). Approximately 6,600 employees per returned corporate data. Founded 1948/1953. No bankruptcy, dissolution, or acquisition signal — the opposite of the Kodak/Nortel/Polaroid fire-sale scenario.
• Primary line of business: Manufacture and sale of photodetectors, photomultiplier tubes, imaging devices, light sources, opto-semiconductors, and — directly relevant here — analytical/measurement instrumentation. Its segments are Electron Tube, Opto-semiconductor, Imaging Measurement Instruments, and Other.
• Does it ship a product embodying the claims? The claimed subject matter is a method (assay/analysis), and a method claim is not "shipped." However, the assignee commercially sells the instrument the specification prescribes for practicing it: the examples expressly use the Quantaurus-Tau compact fluorescence lifetime measurement device, manufactured by Hamamatsu Photonics K.K. (time-correlated single photon counting, 405 nm excitation, emission scanned 420–620 nm). So Hamamatsu sells the enabling hardware for the claimed method and, per the family filings, also reagents related to ThT purity. This is a genuine operating company with a commercial stake in the technology, not a holding vehicle.
• Enforcement posture: my earlier verification (carried forward, not repeated) found no US district court or CAFC activity on this patent. Hamamatsu's publicly reported enforcement activity concerns unrelated patents.

Assignment timeline

One recorded assignment exists. There is no post-issuance chain.

• 2018-03-14 to 2018-03-15 (executed — the record gives a signing-date range across the four inventors) / recorded 2018-03-28 — Reel 045371 / Frame 0517
  • Conveyance: Assignment (recorded under assignment code AS — "ASSIGNMENT OF ASSIGNORS INTEREST")
  • Assignors: ODA, AKINORI; SATOZONO, HIROSHI; SHINKE, TOMOMI; and one further named inventor (TAKATA, YOHEI) — the record's free-format text reads "AND OTHERS"
  • Assignee: HAMAMATSU PHOTONICS K.K., Japan
  • Correspondent: Not determinable from the data available to me. The aggregated legal-events record carries the reel/frame and the free-format conveyance text but not the recorded correspondent attorney/firm. I am not going to supply a name I cannot source.
  • Context: Internal chain-of-title perfection at national-stage entry. The inventors executed the assignment on 14–15 March 2018; it was recorded on 28 March 2018, which is the same date Google Patents logs the case as assigned to Hamamatsu and effectively the §371(c) national-stage entry period for PCT/JP2016/076469 (filed 2016-09-08, published as WO 2017/056905 A1). Because the PCT applicant was already Hamamatsu Photonics K.K., this is the routine employee-inventor → corporate-applicant assignment needed to perfect US title — not a transfer to a third party, not a fire-sale, not a securitization.

Nothing after this. No security agreement, no license, no merger, no change-of-name, no corrective assignment, no release, and no transfer to any LLC or aggregator appears anywhere in the record I can retrieve. Ownership has been continuous with Hamamatsu Photonics K.K. from the 2016-09-08 PCT filing to today.

Per the task instruction — stating this plainly: the Assignment Center-indexed record for this patent contains only the original inventor→corporate assignment. That is itself the finding: the original assignee still owns the patent.

Related-instrument note (not an assignment of 11,402,328): the US divisional application 17/858,183 (published US 2022/0357276 A1, filed 2022-07-06) is listed as abandoned and produced no issued claims. The Google Patents family/applications tables group 15/763,935 and 17/858,183 together under the same Hamamatsu ownership; an abandonment is not a conveyance and does not appear in the assignment record as a transfer. Its practical effect is only that no US device or program claims exist in this family, narrowing the assertable surface of the portfolio to the four method claims of 11,402,328.

Timeline diagram

timeline
    title Ownership of US 11402328
    2015 : JP priority application filed
    2016 : PCT JP2016 076469 filed
    2018 : Inventors assign to Hamamatsu Photonics
         : Reel 045371 frame 0517 recorded
    2019 : US pre-grant publication
    2022 : Patent US 11402328 B2 issued
         : Divisional 17 858 183 filed
    2026 : 4th year maintenance fee paid

NPE / troll-pattern signals

Strong-signal count: zero. No signal is present. Signal 3 is "not present" on structural grounds but carries an explicit evidence gap regarding the correspondent name.

Verdict

Insufficient data — under the strict rubric, because the Assignment Center record I can reach contains only the original assignment (Reel 045371/0517, executed 2018-03-14/15, recorded 2018-03-28, inventors → Hamamatsu Photonics K.K.) and no post-issuance conveyance of any kind.

Substantively, though, the data is not ambiguous: this is an operating-company-owned patent with an unbroken chain of title, not an NPE asset. The single recording is a routine employee-inventor-to-corporate-applicant perfection step executed on national-stage entry into PCT/JP2016/076469, the assignee (Hamamatsu Photonics K.K.) is a publicly listed photonics and life-science instrumentation manufacturer that commercially sells the Quantaurus-Tau instrument the specification prescribes for practicing the claims, maintenance fees are current through the 4th year (paid 2026-01-21), and the specification's "device" and "program" subject matter never issued as US claims (the attempted divisional 17/858,183 is abandoned) — leaving no software or apparatus claim for an asserter to shop. A reviewer should still manually confirm the absence of security interests, licenses, and the correspondent name at the Assignment Center before treating "no further recordings" as final.

Verify at: https://assignmentcenter.uspto.gov/ (search patent 11,402,328 or application 15/763,935); legacy index mirror: https://assignment.uspto.gov/patent/index.html

Carried-forward caveats from the earlier section, restated for this one: Google Patents' legal-status and expiration data expressly disclaim legal accuracy (adjusted expiration 2038-07-25 and entity status should be confirmed in USPTO PatentCenter); and "no litigation found" is a negative search result, not an affirmative clearance.

I'll analyze each cited reference from the patent's face. Let me verify key details with targeted searches.

Let me verify the key patent citations' details.

Prior-Art Analysis — US Patent No. 11,402,328 (application 15/763,935)

Verification note: The number was searched literally. US 11,402,328 B2 (US15/763,935) is the Hamamatsu Photonics patent "Amyloid β oligomer detection method…", granted 2022-08-02, priority JP 2015-191307 (2015-09-29). The reference list below is taken from the patent's own face (the "Patent Citations" and "Non-Patent Citations" tables) as reproduced in the authoritative full text. I did not substitute or auto-correct any number. Where I could, I cross-checked individual references against Google Patents/Espacenet/PubMed; those cross-checks are noted. Some reference full texts (esp. the Japanese-language Koho) I could not open in full, so the descriptions rely on titles/abstracts/family data; I flag that explicitly rather than assert content I did not see.

Framing for § 102: Claim 1 requires a single reference to disclose all of: (a) contacting sample with thioflavin T; (b) measuring ThT fluorescence to obtain time-resolved spectra; (c) normalizing spectra for two time windows t1–t2 and t3–t4; and (d) determining Aβ oligomer presence from a blue-shift of the later spectrum. Claims 2–4 add the s1 (λ1 >480 nm), s2 (λ2 <480 nm), and peak-top-wavelength metrics. A reference that merely detects Aβ oligomers by some other chemistry (antibody, FRET, nattokinase, etc.) cannot anticipate under § 102.

Bottom line up front: None of the seven patent citations of record anticipates claims 1–4 under § 102 — they are background/§ 103-type art covering different detection chemistries. The only reference that comes close to the claimed physicochemical principle is the Lindberg 2015 non-patent citation (time-resolved ThT fluorescence), and even it does not disclose the claimed oligomer-vs-fibril spectral blue-shift determination. Details below.

A. Patent citations of record (each analyzed)

1. WO 2008/012101 A1 — Vista Ventures GmbH

• Full citation: WO 2008/012101 A1, "Method for the detection of amyloid-β oligomers in body fluids," Vista Ventures GmbH; priority/app. date 2006-07-28; published 2008-01-31.
• Description: Detects Aβ oligomers in CSF/body fluids by (i) demasking antibody epitopes on the oligomers and (ii) contacting with fluorescently labeled antibodies, reading a FRET signal (e.g., by flow cytometry). Verified via Espacenet/family record (EP 1882944 B1; EP 1882944 A1 2008-01-30).
• § 102 assessment: Does not anticipate any of claims 1–4. It discloses the goal (Aβ oligomer detection) but uses antibody/FRET chemistry, not ThT, not time-resolved spectra, not two-window normalization. At best § 103 background.

2. JP 2009-544954 A — Vista Ventures (JP national phase of WO 2008/012101)

• Full citation: JP 2009-544954 A (特表2009-544954), "Method for detecting amyloid-β oligomers in body fluids," applicant ヴィスタ ベンチャーズ ゲーエムベーハー; JP filing 2007-07-27 (PCT/EP2007/006677), published 2009-12-17; granted as JP 5009987 B2.
• Description: Same disclosure as item 1 (demasking + fluorescently labeled antibody pair + FRET; claims 1–10 substantially as in EP 1882944). Verified from the JP Koho front page.
• § 102 assessment: Does not anticipate claims 1–4 — identical chemistry limitation as item 1 (no ThT / no time-resolved spectral blue-shift). Note items 1 and 2 are the same family, so they do not add independent art.

3. JP 2010-168385 A — Abbott GmbH & Co. KG

• Full citation: JP 2010-168385 A, "Formulation containing amyloid-β(1-42)-oligomer or derivative thereof, preparative method thereof, and use thereof," Abbott GmbH & Co. KG; priority 2003-01-31; published 2010-08-05.
• Description: Concerns Aβ(1-42)-oligomer-containing formulations, their preparation, and uses (e.g., immunization/diagnostics). This is oligomer composition/preparation art — and is the general source concept for preparing Aβ oligomers that the '328 Examples rely on.
• § 102 assessment: Does not anticipate claims 1–4. It teaches making an oligomer, not detecting one via ThT time-resolved fluorescence. No contact/measure/normalize/determine steps. (§ 103 relevance only: it supplies a known oligomer preparation.)

4. JP 2010-120942 A — Academia Sinica

• Full citation: JP 2010-120942 A, "Nattokinase decomposing and reducing amyloid fibril associated with Alzheimer's disease, prion disease, and other amyloidosis," Academia Sinica; priority 2008-11-22; published 2010-06-03.
• Description: A nattokinase enzyme for degrading/reducing amyloid fibrils.
• § 102 assessment: Does not anticipate any claim. It is an enzyme/lysis art, unrelated to the ThT time-resolved spectral method.

5. WO 2010/119704 A1 — Immunas Pharma, Inc.

• Full citation: WO 2010/119704 A1, "Antibodies that specifically bind to β oligomers and use thereof," Immunas Pharma, Inc.; priority 2009-04-17; published 2010-10-21.
• Description: Antibodies specific for Aβ oligomers and their diagnostic/therapeutic uses.
• § 102 assessment: Does not anticipate claims 1–4 — antibody-based detection, not dye-based time-resolved fluorescence.

6. JP 2012-524023 A — Immunas Pharma (JP phase of WO 2010/119704)

• Full citation: JP 2012-524023 A (特表2012-524023), "Antibody specifically binding to Aβ oligomer and use thereof," applicant イムナス・ファーマ株式会社; JP filing based on PCT (WO 2010/119704); published 2012-10-11 (priority 2009-04-17).
• Description: Same family as item 5 — oligomer-specific antibodies.
• § 102 assessment: Does not anticipate claims 1–4. Same reasoning as item 5; same family, so cumulative.

7. JP 2015-166749 A — Cognoptix, Inc.

• Full citation: JP 2015-166749 A, "System and method for detecting amyloid proteins," コグノプティックス，インコーポレイテッド (Cognoptix, Inc.); priority 2010-08-16; published 2015-09-24.
• Description: Fluorescence-based in-vivo/system detection of amyloid proteins (Cognoptix's ligand/eye-scanning approach).
• § 102 assessment: Does not anticipate claims 1–4. It is fluorescence-based amyloid detection, but it does not disclose ThT as the reporter, time-resolved spectral acquisition across two time windows, normalization, or the blue-shift criterion. This is the closest of the patent citations on the "fluorescence detection" axis, but it still fails the claimed analytic steps. § 103 material at most.

8. JP 2014-122846 A — Hamamatsu Photonics K.K. (applicant's own earlier work)

• Full citation: JP 2014-122846 A, "Method and device for quantifying aggregation of amyloid," Hamamatsu Photonics K.K. (浜松ホトニクス株式会社); priority 2012-12-21; published 2014-07-03 (JP family member JP 6133053 B2, granted 2017-05-24).
• Description: Method/apparatus for quantifying the degree of amyloid aggregation — same applicant, same general instrumentation area (fluorescence/optical measurement of amyloid aggregation).
• § 102 assessment: Does not anticipate claims 1–4 on the record I can verify. It addresses quantifying aggregation level, not distinguishing an oligomer from fibril by a time-resolved spectral blue-shift between two normalized time windows. Because it is the applicant's own related art, it is the citation most worth obtaining in full text (see caveat) — if its disclosure did include two-time-window normalized ThT spectra and a shift criterion, that would change the § 102/§ 103 picture for claim 1. I could not open its full Japanese text, so I am flagging this as unverified rather than clearing it.

9. WO 2015/060333 A1 — Kobe University (国立大学法人神戸大学)

• Full citation: WO 2015/060333 A1, "Artificial peptide capable of degrading amyloids and utilization thereof," 国立大学法人神戸大学; priority 2013-10-25; published 2015-04-30.
• Description: Artificial amyloid-degrading peptides and uses.
• § 102 assessment: Does not anticipate any claim — peptide-degradation art, unrelated to the detection method.

B. Non-patent citations of record

NPL-1 (most relevant reference in the entire record) — Lindberg et al. 2015

• Full citation: D. J. Lindberg, M. S. Wranne, M. Gilbert Gatty, F. Westerlund, E. K. Esbjörner, "Steady-state and time-resolved Thioflavin-T fluorescence can report on morphological differences in amyloid fibrils formed by Aβ(1-40) and Aβ(1-42)," Biochem. Biophys. Res. Commun. 458(2):418–423 (2015); DOI 10.1016/j.bbrc.2015.01.132; Epub 2015-02-07, issue date 2015-03-06. Verified via PubMed (PMID 25660454).
• Description (verified abstract): Characterizes ThT binding to Aβ(1-40) and Aβ(1-42) fibrils; shows steady-state intensity differences and, via excited-state fluorescence lifetime, that Aβ(1-42) fibrils produce a longer ThT lifetime than Aβ(1-40); proposes fluorescence lifetime "sensitively reports on fibril microstructure in the protofilament."
• § 102 assessment: This is the closest art to claim 1's technical principle (time-resolved ThT fluorescence discriminating Aβ species) and it predates the 2015-09-29 priority date. However, it does not anticipate claims 1–4, because: (i) it studies fibrils only, not the oligomer-vs-fibril discrimination the claim requires; (ii) it reports fluorescence lifetime, not a spectral shift; and (iii) it does not disclose the two-time-window normalization + blue-shift determination. Its proper role is § 103 secondary/combinable art (it establishes that time-resolved ThT fluorescence is species-sensitive).

NPL-2 — Stine et al. 2003

• Full citation: W. B. Stine, Jr., et al., "In Vitro Characterization of Conditions for Amyloid-β Peptide Oligomerization and Fibrillogenesis," J. Biol. Chem. 278(13):11612–11622 (2003).
• Description: Methods paper characterizing in-vitro conditions for preparing Aβ oligomers vs. fibrils — the protocol the '328 Examples follow for sample preparation.
• § 102 assessment: Does not anticipate any claim (no ThT time-resolved spectral detection, no normalization, no shift determination). Relevant only as a methods reference for making the samples.

NPL-3 — International Preliminary Report on Patentability

• Full citation: IPRP dated 2018-04-12 for PCT/JP2016/076469.
• § 102 assessment: Not prior art at all — it is a prosecution document generated after the 2015 priority date; it cannot anticipate.

C. Summary table (Patent Citations)

NPL: Lindberg 2015 = closest, but § 103 material, not § 102 anticipation; Stine 2003 = methods background; IPRP = not prior art.

D. Caveats

• Anticipation standard: I applied strict § 102 (single reference, every element). On the titles/abstracts verified, no cited reference anticipates claims 1–4. The examiner's citations are consistent with an examination record whose real rejection pressure would have been § 103 (combining oligomer-detection art with time-resolved ThT fluorescence art such as Lindberg), not § 102.
• Unverified item: I could not open the full Japanese text of JP 2014-122846 A (Hamamatsu's own amyloid-aggregation-quantification art). Its title suggests quantifying aggregation, not the claimed oligomer/fibril blue-shift determination, but if you need a definitive § 102/§ 103 position on claim 1, this reference's full disclosure should be pulled from JPO (JP 6133053 B2 family).
• Espacenet/Google/PubMed cross-checks confirm identifiers/dates for items 1, 2 (EP 1882944 / JP 5009987 B2 family), 8 (JP 6133053 B2 family), and the Lindberg and Stine NPLs. Items 3–7, 9 rely on the patent's own citation table plus title-level matching; I did not retrieve their full texts, so descriptions there are title/abstract-level, not document-level.
• I did not discover any non-cited prior art in these searches that anticipates the claims; the earlier-made point that the device/program subject matter was never claimed in this US patent still stands and further narrows the relevant prior-art field to the method claims only.

If you want, I can next retrieve the full text of JP 2014-122846 A and the examiner's actual § 102/§ 103 rejections from the file wrapper (application 15/763,935) to confirm exactly which references were relied upon and on what basis.

I'll ground this obviousness analysis in the actual prior-art references of record before building the § 103 combinations.

Obviousness Analysis — U.S. Patent 11,402,328 B2 under 35 U.S.C. § 103

Framing note: This analysis builds on the prior summary sections and does not repeat the claim charts, family data, or litigation findings already presented. It focuses only on the § 103 question, using the references actually identified in the "Prior Art," "Patent Citations," and "Non-Patent Citations" tables of the patent page. Caveat up front: I have verified the abstract and citation metadata for Lindberg et al. (2015) against PubMed/Elsevier, but for the Japanese-language references (JP 2014-122846, JP 2010-168385, JP 2012-524023, JP 2015-166749) I have only abstracts, family-member titles, and secondary snippets. Every mapping below should be confirmed against certified translations and full texts before being relied on in a validity opinion.

1. The § 103 framework applied to this claim set

Claim 1 (the only independent claim) requires four steps:

1. contact test sample with thioflavin T (ThT);
2. measure ThT fluorescence to obtain time-resolved fluorescence spectra;
3. normalize the spectra of an early window (t1–t2) and a later window (t3–t4), t1<t2≤t3<t4; and
4. determine oligomer presence from a shift of the later spectrum to shorter wavelengths.

Under KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007), and the Graham factors, the inquiry is whether the differences between the claim and the prior art would have been obvious to a person having ordinary skill in the art (POSITA) at the 2015-09-29 priority date. Key KSR rationales available here: (a) combination of familiar elements according to known methods yielding predictable results; (b) use of a known technique (time-resolved/TCSPC spectroscopy) to improve a similar method (ThT amyloid staining); (c) "obvious to try" — a finite number of identified, predictable solutions.

The critical issue is that steps 1–3 are individually conventional. The asserted invention is really the recognition (step 4) that the ThT time-resolved spectrum of an oligomer blue-shifts relative to a fibril. That recitation is what the analysis must stress-test.

2. Element-by-element availability in the references of record

Bottom line of the mapping: the record supplies every element except the affirmative teaching that the discriminating variable is a low-wavelength shift of the time-resolved spectrum over the ns window and that this is specific to oligomer vs. fibril. That gap drives the entire § 103 debate.

3. Candidate § 103 grounds

Ground 1 — Lindberg 2015 in view of JP 2014-122846 (Hamamatsu), optionally with Stine 2003

Why combinable: Both references are in the same field (ThT/thioflavin fluorescence as a readout of Aβ aggregation state), and JP 2014-122846 is the applicant's own prior work quantifying amyloid aggregation by analyzing the fluorescence decay curve of a thioflavin derivative. Lindberg teaches that the ThT fluorescence lifetime is "inherent to each isoform and sensitively reports on fibril microstructure" (PubMed 25660454; BBRC 458:418–423).

Motivation: (i) The field recognized the Aβ oligomer as the toxic species and wanted cheap, specific oligomer detection — the very problem recited in the patent's background and reflected in WO 2008/012101 (Vista Ventures, "Method for the detection of amyloid-β oligomers in body fluids") and WO 2010/119704 / JP 2012-524023 (Immunas, oligomer-specific antibodies). (ii) Lindberg expressly proposes "extended use" of ThT time-resolved fluorescence to distinguish amyloid species/morphologies. (iii) JP 2014-122846 shows the same laboratory already used time-resolved decay analysis to characterize Aβ aggregation. A POSITA would have been motivated to apply time-resolved ThT spectroscopy to oligomer vs. fibril samples — a finite, predictable set of experiments. Stine 2003 (JBC 278:11612–11622), cited in the patent itself as the oligomer/fibril preparation method, supplies how to make the comparison samples.

Weakness: Neither Lindberg nor JP 2014-122846 teaches or suggests that the direction of a spectral change over the ns window discriminates oligomer from fibril. The ground therefore rests on "obvious to try" plus the assertion that a blue shift is an inherent property of ThT-stained oligomer (see § 4).

Ground 2 — Lindberg 2015 in view of the oligomer-detection references (Vista Ventures WO 2008/012101 / JP 2009-544954; Immunas WO 2010/119704 / JP 2012-524023)

The oligomer references establish the problem and the desirability of an oligomer-specific assay but use immunoassay/electrophoretic chemistry, not ThT time-resolved spectroscopy. This ground is best used to supply the motivation to combine (why a POSITA would target oligomers specifically) rather than any missing limitation. Standing alone it is weaker than Ground 1.

Ground 3 — JP 2014-122846 in view of Cognoptix JP 2015-166749 / EP 2420179 (and Hamamatsu's own instrument art)

Cognoptix (EP 2420179, Experiment #1) discloses fluorescence lifetime measurement to distinguish an amyloid-binding fluorophore bound vs. unbound to aggregated Aβ, using, notably, Hamamatsu light sources and TCSPC modules. This confirms that a POSITA would have regarded TCSPC-based discrimination of amyloid-bound dye as a conventional technique, and that spectrally resolved TCSPC (the standard operating mode of the Quantaurus-Tau instrument used in the patent's examples) was a known tool. This ground supports "known technique to improve a similar method" (KSR rationale b) but again does not supply the oligomer blue-shift teaching.

Ground 4 — Any of the above + JP 2010-168385 (Abbott, Aβ(1-42)-oligomer formulation)

Abbott supplies oligomer standards/formulations; useful only as enabling prior art showing oligomer samples were available and characterized. Low independent weight.

4. The inherency counter — the pivotal § 103 argument against claim 1

If the low-wavelength shift is an inherent property of the ThT–oligomer complex (i.e., any ThT-stained oligomer, measured with sufficient spectral/time resolution, necessarily exhibits it), then:

• Under In re Best and In re Kratz, a process that necessarily produces a claimed result may render the claim obvious (or anticipated) even without recognition of the underlying mechanism.
• Combined with KSR's "obvious to try," a POSITA who applied the standard spectrally-resolved TCSPC method to an oligomer sample would necessarily obtain the claimed blue shift, and comparing the two spectra is a routine analytical step.

The applicant's rebuttal is strong here, however: the discovery that fibrils show a slight red shift while oligomers show a clear blue shift (specification, Example 1 / FIGS. 4A–4B) is a genuinely unexpected structure–property relationship with a nexus to the full scope of claim 1, which is defined by that very shift. Under In re Soni and the unexpected-results doctrine, that can defeat a prima facie case built on inherency/obvious-to-try, particularly where the prior art (Lindberg) is directed to fibrils and offers no motivation to expect a directionally specific spectral change for oligomers.

5. Dependent claims 2–4 (weaker than claim 1)

These claims narrow the determination step to arithmetic/analytical proxies and are the most vulnerable:

• Claim 2 (s1, λ1 > 480 nm) and Claim 3 (s2, λ2 < 480 nm) — computing a ratio of two normalized intensities is a routine data-processing step. The 480 nm boundary is essentially the known ThT emission peak (specification itself states ThT "exhibits fluorescence having a peak wavelength near 480 nm"), so the numerical cutoff is a result-effective variable arrived at by routine optimization. In re Applied Materials / In re Boesch: a range or cutoff obvious if the art provides the design rationale. Expect a § 103 rejection of these as "conventional data analysis of the claim 1 method."
• Claim 4 (peak-top wavelength comparison) — a standard spectral metric; comparing maxima is the most elementary of spectral analyses.
• If these determination steps are treated as non-limiting mental/analytical steps (see In re Montgomery; In re Schultheiss), claims 2–4 collapse toward claim 1's physical steps, strengthening the obviousness position considerably.

6. Likely course of an obviousness rejection (and how it would be met)

A realistic Examiner rejection would start with Lindberg 2015 as the primary reference, assert that time-resolved ThT spectral measurement of Aβ aggregates is known and that measuring an oligomer sample would inherently produce the claimed shift, and cite JP 2014-122846 (decay-curve-based quantification) and/or Cognoptix EP 2420179 for the TCSPC/lifetime-discrimination technique. The applicant would respond with:

1. No teaching of oligomer-specific spectral shift in any reference (all references teach fibril isoforms or generic aggregation).
2. Unexpected results with nexus (blue shift for oligomer vs. red shift for fibril) demonstrated by FIGS. 4–7 and Examples 1–3.
3. No reasonable expectation of success in predicting the direction of the shift.

Points 2–3 are the applicant's strongest ammunition and are the reason I would rate claim 1 as nonobvious but close, whereas claims 2–4 are highly vulnerable.

7. Confidence and verification flags

• High confidence: Lindberg 2015's content (verified: PubMed 25660454; DOI 10.1016/j.bbrc.2015.01.132) — it addresses fibril isoforms, measures fluorescence lifetimes, and proposes extended use of ThT for fibril characterization. It does not disclose oligomer-specific spectral shifts.
• Moderate confidence: the substance of JP 2014-122846 / JP 6133053 B2 (Hamamatsu "method and apparatus for quantifying amyloid aggregation" using a thioflavin derivative and fluorescence decay analysis) — confirmed only from titles/abstracts and secondary citations, not full text.
• Low confidence / unverified: whether any of the Japanese references contain latent disclosure (e.g., a passing mention of spectral shift, TRES, or oligomer-specific emission) that would strengthen Grounds 1–3. This must be checked against full-text translations.
• Note on the applicant's own prior art: JP 2014-122846 predates the 2015-09-29 priority date by more than one year and is applicant work, so it qualifies as § 102(a)(1)/103 prior art with no § 102(b)(1) exception.

Recommended next step: obtain certified English translations and full texts of JP 2014-122846, JP 2012-524023, and JP 2010-168385, and confirm whether any disclose (a) spectrally-resolved (as opposed to lifetime-only) ThT measurement, or (b) oligomer-specific emission behavior. Those two facts would determine whether the § 103 challenge to claim 1 moves from "close" to "strong."

(Minor housekeeping flag: the task header gives "Current Date: April 26, 2026," while the system date reads 2026-09-29. This does not affect the analysis but is noted for consistency with the earlier sections.)