US 11402375

I'll search for this specific patent number.

Let me verify the granted claim text and check for any 2026 litigation/appeal activity.

US 11,402,375 B2 — Summary

Important note on method: I ran targeted searches and did not have direct access to the USPTO PatentCenter/Patent Full-Text (patft) or PACER/CAFC docket databases. Everything below is grounded in the sources I could retrieve, and I flag the one point of internal tension I found.

Bibliographic data

Sources: https://patents.justia.com/patent/[11402375](/patent/11402375) ; https://patents.google.com/patent/US11402375/en ; https://mtec-sc.org/patents/US-11402375-B2

Abstract (as granted)

"The present invention provides apparatus and methods for the rapid determination of analytes in liquid samples by immunoassays incorporating magnetic capture of beads on a sensor capable of being used in the point-of-care diagnostic field."

Independent claim 1 — plain-language overview

Per the claim text reflected in secondary sources, claim 1 (the identified independent claim; 27 claims total) is a device claim directed to a point-of-care cartridge with magnetic bead capture in a trench:

1. Cartridge housing with a base — a disposable body.
2. Sample chamber with a sample inlet — receives the liquid sample (e.g., whole blood).
3. A conduit in fluidic communication with the sample chamber.
4. A sensor chip inside the conduit, formed on the cartridge base — a "single sensing electrode" built on a silicon wafer having a single trench, an insulating oxide layer, metal layers over the oxide, and a photodefinable polyimide over the metal layers with electrode openings cut into it. Those openings expose portions of the metal to define a two-dimensional array of microfabricated electrodes at the bottom of the single trench, including a line of microelectrodes in that trench.
5. A dissolvable dry matrix of magnetically susceptible beads located in the sample chamber or the conduit, designed to dissolve into the sample fluid.
6. A permanent high-field magnet formed in the base, abutting the bottom of the sensor chip, that retains at least a portion of the beads in the trench.
7. A pump that moves the sample from the sample chamber through the conduit to the sensing electrode.

Plain-language gist: a single-use cartridge where antibody-coated magnetic beads dissolve into the sample, are pumped to a microfabricated gold/polyimide electrode array recessed in a trench, and are held in place by a magnet mounted directly under the chip so the bound label can be measured electrochemically after washing.

Representative dependent claims visible in search results (Justia): claim 21 (event horizon < about 200 µm), 22 (amperometric array), 23 (gold microarray), 24 (trench width/height/length each ≥ 2× mean bead size), 25 (conduit coated with the dry matrix), 26 (sample chamber coated, connected between inlet and array), 27 (trench width 0.1–50 µm and height 0.1–50 µm).

⚠️ Discrepancy you should be aware of

The specification's "Summary of the Invention" paragraph states the array is "positioned within the troughs of a plurality of trenches, wherein the average width, height and length of each trench are each at least twice the mean average particle size of the beads." The granted claims instead recite "a single trench" (corroborated by dependent claims 21–27, which all refer to "the single trench"). This is consistent with the claims having been narrowed during the unusually long 11-year prosecution (the file history cited numerous prior-art rejections across related applications 13/204,109, 13/204,121 and 13/204,172). I could not retrieve the full verbatim text of claim 1 from an official source (USPTO/Google Patents claim listing) within this session, so treat the claim-1 wording above as a high-confidence reconstruction rather than a certified transcription. If precise claim language matters, verify against the USPTO PatentCenter grant document for 13/204,094.

I also cannot rule out that the patent contains a second independent claim (e.g., a method claim); the sources I retrieved only surfaced the device claim set through claim 27.

CAFC 2026 docket search — no results

I searched for Federal Circuit 2026 docket activity involving US 11,402,375 and found nothing. No appeal, IPR appeal, or CAFC proceeding tied to this patent number appeared in any retrieved result. The only 2026 Abbott-related items returned were unrelated matters:

• New Directions Technology Consulting v. Abbott Laboratories (D. Del., Judge Andrews, March 2026 — pacemaker/glucose-monitor patents), and
• An Abbott CGM provisional-measure action at the UPC Milan Local Division concerning EP'072.

Conclusion: as of this search, there is no evidence of CAFC 2026 litigation or appeal activity for 11402375. That is a negative finding, not proof of absence — a PACER/CAFC CM/ECF docket lookup would be required to confirm.

Other notes

• The patent claims priority to provisional 61/371,077 (Aug. 5, 2010) and has a child filing: application 17/804,330 (filed May 27, 2022), published as US 2022/0326232 A1.
• The patent shares its specification with the family including US 9,958,440 ("Magnetic immunosensor and method of use") and pre-grant publication US 2019/0033305 A1.
• A third-party site (patentleaderboard.com) lists an aggregate figure of $170,205,000 associated with this patent. That is a commercially derived valuation estimate, not an official USPTO or court record, and I would not rely on it.

I'll search for litigation involving US patent 11402375 across patent litigation databases.

The first searches returned mostly unrelated results (other "'023" patents). Let me narrow the search specifically to this patent number and litigation databases.

Summary

Based on my searches across patent-litigation sources, I was unable to find any litigation (district court action, ITC investigation, or PTAB proceeding) that specifically names U.S. Patent No. 11,402,375.

What I searched

• General web searches for "11402375" combined with litigation/lawsuit terms
• The Unified Patents litigation portal (portal.unifiedpatents.com)
• Stanford's NPE Litigation Database
• CAFC/PTAB-adjacent document sources
• Searches combining the patent number with its assignee (Abbott Point of Care Inc.)

Result: no case found

None of the hits returned a case in which 11,402,375 is an asserted or challenged patent. The relevant-looking results were for different patents with similar or overlapping-sounding numbers, and per your strict rule I am not treating them as the same patent:

• U.S. 10,853,023 — a Sonos/Linkplay dispute (Delaware), unrelated.
• U.S. 7,979,023 — Unified Patents v. Carucel Investments, unrelated.
• U.S. 5,112,455 — Abbott Point of Care Inc. v. Epocal, Inc., No. 5:08-cv-00543 (N.D. Ala.), from the Stanford NPE database. This is a different patent number and predates 11,402,375's issuance by more than a decade. I mention it only to flag it as a near-miss you should not confuse with 11,402,375.

I found no plaintiff/defendant pairing, jurisdiction, case number, or status to report for 11,402,375.

Context that bears on the finding

The patent itself (from the full text you provided) has these attributes:

Two observations:

1. The patent issued relatively recently (2022-08-02), which reduces the window in which infringement suits could have been filed.
2. The assignee is Abbott Point of Care Inc., a practicing entity (not an NPE). Its patent assertions, where they exist, would typically appear as Abbott Point of Care v. [competitor] cases. I found no such case naming this patent.

Caveats

• My search coverage is not exhaustive. Litigation data (especially recent district court complaints, PACER dockets, and ITC filings) is not fully indexed by general web search, and I did not have direct PACER access in this session.
• A case could exist that names this patent but is not surfaced by the sources I could reach.
• To be certain, I'd recommend a direct check of PACER (party search: "Abbott Point of Care") and Lex Machina / Docket Navigator patent-by-patent lookups, plus the USPTO PatentCenter "Litigation" tab for 11,402,375.

Bottom line: No known litigation involving U.S. Patent No. 11,402,375 was located in my search; treat the near-miss "023" and "455" results as unrelated patents.

I'll verify the structured block's default against live sources before writing this up.

Proceedings overview

Zero AIA trial proceedings are on file against US 11,402,375 as of 2026-09-29. The structured PTAB block supplied in this prompt states the USPTO Open Data Portal returns no AIA trial proceedings, and my independent web checks (below) surfaced none — so the breakdown by status (active / claims invalidated / claims sustained / settled / institution-denied) is 0 / 0 / 0 / 0 / 0, not because proceedings were resolved favorably to the patent owner, but because no petition has ever been filed.

Bottom-line defensive posture for a defendant: you are not facing a patent that has been hardened by surviving IPRs — you are facing a patent that has never been tested at the Board. Every claim is UNTESTED, no claim is CANCELED, and no § 315(e) estoppel attaches to anyone. That cuts both ways: there is no FWD you can point to and say "claim 1 is dead," but there is also no adverse Board precedent, no claim-construction ruling, and no Patent Owner Response record you have to overcome. The freedom to file a first IPR is intact — subject only to the § 315(b) one-year clock and the fact that the patent's prosecution history (11 years, app. 13/204,094 filed 2011-08-05, granted 2022-08-02) is a long, rich § 325(d) / prosecution-history record to work with.

Per-proceeding detail

None. There is no proceeding to profile, so the standard template (type / filing date / status / panel / grounds / institution decision / FWD / settlement / appeal / defensive value) cannot be populated for any number without fabricating it, which I will not do.

Verification log — what I actually checked

I want to be explicit about the limits of this: PTAB E2E at https://ptacts.uspto.gov/ is the authoritative docket, and I did not run a native E2E query — I am reporting the ODP block plus negative web-search corroboration. If a petition was filed in the last few weeks and not yet indexed, the block would not reflect it. Treat "no PTAB activity" as high-confidence but re-verify against PTAB E2E before you build a budget around it.

Strategic summary

Claim status: 100% UNTESTED. Because no IPR, PGR, or CBM has been filed, there is no claim of US 11,402,375 that has been canceled, confirmed, or even construed by the Board. Contrast this with the family's more heavily-exercised siblings — U.S. 9,233,370 and U.S. 9,958,440 (Miller et al., from sibling application 13/204,121, filed the same day) — which are the natural first targets for anyone attacking the magnetic-immunosensor family. Nothing I found indicates those have been challenged either. One caveat on claim scope that a defendant should verify claim-by-claim against the printed claims: the summary of the invention describes an array of electrodes "positioned within the troughs of a plurality of trenches" with each trench dimensioned at least twice the mean bead size, whereas downstream claim snippets in public databases (e.g., claim 21 and claim 27, both depending from claim 1) refer back to "the single trench" — suggesting the independent claims may recite a single trench rather than a plurality. That is exactly the kind of drafting mismatch that makes a § 112(b) or § 102/§ 103 theory attractive, but I could not verify the full claim set from the sources retrieved and flag it as unverified.

Estoppel landscape: a clean slate — the § 315(e)(2) bar is empty. Because no IPR has reached a final written decision, no petitioner, real party in interest, or privy is estopped from raising anything, in the district court or the Office. Your § 102/§ 103 grounds based on patents and printed publications are all fully available, as are § 112 and § 101 challenges (which an IPR could not have carried anyway). Two practical constraints govern:

• § 315(b) one-year bar. If and when you are served with a complaint alleging infringement of the '375, the clock starts. The patent issued 2022-08-02 and IPR availability opened 2023-05-02 (nine months post-grant), so the patent is IPR-eligible; only your own service date limits you.
• Pre-AIA status. The application was filed 2011-08-05, so it is pre-AIA — which means PGR was never available (PGR is limited to first-inventor-to-file patents) and CBM is unavailable (expired 2020 and this is not a financial-services patent). IPR based on patents and printed publications is your only Board vehicle. That arguably makes the total absence of IPR activity more striking, not less.

Pattern signals. There is no pattern because there is no activity. No serial petitioner, no defensive aggregator in the chain (Unified Patents and similar entities show nothing), no PTAB appeal, and no Federal Circuit docket. The absence is best explained by the patent owner's identity rather than by patent strength: Abbott Point of Care Inc. is a large operating company (i-STAT® point-of-care business), not a monetization entity, and it holds this family defensively alongside a deep i-STAT portfolio. Well-asserted patents attract IPRs; defensively-held operating-company patents often attract none. That is the single most important read of this record — do not mistake "never challenged" for "bulletproof."

One forward-looking note for portfolio-watchers: the family is live. A continuation of the '375 (application 17/804,330, filed 2022-05-27) has now issued as US 12,687,541 B2 (patent date 2026-07-21). Its own IPR window opens on or about 2027-04-21. A challenge aimed only at the '375 would leave that continuation standing, so any validity strategy should be scoped to the family, not the single patent.

Recommended next steps

1. If you are a defendant, do not expect a silver bullet. There is no FWD to cite, no canceled claim, and no Board claim construction to leverage. Your invalidity case must be built from scratch in the district court or in a first-filed IPR. Link to the docket you verified yourself: PTAB E2E and PTAB Decisions for the negative check, and CourtListener for any CAFC activity.
2. Build the prosecution-history attack. An 11-year pendency (2011-08-05 filing → 2022-08-02 grant) with a 2020-12-19 non-final action showing claims 1, 3-6, 13 and 29 allowed and claims 31-33 rejected (per the file-history excerpts surfaced) is a large, well-documented § 325(d)/§ 112 record. Mine the 13/204,094 file wrapper for admissions, art cited and distinguished, and the record of the intervening US20120034684A1 publication (published 2012-02-09) — which is itself prior art as of its publication date against any later-filed family member.
3. Scope any IPR to the whole family. Because US 12,687,541 B2 issued 2026-07-21, and because 9,233,370 / 9,958,440 share the 2010-08-05 priority and the same specification, evaluate whether one petition per patent or a consolidated strategy is required. Note the 2027-04-21 window opening on the '541.
4. Watch the § 315(b) clock. If you are served, calendar the one-year IPR deadline immediately; the absence of any prior petition means there is no earlier-filed proceeding to join under § 315(c) and no § 315(e) estoppel reservoir to inherit.
5. Re-verify before relying. Because the block is ODP-sourced and ODP indexing lags, re-run the E2E query for "11,402,375" on the day you file or answer. I have flagged this rather than asserted freshness I cannot demonstrate.

No proceedings found — and I am saying so plainly rather than implying a merits outcome. The absence of PTAB activity is a signal about the patent owner's posture, not a finding of validity.

I'll start by attempting to pull the assignment records and corroborating legal-event data for this patent.

Let me try to pin down the actual reel/frame and check for any post-issuance transfers.

Let me look for the specific assignment record and any related-family recordings.

Assignment & Ownership Analysis — US 11,402,375 B2

Patent: US 11,402,375 B2 — "Magnetic immunosensor with trench configuration and method of use"
Application: 13/204,094 (filed 2011-08-05) · Pre-grant pub. US 2012/0034684 A1
Priority: US provisional 61/371,077, filed 2010-08-05
Granted: 2022-08-02 · Legal status: Active, adjusted expiration 2031-12-20
Current assignee of record (per Google Patents legal events): Abbott Point of Care Inc.

Source caveat, stated up front: I was unable to retrieve the reel/frame numbers or the correspondent of record for this patent's assignment during this session. The Authorization-Center / Assignment-Search index did not render a usable record for 11,402,375, and only one legal event (the original inventor→Abbott assignment) is exposed by Google Patents. Per your constraints I have not fabricated reel/frame or correspondent data. Fields I could not verify are marked "not retrievable." Verify directly at USPTO Assignment Center and the Assignment Search index.

Inventors

Pattern notes:

• Only two named inventors on a mechanical/electrochemical device patent — normal for a point-of-care cartridge improvement.
• No inventor-departure pattern detected. Nothing in the record indicates either inventor left Abbott within 12 months of filing; to the contrary, both continue to appear as inventors on later Abbott Point of Care filings (Miller across dozens of Abbott families, including the sibling division US 9,958,440, which claims priority to application 13/204,121 — the co-filed sibling of this case). The "inventors bail out early, portfolio fire-sale follows" tell is absent here.
• Inventor addresses are Canadian, consistent with Abbott's Ottawa-area point-of-care R&D operation (the former i-STAT / Abbott Laboratories Canada site). This is an operating-company R&D shop, not a holding structure.

Original assignee

Abbott Point of Care Inc. (Princeton / East Windsor, NJ), a subsidiary of Abbott Laboratories (NYSE: ABT).

• Primary line of business: point-of-care in vitro diagnostics — the i-STAT® handheld blood analyzer and its disposable single-use test cartridges (including the i-STAT cTnI cardiac troponin cartridge). The specification in this patent repeatedly adapts "the i-STAT® immunoassay cartridge format" and describes a commercial cTnI assay range (0.20–36.00 ng/mL) that the magnetic sensor is meant to extend downward (0.002–1.0 ng/mL).
• Did they ship a product embodying the claims? Yes — an operating, product-shipping company. The claimed subject matter is a cartridge-based magnetic immunosensor designed for the i-STAT platform; the specification explicitly frames it as a modification of the then-current commercial cTnI cartridge. (Note: the claims as granted are directed to the single-trench cartridge architecture; whether any one shipped SKU reads on every limitation is a separate infringement question I cannot resolve from the record.)
• Status: Operating. Parent Abbott Laboratories is a large, publicly traded, profitable diagnostics/medical-device company. No bankruptcy, dissolution, or acquisition-driven fire-sale anywhere in this chain.

Assignment timeline

Only one conveyance is recorded/exposed for this patent:

• 2011-10-18 (recording date; execution date not retrievable) — Reel/Frame not retrievable (Assignment Center record did not render in this session)
  • Conveyance: Assignment of Assignors' Interest (original inventor→company assignment)
  • Assignor: Campbell, John Lewis Emerson; Miller, Cary James
  • Assignee: Abbott Point of Care Inc., Princeton, NJ (per Google Patents legal events)
  • Correspondent: not retrievable — no attorney/firm of record surfaced for this entry. Because the correspondent could not be captured, the "repeat correspondent" signal cannot be scored on evidence and is marked unclear below.
  • Context: Routine new-hire/inventor-to-employer assignment of rights at filing — standard operating-company practice, not an acquisition, securitization, or transfer-to-asserter event.

Adjacent-family data point (do NOT confuse with this patent): A separate Abbott Point of Care recording surfaced in search — Assignment 36608/816, "Assignment of Assignors Interest," Miller, Cary James → Abbott Point of Care Inc. (104 Windsor Center Drive, East Windsor, NJ 08520), executed 2011-12-13, recorded 2015-09-21, tied to application 14/723,917 (issued as US 10,058,867). That is a different patent in the same Abbott program, not this one. It is useful only as corroboration that Abbott Point of Care runs a normal centralized NJ-based assignment program with mid-2010s recording latencies. No post-issuance assignment exists for 11,402,375 — the 2022 Google Patents entry ("Priority to US17/804,330") is a domestic continuation priority claim, not a title transfer.

Bottom line for this section: There is no recorded post-issuance assignment of US 11,402,375. The patent is held by its original operating-company assignee, Abbott Point of Care Inc. That absence is itself the finding.

Timeline diagram

timeline
    title Ownership of US 11402375
    2010 : Priority provisional 61371077 filed
    2011 : Nonprovisional 13204094 filed by Abbott
         : Inventors Campbell and Miller assign to Abbott Point of Care
    2022 : Patent issued to Abbott Point of Care
         : Continuation family filed 17804330

(Note: the continuation event at 2022 is a priority claim, not an ownership change; it is shown only for family completeness.)

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. No transfer to any IP/Holdings/Licensing/Ventures LLC. The only assignee ever of record is Abbott Point of Care Inc., an operating diagnostics subsidiary (2011-10-18 recording).

2. Known asserter in the chain — Not present. No assignee matches any public NPE list (Acacia, Marathon, IV, IPNav, Wi-LAN/Conversant, Vringo, Pendrell, Round Rock, Spangenberg entities, etc.). The chain is Abbott → Abbott.

3. Repeat correspondent across the chain — Unclear (not scorable). With only a single link in the chain, "recurrence" is definitionally impossible; and the correspondent of record for the 2011-10-18 entry could not be captured this session. One data point exists at the firm level (Abbott's NJ address, 104 Windsor Center Drive, on the unrelated 36608/816 recording), but no attorney name was surfaced, so no finding is made.

4. Cascading transfers — Not present. Exactly one recorded assignment across an 11-year prosecution-to-grant span. No chained LLCs, no common-principal clustering.

5. Pre-litigation transfer — Not present. No assignment within 6 months of any infringement suit; no suit naming this patent was found. The sole recording (2011-10-18) predates grant by ~11 years.

6. Bankruptcy fire-sale — Not present. No Chapter 7/11 by Abbott Point of Care or Abbott Laboratories; no IP sold in proceedings.

7. Privateering — Not present. No operating-company→NPE transfer; Abbott has not parked this patent with an outside assertion vehicle.

8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates at the operating originator (Abbott), which is a neutral/"retained" outcome, not a "neutralized-by-aggregator" one.

Verdict

Insufficient data (chain contains only the original assignment).

The record shows a single inventor→Employer assignment to Abbott Point of Care Inc. on 2011-10-18, with no post-issuance transfer, no NPE-list assignee, no LLC cascade, no bankruptcy, and no litigation surfaced for US 11,402,375. Every NPE/troll signal is present-absent except the correspondent-recurrence signal, which is unscorable because the Assignment Center reel/frame and correspondent of record could not be retrieved this session. The affirmative finding is that ownership was retained by the operating originator — a clean, non-NPE chain — but because I could not pull the reel/frame or correspondent to fully verify, I stop short of "Defensive / non-asserting" or any assertion-based verdict.

Verify at: https://assignmentcenter.uspto.gov/ and https://assignment.uspto.gov/patent/index.html (search "11402375" or application "13/204,094"). If the Assignment Center returns a reel/frame for the 2011-10-18 recording plus any unknown later entries, re-score signals 3 and 4 accordingly — those are the only two that could move the verdict.

I'll research the prior art citations for US 11,402,375. Let me search the USPTO and patent databases.

Let me get the complete list of referenced cited documents, including foreign patents and the truncated entries.

Prior-Art Analysis: U.S. Patent No. 11,402,375 B2

"Magnetic immunosensor with trench configuration and method of use"

Source note: The "References Cited" list below was assembled from the patent's own front-page list (Justia patents.justia.com/patent/11402375) cross-checked against a second index record (Chungnam National Univ. library EDS record for patent 11402375), which is where the WO references and the examiner-vs-applicant attribution of the non-patent literature come from. I was not able to pull the actual USPTO PTO-892 / examiner's "Notice of References Cited" or the PatentCenter file-wrapper within this session, so I cannot tell you for every patent reference whether the examiner applied it or the applicant merely disclosed it in an IDS. That distinction matters and is flagged where relevant.

⚠️ A contradiction you should know about before reading the § 102 mapping

The two public renderings of this patent conflict on a material claim term, and per the operating rules I am not resolving it silently:

• Justia's page for 11,402,375 reproduces claim 1 as: "a two-dimensional array of microfabricated electrodes positioned within the troughs of a plurality of trenches, wherein the average width, height and length of each trench are each at least the mean average particle size of the beads…" — which matches the published application (US 2012/0034684 A1).
• The mtec-sc.org patent record (US-11402375-B2) describes the granted independent claim 1 as a cartridge-based claim with "a silicon wafer with a single trench…electrode openings…to form a two-dimensional array of microfabricated electrodes at a bottom of a single trench…a permanent high-field magnet…formed in the base abutting a bottom of the sensor chip…a pump for moving the sample…"

Note also that Justia's own dependent claims 24–27 recite "the single trench," which is internally inconsistent with the "plurality of trenches" it shows in claim 1. Conclusion: the issued claim 1 almost certainly recites a single trench within a cartridge, and the Justia claim-1 text is the pre-issue published version. This matters enormously to the § 102 analysis, because the narrower granted claim is much harder to anticipate than the published claim. I flag this rather than pick a winner.

Part A — U.S. Patent References Cited

All are U.S. patents named on the face of 11,402,375. Dates are the printed issue dates. "Anticipates?" reflects whether the reference could, standing alone and as an enabling disclosure, meet the claim(s) — not whether the examiner actually used it.

Part B — Foreign Patent References Cited

Part C — Non-Patent Literature

C.1 — Cited by the EXAMINER (per the index record's "cited by examiner" attributions):

• Rossier et al., "Plasma etched polymer microelectrochemical systems," Lab Chip 2002, 2, 145–150 — plasma-etched polymer micro-electrochemical systems. Directly on point for the trench/etched-electrode structural element. Potentially § 102 art for the trench-fabrication aspect, but not magnetic bead capture.
• J. Lab. Autom., Dec. 2008, vol. 13, no. 6, 322–329 — laboratory-automation/assay-format reference. Relevant to cartridge/automation context.
• Ramanujan, "Magnetic particles for biomedical applications," Ch. 17, Biomedical Materials, Springer, NY, 2009 — magnetic-particle therapeutics/assays. Bead element only.
• Kuhn et al., "Developing Multiplexed Assays for Troponin I and Interleukin-33…," Clin. Chem. 55:6, 1108–1117 (2009) — troponin I assay methodology (mass spec). Analyte/assay-format only.
• Rossier & Reymond, "Microfluidic-based electrochemical platform for rapid immunological analysis in small volumes," Comprehensive Analytical Chemistry 49 (2007) — microfluidic electrochemical immunoassay platform. The closest examiner-cited NPL to the claimed principles (microfluidic + electrochemical immunoassay), but no trench-magnet bead retention.

C.2 — Cited by the APPLICANT (background/IDS support):

• Laurell et al., Methods in Enzymology, vol. 73, "Electroimmunoassay" (1981) — early electrochemical immunoassay review.
• M. J. Green (1987), Philos. Trans. R. Soc. Lond. B 316:135–142 — electrochemical immunosensor review.
• Bruls et al., Lab Chip 9, 3504–3510 (2009) — integrated biosensor for multiplexed immunoassays based on actuated magnetic nanoparticles.
• Dittmer et al., Clin. Chim. Acta (2010) — high-sensitivity point-of-care cardiac troponin optomagnetic biosensor.
• Berti et al., "Microfluidic-based electrochemical genosensor coupled to magnetic beads for hybridization detection" (2009) — magnetic-bead + electrochemical microfluidic detection.
• Estes et al., "On chip cell separator using magnetic bead-based enrichment/depletion," Biomed. Microdevices 11:509–515 (2009) — on-chip magnetic bead manipulation.
• Peng et al., "A Bead-Based Electrochemical Biosensor with Integrated Magnetic Manipulation for Controllable Sample Preconcentration," Transducers 2009:1802–1805 — bead-based electrochemical biosensor + magnetic manipulation. One of the closest "combination" NPL items (beads + electrochemical + magnetic localization), but no trench geometry.
• ISR/WO for PCT/US2011/046758 (Oct. 7, 2011); ISR/WO for PCT/US2011/046753 (Dec. 30, 2011); PCT/US2011/046757 (Oct. 12, 2011); PCT/US2011/046761 (Oct. 7, 2011) — these are the search reports for the sibling/counterpart PCT applications in the same family (the '107/'104/'108 filings), i.e., the applicant's own family prosecutions.
• Office Action for U.S. Appl. No. 13/204,121 (Nov. 9, 2012) — prosecution of a sibling application, not prior art per se.

Part D — Bottom-line anticipation assessment

1. No single reference listed on the face of 11,402,375 appears to fully anticipate issued claim 1. The granted claim 1 (per the mtec-sc record) requires the combination of: (a) a cartridge housing with sample chamber + conduit, (b) a sensor chip with a single-trench microfabricated two-dimensional microelectrode array (silicon wafer / oxide / metal layers / photodefinable polyimide with electrode openings), (c) a dissolvable dry matrix of magnetically susceptible beads in the chamber/conduit, (d) a permanent high-field magnet formed in the base abutting the sensor chip, and (e) a pump moving sample through the conduit. Each element is individually taught somewhere (e.g., trench/micro-electrode fabrication: Rossier; cartridge + dry reagent + pump: Davis 7,419,821; magnetic-electrochemical bead assay: Forrest ×3, Peng, Berti, Bruls), but no single reference discloses the whole.

2. Most of the cited patents are 35 U.S.C. § 103 combination art, not § 102 anticipation art. The bead/magnetic-particle patents (Senyei, Whitehead, Chagnon, Rohr ×2, Siddiqi, Kreuwel, Prins) and the magnetic-coating patents (Stern, Deetz, Gambino, Knoll) are background/materials references that touch individual dependent-claim limitations (bead composition, magnetic layer), not claim 1.

3. The references with the best § 102 potential against dependent claims are: Cozzette 5,200,051 and 5,554,339 (sensor fabrication / reagent printing) and Davis 7,419,821 (cartridge architecture), but only as § 103 building blocks for claim 1.

4. The two WO references — WO 00/51814 and especially WO 01/87458 "Magnetic bead-based arrays" — are the strongest foreign candidates on the bead-array concept, but neither is shown to disclose the trench + permanent-magnet-in-base retention architecture.

5. Procedural reality check: This application sat in prosecution from 2011 to 2022 (~11 years), which strongly suggests the claims were repeatedly rejected over some of the above art and then narrowed (e.g., to the "single trench" + "formed in the base" + cartridge combination) before allowance. That narrowing is exactly why none of the cited references anticipates the granted claim.

Caveats and limitations of this analysis

• I hit my tool-call budget and could not retrieve (a) the examiner's PTO-892 / "Notice of References Cited," (b) the full front-page citation list (it truncates after US 8,084,272), or (c) the full text of several references. Per your strict rule, I did not fill gaps with assumed content.
• Verification gaps flagged: US 7,572,355 (Arumugam), US 8,084,272 (Campbell et al.), WO 00/51814, and the J. Lab. Autom. article — I could not confirm titles/teachings from the sources reached; do not rely on my one-line descriptors for those.
• § 102 vs § 103: I deliberately state "not claim 1" where a reference teaches only a subset; a reference that teaches a subset is § 103 material when combined, which is the actual posture of this art.
• The "plurality of trenches" vs "single trench" discrepancy (Part ⚠️ above) is the single most important unresolved item; if you need a definitive § 102 mapping, pull the granted claims from USPTO PatentCenter / the printed patent first, because the entire anticipation analysis pivots on which version of claim 1 governs.
• Because the application was filed 2011-08-05 (pre-AIA), § 102 analysis uses the pre-AIA framework: references published more than one year before the 2010-08-05 priority date are § 102(b) statutory bars; later-published references qualify only under § 102(a)/(e) and only if they predate the invention / have an earlier effective date.

I'll ground this obviousness analysis in the actual prior-art references cited in the patent and verify key facts about them before building the § 103 combinations.

Let me pin down the exact granted claim language and check a few more of the cited prior-art references.

Obviousness Analysis — U.S. Patent No. 11,402,375 (35 U.S.C. § 103)

Analyst note on sources and a flagged discrepancy. This analysis builds on the litigation summary already generated (no litigation found; assignee Abbott Point of Care; priority 2010‑08‑05) and does not repeat it. It also relies on the prior‑art references cited in the patent's own Background/Description (the "Prior Art" material on the page), plus the third‑party literature the patent cites (Bruls 2009; Dittmer 2010).

⚠️ Discrepancy I must flag explicitly. The Summary of the Invention text on the Google Patents page (the "Definitions" block) describes an embodiment/claim reciting "a two‑dimensional array of microfabricated electrodes positioned within the troughs of a plurality of trenches, wherein the average width, height and length of each trench are each at least twice the mean average particle size of the beads." However, the granted independent claim 1, as summarized by the third‑party MTEC record and Justia, recites a single trench (silicon wafer with a single trench; "a line of microelectrodes in the single trench") and does not carry the "at least twice" sizing limitation in claim 1 — that sizing appears in dependent claim 24, and trench dimensions of 0.1–50 µm appear in dependent claim 27. I could not retrieve verbatim granted claim 1 in this session, so I analyze both readings and treat the claim language below as reconstructed, not verbatim.

1. Governing framework and prior‑art window

• Effective filing date: 2010‑08‑05 (provisional 61/371,077). Filed 2011‑08‑05; granted 2022‑08‑02.
• Law: Application filed before 2013‑03‑16 → pre‑AIA §§ 102/103, Graham v. John Deere factors, as elaborated by KSR Int'l v. Teleflex.
• Common‑ownership caveat (important). Several of the strongest references are expressly described in the patent as "jointly‑owned" (Davis '821; Miller '833/'099; 61/288,189; Ser. Nos. 12/620,230; 12/620,179; 12/411,325). Under pre‑AIA § 103(c), commonly owned art that qualifies only under § 102(e)/(f)/(g) is disqualified from a § 103 combination. This matters for late‑issued Abbott references (e.g., '833 and '099, both issued in early‑mid 2010, within one year of the critical date). Cozzette '051 (1993), Zelin '399 (1998), Forrest '045/'610/'630, Rohr '224/'342, Deetz, Stern, Prins, Mirkin, Senyei/Whitehead/Chagnon, Siddiqi/Kreuwel, and the Bruls/Dittmer publications are NOT commonly owned and are fully available under § 102(b)/(a). A § 103 case should therefore be built primarily on the third‑party art, with the Abbott references supplying background/context and, where they qualify as § 102(b) art (more than one year pre‑critical‑date, e.g., '821 issued 2008, '051 issued 1993), full combination weight.

2. Claim 1 deconstructed (reconstructed)

3. Combination A (primary): Davis '821 + Cozzette '051/'339 + Forrest (or Rohr) + Zelin '399

What each teaches:

• Davis '821 (disposable sensing device; cartridge + reader; electrochemical immunosensor; air‑segment wash) supplies elements (a) and (e) almost verbatim — the very cartridge architecture the patent says its Examples are "adapted from."
• Cozzette '051 (wholly microfabricated biosensors; verified: silicon wafer thermally oxidized ~1 µm, Ti/W sputter, gold layer, photodefinable polyimide patterned with openings defining microelectrode arrays — https://insight.rpxcorp.com/patent/[US5200051A](/patent/US5200051A)) supplies element (b), including the insulating oxide, metal layers, photodefinable polyimide, and patterned electrode openings.
• Cozzette '339 supplies element (c) — microdispensed/printed dissolvable reagent matrices, the same technique the patent uses for its dry bead matrix.
• Forrest '045/'610/'630 ("magnetic components have been integrated with electrochemical immunoassays") and Rohr '224/'342 supply magnetically susceptible reagent + a magnetic field influencing a measurable binding signal — i.e., the functional core of element (d).
• Zelin '399 supplies the conductimetric flow‑compensation/reader control that makes the cartridge reproducible.

Motivation (KSR‑sufficient): The patent's own Background concedes the two driving problems: (i) "only a small fraction of analyte present in the sample is captured… low due to mass transport limitations," and (ii) "there remains a need… for improved immunosensing devices with greater sensitivity… including cardiac troponin I." Magnetic bead capture proximate to a sensing electrode was a known technique to solve exactly that mass‑transport problem (Forrest; Rohr; Bruls 2009). A POSA integrating a known magnetic‑capture bead reagent into Davis's cartridge — using Cozzette's known microfabrication to build the electrode — would have had a reasonable expectation of success, because every building block was independently known and the combination is a "predictable variation."

Residual gap: the trench (and, under the "plurality" reading, the trench sizing). This is Combination A's weak point and is addressed next.

4. Combination B (fills the trench gap): + Bruls 2009 / Dittmer 2010 / microfabricated‑groove art, under KSR

The trench is the feature the patent leans on: it "beneficially inhibit[s] fluid motion… from removing any magnetically susceptible beads… (with the intentional fabrication of a stagnant layer)."

Why the trench is obvious:

1. Bruls et al. (Lab Chip 9, 3504–3510, 2009) and Dittmer et al. (Clin. Chim. Acta, 2010) both describe point‑of‑care magnetic‑nanoparticle/optomagnetic sensors where magnetic particles are actuated and accumulated at a sensor surface; retention against fluid shear is a recognized design constraint in that art.
2. The specification itself supplies the rationale a POSA would apply, and it undercuts novelty of the sizing choice: "the dimensions of the bead retention feature (e.g., trenches) are of secondary importance provided that they supply sufficient volume to contain the beads." A recess must, by definition, be at least large enough to hold the bead; requiring each dimension to be ≥ 2× the bead diameter is routine capacity‑sizing — a result‑effective variable with no disclosed criticality. The patent expressly states the purpose is simply to "allow for localization and consolidation of the beads and enhanced resistance against fluid motion."
3. Mechanical‑retention reasoning is ordinary engineering: fabricating grooves/recesses in a microfabricated polyimide/silicon structure to shield particles from shear is a known technique available to a POSA, requiring only the ordinary skill of a lithography engineer (KSR: "known technique… to improve similar devices in the same way").
4. Single trench + a line of microelectrodes is a straightforward application of Cozzette '051's "masking and etching… independent electrodes and leads may be deposited" and its "large array of sensors… assembled in this way" teaching — narrowing to a single trench with a line of electrodes is an obvious design choice for a single‑analyte point‑of‑care assay.

Combination B motivation: Given Davis's wash step (air segments creating high meniscus shear — a problem the patent calls "surprisingly and unexpectedly" disruptive), a POSA seeking to prevent bead loss would predictably add a physical retention recess and size it to hold the beads. No teaching away exists in the cited art.

5. Combination C (magnet formed in the base): + Deetz/Stern/Deetz + 61/288,189

Element (d) "formed in the base abutting a bottom of the sensor chip" is paralleled by:

• US 2009/0191401 (Deetz) and US 5,843,329 (Deetz) and US 5,587,102 (Stern) — ferromagnetic particles blended into a resin/paint matrix (i.e., a moldable/printable magnetic material), directly analogous to the patent's "NdFeB powder in a polyimide matrix" screen‑printed line.
• The patent's own FIG. 7/8 and 61/288,189 describe the bulk magnet positioned under the chip in the cartridge base — the same placement recited in claim 1.

Motivation: Placing the magnet in the cartridge base (rather than the reader) at the chip underside is the most direct way to minimize the gap to the electrode, and the patent concedes the goal ("preferable that the high‑field magnet be within a few tens of microns of the amperometric sensor electrode surface in order to speed up the time constant"). Minimizing magnet‑to‑sensor distance is a predictable, result‑effective optimization.

6. Dependent‑claim obviousness (compact)

7. KSR / Graham framing and the counterarguments

Supporting Graham factors: scope/content above; differences are narrow (trench + magnet placement + a single‑trench electrode layout); PHOSITA skill is high (microfabrication, immunochemistry, magnetics); commercial/regulatory pressure toward sensitive point‑of‑care cTnI is cited in the Background; all cited art is analogous (same field, same problem).

Genuine non‑obviousness counter‑arguments (the patentee's best case):

1. The "single trench + line of microelectrodes" — the granted claim is narrower than the Summary and may present a specific micro‑architecture not squarely taught by Cozzette '051 (which teaches arrays generally). If the art does not teach co‑locating the magnetic retention feature with the microelectrode array bottom, the applicant will argue a structural distinction.
2. The "≥ 2× bead dimension" limitation — a POSA might argue a specific ratio would not have been predictable, though the specification's own "secondary importance" statement undermines this.
3. Unexpected results — the specification asserts the meniscus‑shear finding and >75% bead retention were "surprising and unexpected." Even under KSR, objective evidence of unexpected results can rebut prima facie obviousness if a nexus to the claim is shown. Note the tension: the patent simultaneously calls trench dimensions "of secondary importance," which weakens any nexus argument built on trench sizing.
4. § 103(c) common ownership — as noted, several of the most on‑point references (Miller '099/'833) may be disqualified if they are only § 102(e) art; a rejection must lean on the non‑commonly‑owned art.

8. Bottom line

A prima facie § 103 case is available and reasonably strong, built as: Davis '821 (cartridge/conduit/pump/wash) + Cozzette '051 (silicon‑on‑oxide / photodefinable polyimide microelectrode fabrication) + Cozzette '339 (printed dissolvable reagent matrix) + Forrest or Rohr (magnetic‑bead capture at an electrochemical electrode) [ + Bruls 2009 / Dittmer 2010 for magnetic actuation/retention at a sensor surface ] + Deetz/Stern (magnetic‑particle‑in‑resin composite and base placement), all motivated by the admitted mass‑transport/sensitivity problem and the predictable goal of maximizing bead retention against wash shear. The trench and its "≥ 2×" sizing are the only contestable limitations, and both are the kind of routine, result‑effective design choices KSR treats as obvious — the patent's own specification ("dimensions… of secondary importance") supplying the strongest support for that conclusion.

Caveats: (i) Claim 1's verbatim language is reconstructed, not confirmed; (ii) I could not verify exact issue dates for the commonly owned Miller references, which bear directly on the § 103(c) analysis; (iii) no litigation exists (per the earlier section), so there is no validity ruling or IPR outcome to corroborate or contradict these conclusions.