US 7461418

I'll run searches for the patent number and any associated litigation.

Let me check specifically for any litigation or PTAB/CAFC proceedings involving this patent.

Summary — US Patent 7,461,418 B2

Bottom line: I located authoritative bibliographic and full-text data for this patent. I found no evidence of any CAFC 2026 docket, PTAB proceeding, or district-court litigation involving this patent in the sources searched (details and caveats below).

Bibliographic data

Source: https://patents.google.com/patent/US7461418/en ; https://patents.justia.com/patent/7461418

Abstract (verbatim)

"A system encouraging users to cleanse their hands after use of a tankless toilet having a flush valve controlling the flow of water into a toilet bowl through a conduit, in which an abrupt temperature change in the conduit is used to trigger a recorded message urging the user to wash his or her hands."

Plain-language overview of the independent claims

Claim 1 (system): A hand-hygiene prompting system for a tankless toilet in which a flush valve controls water flow through a conduit into the bowl. The system includes:

1. a sensor detecting the temperature of the conduit wall;
2. means for interrogating the sensor at selected intervals;
3. means for comparing the conduit-wall temperature at the beginning of one interval with that at a succeeding interval;
4. means for detecting the rate of change of the conduit-wall temperature; and
5. means for triggering a recorded announcement urging the toilet user to wash his or her hands when a preselected rate of change is detected.

In short: sample the pipe-wall temperature over time, compute a rate of change, and if it crosses a threshold, play a pre-recorded "wash your hands" message.

Claim 5 (method): A method of encouraging toilet users to wash their hands after flushing a tankless toilet whose flushing means controls water flow through a conduit into the bowl, comprising:

1. sensing the temperature of the wall of the conduit downstream of the flushing means at preselected time intervals;
2. detecting the rate of change of that temperature between intervals; and
3. triggering a recorded announcement urging the user to wash his or her hands when the detected rate of change exceeds a preselected value.

Dependent claims (for context)

• Claim 2: the conduit-wall temperature decreases upon opening of the flush valve (cold-water-supply case).
• Claim 3: the conduit-wall temperature increases upon opening of the flush valve (warm-water-supply / air-conditioned facility case).
• Claim 4: the preselected rate of change is at least about 0.2° F. in 30 seconds (system claim).
• Claim 6: the preselected value is at least about 0.2° F. in 30 seconds (method claim).

Technical context from the specification

• The system is a follow-on to the inventors' earlier U.S. Pat. No. 6,417,773 (sound-actuated hand-hygiene reminder), which is incorporated by reference. The '418 patent's stated object is to provide a simpler flush-detection trigger than sound recognition, which the specification says required >90% sound recognition and >90% noise rejection.
• It relies on the observation that the discharge conduit between the flush valve and the bowl is normally empty (equilibrated near ambient), so a flush causes a rapid surface-temperature excursion toward the supply-water temperature. The specification's worked example shows ~67 °F steady state dropping to slightly above 55 °F, reaching minimum in about 1 minute.
• A temperature sensor (thermocouple or, more desirably, a resistance temperature detector) is placed in conductive contact with the outside wall of the discharge conduit; examples reference a Sloan Valve "ROYAL" flush valve and a commercial detector/transmitter + receiver/processor system from Springfield Precision Instruments, Inc. (Wood-Ridge, N.J.).

Litigation / docket search — findings and uncertainty

• No CAFC or PTAB proceeding involving 7,461,418 was found. Cited-by records for the patent show only later-issued patents (e.g., Elwha LLC, Ecolab, Microsensor Labs, Leung Sik Yuen), not adversarial proceedings.
• The only "Vlahos" case surfacing in an appeals-docket search was Vlahos v. Old Chicago Restaurant, et al., No. 25-8015, filed 02/13/2026 (U.S. District Court for the District of Wyoming – Cheyenne; Tenth Circuit). This is a Tenth Circuit, not CAFC, matter, and there is no indication from the docket title that it involves U.S. Patent 7,461,418. I would not treat it as related without confirmation.
• Caveats on method: I do not have direct, credentialed access to the USPTO PatentCenter/assignment or CAFC CM-ECF docket databases; findings rely on public web sources (Google Patents, Justia, and general court-opinion search engines) fetched today. Absence of a litigation record in these sources is not proof that no proceeding exists. If you need an authoritative litigation check, the definitive tools are USPTO PatentCenter's "Litigation" tab / PTAB API and the CAFC CM-ECF docket, which should be queried directly.

Note on claim format

The system claim (claim 1) is drafted in means-plus-function form ("means for interrogating…", "means for comparing…", "means detecting…", "means triggering…"). Under 35 U.S.C. § 112 ¶ 6, those limitations would be construed to cover only the corresponding structures disclosed in the specification (e.g., the Springfield Precision detector/transmitter 23 and receiver/processor 25) and equivalents. I flag this as an observation on claim scope, not as a legal conclusion, and I did not find any judicial or administrative construction of these terms.

I'll search for litigation involving US patent 7461418.

Let me run more targeted searches on litigation databases.

Litigation Search — U.S. Patent No. 7,461,418 ("System for encouraging good personal hygiene in toilet facilities")

Bottom line

I found no evidence of any litigation involving U.S. Patent No. 7,461,418. Based on the sources I was able to search, there do not appear to be any infringement suits, declaratory judgment actions, ITC investigations, or PTAB proceedings (IPRs/PGRs/CBMs) naming this patent as an asserted patent.

What I searched and what I found

Why the absence is plausible

Several facts in the record are consistent with this patent never having been litigated:

• Ownership/inventors: Original assignee Vlahos Enterprises (Illinois); inventors Gustav Vlahos and Robert B. Jones (assignment recorded 2006-02-21, appl. 11/358,551).
• Terminal status: The patent is recorded as "Expired – Fee Related." Per the legal events, a maintenance-fee reminder was mailed 2012-07-23, it lapsed for failure to pay maintenance fees (37 CFR 1.362) on 2012-12-09, and expired 2013-01-29. A patent that went abandoned for non-payment only ~5 years after issuance is an unlikely candidate for assertion.
• Field: The technology is a narrow, plumbing-fixture-adjacent "reminder" system (temperature sensor on a tankless-toilet flush conduit triggering a hand-washing recording). It overlaps a crowded, mostly non-practicing, low-value space (see related prior art U.S. 6,417,773; 6,028,520; 5,872,015; 5,952,924; 6,037,871; etc.), which typically does not attract litigation.

Important caveats / limits on this answer

1. No direct PACER/CourtListener docket verification for this patent number was returned. My web searches did not surface a PACER docket or a CourtListener case page tied to 7,461,418. I therefore cannot affirmatively certify a negative from primary docket data — I can only report that no litigation was found in the sources searched.
2. "Absence of evidence" ≠ proof of no suits. A short-lived, fee-abandoned patent could conceivably have been named in a suit filed between 2008 and 2013 that is not well-indexed in the free sources I could reach. If you need a definitive answer, the authoritative checks are:
   • USPTO Patent Public Search / Patent Center "Litigation" tab and the USPTO Patent Litigation Docket Report for Patent No. 7,461,418;
   • PACER docket search (party = "Vlahos Enterprises" or inventors "Vlahos"/"Jones") for 2008–present;
   • Docket Navigator / Lex Machina / RPX Insight (subscription) for patent-level litigation and PTAB history.
3. Per the operating rule, I am not treating similarly numbered patents as this patent. Hits for "the '141 patent" (U.S. 8,167,141) and "7,463,703" are explicitly not U.S. 7,461,418 and are excluded.

Requested case table

If you can supply a subscription-database screenshot or a PACER hit that contradicts this, I'll update the table accordingly — and per your rule, I'll treat that as ground truth over any default assumption.

PTAB / AIA Trial Analysis — U.S. Patent No. 7,461,418 B2

Canonical source note: The structured "PTAB proceedings on file" block supplied with this prompt (USPTO Open Data Portal extract) reports no AIA trial proceedings associated with US 7,461,418. Web search was used to look for anything ODP has not yet indexed. I searched Google Patents, Justia, FreePatentsOnline, Docket Alarm, P-TACTS/PTAB E2E petition documents, and general web queries pairing the patent number and "Vlahos Enterprises" with IPR/PGR/CBM terminology. Nothing surfaced. No proceeding numbers are invented below, because there are none to report.

Proceedings overview

Total AIA trial proceedings on file: 0 — 0 active, 0 with claims invalidated, 0 with claims sustained, 0 settled, 0 institution-denied. The patent has never been the subject of an IPR, PGR, or CBM review, and the bottom-line defensive posture is therefore "untested, not hardened": there is no PTAB record either validating or striking any of claims 1–6, so a defendant gets no free invalidity win from the Board and must build any challenge from scratch — but also faces a Patent Owner with zero PTAB litigation history, zero surviving-claim precedent, and (more importantly) a patent that the public record shows lapsed for non-payment of maintenance fees in 2012. The real defensive asset here is the fee lapse, not the PTAB docket.

Per-proceeding detail

Not applicable. There are no proceedings to describe. Per the operating instruction not to fabricate, I am not creating placeholder IPR numbers, panels, or grounds. For completeness, here is what the absence rules out:

Why two of the three vehicle types are legally unavailable anyway (useful framing for a defendant):

• PGR is unavailable. The '418 has an effective filing date of 2005-02-25 (provisional 60/656,491) and was filed 2006-02-21 — well before the 2013-03-16 AIA cutover. PGR under 35 U.S.C. § 321 applies only to patents with an effective filing date on or after that date.
• CBM is unavailable. The claimed subject matter — a conduit-wall temperature sensor, an interrogation/comparison circuit, and a recorded hand-washing announcement — is not a "covered business method" (no financial-product or financial-service prong).
• IPR is the only AIA vehicle that ever applied, and no one used it. An IPR would have been limited to § 102/§ 103 grounds on patents and printed publications (35 U.S.C. § 311(b)).

Strategic summary

Claim-by-claim status: all six claims UNTESTED. Claims 1–6 have never been construed or adjudicated by the Board. Nothing is canceled; nothing is sustained. For a defendant, that cuts both ways — there is no IPR-killed independent claim to point to, but there is also no PTAB precedent that a Patent Owner could use to argue the claims are "hardened." Independent claim 1 (system) and independent claim 5 (method) remain live on paper, with dependents 2 (temperature decreases on flushing), 3 (temperature increases on flushing), 4 (≥ about 0.2 °F in 30 seconds), and 6 (same threshold, method form) untested as well.

Estoppel landscape: there is none. § 315(e)(2) estoppel is triggered by a petitioner's participation in an instituted IPR that reaches a final written decision. Because no IPR was ever instituted, no party — and no privy of any party — is estopped from anything. Every § 102/§ 103 ground, on every reference, in every forum, remains fully available. That is an unusually clean slate. Note the corollary: filing the first IPR against this patent carries no § 325(d) "substantially the same prior art or arguments previously presented" risk and no General Plastic follow-on petition problems (there is no first petition to be a follow-on to).

Pattern signals: none, on either side. No serial petitioner; no defensive aggregator (I found no Unified Patents, RPX, or similar filing); no Patent Owner trend of appealing adverse Board decisions (there are none to appeal); no parallel district court litigation surfaced in searches pairing "Vlahos Enterprises" with infringement terms. The absence of any IPR is itself the signal the prompt anticipates — but here it is not the usual "hardened patent" signal. The explanation is almost certainly economic: this was a one-off, narrowly claimed restroom-reminder patent with no visible assertion campaign, and it went abandoned in 2012, six years before the AIA trial regime matured into a routine defensive tool.

The expiry issue is the real story, and it should be verified before anything else. The public record shows internal tension that a defendant must resolve:

• Legal events per Google Patents: maintenance-fee reminder mailed 2012-07-23; LAPS — lapse for failure to pay maintenance fees 2012-12-09; STCH — patent discontinuation 2013-01-07 ("PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362"); FP — expired due to failure to pay maintenance fee 2013-01-29, effective 2012-12-09. That is the 3.5-year maintenance fee.
• Yet the same page's status field reads "Expired - Fee Related, expires 2027-06-25," i.e., a nominal adjusted expiration that reflects term computation, not reinstatement.
• No reinstatement event (e.g., a petition to accept unintentionally delayed payment under 37 C.F.R. § 1.378) appears in the legal-events timeline I retrieved.

If the lapse was never cured, the Patent Owner's rights ceased in 2012 and there is no prospective infringement to enjoin — which makes the patent effectively unassertable for ongoing conduct and limits any residual damages theory to the pre-2012-12-09 window, itself bounded by the 35 U.S.C. § 286 six-year lookback. That is a far cheaper and cleaner case-dispositive argument than any IPR. I have not verified reinstatement status, and I flag this as the single highest-value item to confirm in USPTO Patent Center before relying on it.

Recommended next steps

1. Confirm the fee lapse and reinstatement status in USPTO Patent Center (https://patentcenter.uspto.gov) for application 11/358,551. Pull the fee-transaction history and any § 1.378 petition. If no reinstatement occurred, lead with expiration/lack of enforceable rights rather than with validity — it resolves the matter without an IPR and without the cost of an invalidity case.
2. Do not file an IPR reflexively. Because all claims are untested and zero estoppel exists, an IPR is available — but IPR against an expired patent addresses only the patentability of claims for past-infringement purposes, and the Board's discretionary-denial practice (Fintiv and its successors; note the Director's 2025-10-16 centralized-institution memorandum, which shifted institution decisions to the Director) makes the calculus less predictable than it once was. If the patent really lapsed, an IPR is likely unnecessary spend.
3. If the patent turns out to be revived, the attack surface is straightforward and untested: claim 1 is a means-plus-function claim ("means for interrogating," "means for comparing," "means detecting the rate of change," "means triggering") — § 112(f) construction against the corresponding structure disclosed (the Springfield Precision Instruments detector/transmitter and receiver/processor) is the opening move, and the ≥ 0.2 °F/30 s threshold of claims 4 and 6 invites § 103 treatment. The Patent Owner's own specification supplies the admission set: flush valve, temperature sensor/RTD, wireless detector/transmitter, and receiver/processor were all off-the-shelf (the Sloan "ROYAL" valve; the Springfield Precision Instruments system being a commercially available, pre-existing product). Compare the pre-AIA art already of record in the file — U.S. Pat. Nos. 5,573,407; 5,870,015; 5,952,924; 6,028,520; 6,037,871; 6,038,711; 6,282,732; 6,417,773; and US 2004/0155779 — all cited on the face of the '418.
4. Proceeding-level milestones: none exist. With no institution decision on file, there is no 1-year statutory FWD deadline under § 318(a) running, no institution-decision deadline, and no oral hearing date. Any dates would have to be created by a future petition.
5. Public-source verification links for the record: patent text and legal events — https://patents.google.com/patent/[US7461418B2](/patent/US7461418B2)/en; PTAB decisions and trial records — https://www.uspto.gov/patents/ptab/decisions and https://ptacts.uspto.gov/ptacts/; CourtListener docket search for the patent number — https://www.courtlistener.com/. There is no Final Written Decision, Board decision, or Federal Circuit opinion to cite, because none exists.

Confidence caveat, stated plainly: I searched public sources and found no AIA trial activity of any kind on the '418, which is consistent with the ODP structured block. That is strong but not conclusive — pre-2012 PTAB filings are scanned and unevenly indexed, and a petition that was filed and terminated before institution sometimes leaves only a mail-room receipt. If full certainty is required, run the patent number against PTAB E2E (https://ptacts.uspto.gov/ptacts/) and the Board's decision-archive search directly. I did not verify reinstatement of the patent after the 2012-12-09 lapse, and I did not find an ex parte reexamination certificate for the '418.

I'll reconstruct this from the authoritative patent record first, then cross-check with assignment/legal-event sources.

Ownership & Assignment Reconstruction — US 7,461,418 B2

Data-access caveat up front: the USPTO Assignment Center (assignmentcenter.uspto.gov / assignment.uspto.gov) and RPX/Unified NPE directories were not directly retrievable in this session; the assignment data below is taken from the authoritative patent record (Google Patents legal-events block, which mirrors the Assignment Center entries) and is limited to what that record exposes. The correspondent of record is not exposed in the rendering I could retrieve and is therefore reported as not determinable — I will not guess it.

Inventors

Unusual patterns: none of the classic fire-sale tells. No inventor departed the assignee within 12 months; rather, both inventors assigned in to a company they controlled (execution date 2006-02-16, five days before recording). The notable structural quirk is that co-inventor Jones is himself a patent attorney — meaning the drafting and the assignment filing plausibly ran through the inventors' own hands, not an outside prosecution shop. Both inventors are the same pair named on the earlier, related US 6,417,773 ('773 patent), so this is a two-person, two-patent family, not a large corporate portfolio.

Original assignee

Vlahos Enterprises, recorded with USPTO as an Illinois entity (assignment "Owner name: VLAHOS ENTERPRISES, ILLINOIS"). Google Patents lists it as both Original Assignee and Current Assignee.

• Primary line of business: small, closely held hygiene/restroom-systems venture built around the inventors' hand-washing reminder technology. It is not a manufacturer of restroom hardware in the institutional channel — the '418 patent expressly points to a third-party commercial component, a "detector/transmitter" and "receiver/processor" system "available from Springfield Precision Instruments, Inc." (spec, FIGS. 3–4).
• Did it ship a product embodying the claims? Unclear, leaning no. The only contemporaneous press coverage of this family (the '773-based device, Chicago Tribune, 2002-08-19) reports the invention "has no name, as yet, and negotiations are under way to bring it into production." I found no evidence of a commercial Vlahos Enterprises hygiene product, no trademark registration, no retail/ institutional listings, and no revenue disclosures.
• Current status: not operating in any capacity I could document; patent abandoned. Maintenance fees were never paid past the first window — USPTO legal events show a maintenance-fee reminder 2012-07-23 and "Expired due to failure to pay maintenance fee," effective 2012-12-09. No bankruptcy, acquisition, merger, or change-of-name record exists. The company left the patent to die rather than license or assert it.

Assignment timeline

There is exactly one recorded assignment in this chain. No post-issuance transfers, no security interests, no liens, no releases, no name changes.

• 2006-02-16 (executed) / recorded 2006-02-21 — Reel 017603/0907
  • Conveyance: Assignment
  • Assignor: Gustav Vlahos; Robert B. Jones (recorded as "VLAHOS, GUSTAV; JONES, ROBERT B.")
  • Assignee: Vlahos Enterprises (Illinois)
  • Correspondent: Not determinable from the sources retrieved. The legal-events rendering exposes the reel/frame and the assignment text ("ASSIGNMENT OF ASSIGNMENT OF INTEREST … REEL/FRAME: 017603/0907") but not the recording correspondent. Given that assignor Jones is a Chicago patent attorney and a named partner of the other assignor, the recording was plausibly self-filed, but I will not assert that as fact — it must be confirmed against the reel image in the Assignment Center.
  • Context: Founder-to-company consolidation at filing — the two inventors conveyed their rights to their own venture, effective 5 days before the 2006-02-21 filing date of application 11/358,551. Not a sale, not a securitization, not a transfer-to-asserter.

No subsequent record exists. If the Assignment Center shows any additional entry for 7,461,418 that is not in the Google Patents legal-events feed, I did not see it and cannot report it.

Timeline diagram

timeline
    title Ownership of US 7461418
    2005 : Provisional filed Feb 25
    2006 : Assignment to Vlahos Enterprises
         : Reel 017603 frame 0907 recorded
    2008 : Patent issued Dec 9
    2012 : Maintenance fee lapsed
    2027 : Nominal adjusted expiration

NPE / troll-pattern signals

1. Shell-entity transfer — Not present. The only transfer (reel 017603/0907) runs from two natural-person inventors into their own operating venture. "Enterprises" is a generic business suffix, not an "IP/Holdings/Licensing/Ventures" monetization suffix, and there is no registered-agent-service address, no single-member Delaware/Texas LLC, and no successor LLC at all. Signalling on the name alone would be improper.

2. Known asserter in the chain — Not present. Assignee Vlahos Enterprises matches no entity on the public NPE lists (Acacia, Marathon, Intellectual Ventures, IPNav, Wi-LAN, Mosaid/Conversant, Vringo, Pendrell, Innovatio, MPHJ, Lumen View, Round Rock, Document Generation, Spangenberg entities). It is not named by RPX or Unified Patents as a high-frequency plaintiff. Neither inventor appears as a serial plaintiff principal.

3. Repeat correspondent across the chain — Not present / not determinable. Only one link exists, so recurrence is definitionally absent. Because only one appearance is possible, even if the correspondent were identified it would not be a finding under your rule ("the signal is recurrence"). No Unified Patents / RPX / Patent Progress NPE-assertion correspondent name is implicated by anything in this record.

4. Cascading transfers — Not present. One assignment, on a single date, in 2006. No chained LLCs, no shared correspondent addresses, no common-principal transfers.

5. Pre-litigation transfer — Not present. No infringement suit naming 7,461,418 (or its sibling 6,417,773) surfaced in any search. The only 2006 assignment predates issuance by nearly three years and is contemporaneous with filing — the opposite of a pre-suit standing-cleanup transfer.

6. Bankruptcy fire-sale — Not present. No Chapter 7/11 record for Vlahos Enterprises. The patent was simply abandoned for non-payment of maintenance fees effective 2012-12-09 (REMI 2012-07-23; LAPS 2012-12-09; FP notice 2013-01-29) — an economic write-off by a tiny private venture, not a court-supervised sale.

7. Privateering — Not present. No operating-company transferor, no SEC-reporting entity, no back-end licensing arrangement. Vlahos Enterprises never had a competitor portfolio to leverage.

8. Defensive aggregator — Not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. It terminates where it started: with the original assignee, at which point the asset lapsed for fee non-payment.

Verdict

Insufficient data — and, secondarily, a dead asset.

The entire recorded chain is a single founder-to-company assignment: executed 2006-02-16, recorded 2006-02-21 at reel 017603/0907, conveying Gustav Vlahos' and Robert B. Jones' rights to Vlahos Enterprises (Illinois). Google Patents' legal-events feed shows no further conveyance of any type, no security interest, and no change of name; the current assignee remains the original assignee. The patent was then allowed to expire for failure to pay maintenance fees effective 2012-12-09, which is itself the strongest anti-troll evidence available here — an entity running an assertion program does not abandon its only two patents for non-payment. No NPE signal rises above not present, and I decline to upgrade any of them on the strength of the "Enterprises" name alone.

Verify at: https://assignment.uspto.gov/patent/index.html — search "7461418"; the only entry should be reel 017603/0907. (The reel image is the one place to recover the recording correspondent, which the indexed feeds do not display.)

One open item worth a manual pull: the correspondent of record on reel 017603/0907 is the only field I could not fill. If that reel shows an outside law firm rather than co-inventor Jones filing pro se, it slightly changes the read on whether the 2006 filing was professionally prosecuted — but it would not change the verdict, since no monetization or assertion ever followed.

I'll verify the patent and pull details on each cited reference.

Now the remaining cited references.

Prior-art analysis — US 7,461,418 B2

Patent under analysis (as identified on the face of the record): US 7,461,418 B2 (rendered "US7461418B2" by Google Patents), "System for encouraging good personal hygiene in toilet facilities," inventors Gustav Vlahos and Robert B. Jones, assignee Vlahos Enterprises, Appl. No. 11/358,551, filed 2006‑02‑21, claiming benefit of provisional US 60/656,491 filed 2005‑02‑25, issued 2008‑12‑09, 6 claims.

Verified via: the patent document itself at https://patents.google.com/patent/US7461418/en (the front‑page "Patent Citations (9)" table, which reproduces the USPTO examiner‑cited references), plus targeted verification searches for individual references (Google Patents, FreePatentsOnline, Justia, EveryPatent). I did not auto-correct any citation; every number below is reproduced literally from the '418 front page.

Governing law note: Because the application was filed 2006‑02‑21, pre‑AIA 35 U.S.C. § 102 applies. The § 102(b) critical date is one year before the earliest effective U.S. filing date (2004‑02‑25, measured from the provisional); references published/granted before that date are statutory bars. I flag this because it materially affects the Ballard application (below).

I note for consistency that this builds on, and does not contradict, the earlier sections (bibliography, claim summary, and the "no litigation found" conclusion).

The nine examiner-cited references

Caveat on retrieved text: References (5), (6), (7), and (9) were not full‑text retrieved within this analysis pass (tool step limit). Their dates and titles are taken verbatim from the '418 front‑page citation table; my one‑line characterizations of those four are inferential from the titles/classification and should be confirmed against the documents before being relied on. References (1), (2), (3), (4), and (8) were text‑verified.

§ 102 anticipation analysis, element by element

The novelty of the '418 resides in one specific mechanism. Every independent claim requires, in substance:

• Claim 1: a sensor detecting the temperature of the conduit wall between a tankless‑toilet flush valve and the bowl; means for interrogating the sensor at selected intervals; means for comparing the wall temperature at the beginning of one interval with a succeeding interval; means for detecting the rate of change; and means for triggering the recorded hand‑washing announcement upon a preselected rate of change.
• Claim 5 (method): sensing the conduit‑wall temperature downstream of the flushing means at preselected intervals, detecting the rate of change, and triggering the announcement when the rate of change exceeds a preselected value.
• Claims 2–4 and 6 add only the sign of the change (decrease/increase) and the numeric threshold (at least about 0.2 °F in 30 seconds).

Result: no cited reference anticipates any of claims 1–6.

Why the "flush‑triggered hand‑wash reminder" references (4, 8 and arguably 2 and 9) still do not anticipate: each discloses a triggering event for a recorded hand‑washing message, but each trigger is a binary event sensor — a handle switch, a proximity/motion sensor, a water‑level sensor, or a sound recognizer. None measures a physical property of the discharge conduit, and none performs successive interval sampling with a rate‑of‑change comparison. Under § 102, a reference must disclose every limitation as arranged in the claim; a different trigger modality does not anticipate a claim that positively recites a conduit‑wall temperature sensor and a computed rate of change. The '418's own background section confirms this is exactly the gap the invention was addressing — it distinguishes Maehre's motion sensor ("needless repetition") and lever switch ("undesired mechanical modification") and characterizes its own '773 sound system as requiring >90% recognition and >90% noise rejection.

Most relevant prior art (for § 103, not § 102):

1. US 6,417,773 (Vlahos) — same inventors, same field, same object, incorporated by reference; the primary reference for any obviousness challenge to the "detect the flush to trigger a hand‑wash message" concept, and the source of the voice‑chip/speaker disclosure the '418 itself relies on.
2. US 6,028,520 (Maehre) — flush‑event‑triggered spoken hand‑washing instruction; supplies the "trigger a recorded hand‑wash message on toilet use" element.
3. US 5,870,015 (Hinkel) — detector unit (expressly including a "sensor … adapted to respond to the level of water … within the toilet reservoir tank … or to respond to water activity within the toilet bowl or basin") + control unit + message storage + speaker issuing hand‑washing instructions; the most suggestive reference on a non‑contact, plumbing‑sensed flush detector.

None of these, alone or in the combinations above, is shown in the record to teach or suggest placing a temperature sensor on the flush‑valve discharge conduit, interrogating it at timed intervals, and triggering on a computed rate of change (≳0.2 °F per 30 s), in either the cooling (claim 2 / cold supply) or warming (claim 3 / warm supply) direction. That is the entire inventive contribution, and it appears to be unanticipated by, and not addressed in, any cited reference.

Two things worth flagging explicitly

1. The "Cited By" and "Families Citing this family" lists are not prior art. They contain only later documents (US 2009/0113614; US 8,205,275; the Elwha LLC regimen‑compliance family; Ecolab; Microsensor Labs; WO 2018/187557; EP 3900307), all post‑dating the '418. They were excluded from this § 102 analysis, consistent with the instruction not to substitute similarly numbered or otherwise non‑pertinent references.
2. US 6,417,773 is both prior art and incorporated by reference. It is a § 102(b) reference as to the '418 (granted 2002‑07‑09, more than one year before the earliest effective filing date), and it is also the document the '418 incorporates to supply its voice‑chip/speaker disclosure. If you are building an invalidity position, this dual role is analytically important: the '418 cannot claim the recorded‑message hardware as its own point of novelty, so the case will turn entirely on the temperature‑sensing/rate‑of‑change trigger.

Bottom line

I identified and analyzed all nine examiner‑cited references on the face of US 7,461,418, with citations, dates, and per‑reference descriptions. No cited reference anticipates claims 1–6 under § 102, because none discloses the conduit‑wall temperature sensor or the interval‑sampled rate‑of‑change trigger that defines every independent claim. The references are instead § 102(b) (and, for Ballard, § 102(a)/(e)) § 103 prior art, of which US 6,417,773, US 6,028,520, and US 5,870,015 are the most relevant. If you want, I can next pull the full texts of the four unverified references (Babylon, Clarke, Krvavica, Ballard) so their descriptions and any incidental flush‑sensing disclosure can be nailed down rather than inferred.

I'll ground this analysis in the cited prior art and related flush-detection art.

Now let me examine the remaining cited references and thermal flow-detection art.

Obviousness Analysis — U.S. Patent No. 7,461,418 B2 under 35 U.S.C. § 103

Building on the prior sections: I do not repeat the bibliographic data, claim summaries, or litigation findings. Where relevant I cross-reference them.

1. Framework and the record I am working from

The prior art "of record" on this page is the Patent Citations (9) list:

§103 analysis proceeds under Graham v. John Deere, 383 U.S. 1 (1966), and KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398 (2007). Because claim 1 is in means-plus-function form (see the earlier claim-format note), each "means" limitation is construed under 35 U.S.C. § 112 ¶ 6 to cover the corresponding disclosed structure (the Springfield Precision detector/transmitter 23 and receiver/processor 25) and equivalents. For §103, the question is whether the function recited was known or obvious in the art.

2. The single dispositive gap in the cited art

Mapping the independent claims against the nine cited references:

Conclusion on the record as cited: every cited reference supplies the hygiene-prompt architecture (sensor → controller → voice chip/speaker → recorded admonition), but none supplies the temperature-based flush-detection trigger. On the nine cited references alone, claims 1–6 would not be rendered obvious — the point of novelty and the point of departure from the art is exactly the parameter sensed (conduit wall temperature and its rate of change).

That is not the end of the §103 inquiry, however. The correct question is whether a person of ordinary skill in the art (PHOSITA) would have combined a hygiene-prompt reference with a secondary reference from the analogous pipe-flow/thermal-sensing art teaching detection of fluid flow by the change in a conduit's surface temperature.

3. The secondary reference a PHOSITA would supply

The technique at the heart of claims 1–6 — inferring that water is flowing in a pipe from a change in the pipe's surface temperature — was, by 2005, an old and standard technique in the plumbing/process-control art. Two vintages are worth separating:

• Pre-2005 (potentially available as prior art): thermal flow switches / thermistor-on-pipe flow detectors, and heated-element flow sensors. A representative example is US 6,535,134 B2 / US 2001/0035826 A1 ("Method for the generation of an electrical signal, sensor device for executing the method and the use of the sensor device"), which uses a temperature-dependent (NTC) element whose heat-transfer rate changes when the fluid around it changes or begins to flow, and expressly names automated flushing of urinal or toilet bowls as a use. This is directly analogous art (same field of endeavour: sanitary fixtures + thermal sensing).
• Post-2005 (context only, not prior art here): e.g., HomeServe's US 11,209,333 / US 2018/0010978 A1 "Flow detection device," which detects "sudden changes in pipe temperature relative to air temperature" to infer flow. I cite this only to show the technique is conventional; it is not available against the 2005-02-25 priority date and must not be used in a rejection.

Under the analogous-art test (In re Clay; In re Bigio), a thermal pipe-flow sensor is "reasonably pertinent to the particular problem" — detecting the flow of water through the toilet's discharge conduit — even though it originates outside restroom fixtures.

4. Proposed combinations and motivations to combine

Combination A — Vlahos '773 (cited) + thermal conduit-flow sensor (secondary)

• What '773 supplies: the complete reminder architecture — microphone → amplifier → microcontroller (PIC16C56) → voice chip (ISD 1020A) → speaker, expressly to play "an audible announcement urging the toilet user to wash his or her hands" (US 6,417,773, claim 1; https://patents.google.com/patent/US6417773). As the earlier section notes, '773 issued 2002-07-09, more than one year before the 2005-02-25 priority date, so it is §102(b) art notwithstanding common inventorship (§103(c) removes only §102(e)/(f)/(g) art).
• What the secondary reference supplies: the temperature-sensor-on-conduit element and the notion that a change in conduit surface temperature signals water flow.
• Motivation: the '418 specification itself states the motivation verbatim — the '773 system "requires sophisticated sound detection and recognition circuitry, capable of greater than 90% sound recognition and greater than 90% rejection of noise… Noise rejection is complicated by the different acoustics of institutional restrooms." An applicant's own admission in the specification of a known deficiency in the closest prior art is a classic KSR-style motivation to look for a simpler, physically direct flush-detector.

Combination B — Maehre '520 (cited) + Ballard '779 (cited) + thermal conduit sensor

• Maehre '520 teaches a controller that "determines which prerecorded message or messages to play based on the inputs from the sensors," including a flush sensor (Hall-effect switch on the handle), a seat pressure switch, a tilt switch, and an IR motion detector (https://patents.google.com/patent/[US6028520A](/patent/US6028520A)/en). It thus teaches that the flush event is the trigger of interest and that plural sensing modalities may be used.
• Ballard '779 teaches substituting an electrical-property flush sensor for a mechanical one: an "open-circuit probe 80… immersed in the water 20 of the toilet tank 10 when the tank is filled, and not immersed… when the tank is flushed," where "the electrical resistance raises triggering the 2N2222 transistor" (US 2004/0155779 A1, ¶¶[0037]–[0038]; https://patents.google.com/patent/US20040155779). Ballard alternatively uses a microphone/notch-filter and states — a key teaching — that "the filter 82 may be tuned to any narrow band pass that will discriminate between the toilet flush sounds and other sounds… such as tap water sounds, voice sounds."
• Motivation: Ballard teaches that any flush-correlated physical variable is an acceptable trigger and that the sensing modality is a design choice driven by discrimination/reliability. Motion and sound are shown to produce false triggers (Maehre's own IR detector; the '418 spec's complaint about noise). A PHOSITA seeking a flush-only, noise-immune trigger is led directly to a physical parameter of the water path. The discharge conduit is the one component that is normally empty and fills only during flush — making its surface temperature the natural, self-gating parameter.

Combination C — Hinkel '015 (cited) + thermal conduit sensor

Hinkel is unusually explicit: the detector unit "could include a sensor or switching mechanism adapted to respond to the level of water contained within the toilet reservoir tank…, or to respond to water activity within the toilet bowl or basin. Indeed, any of a variety of means for detecting toilet use… may be suitably adapted for use as the detector unit 120" (US 5,870,015; https://patents.google.com/patent/[US5870015A](/patent/US5870015A)). This is a "any suitable detector" teaching — an express invitation to substitute alternative flush-sensing means, which under KSR supports obviousness of substituting a thermal detector.

Combination D — Ballard '779 alone, adapted to a tankless fixture

Ballard's water-probe mode fails on a tankless (flushometer) toilet because there is no tank. A PHOSITA asked to port the "sense a physical property of the water path" idea to the institutional tankless restroom the '418 addresses would have no tank to probe — leaving the discharge conduit between the flush valve and the bowl as the obvious remaining water-path element, with temperature as the obvious property to sense.

5. Claim-by-claim obviousness outcome

6. KSR factors favoring the combination

1. "Finite number of identified, predictable solutions." By 2005 the flush-trigger art was a crowded, closed set: mechanical lever switch (Hinkel, Maehre), water level (Ballard), motion (Maehre), sound (Vlahos), and physical-property sensing. Temperature was simply another member of that finite set, with predictable behavior (a flush introduces water at supply temperature into a normally-empty conduit).
2. Design incentive / known problem. The '418 specification states the problem ("simpler apparatus… to trigger an announcement") and the reason sound is unsatisfactory (noise rejection). A PHOSITA has an explicit incentive to move from acoustic to physical sensing.
3. Predictable results. Nothing about a 67 °F → 55 °F wall-temperature excursion (the patent's own FIG. 2) would be surprising to an engineer; it is the expected thermal response of a pipe that begins to carry cold water. Predictable variation ⇒ obviousness.
4. No teaching away. None of the nine references disparages temperature sensing; Hinkel's "any of a variety of means" and Ballard's tunable-discrimination discussion both point toward alternative physical sensors.

7. Anticipated applicant rebuttals and their strength

8. Bottom line

• On the nine cited references standing alone: claims 1–6 are NOT obvious. The temperature-sensing, rate-of-change trigger — the sole point of novelty over Vlahos '773 — is absent from every cited reference.
• Assuming a secondary reference from the analogous thermal/pipe-flow art (e.g., the NTC/heated-element flow sensor of US 6,535,134 / US 2001/0035826 A1, which expressly contemplates automated toilet/urinal flushing), claims 1, 2, 3, and 5 would likely be obvious under §103 as: Vlahos '773 (or Maehre '520 + Ballard '779, or Hinkel '015) in view of the thermal conduit-flow sensor. Claims 4 and 6 would be obvious as routine optimization absent a criticality showing.
• The strongest genuine nonobviousness argument is the absence of the thermal limitation from the art of record plus the normally-empty-conduit insight; the weakest aspect from applicant's perspective is that the specification itself supplies the motivation (simplify over '773) and the predictable physical basis.

9. Caveats and verification limits

• I attempted to fetch the full texts of Dunford US 5,573,407, Babylon US 6,037,871, Clarke US 6,038,711, Krvavica US 6,282,732, and Evans US 5,952,924 but reached the tool limit before retrieving them. My conclusion that none of the nine cited references discloses temperature sensing rests on the verified texts of '773, '520, '779, and '015 plus the titles/abstracts of the rest. Before relying on this analysis, the full texts of those five should be checked — if any one of them (particularly Dunford or Krvavica, both toilet-trainer devices) happens to sense a temperature, the rejection would become much simpler and would not need an analogous-art secondary reference.
• I did not locate a PTAB IPR/PGR decision or any court construction of claims 1–6 (consistent with the prior "no litigation found" section), so the §112 ¶ 6 constructions above are my own reading, not a judicial construction.
• No patent number above has been auto-corrected; each is reproduced as found. Note again that US 11,209,333 / US 2018/0010978 is cited as context only and is not §103 prior art against the 2005 priority date.