US 11402450

I'll search for the specific patent number as requested.

Let me run a couple more targeted searches for any litigation/CAFC activity.

Summary — US 11,402,450 B2

Important caveat on scope of search: Google Patents and general web sources confirm this patent's bibliographic data and full text. I did not find any CAFC docket, district-court litigation, or USPTO proceeding involving US 11,402,450 in the searches run. That does not establish with certainty that no such proceeding exists — court dockets aren't fully indexed in general web search, so treat "no litigation found" as a negative search result, not an affirmative finding. Also note: nothing in my searches tied this patent to any 2026 CAFC activity.

Bibliographic data (per authoritative patent text)

Abstract

An RF shield device for an MR examination system has a first shield and a second shield arranged about a common center axis. The first shield has a shield structure different from that of the second shield, and the two shields are designed for different modes of operation of an RF coil device. A companion RF coil device has first and second birdcage coils on a common center axis, with rungs arranged non-parallel to the center axis, the first coil having a coil structure different from the second, and the coils switchable to be active for different modes of operation. An MR imaging system incorporating either or both is also disclosed.

Plain-language overview of the independent claims

The granted claims (13 total) are directed to RF coil devices. Note that claim 1 as granted recites a "mirrored" relationship between the two coil structures, whereas the published application US 2019/0317164 A1 claim 1 recited merely "different from" — so claim 1 was narrowed during prosecution to the mirror-image requirement.

• Claim 1 — RF coil device (birdcage, dual-coil): Two birdcage coils share a common center axis. Their rungs run at an angle (non-parallel) to that axis. The first coil's conductor pattern is a mirror image of the second coil's pattern. The two coils can be switched so that only one is active at a time, for different operating modes. In addition, one coil is designated the transmit (TX) coil and is built for high-power transmission, while the other is the receive (RX) coil and is built as a low-power design.

• Claim 3 — RF coil device integrate with an RF screen: Two coils share a common center axis; their rungs are non-parallel to that axis. Unlike claim 1, this claim does not require that the coils be birdcage coils. The coil device is formed integrally with an RF screen device that surrounds both coils, and the coil rungs are coupled to that screen. Again, the first coil's structure is mirrored relative to the second's, the coils are switchable between different operating modes, and one coil is a high-power TX coil while the other is a low-power RX coil.

• Claim 9 — RF coil device with a dual-shield RF screen: Two coils, sharing a common center axis, have different coil structures (note: here the claim language uses "different from," not "mirrored"). The rungs are non-parallel to the axis and are coupled to an RF screen device that surrounds both coils. The coils are switchable between different operating modes. The RF screen device itself contains a first shield and a second shield about the common axis, with the first shield's shield structure differing from the second's, each designed for a respective one of the different operating modes. (The claim text supplied was truncated at this point, so I cannot confirm the exact closing limitation.)

Dependent claims (2, 4–8) add: shared conductive end ring between the coils (2); cylindrical coil PCB with rungs as metallization layers on inner and outer sides (4); coil elements on both PCB sides (5); rung shapes — sinusoidal, parabolic, V-, spiral, or sinc (6); TX/RX as the different modes (7); and separate tuning devices at different cylindrical positions (8). Claims 10–13 were not included in the text I retrieved, so their content is unverified.

Technical gist

The invention addresses a known trade-off: once birdcage rungs are made non-parallel to the bore axis to improve B1 homogeneity at high field (3T/7T), no single coil geometry is optimal for both transmit and receive. The solution is to stack two differently-shaped (mirrored) coils on one axis and electronically switch which one is active for TX versus RX, and similarly to stack two differently-patterned RF shields so each mode gets shielding tailored to it. Practical embodiments put the two coils as metallizations on opposite faces of one cylindrical FR-4 printed circuit board (and likewise for the two shields), and switch them with a switch matrix / switchable resonator that routes the transmit path to the high-power coil and the receive path to the low-power coil.

Uncertainty notes

• The search returned no CAFC 2026 docket entries or district-court cases naming US 11,402,450; I cannot rule out unindexed litigation.
• Claims 10–13, and the tail end of claim 9, were not present in the retrieved text; the overview above covers only claims 1–9 as verified.
• Legal status and expiration date are as listed by the source and are not a legal conclusion.

I'll search for litigation involving US patent 11402450.

Let me try more targeted searches.

Let me search specific litigation databases.

Litigation Search: US Patent No. 11,402,450

Bottom line: I found no litigation involving US Patent No. 11,402,450.

I ran multiple targeted searches (including the Unified Patents litigation portal, CourtListener/PACER-indexed materials, Justia, and general web searches keyed to the exact numbers "11402450" / "11,402,450" and to the patent owner, Koninklijke Philips N.V.). None of the results corresponded to this patent. Instead, the searches returned unrelated matters involving different patents — e.g., US 11,341,450 (a Different patent, tied to a healtcare/insurance workflow family), US 10,624,970 (Novartis/Pluvicto), US 7,698,019, and various other dockets (ASUSTeK v. Force Mos, Multimedia Technologies v. LG, ContentGuard v. Google, etc.). Per your instruction, I am not treating those similar-looking numbers as this patent.

Findings

Confidence and caveats

• High confidence that no reported district court or Federal Circuit litigation expressly naming US 11,402,450 has surfaced in searchable sources as of the search date.
• Caveat: Absence of search hits is not proof of non-existence:
  1. This patent is a Koninklijke Philips N.V. patent (inventors Christoph Leussler, Christian Findeklee, Oliver Lips), granted 2022-08-02, from PCT/EP2017/083987. Philips historically enforces its portfolio selectively and often via ITC Section 337 investigations and district court (notably D. Del. and N.D. Cal.) rather than frequent standalone suits on individual patents.
  2. A patent granted in 2022 may simply not yet be part of any asserted set — many portfolio patents are never litigated.
  3. Some dockets (especially recent ITC complaints and newer district court cases) may not yet be fully indexed in the free sources I can query.

Suggested next steps to confirm

To verify definitively, check (a) the Unified Patents litigation portal case list, (b) Docket Navigator / Lex Machina by patent number, (c) USPTO Patent Center / Global Dossier "litigation" tab for this patent, and (d) ITC EDIS for Section 337 complaints filed by Koninklijke Philips N.V. or Philips North America LLC naming this patent.

If you can point me to a specific docket or source you believe references this number, I'll pull the details, but based on what is available I cannot report any known litigation for US 11,402,450.

I'll verify the ODP default against live sources before concluding.

Let me confirm with targeted searches against PTAB docket naming conventions for this patent and its inventors.

One final verification pass against docket aggregators and the patent's litigation/PTAB sections.

Proceedings overview

Zero AIA trial proceedings are on file for US 11,402,450. The USPTO Open Data Portal returns no IPR, PGR, or CBM naming this patent, and independent web searches against PTAB docket aggregators and USPTO PTAB document repositories surfaced no petition, institution decision, Final Written Decision, or appeal involving US 11,402,450. The breakdown is therefore: 0 active / 0 claims invalidated / 0 claims sustained / 0 settled / 0 institution denied.

Bottom line for a defendant: all 13 claims are untested — the patent has never been before the Board. This is not the "hardened by two IPRs" posture, and it is also not the "claims 1–5 are canceled" posture. It is a blank slate: every invalidity ground is still available to you, with no § 315(e)(2) estoppel and no prior panel findings to build on or fight.

No proceedings to report

I am deliberately not generating per-proceeding entries. There is no proceeding number to cite, and inventing one (or importing the dockets of lookalike patents) would be the single worst error in this analysis.

Do not be misled by search noise. Searches for this patent number surface IPRs against other patents whose numbers happen to end in "450" — e.g. US 11,089,450 (HBCU Messaging, IPR2025-01493) and US 10,447,450 (Neo Wireless). Those are unrelated patents with unrelated owners and unrelated technology. Neither is US 11,402,450.

Caveat on completeness: the ODP ingest can lag newly filed petitions by some weeks. My searches covered PTAB dockets and published PTAB papers as of 2026-09-29 and found nothing, but a very recently filed petition that has not yet been indexed would not be visible. Treat "zero" as high-confidence, not absolute.

Strategic summary

Claim status. US 11,402,450 issued 2022-08-02 with 13 claims (per the "Claims (13)" heading). The fetched text reproduces claims 1–9, of which claims 1, 3, and 9 are independent and claims 2, 4–8 are dependent. Because no IPR/PGR has ever been instituted, no claim has been canceled, disclaimed via certificate, or held unpatentable by the Board. Claims 1, 3, and 9 read on: a birdcage RF coil device with two coils on a common axis, non-parallel rungs, mirrored coil structures, TX/RX switching, with the TX coil having a high-power structure and the RX coil a low-power design (claims 1, 3); plus a variant where the rungs are coupled to an RF screen device having first and second shields designed for the different modes (claim 9). Claim 9 is the broadest commercially interesting claim because it folds the mode-specific dual-shield RF screen into the coil claim — worth noting if the assertion you face is against a whole-body or head coil assembly rather than a standalone coil.

Estoppel landscape. Because no petition reached a final written decision, § 315(e)(2) estoppel is completely absent. No petitioner, real party in interest, or privy is barred from anything. For a defendant being asserted against today, the entire invalidity toolkit remains open:

• In an IPR you file: all § 102 and § 103 grounds on patents and printed publications, on any claim.
• In district court/ITC: § 112 written description, enablement, and indefiniteness; § 101; and — critically — non-patent prior art (system art, on-sale, public use) that IPR cannot reach. With no prior IPR, there is also no estoppel tail constraining what you can run in the district court in parallel.
• § 315(b) timing is the only trap. If you or your privies have been served with a complaint alleging infringement of this patent, the one-year clock is running. Given the absence of any prior challenge, there is no later challenger race to lose — you would be first to the Board.

Pattern signals. None. There is no serial-petitioner pattern, no defensive aggregator (no Unified Patents or similar) in the chain, and no Philips appeal activity tied to this patent. Philips does litigate and does get challenged in this technology space — the Philips RF-coil portfolio (e.g. US 9,983,279, also a Leussler birdcage-coil patent) is the kind of asset that attracts challenges — but this particular patent has drawn no fire. Philips has not needed to defend it at the Board because nobody has attacked it.

One forward-looking policy note. As of 2025-10-20 the USPTO Director decides institution in all IPR/PGR proceedings, and proposed rules would bar IPRs against patents that have already survived a validity challenge anywhere. Neither change blocks a petition against US 11,402,450 — the patent has survived nothing, so it is squarely eligible. If anything, the current posture makes it more attractive to file early, before a first-mover locks in the "survived a challenge" shield.

Recommended next steps

1. If you are a defendant: there is nothing to cite and no FWD to link. Confirm yourself on PTAB E2E (https://ptacts.uspto.gov/) by searching party name "Koninklijke Philips" and patent number 11,402,450 — this is the authoritative check, and it is where a newly filed petition would first appear.
2. Pull the prosecution history. US 11,402,450 is the US national phase of PCT/EP2017/083987 (filed 2017-12-21), claiming EP priority 16206076.8 (2016-12-22). The WO/EP prosecution and any EPO opposition outcome on the EP counterpart is fair game for § 112 and claim-construction ammunition, and is not constrained by PTAB estoppel.
3. Mind the clock. If you have been served, calendar the § 315(b) one-year bar immediately. This is the only date that can forfeit your best forum.
4. Decide forum strategy deliberately. With no prior IPR estoppel, you can run patents-and-printed-publications art at the Board and reserve system/on-sale/public-use art for the district court without the risk of a broad estoppel wiping out your district-court case.
5. Do not treat the absence of PTAB activity as a validity signal. It means only that no one has chosen to attack this patent yet — often because it has not been asserted, or not asserted against a well-funded defendant. A Leussler birdcage-coil asset sitting in a large Philips portfolio can easily go unchallenged for years.

Confidence note: I found no proceeding, and I am not aware of any. I could not confirm this with a single authoritative structured source beyond the empty ODP list plus negative web-search results, so verify on PTAB E2E before relying on it in a filing or an opinion letter.

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

Let me dig into the specific assignment records and prosecution history.

I've hit my research budget for this session. Here's the analysis based on the authoritative patent text plus what I was able to retrieve from secondary assignment indexes (Google Patents legal events, uspto.report, plai nsite, Espacenet INPADOC). I'll flag clearly where I could not verify a data point rather than invent it.

Inventors

Pattern note: All three inventors are career Philips personnel and none shows up in the sources I could reach as having departed the original assignee. I found no evidence of the "all inventors leave within 12 months of filing" precursor to a fire-sale. I cannot conclusively rule it out (I could not pull the full Assignment Center record), but the filing itself is a Philips-internal PCT (PCT/EP2017/083987), which is inconsistent with a star-team departure scenario.

Original assignee

Koninklijke Philips N.V. (a.k.a. Royal Philips), High Tech Campus, Eindhoven, the Netherlands — the entity named on the issued patent (per the patent front page and Espacenet (73) Koninklijke Philips N.V.).

• Product embodiment: Yes, plausibly. The claims cover a dual-coil birdcage/TEM RF coil device and a dual-shield RF shield for MRI. Philips is an active MRI scanner OEM (Ingenia, Achieva, MR 7700 families) and RF body coils / RF shields are integral scanner subsystems. This is core scanner hardware, not a paper patent.
• Line of business: Diversified health-technology conglomerate; the relevant division here is Philips Healthcare (MRI) — a well-known standard-participant and high-volume medical-device manufacturer.
• Status: Operating (publicly listed; NYSE: PHG). Not in bankruptcy, not dissolved, not acquired. Philips also runs an active out-licensing arm (Philips Intellectual Property & Standards, "IP&S") that periodically sells de-prioritized IP — a normal corporate IP-management function, not an NPE signal on its own.

Assignment timeline

The only recorded post-filing assignment I can substantiate is the inventor→Philips assignment surfaced in the Google Patents legal-events feed:

• 2019-06-12 (recorded; execution date not shown in the feed) — Reel/Frame: NOT RETRIEVABLE from the sources I could access
  • Conveyance: Assignment of Assignors' Interest ("ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS)")
  • Assignor: LIPS, Oliver; FINDEKLEE, Christian; LEUSSLER, Christoph (the three named inventors)
  • Assignee: KONINKLIJKE PHILIPS N.V., Eindhoven, NL
  • Correspondent: Not verified for this record. Philips assignments are characteristically filed through Philips Intellectual Property & Standards (465 Columbus Avenue / later 1600 Summer Street, Stamford CT; historically Valhalla NY) — plai nsite shows this correspondent on multiple other Philips patent assignments (e.g. Assignments 54561/472, 56019/925, 63321/440). I am not asserting that firm is the correspondent on this reel; it is the recurring Philips correspondent across its portfolio. Do not treat this as verified for 11402450.
  • Context: Ordinary inventor-to-corporate-assignee recordation — a formality confirming Philips' pre-existing ownership of the PCT national-phase filing. Not a fire-sale, not a reorg, not a transfer to an asserter.

No other assignment records (security agreements, mergers, licenses, releases, corrections, or transfers to LLCs) appear in the Google Patents legal-events feed for this patent. I could not complete a direct query of the USPTO Assignment Center in this session, so I cannot rule out a record that Google hasn't indexed — but Google Patents' legal events are ordinarily complete for recorded assignments, and they show exactly one.

Caveat on reel/frame: The brief requires a reel/frame for each entry and I do not have it. Fabricating a code (e.g. "011004/0608") would be exactly the error to avoid — please verify the reel/frame directly at the Assignment Center before citing this in any filing.

Timeline diagram

timeline
    title Ownership of US 11402450
    2016 : EP priority filed by Philips
    2017 : PCT application filed EP2017083987
    2019 : Inventors assign rights to Koninklijke Philips
         : Assignment recorded at USPTO
    2022 : US 11402450 granted
    2038 : Adjusted expiration date

NPE / troll-pattern signals

1. Shell-entity transfer — not present. No assignment to any "IP / Patents / Licensing / Holdings / Ventures" entity. The only assignee in the chain is operating-company Philips N.V. (a Dutch public company), not a single-purpose LLC. No registered-agent-service address appears.

2. Known asserter in the chain — not present. Current assignee is Koninklijke Philips N.V. It does not match any entity on the standard NPE lists (Acacia, Marathon, IV, Wi-LAN/Conversant, Vringo, Pendrell, Round Rock, etc.). Note Philips' IP&S unit is a legitimate corporate licensing/divestiture arm — being a licensor is not the same as being an NPE, and I found no evidence IP&S moved this patent to an assertion vehicle.

3. Repeat correspondent across the chain — not present (single link only). There is only one assignment link, so the "recurring attorney across multiple links" tell cannot fire. Philips IP&S does recur across Philips' broader portfolio, but that is a large operating company's in-house filing practice, not a troll pattern. I could not verify the correspondent name on this specific record.

4. Cascading transfers — not present. No chained LLC transfers occur at all. Nothing in <24 months to analyze.

5. Pre-litigation transfer — not present. No assignment within 6 months before any infringement suit, because I found no infringement litigation naming this patent, and the only transfer is the 2019 formality — three years before the 2022 grant, so it cannot be a pre-suit transfer by construction.

6. Bankruptcy fire-sale — not present. Philips is solvent and operating; no Chapter 7/11 sale, no Kodak/Nortel-style auction.

7. Privateering — not present. No transfer from an operating company to an NPE asserting on its behalf. Philips retains the patent and is not (per available records) asserting it through a proxy.

8. Defensive aggregator — not present. The chain does not terminate at RPX, AST, LOT, Unified Patents, or OIN. There is no neutralization event; the patent sits with its original operating-company owner. Consequently this is not the "inverse/neutralized" signal either.

Verdict

Insufficient data — specifically, the benign sub-case: only the original assignment exists.

Justification: the single recorded assignment is the 2019-06-12 inventor-to-Koninklijke Philips N.V. recordation (Google Patents legal events; assignors Leussler / Findeklee / Lips), and no subsequent transfer, security interest, or LLC chain appears. That produces zero NPE signals — no shell LLC, no listed asserter, no cascading transfers, no pre-suit assignment, no bankruptcy — so the patent is best characterized as ordinary operating-company ownership by Philips, with the caveat that the exact reel/frame and correspondent of record for this patent remain unverified in my session. Under the rubric's own definition ("no records, or only the original assignment"), the label is Insufficient data; the substance is "no NPE pattern."

Verify the reel/frame and correspondent directly at:
https://assignmentcenter.uspto.gov/ (search patent number 11,402,450) — mirror index: https://assignment.uspto.gov/patent/index.html

If you need me to nail down the exact reel/frame, execution date, and correspondent of record, that requires a live query of the Assignment Center that I could not complete here; I'd rather flag the gap than fill it with a fabricated citation.

I have the citation list. Let me verify details on the key references.

Prior-Art Analysis — US 11,402,450 B2

Scope note / method: I pulled the citation list of record from the patent's own front-page listing (as mirrored on Justia's record for patent 11402450) and cross-checked a subset against Google Patents. I did not auto-correct any identifier. Where I could independently confirm a reference's title/subject matter I say so; where I could only confirm the number/date/inventor, I flag the description as lower confidence. I hit the search-query limit before verifying every entry in depth, so treat unverified descriptions accordingly.

One discrepancy to flag up front (per operating rules):

• The Google Patents inline "Citations (7)" list for the WO/US family shows only a subset: US 4,638,253; US 4,642,569; US 5,243,286; US 6,420,871; US 2003/0020476; US 2009/0243611; US 2013/0082709 (plus NPL: King et al., TRASE‑FSE).
• The full front-page "Referenced Cited" list (Justia) shows 23 US patent documents + 5 NPL items. The two sources are consistent as far as they overlap; the difference is completeness, not conflict.

A. U.S. patent documents cited of record

B. Non-patent literature (NPL) cited of record

C. Bottom line on §102 anticipation

Taking the citations of record as a whole:

• No single cited reference discloses every limitation of granted claim 1, 3, or 9. All three independent claims require, together, (i) two coils on a common axis with non-parallel rungs, (ii) a mirrored relationship (claims 1 and 3 as granted) or at least a different structure (claim 9), (iii) mode-switchability, and (iv) a high-power TX coil vs. low-power RX coil pairing. The cited art splits these features across different references.
• Closest single-reference candidates (still not anticipatory):
  • US 6,420,871 (Wong) — nested birdcage coils, spiral/non-parallel legs, shared ring, dual PCB metallization. Lacks the mirrored requirement and the TX-power/RX-power distinction.
  • US 8,659,296 (Leussler) — TX strip and RX strip as distinct layers relative to the shield, i.e. a TX/RX power/physics differentiation. Lacks the two mirrored birdcage coils and mode switching.
  • US 6,100,691 (Yeung) — non-parallel (curved) birdcage rungs, but only one coil.
• Most likely role of these references is §103 background/combination, not §102 anticipation: e.g., Wong (two coil structures on one axis with non-parallel rungs) in view of Leussler '296 (separate TX/RX designs for high-field SAR control), and/or the Alsop spiral-coil and Reykowski V-cage papers for the rung-shape limitations. That combination landscape is consistent with the prosecution outcome already noted in the earlier summary — claim 1 was narrowed to require "mirrored" coil structures, which is exactly the limitation the cited art does not appear to show.
• Caveats: (1) My reference-description verification was partial, as the search steps were exhausted; items 7–10, 12–15, 18–21, 23 are confirmed only as to number/date/inventor. (2) Item US 2009/0243511 (Wang) shows a contradictory identification (LED module) and should be re-checked directly on the USPTO/Google Patents page. (3) Items cited on a patent's face are not necessarily the references the examiner relied on for rejection; the actual §102/§103 rejections appear in the file wrapper (PCT/EP2017/083987 and U.S. 16/468,759), which I did not retrieve here. If you want the examiner-applied art rather than the listed art, the next step is the file wrapper on Patent Center / Global Dossier for application 16/468,759.

I've retrieved the prior-art citation list from the patent's front page. Let me pull details on the most salient references before building the §103 analysis.

Obviousness Analysis — US 11,402,450 B2 under 35 U.S.C. § 103

Analyst note on the "Prior Art section" you referenced: The full-text download I was given for this patent contains the specification, claims 1–9, and the front-page bibliographic data, but it does not include a machine-readable "Citations / Prior Art" block. I therefore reconstructed the reference set from (a) the "(56) References Cited" list that appears on the face of the granted patent PDF and (b) targeted searches. Where a reference is drawn only from my own field search and I could not confirm it appears on the patent's face, I say so explicitly. I did not obtain the text of the International Search Report dated 2018-05-23 in PCT/EP2017/083987, which is the examiner's own citation set for this family.

A. Legal framework applied

I apply the Graham v. John Deere factors as refined by KSR Int'l Co. v. Teleflex:

1. Scope and content of the prior art; 2. Differences between the prior art and the claims; 3. Level of ordinary skill; 4. Secondary considerations. Obviousness may be shown by a combination of references where a POSITA had reason to combine them, and KSR expressly endorses: (i) combining known elements to yield predictable results; (ii) simple substitution of one known element for another; (iii) use of a known technique to improve a similar device in the same way; and (iv) applying a known technique to a known device "ready for improvement."

Level of ordinary skill: a B.Sc./M.Sc.-level engineer or medical physicist with several years of MRI RF coil design experience, familiar with birdcage/TEM resonator theory, quadrature/degenerate modes, and MRI TX/RX chain switching. The field is small and highly concentrated (essentially the same handful of Philips/GE/Siemens/QED engineers appear repeatedly in these citations — note the patent's own inventors Leussler and Lips appear on cited art).

Critical admission in the patent's own background: the specification states that non-linear-rung birdcage designs were already "introduced to improve field homogeneity," that "there are typically two orientations for a non-linear extensions of the rung conductors," and that "no coil arrangement is optimal for both reception and transmission mode." These are admissions that establish (1) the non-parallel-rung geometry is prior art, and (2) the TX/RX trade-off motivating the invention was already known. This materially lowers the § 103 burden for the independent claims.

B. The prior-art reference set (from the patent's face)

U.S. patent documents listed under (56), with the class the examiner assigned:

• US 5,243,286 A (Rzedzian), 9/1993 — G01R 33/3854
• US 5,680,046 A (Frederick et al.), 10/1997
• US 6,100,691 A (Yeung), 8/2000
• US 6,420,871 B1 (Wong), 7/2002 — G01R 33/34046
• US 6,791,328 B1 (Nabetani), 9/2004 — G01R 33/34076
• US 7,145,339 B2 (Kramer et al.), 12/2006
• US 7,498,809 B2 (Takahashi et al.), 3/2009
• US 7,501,828 B1 (Wong), 3/2009 — G01R 33/34046
• US 8,659,296 B2 (Leussler), 2/2014
• US 2001/0035504 A1 (Hayes), 11/2001
• US 2003/0020476 A1 (Duensing), 1/2003 — G01R 33/34046
• US 2003/0071622 A1 (Reisker et al.), 4/2003
• US 2007/0079253 A1 (Leussler), 4/2007
• US 2009/0243511 A1 (Wang), 10/2009
• US 2009/0243611 A1 (Holle et al.), 10/2009
• US 2009/0302841 A1 (Avdievich et al.), 12/2009
• US 2010/0033185 A1 (Saha), 2/2010 — G01R 33/34076
• US 2013/0082709 A1 (Rath), 4/2013 — G01R 33/34076
• US 2014/0253126 A1 (Habara), 9/2014 — G01R 33/3453 (TEM coil class)
• US 2015/0130466 A1 (Lips et al.), 5/2015
• US 2018/0321339 A1 (Yang), 11/2018 — G01R 33/3415

Non-patent literature listed under (56):

• Alsop, Connick & Mizsei, "A spiral volume coil for improved RF field homogeneity at high static magnetic field strength," MRM 40:1, 49–54 (1998) — the canonical spiral-rung volume coil.
• A. Reykowski, "V-Cage and V-Array: Novel Coil Structures for Higher Field Strengths," Proc. Intl. Soc. Mag. Reson. Med. 13 (2005) p. 950 — the canonical V-shaped-rung coil.
• King et al., "Phase Encoding Without Gradients Using Trase-FSE MRI," ISMRM vol. 15, 2007, p. 680.
• ISR in PCT/EP2017/083987, dated 2018-05-23 (contents not retrieved).

Additional field references I found by search — NOT confirmed as being on this patent's face (flagged for verification):

• US 7,733,088 B2, "MRI system RF coil assembly with a birdcage transmit-only coil and a pseudo-chain-link receive-only coil array" (Grant 2010-06-08) — https://patents.google.com/patent/US7733088
• EP 1 581 818 A2 / WO 2004/048987 A2, "Degenerate birdcage coil and transmit/receive apparatus and method for same"
• US 9,983,279 B2, "Radio frequency (RF) birdcage coil with separately controlled ring members and rungs" (Leussler) — https://patentimages.storage.googleapis.com/7a/fa/d5/9036d3f2cacf58/US9983279.pdf
• US 2007/0279061 A1, "Double-sided RF shield for RF coil contained within gradient coils" (surfaced adjacent to US 5,680,046 in the citation network)

C. Claim-by-claim analysis

Claim 1 — RF coil device (two birdcage coils, common axis, non-parallel rungs, mirrored, mode-switchable, TX-high-power / RX-low-power)

Element-by-element mapping:

Assessment: Claim 1 is a combination of known elements with predictably combined functions. Alsop/Reykowski supply the non-parallel-rung geometry; EP 1 581 818 supplies mode-switching of a birdcage; US 7,733,088 supplies the TX-only (high-power) vs. RX-only (low-power) split. The only recitation arguably not squarely disclosed is the "mirrored" relationship — and that limitation is (a) a predictable geometric variant of known spiral/V rung shapes, and (b) acknowledged in the background as one of two known orientations. Under KSR ground (iii) ("known technique to improve a similar device in the same way"), the claimed aggregation is prima facie obvious.

Claim 3 — same as claim 1 but not limited to birdcage, with integral RF screen and rungs coupled to the screen

Difference from claim 1: (i) no "birdcage" requirement, (ii) an RF screen device formed integrally, and (iii) the rungs coupled to the RF screen. All three are standard TEM-coil practice. The patent's own description concedes the TEM coil "requires the RF shield device for coupling the rungs thereto, so that the RF shield device provides a ground connection," and the examiner classified US 2014/0253126 A1 (Habara) in G01R 33/3453 (TEM coils). Integration of coil + screen in one component is routine (see also the double-sided-PCB and double-sided-shield art). Claim 3 is obvious for the same reasons as claim 1, with an even thinner margin because it drops the birdcage restriction.

Claim 9 — coils with different (not necessarily mirrored) structures + dual-shield RF screen, each shield designed per mode

This is the independent claim whose novelty resides most heavily in the two-shield, mode-specific shield device. Mapping:

• Two coils, common axis, non-parallel rungs coupled to an RF screen → Alsop/Reykowski + US 2014/0253126 (TEM) + EP 1 581 818 (switching).
• RF screen with a first and second shield on a common axis, different shield structures, each designed for a different mode → the double-sided shield concept (US 2007/0279061 A1, "Double-sided RF shield for RF coil contained within gradient coils") discloses a multi-layer shield structure; conventional shielded birdcages already use slotted shields (slits to suppress eddy currents — a point the patent itself repeats). Once the coil is split into two mode-specific, differently-structured conductors, it is a predictable step to likewise split the return-path/shield into two mode-matched structures, because the shield's job in a TEM/high-field coil is to terminate the rung currents for the mode in use.

Assessment: Claim 9 is obvious as an application of the same "optimize-per-mode" idea to the shield that the art already applies to the coil. No teaching away; the double-sided shield art establishes that layering/pattern-differing shields were known.

Dependent claims 2, 4–8 (and unretrieved 10–13)

• Claim 2 (shared end ring): US 7,733,088 and the QED art describe birdcages with shared end rings; sharing capacitors/end rings is a routine cost-reduction choice the patent itself frames as an alternative.
• Claim 4–5 (cylindrical coil PCB; rungs as metallization layers inner/outer sides; elements on both sides): Conventional printed-circuit coil fabrication; the examiner cited multiple 33/34076 references (Nabetani, Saha, Rath) precisely in this area. Interleaving coil elements across two copper layers is a known technique (also the subject of the double-sided shield art).
• Claim 6 (sinusoidal / parabolic / V / spiral / sinc rung shapes): Disclosed or obvious from Alsop (spiral), Reykowski (V), and US 9,983,279 (varied rung/ring geometries).
• Claim 7 (TX and RX as the modes): EP 1 581 818; US 7,733,088.
• Claim 8 (tuning devices at different cylindrical positions): Routine placement choice; multi-tuned coils (US 6,420,871 Wong; US 2008/0150533 dual-tuned family) show tuning hardware at distributed positions.

D. Motivation to combine (the keystone of the § 103 case)

A POSITA at the 2016 priority date would have been motivated to combine these teachings because:

1. The problem was expressly identified in the art. Both US 7,733,088 and the patent's own background state the same problem — at ≥3T the B1 field becomes inhomogeneous and a single TX/RX coil cannot serve both roles well. The references are drawn from the same narrow field (high-field MRI RF coils) and address the same known deficiency, so they are combinable for their intended purpose.

2. The design space was already narrowed to non-parallel rung geometries. Alsop (spiral) and Reykowski (V-cage) were the reference publications for improving homogeneity via non-linear rung shapes — and both are cited on the patent's face. A POSITA seeking improved homogeneity would begin there.

3. TX/RX separation was a known, standard remedy. US 7,733,088 and EP 1 581 818 show the art already (a) building a dedicated high-power transmit coil separate from a low-power receive structure, and (b) switching a birdcage between TX and RX. Combining "two non-parallel-rung coil geometries" with "switch between TX and RX" yields only the predictable result of using each geometry where it performs best.

4. Mirroring is a predictable design variant, not a new result. Handedness of a spiral/V rung is a binary choice; the patent admits "two orientations." Selecting the handedness that best suits TX and the mirrored one for RX is exactly the "use of a known technique to improve similar devices in the same way" endorsed by KSR. It also dovetails with quadrature-mode practice, where the two degenerate birdcage modes (the sine/cosine pair the patent describes at ¶ referencing arrows 256) are inherently orthogonal/mirrored.

5. Dual-layer PCB/shield implementation was routine. Once the two-coil, two-mode concept was set, fabricating the coils (and the matching shields) as inner/outer metallization layers of one FR-4 cylinder is standard PCB practice with a predictable benefit (compact, low-cost, structurally integral).

Expected result is predictable: each coil/shield optimized for its mode, with switching routing TX to the high-power coil and RX to the low-power coil. No unexpected result is recited; the claimed benefit (better B1 homogeneity, mode-independent shielding) is the aggregation of each reference's own disclosed benefit.

E. Secondary considerations (Graham factor 4)

On the record I retrieved, I found no evidence of secondary considerations:

• No indication in the searchable material of unexpected results beyond the additive benefits of the combined references.
• No evidence of industry praise, licensing, or copying specifically tied to US 11,402,450.
• The "mirrored" limitation was added during prosecution (published claim 1 said only "different from"), which is consistent with a narrow geometric distinction rather than a technical breakthrough, and it is precisely the kind of limitation most vulnerable under KSR.

F. Weakest points / where a § 103 challenge would be contested

To be candid about the counterarguments a patentee would raise:

1. "Mirrored" (claim 1) / "different, mode-specific shield structures" (claim 9). The patentee will argue the cited references disclose separate coils (TX-only birdcage + RX-only array) but not two co-axial, same-type, mirrored coils whose both geometries use non-parallel rungs. A petitioner should be prepared to show that a spiral or V rung's mirror is disclosed or obvious (Alsop/Reykowski figures showing both handedness; the patent's own "two orientations" admission) and to supplement with an ISR reference I could not retrieve.
2. Claim 9's dual shield "each designed in accordance with the different modes." This is the most defensible independent claim, because the shield being split per mode is a rarer disclosure. A petitioner must find a reference teaching a mode-specific (not merely eddy-current-slotted) shield, or rely on the "predictable application" rationale plus double-sided-shield art.
3. Missing ISR content. The examiner's actual PCT/EP2017/083987 search report (2018-05-23) is the most probative document and I could not read it; it may already contain art closer to the mirrored limitation.

G. Bottom line

• Claims 1, 2, 4–8 (and, on the retrieved text, claim 3): prima facie obvious over Alsop 1998 / Reykowski 2005 (non-parallel rungs) in view of EP 1 581 818 / WO 2004/048987 and US 7,733,088 (mode-switchable birdcage; dedicated high-power TX vs. low-power RX), optionally with US 9,983,279 or the double-sided-coil/shield art for the multi-layer PCB and mirrored-geometry details.
• Claim 9: prima facie obvious over the same combination further in view of the double-sided / multi-layer RF shield art (e.g., US 2007/0279061 A1), applying the per-mode optimization to the shield.
• Claims 10–13: unverified (text not retrieved); analysis deferred.

H. Caveats and confidence

• Confidence — moderately high on the rationale (the patent's own background admits the problem and the prior geometry; the TX/RX-splitting and mode-switching arts are directly on point). Moderate on any single reference mapping, because I worked from abstracts/front-page citations rather than full reference texts.
• I could not retrieve the Google Patents "Citations" block or the PCT ISR for this family; the reference list above is reconstructed from the patent PDF's face and search. Verify the on-face status of US 7,733,088, EP 1 581 818, US 9,983,279, and US 2007/0279061 before relying on them in a formal challenge.
• This is a preliminary technical obviousness assessment, not a legal opinion, and does not account for claim-construction disputes, prosecution history estoppel (notably the "different from" → "mirrored" amendment), or any secondary-consideration evidence not surfaced in my searches.