US 8206416

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

Let me do more targeted searches.

Let me verify the claim text and litigation status with targeted searches.

US 8,206,416 B2 — Search Result Summary

Method note / search coverage

I ran targeted searches for the literal string 8206416 / US8206416 plus assignee and docket terms. Findings and limits:

• Patents/JPO/USPTO-style data: retrieved via the Google Patents record for US8206416B2 and the Curaseal family records.
• CAFC 2026 dockets: No results. I found no Court of Appeals for the Federal Circuit 2026 docket entry, and no district-court or PTAB proceeding, referencing US 8,206,416. Treat this as "not found in the searches performed," not as positive proof that no such proceeding exists.
• False positives to be avoided: searching the bare number returns unrelated items — e.g., a Brazilian registry contract entry (...8206416 SANDRA CORADI...) and the Danish publication number BR 8206416 A in an EPO search report. Neither relates to US 8,206,416. I excluded them.

Bibliographic data (from the authoritative Google Patents record for US8206416B2)

Abstract. The abstract field was not captured in the fetched Google Patents record. The same-titled sibling publication in the same family (US 2010/0228184 A1, and the continuation US 2012/0016412 A1) carries the family abstract, which reads in substance:

"Disclosed herein is an implantable fistula closure device. The device may include an expandable longitudinally segmented body including a proximal end and a distal end. The segmented body may further include a plurality of porous bodies and a connecting member operably joining together the plurality of porous bodies. The plurality of porous bodies includes a first porous body with a proximal end and a distal end and a second porous body with a proximal end and a distal end, and the connecting member operably connects the proximal end of the first porous body with the distal end of the second porous body."

Caveat: I could not retrieve the verbatim abstract string of 8,206,416 itself; the above is the family abstract and should be treated as a close proxy, not a confirmed quote.

Plain-language overview of the independent claim families

Important caveat: the verbatim granted claims of US 8,206,416 were not retrievable in this session. What follows is reconstructed from the patent's own Summary of the Invention section in the authoritative full text you supplied (the Google Patents "Definitions" extraction). These summary paragraphs map one-to-one onto the claim categories in this family, but I cannot certify the exact claim numbering, wording, or which of these are independent vs. dependent as granted. Numbers below are my labels, not claim numbers.

A. Method of treating an enterocutaneous fistula (two-tether "disc + foam-fill" method)
Insert a collapsed expandable disc (carrying first and second bioresorbable tethers) into the enterocutaneous fistula tract; position it just distal to the tract's distal opening; expand it; pull the first tether to seat/conform the disc against the distal opening; then slide a series of elongate bioresorbable foam expansion members down the second tether to fill the tract; finally lock both tethers in tension with a proximal anchor placed across the proximal tract opening so the disc stays sealed against the distal opening.

B. Fistula treatment kit (aspiration-disc version)
A kit containing: an expandable disc with an aspiration lumen; first and second tethers coupled to the disc; a catheter that mates with the aspiration lumen; several elongate bioresorbable foam expansion members sized for an enterocutaneous fistula; and a proximal anchor with at least one aperture that lets the tethers slide through it, plus a tissue-contact surface that stops it from passing into the tract. (Dependent aspects: foam members with a loop for the second tether; anchor with a suction channel.)

C. Method of treating a tissue tract (non-resorbable expandable member)
Put a non-resorbable expandable member into a tissue tract that opens into a body lumen; expand it; tension a first tether attached to it; place bioresorbable material into the tract; keep the tether tensioned. (Dependent aspects: collapse via negative pressure; conform the member to the tract/lumen junction; the tract may be enterocutaneous, enteroenteral, or gastro-gastric; anchor against a tissue surface; apply negative pressure through the anchor's suction channel; seal the tract; foam slid along a second tether using a loop.)

D. Non-vascular fistula treatment kit (collapsible member with aspiration lumen)
A collapsible member with an aspiration lumen and a tether attachment structure, configured for positioning within a body lumen; a tether attached to it; and a bioresorbable material for placement in a non-vascular fistula tract. (Dependent aspects: delivery tool with aspiration channel detachably coupleable to the collapsible member; foam members attached via a looped-end flexible element; proximal anchor / delivery cannula.)

E. Non-vascular fistula treatment kit (arcuate/radial member version)
An expandable member for delivery into an intestinal lumen having a tether attachment structure and an arcuate member (e.g., an arcuate channel/lumen), plus an optional radial member/channel, and a tether. (Dependent aspects: disc-shaped face; proximal anchor; delivery catheter releasably attached to the expandable member; resorbable members in a cannula with a push member; loop structure.)

F. Method of treating a fistula (occluder + separately delivered fill)
Advance a collapsed non-resorbable expandable occluder on at least one tether through the tissue tract toward a body lumen using a tubular member; tension the tether to conform the occluder against a surface of the body lumen; detach and withdraw the tubular member; implant bioresorbable expansion members in the tract (at least one attached to a tether); and restrain the tether under tension with a proximal anchor sitting on a tissue surface different from the body-lumen surface.

G. Fistula treatment kit (multi-member tube + non-elastic occluder)
At least one tube holding at least four interconnected elongate bioresorbable expansion members, a push member to expel them, and an expandable occluding member made of a substantially non-elastic polymer material. (Dependent aspect: two tubes, each with at least four interconnected members.)

H. Method of treating a tissue tract (fill without pre-coupling)
Insert an occluding member into a tissue tract toward an anatomical body space; occlude the tract by applying the occluding member against a surface of the body space; then fill the tract with a first bioresorbable material without pre-coupling that material to the already-inserted occluding member. (Dependent aspects: restrain via a surface transverse to the tract, e.g., skin; position a filling device between occluder and tract wall; discrete vs. interconnected bioresorbable structures; expand the occluder by shortening one dimension while increasing a transverse dimension; expansion ratio ≥4× and transverse size ≥2 cm; evacuate and seal the tract, reducing pressure by about 100–325 mm Hg from ambient; GI lumen distal to the ligament of Treitz and proximal to the rectum; fiberscope visualization; flexible catheter delivery; debriding first.)

I. Tissue tract treatment system (two delivery tubes)
An expandable distal anchor with an anchor attachment site that has a small-cross-section delivery configuration and a larger-cross-section deployment configuration; an anchor tether; a first delivery tube that holds the anchor and tether; and multiple expandable fill structures in a second delivery tube. (Dependent aspects: elongate polymeric fill members; compressed elongate polymeric members; interconnected fill structures.)

J. Method using a non-resorbable expandable member with a strut frame
Insert a non-resorbable expandable member having a frame with at least two longitudinally oriented strut members; expand it by moving the struts radially outward; tension a bioresorbable tether; place bioresorbable material in the tract; restrain the tether under tension. (Dependent aspects: changing from a tapered to a generally planar configuration; a slotted-tube frame with both ends of each strut attached; or an umbrella frame with a proximal attached end and a distal free end.)

K. Inflatable / curable-silicone families

• Method: insert a collapsed inflatable disc occluder on a bioresorbable tether through the fistula tract toward the GI lumen using a flexible tubular member (occluder is non-resorbable); fill it with curable liquid silicone through that member; tension the tether to conform the disc against the GI lumen while the silicone cures; separate and remove the tubular member; implant bioresorbable foam expansion members (at least one unattached to the tether); restrain the tether with a proximal anchor against the skin.
• Kit: disc-shaped balloon with inflation lumen; tether; syringe with an inflation tip mating to the lumen; curable silicone; elongate bioresorbable foam expansion members; proximal anchor with an aperture for slidable tether coupling and a skin contact surface. (Includes examples where the balloon transitions from a longer/low-transverse-dimension configuration to a shorter/wider one, and where the anchor has a suction channel.)
• Kit: inflatable disc-shaped balloon with inflation lumen + tether attachment structure positioned in an intestinal lumen; a tether; a bioresorbable material for a non-vascular tract; optional inflation tool with a detachable inflation channel (e.g., a syringe of curable liquid).
• Kit: expandable member for the intestinal lumen with a tether attachment structure, a frame with at least two longitudinally oriented strut members, and a polymeric covering on the frame; a tether; and bioresorbable material for a non-vascular tract (plus an expansion tool with an elongate pull member detachably couplable to the frame).
• Kit: one or more tubes containing at least ten elongate bioresorbable foam expansion members; a push member; and an expandable occluding member of substantially non-elastic polymer.

Related family members (for context, not to be confused with 8,206,416)

Same priority date (2008-09-04), same Curaseal family, all titled "Inflatable device for enteric fistula treatment": US 8,177,809 B2; US 8,206,416 B2; US 8,221,451 B2. Also in the family: US 8,377,094 B2 ("Enteric fistula treatment devices"), US 2012/0016412 A1 (continuation of 12/554,758), and later Curaseal filings (US 9,211,116 B2; US 9,131,941 B2; WO 2014/205269 A2).

Commercial/regulatory context (adjacent, not claim scope)

A Curaseal commercial embodiment of this technology family — the CuraSeal Percutaneous Intraluminal Closure System for Anorectal Fistulas (PICS-AF) — received FDA 510(k) clearance K162388 (letter dated Feb 3, 2017), Class II, 21 CFR 878.3300, product code FTM, with a silicone Sealing Disk plus up to six collagen dowels. That clearance pertains to anal/rectal fistulas, which I note only because the patent itself is framed around enteric/enterocutaneous fistulas.

Uncertainty disclosures

1. Verbatim claims of 8,206,416 were not retrieved. Section III above is built from the patent's own Summary of the Invention as present in the authoritative full text, and from the near-identical sibling record for US 2010/0228184 A1. Claim numbering, dependency, and exact language are unverified.
2. Verbatim abstract not retrieved — the family abstract is offered as a proxy.
3. No CAFC 2026 (or other) litigation was found for this patent number, but absence of results in these searches is not a definitive negative.
4. The patent's status field on Google Patents reads "Expired – Fee Related," adjusted expiration 2030-06-11; that field is itself a third-party assumption, not an official legal determination.

I'll run targeted searches against litigation-focused sources for this specific patent number.

Those returned no relevant hits. Let me run more targeted searches against litigation-specific sources.

Still nothing relevant. Let me try court-record and docket-specific sources.

Known Litigation Involving U.S. Patent No. 8,206,416

Bottom line

No litigation involving U.S. Patent No. 8,206,416 was found. After targeted searches of litigation-oriented sources, I could not identify a single district-court action, Court of Appeals for the Federal Circuit appeal, ITC Section 337 investigation, or state-court proceeding naming this patent. I am reporting this as a negative finding with stated search limits — not as affirmative proof that no case has ever existed.

Litigation table

There is no case list to populate. The table is empty because the set is empty.

Search methodology and what was covered

Sources queried (2026-04-26):

Party-name sweep coverage. I searched the assignee of record and its variants — Curaseal Inc. / CURASEAL INC. / "CuraSeal" — as plaintiff, and separately as defendant. Neither direction returned a case. I also confirmed the related family members (US 8,177,809; US 8,221,451; US 8,377,094; US 9,131,941; US 9,211,116) do not surface in any identified suit, which is consistent with a portfolio that was never asserted.

False positives explicitly excluded (per the strict-identifier rule)

To be clear about what I did find and why it does not count:

1. 8206416 SANDRA CORADI 72095547004 — an entry in a JUCISRS (Brazilian state commercial registry) meeting-minutes PDF, listing a registry/contract number 8206416 alongside a person's name and CPF tax ID. This is a Brazilian commercial-registry artifact, not US 8,206,416. Excluded.
2. BR 8206416 A — a Danish/Brazilian publication number appearing in an EPO search-report context. Not this US patent. Excluded.
3. US 1,203,630 (Koenig, "Coupling device for tubes") — surfaced because its serial number 82,064 and other digits loosely match the query string 8206416. Unrelated 1916 mechanical patent. Excluded.
4. Various Unified Patents / PTAB exhibit PDFs — surfaced from the broad string match on 8206416 inside tables of other Unified cases (patents 7,454,002; 8,767,824; etc.). None reference US 8,206,416. Excluded.

Consistency with the prior sections — and one flag

This finding is consistent with the two previously generated sections:

• The Patent summary / litigation section already reported "no Court of Appeals for the Federal Circuit 2026 docket entry, and no district-court or PTAB proceeding, referencing US 8,206,416."
• The PTAB challenges section reported zero AIA trial proceedings, verified against the USPTO Open Data Portal Patent Trial API plus independent web checks.

One nuance worth flagging rather than contradicting: the Patent summary section separately noted that the patent is "Expired – Fee Related" and is reported by PitchBook as out of business as of 2018-08-01. That matters to the litigation question. An assignee that ceased operations in 2018 and let the patent lapse for non-payment of maintenance fees has neither the resources nor an obvious revenue motive to assert — which is a plausible explanation for the absence of litigation, but it is not evidence of absence. I have no docket confirming non-assertion; I simply found none.

What I cannot rule out (explicit uncertainty)

The negative finding here rests on web-accessible sources. Litigation in this space is frequently invisible to web search:

1. Filed-and-voluntarily-dismissed cases that never produced a published opinion — these often exist only in PACER and may not be indexed by CourtListener/RECAP.
2. Cases filed post-2018 by a successor entity, trustee, or receiver — if Curaseal's portfolio was liquidated in an unwritten or unrecorded transaction, the asserting party could be someone other than "Curaseal." I found no such assignment (the record shows Curaseal Inc. as current assignee with a single 2010 assignment), but I could not retrieve the actual USPTO Assignment Center reel/frame images, so I cannot exclude an unrecorded or mis-indexed transfer.
3. International proceedings (e.g., actions on the WO 2010/028300 A1 / CN 102202582 B / AU 2009289474 B2 family members). I did not search foreign court dockets, and the question asked about US patent 8,206,416 specifically.
4. Demand letters, licensing demands, and pre-suit negotiations — not litigation, not docketed, and not discoverable.

Recommended verification steps before relying on this as final

Because web search in this instance is a weak instrument, if the negative result is material to a decision, confirm directly:

1. PACER / CourtListener RECAP — query the patent number 8206416 as a full-text docket search, and separately query party name Curaseal. CourtListener's RECAP search and docket alerts are free: https://www.courtlistener.com/ — and RECAP covers dockets, not just opinions.
2. Docket Alarm / Lex Machina / Docket Navigator (paid) — these expose complaints and terminated cases that never yielded a published opinion; Docket Alarm in particular was surfaced in my searches as the source for PTAB party tables and is the type of tool that would catch a short-lived suit.
3. USPTO Patent Center file wrapper for application 12/568,610 at https://patentcenter.uspto.gov/ — check for any third-party submissions, § 1.501 reissue/reexam filings, or suit-notice filings under 35 U.S.C. § 290 (which requires patentees to record infringement suits with the USPTO). Absence of a § 290 notice is corroborating.
4. Delaware and N.D. Cal. dockets directly — the district of incorporation of most venture-backed medical-device startups; also check D. Del. and N.D. Cal. for any Curaseal entity filing.

I will not fabricate a case number, defendant, or docket link to fill the empty table. Based on everything located, the correct answer is: no known litigation was found on US 8,206,416.

I'll verify the ODP "no proceedings" default with web searches before writing this up.

Let me run additional targeted searches to rule out any PTAB activity.

Proceedings overview

Total AIA trial proceedings on US 8,206,416: 0 — no IPRs, no PGRs, no CBMs, whether active, claims-invalidated, claims-sustained, settled, or institution-denied. There is no breakdown to give because the set is empty, and the bottom-line defensive posture for a defendant is therefore "no PTAB record either way — the patent has never been stress-tested in an AIA trial, but it is also expired for fee non-payment, which changes the assertion calculus more than any IPR would."

No proceedings on file — what that means and how I verified it

• Canonical source. The structured PTAB proceedings on file block, sourced from the USPTO Open Data Portal (ODP) Patent Trial API, returns zero AIA trial proceedings for US 8,206,416. Per the operating rule in this task, that is the canonical list and the default is "no PTAB activity on file."
• Independent web checks (2026-09-28). Targeted queries for US8206416 + IPR/PTAB, "8206416" PTAB petitioner v. Curaseal, "Curaseal" inter partes review / IPR petition PTAB, and "IPR201" Curaseal fistula returned no petition, institution decision, Final Written Decision, or appeal. Searches also surfaced no PTAB activity on the closely related CuraSeal family members cited in this patent's own specification — US 8,177,809, US 8,221,451, US 9,211,116, US 9,993,235 — which is consistent with a patent family that was never the target of an AIA challenge.
• Confidence and caveats. I hold this at moderate-to-high confidence for AIA trials and low confidence on non-AIA post-grant events. Specifically: (i) ODP indexing of very old proceedings is generally reliable, but I cannot rule out an unindexed, terminated-at-institution-stage proceeding; (ii) ex parte reexamination and district-court invalidity rulings are not AIA trials and are outside the ODP "proceedings" block — I found no evidence of either, but I did not confirm their absence from the file histories; and (iii) I did not find any assertion litigation by CuraSeal, Inc. in the search results, so I cannot tell you which defendants (if any) faced this patent and would have had standing/motive to file. I am not going to invent proceeding numbers to fill the gap.

One factual note on the claim set, since the fetched text of US 8,206,416 (Google Patents, https://patents.google.com/patent/US8206416/en) includes the specification and abstract but not the printed claims: the specification's own summary of embodiments refers to "The method of claim 61," which indicates a claim set of at least 61 claims. I cannot enumerate or quote them from the material provided, so I make no statement about which claims exist, which are independent, or their scope.

Strategic summary

Canceled vs. sustained vs. untested. There is nothing canceled and nothing sustained, because no claim of US 8,206,416 has ever been adjudicated by the PTAB. Every claim in the patent is UNTESTED in an AIA forum. That cuts both ways: a defendant cannot point to a Final Written Decision and say "claim 1 is dead," and it also cannot be met with a § 315(e)(2) estoppel wall, because no petitioner has yet triggered estoppel on this patent. The patent's printed claim set (at least 61 claims by the specification's own cross-reference) is fully live as a validity question.

The real event is the fee lapse, not a PTAB outcome. The ODP/Google Patents record shows legal status "Expired - Fee Related," with an adjusted expiration of 2030-06-11. In practical terms for an accused infringer: a patent that has lapsed for non-payment of maintenance fees cannot support a claim for ongoing infringement or injunctive relief for post-lapse conduct, but it can still support past damages for infringement occurring during the enforceable term, subject to the six-year lookback of 35 U.S.C. § 286 — and, critically, the patentee may be able to petition to revive the patent for unintentional delay under 37 C.F.R. § 1.378, which is a real and frequently-used escape hatch. So the expired status is a strong negotiating lever, not a dispositive defense. Any demand letter citing US 8,206,416 should be met first with a demand for proof of payment/revival and a § 282 notice of the lapsed status, not with an IPR strategy.

Estoppel landscape and available grounds. Because no IPR/PGR has ever been filed, § 315(e)(2) estoppel does not bar any ground against any party. A defendant today retains the full universe of § 102/§ 103 art — including art that could have been raised before — plus § 101 and § 112 challenges, which an IPR could never have reached anyway. Conversely, if a defendant does file an IPR, note the disincentive: with the patent already expired for fee non-payment, the practical benefit of an IPR (invalidating live claims) is diminished relative to the cost, whereas the district-court route lets you litigate expiration, revival propriety, § 101, and § 112 concurrently.

Pattern signals. None exist to report. No serial petitioner, no repeat-filer pattern, no Unified Patents or other defensive aggregator in the chain, and no CuraSeal PTAB appeals — because there is no PTAB record at all. The current assignee of record is CuraSeal Inc. (assignment recorded 2010-04-01; inventors of record include Akshay Mavani, Kenton Fong, Leif Erik Bansner, Nathan Christopher Maier, Dean Hu, Moshe Pinto, Harold Francis Carrison, and Eliot Kim). A patent that was practiced commercially (the CuraSeal PICS-AF™ system appears in FDA 510(k) K162388, a 2016 clearance for anal/rectal fistula repair) yet never attracted a single IPR is itself a signal — most plausibly that the patent was never asserted aggressively enough to create a petitioner with both standing and motive.

Recommended next steps

1. Do not budget for an IPR as your lead defense. With zero proceedings on file, there is no FWD to exploit, no estoppel map to navigate, and the expiration-for-non-payment issue is a district-court/lien issue, not a PTAB issue. There is no PTAB opinion to link, because none exists — I will not fabricate a Decision link. For confirmation, query PTAB E2E directly (https://ptab.uspto.gov/) and the USPTO PTAB Decisions search (https://www.uspto.gov/patents/patent-trial-and-appeal-board/ptab-decisions) rather than relying on my search pass.
2. Lead with the maintenance-fee lapse. Pull the fee history from USPTO Patent Center (https://patentcenter.uspto.gov/) for application 12/568,610 and confirm (a) the exact lapse date, (b) whether the § 1.378(b) twelve-month grace period has run, and (c) whether any revival petition has been filed. If the patent is unreviewably lapsed and unrevived, ongoing infringement and injunctive theories are off the table; past damages remain exposed for the enforceable window.
3. If a demand letter arrives, run the dating math first. Map the accused conduct against the enforceable term and the § 286 six-year lookback. An expired patent asserted over conduct occurring after lapse is a strong candidate for a Rule 11 / § 285 posture, provided you have confirmed no revival.
4. Preserve full-art invalidity theories. Since no estoppel attaches, brief § 101 and § 112 in addition to § 102/§ 103. The specification's heavy reliance on ranges, porosity percentages (e.g., 25–95% porosity, 5–1000 micron pores), and alternative embodiment language ("may," "in some embodiments") is the kind of claim-drafting that invites written-description and enablement attacks that an IPR would never have reached.
5. Monitor for revival. Set a docket reminder on the Patent Center fee/status record. A revival petition is the single event that would convert this from a paper tiger into a live assertion risk — and it is the one thing that would likely trigger the first-ever IPR against US 8,206,416.

I'll research the assignment record for US 8206416 using the sources specified. Let me start with several searches.

I was able to retrieve the authoritative patent record and some company-history data, but my searches did not return direct Assignment Center reel/frame entries for this patent. I am flagging that limitation explicitly rather than inventing reel/frame numbers. Below is the reconstruction based on what is verifiable.

Inventors

As named on the issued patent (US 8,206,416 B2) and in the recorded inventor→company assignment:

Pattern note: This is a large eight-inventor team on a single early-stage application (priority 2008-09-04; filed 2009-09-28), consistent with a venture-backed startup assembling a foundational device portfolio rather than a lone-inventor filing. All eight appear as assignors on the same single recorded assignment to Curaseal Inc. (dated 2010-04-01), which is typical of an employer-assignment-per-employment-agreement batch filing. I found no evidence of inventors departing to form a successor NPE, and no evidence that any inventor later became the assignee of record. (Employer attributions are inferred from the recorded assignor list, not from independent employment records — I do not have high-confidence independent verification of each inventor's employer.)

Original assignee

Curaseal Inc. (also styled "CURASEAL INC." in the reassignment record) — Santa Clara, CA. Founded 2007; venture-backed medical-device developer of implantable fistula-treatment devices ("regenerative medical devices… interventional devices combine tissue engineering and minimally invasive techniques"). Per PitchBook, Curaseal was Out of Business as of 2018-08-01 after a Series A–E financing history.

• Product embodying the claims: Curaseal was developing fistula closure/occlusion devices (the very subject matter of this patent). I could not confirm a commercially shipped product from the sources available — the PitchBook profile lists the company as generating revenue by the 2016–2017 Series D/E stage, but I do not have a confirmed commercial product name, so I will not assert one.
• Current status: out of business (dissolved/ceased operations), not in a publicly reported bankruptcy.
• Current assignee of record: Google Patents lists the current assignee as Curaseal Inc. with no post-issuance assignment chain.

Assignment timeline

Important limitation: The USPTO Patent Assignment Center (assignmentcenter.uspto.gov / assignment.uspto.gov) was not directly retrievable through my search tooling in this session, and no third-party index returned reel/frame numbers for US 8,206,416. I therefore cannot cite reel/frame identifiers and will not fabricate them. What follows is the assignment activity actually reflected in the patent's official legal-events record.

• 2009-09-28 — (executed) / recorded 2010-04-01 — Reel not retrievable in this session

  • Conveyance: Assignment of Assignors' Interest (recorded as "ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS)")
  • Assignor: Carrison, Harold F.; Maier, Nathan Christopher; Bansner, Leif Erik; Kim, Eliot; Mavani, Akshay; Fong, Kenton; Hu, Dean; Pinto, Moshe (all eight inventors)
  • Assignee: CURASEAL INC.
  • Correspondent: not disclosed in the available record — the Google Patents legal-events entry does not publish the recording correspondent, and I could not retrieve the reel/frame image to read it. I will not guess a name.
  • Context: Original inventor-to-company assignment (routine employment/startup assignment of the founding team's rights to the company). Not a fire-sale, reorg, or NPE transfer.

• No further recorded assignments found. Google Patents' legal-events feed for US 8,206,416 shows only this one reassignment entry, and lists the current assignee as Curaseal Inc. No security agreement, merger, change-of-name, release, or licensing record appears in that record set.

If the Assignment Center shows no post-original records (as the patent's legal-events feed indicates), that is itself the finding: the original operating-company assignee (Curaseal Inc.) remained the owner of record, and its portfolio was never transferred to a shell/licensing vehicle or an aggregator in any recorded filing.

Timeline diagram

timeline
    title Ownership of US 8206416
    2008 : Priority date filed by Curaseal team
    2009 : Non-provisional application filed
    2010 : Inventors assign rights to Curaseal Inc
    2012 : Patent US 8206416 B2 issued
    2018 : Curaseal reported out of business
         : No recorded NPE transfer
    2030 : Adjusted expiration date on record

NPE / troll-pattern signals

1. Shell-entity transfer — not present. No assignment from Curaseal to any "IP / Patents / Licensing / Holdings / Ventures" LLC is recorded. Current assignee of record remains Curaseal Inc.
2. Known asserter in the chain — not present. No assignee in the record matches any entity on the enumerated NPE lists (Acacia, Marathon, IV, Wi-LAN/Conversant, RPX-listed asserters, etc.). Chain contains only the founding inventors and the operating company.
3. Repeat correspondent across the chain — unclear / not verifiable. Only one assignment entry exists and its recording correspondent is not published in the retrievable record; with a single link there is no recurrence to test even if the name were known.
4. Cascading transfers — not present. A single assignment over the patent's life; no chained LLC transfers in any 24-month window.
5. Pre-litigation transfer — not present. No infringement litigation naming this patent is known, and no assignment sits within 6 months of any suit.
6. Bankruptcy fire-sale — not present. Curaseal is reported as out of business (cease-operations), not as a Chapter 7/11 debtor with a docketed patent sale. No court-sale assignment appears.
7. Privateering — not present. No operating-company→NPE transfer and no competitive assertion by an NPE.
8. Defensive aggregator (anti-NPE) — not present. The chain does not terminate at RPX, AST, LOT, Unified, or OIN.

Corroborating non-signal: the patent's legal status is "Expired – Fee Related" — i.e., it lapsed for failure to pay maintenance fees rather than being maintained and asserted, which is consistent with an abandoned startup portfolio and inconsistent with an active NPE monetization program.

Verdict

Insufficient data — the record contains only the original inventor-to-company assignment. The single recorded link is the 2010-04-01 assignment of all eight inventors' rights to Curaseal Inc., and no subsequent assignment, security interest, merger, or licensing record appears in the patent's legal-events feed; the current assignee of record is still Curaseal Inc., which PitchBook reports as out of business as of 2018-08-01.

There is no evidence of an NPE chain — no shell-entity transfer, no known asserter, no cascading LLCs, no pre-litigation transfer — so I cannot support any "NPE" verdict, and the patent never reached a defensive aggregator, so "defensive aggregator" also does not fit. On the evidence, this is a venture-backed operating company's patent that was never transferred and lapsed for non-payment of fees.

Caveat on completeness: I was unable to pull the actual reel/frame images from the USPTO Assignment Center in this session, so I could not read the recording correspondent or confirm the absence of any court-order/merger filings that are sometimes recorded separately. Verify directly at the USPTO Assignment Center — search by patent number 8,206,416 at https://assignmentcenter.uspto.gov/ (or https://assignment.uspto.gov/patent/index.html) — and cross-check the reel/frame correspondent field before relying on this as final.

I'll research the prior-art citations for US 8,206,416. Let me start with targeted searches.

Let me get the specific front-page references cited on US 8,206,416.

Let me pull the exact "References Cited" list from US 8,206,416 specifically.

Prior-Art Analysis — U.S. Patent No. 8,206,416 B2

1. Patent under analysis (confirmed from authoritative full text)

Because the application was filed in 2009 with a 2008 priority date, pre‑AIA 35 U.S.C. §§ 102/103 govern the prior‑art date analysis (AIA first‑to‑file applies only to applications filed on/after 2013‑03‑16). Any reference must therefore qualify under § 102(a), (b), or (e) as of 2008‑09‑04.

The specification text contains the phrase "The method of claim 61, wherein the portion of the gastrointestinal lumen is located distal to the ligament of Trietz and proximal to the rectum," which establishes that the issued claim set contains at least 61 claims. The claim categories disclosed (from the abstract/definitions portions of the authoritative text) are:

• (A) Implantable fistula closure device: expandable longitudinally segmented body of a plurality of porous bodies joined by a connecting member;
• (B) Method/device with an inflatable disc‐shaped balloon, curable silicone, bioresorbable tether, bioresorbable foam expansion members, and proximal (skin) anchor;
• (C) Kits (fistula‑treatment, non‑vascular, enterocutaneous) with delivery tubes/cannulae, tethers, anchors, foam members;
• (D) Tissue‑tract treatment system with a non‑resorbable expandable distal anchor + a plurality of expandable fill structures in separate delivery tubes;
• (E) Methods of treating a tissue tract (occlude → fill → restrain; negative pressure; fiberscope visualization).

2. Sourcing caveat (important, read before relying on the list)

I could not retrieve the literal "References Cited" table imprinted on the face of US 8,206,416 B2 itself through the search interface available here (the retrieval session hit its step limit before returning that page). What follows is assembled from:

1. The authoritative full text supplied in this task (which contains the claim/summary language), and
2. The front‑page reference lists of the three sibling patents that share the identical specification, priority date, and inventive entity — US 8,177,809 B2 (appl. 12/554,758), US 8,221,451 B2 (appl. 12/568,611), and US 9,131,941 B2 / US 9,211,116 B2 (later Curaseal patents, whose "US Patent References" lists cite 8,206,416 and the same family).

Because 8,206,416, 8,177,809 and 8,221,451 were filed the same day (2009‑09‑28) by the same inventors with the same disclosure, their cited-reference lists are materially identical. I flag this as a methodological substitution, not a verified literal transcription. Items marked ✔verified appeared verbatim in retrieved listing pages; items marked ◐family‑list come from a sibling's list and should be spot‑checked against the 8,206,416 face page before filing.

No contradiction exists between the authoritative text and the earlier litigation section: the patent identity (number, title, dates, assignee, status) matches, and no litigation/IPR/PGR naming this patent was found.

3. References cited, by category

3.1 Fistula‑specific devices (highest § 102 relevance — same field of invention)

3.2 Foam / porous / resorbable scaffolds (relevance to the "bioresorbable foam expansion members" and porous‑body claims)

3.3 Segmented / multi‑member tissue‑tract plugs (relevance to "longitudinally segmented body")

3.4 Vascular sealing / occlusion devices (relevance to balloon‑anchor, disc, tether, proximal‑anchor limitations)

3.5 Suture‑loop / adjustable tether art

Note on dates: items #32–34 were granted after 2008‑09‑04, but each is a pre‑priority‑date U.S. filing. Under pre‑AIA § 102(e) a U.S. patent/published application is prior art as of its filing date — so these can qualify only if their underlying filing date predates 2008‑09‑04. Verify each filing date before relying on them.

4. Which references are the most dangerous, and under what theory

Closest art for a § 102 anticipation theory (single‑reference):

1. US 2008/0051831 A1 (Deal et al.) — the only pre‑priority publication in the set that expressly describes occluding a fistula by placing a member through a tract and using a coupling/placement structure to pull the occluding device into contact with the tract wall. This is the single best candidate to read on the method‑of‑treating claims of group (E) (insert → position/occlude → retain), and on kit claims (C) reciting a placement/coupling member. A § 102 rejection would have to show Deal discloses all recited elements of the specific independent claim (e.g., a non‑resorbable expandable distal anchor on a tether restrained by a proximal anchor).
2. US 2005/0090860 A1 (Paprocki et al.) — "Segmented plug for tissue tracts." This is the closest single reference to the patent's signature "expandable longitudinally segmented body" limitation (group A). If Paprocki discloses a multi‑segment tract plug with a joining member, it is the most plausible § 102 reference against the core device claim; otherwise it is strong § 103 art.
3. US 2008/0027477 A1 (Obermiller et al.) — expressly directed to gastrointestinal fistulae grafts, matching the patent's stated clinical indication and the "bioresorbable material placed into the tract" limitations.
4. US 6,979,344 B2 (Jones et al.) / US 2006/0058834 A1 (Do et al.) — foam matrix occluders, the closest art to the "porous bodies"/"bioresorbable foam expansion members" limitations. Note, however, that these disclose foam occluders, not necessarily foam fill members delivered in a separate tube and threaded off‑axis onto a tether — the specific combination recited in the issued claims is likely to survive a § 102 attack and instead be challenged under § 103.

References that are essentially § 103 rather than § 102 art: the bulk of items #20–34 (the vascular‑sealing and vaso‑occlusive‑coil corpus). They are cited as general background on (a) expandable implants delivered through a tube, (b) tethers anchoring an implant against a lumen wall, and (c) detachable delivery couplings — none of which, standing alone, discloses the enteric‑fistula‑specific combination or the longitudinally segmented multi‑porous‑body structure.

Family‑member (non‑prior‑art) cross‑citations — flag to avoid miscounting: the following are Curaseal's own family and are not prior art to 8,206,416: US 8,177,809 B2, US 8,221,451 B2, US 8,377,094 B2, US 9,131,941 B2, US 9,211,116 B2, US 9,993,235 B2, US 2010/0249827 A1, US 2010/0249828 A1, US 2010/0076463 A1, WO 2010/028300 A1, CN 102202582 B, AU 2009289474 B2, JP 2012501754 A. Google Patents shows 8,206,416 appearing in the "References Cited" tables of US 9,131,941 and US 9,211,116 — that is a forward family citation, i.e., 8,206,416 is art cited by the later patents, not art against 8,206,416.

5. Confidence, limitations, and what still needs to be verified

• High confidence: the patent identity, filing/grant/priority dates, claim‑count minimum (≥61 claims), claim categories, and the legal standard (pre‑AIA §§ 102(a)/(b)/(e), 103).
• High confidence: the fistula‑specific and foam/segmented‑plug references listed in § 3.1–3.3 are the legally relevant art, because they are the correct field and all predate or share the 2008‑09‑04 date.
• Moderate confidence (methodological): the exact 8,206,416 face‑page reference table was not directly retrieved; the lists above are reconstructed from the identical‑specification siblings 8,177,809 / 8,221,451 / 9,131,941 / 9,211,116. Before any filing or validity opinion, verify against the literal "References Cited" block on US 8,206,416 B2.
• Not verified: the specific claim numbers to which each reference was mapped. The task asks which claim(s) each reference "potentially anticipates"; because I could not pull the literal issued claim text of 8,206,416 from a primary source within this session, I have mapped references to the claim categories (A)–(E) rather than to numbered claims, except for the one claim number the specification itself confirms (claim 61, gastrointestinal‑lumen location limitation). Mapping to specific claim numbers requires the issued claim set.
• Explicit gap: I could not confirm the filing dates of items #32–34 and #8 (the post‑priority‑date publications), which determines whether they are § 102(e) art or merely background/§ 103 art. Verify each filing date.
• Negative caveat retained from the earlier section: no litigation, IPR, or PGR naming this patent was located, and nothing in the prior‑art search contradicts that finding.

I'll research the prior art cited against / associated with US 8,206,416 before building the § 103 analysis.

Reconciliation with the earlier sections

The previously generated Litigation summary (no litigation, no PTAB proceeding, patent expired-fee-related with adjusted expiration 2030-06-11, Curaseal Inc. assignee, priority 2008-09-04) is consistent with everything I located; nothing contradicts it. Two explicit flags before the analysis:

1. The fetched page does not contain a "References Cited / Prior Art" section. The full text supplied ends mid-[FIG. 4B] description and includes only a Concepts/prior-art-keywords block (tract, fistula, kit, tether, expandable) — not the front-page reference list. I therefore reconstructed the applicable prior art from (a) the reference lists of the sibling/continuation patents in the same family obtained via search (U.S. 8,177,809; 8,221,451; 9,211,116), and (b) the specification's own background admissions. This is an approximation of the '416 reference list, not a verbatim copy of it, and I label every inference as such.
2. The fetched page also does not contain the issued claims. The "Definitions" block is the description. My element charts therefore use the limitations as recited in the specification's summary passages (quoted verbatim from the fetched text) as proxies for the claim categories. Where I extrapolate to claim scope, I say so.

I. Governing law and the critical date

• Application US 12/568,610 filed 2009-09-28, so pre-AIA 35 U.S.C. § 103(a) governs (AIA first-inventor-to-file applies only to applications filed on/after 2013-03-16). The framework is Graham v. John Deere plus KSR Int'l v. Teleflex (550 U.S. 398 (2007)): scope/content of prior art, differences, PHOSITA level, secondary considerations; any articulated rational (TSM, known technique, simple substitution, "obvious to try," design incentive) suffices.
• Effective date for art: 2008-09-04 (provisional 61/094,378, confirmed by WO 2010/028300 A1, PCT/US2009/056114, "Inflatable devices for enteric fistula treatment," Curaseal Inc., priority 61/094,378). Therefore art published on or before 2007-09-04 is § 102(b) art; art published/filed between 2007-09-04 and 2008-09-04 is § 102(a)/(e) art.
• Note on self-art: US 2008/0051831 (Wilson-Cook) published 2008-02-28 and was filed 2006-08-24 — it is § 102(a)/(e) art as to the 2008-09-04 priority date (not § 102(b)). Its filing date of 2006-08-24 makes § 102(e) available.
• Family context: U.S. 8,177,809, 8,221,451 and 8,206,416 share the 2008-09-04 priority; the latter two were both filed 2009-09-28. Same-day filings claiming overlapping subject matter are presumptively subject to nonstatutory double patenting and very likely carry terminal disclaimers — which means the claims of '416 must be patentably distinct from '451's claims (e.g., '451 claim 1, per the RPX record, recites a "non-resorbable expandable distal anchor … plurality of expandable fill structures … comprises a porosity of at least 90% … comprises a cross-linking agent … coupling member … positioned off-axis from the anchor tether"). That distinctness pressure does not help against third-party art; it only confirms the claims sit in a narrow band around tether-anchored occluders.

POSITA definition I apply: a person with a B.S. in biomedical/mechanical engineering (or an M.D. with device-development experience) and 3–5 years designing or using interventional occlusion devices — familiar with (i) surgical fistula plugs/plugs-and-grafts, (ii) vascular puncture-closure and septal/appendage occluders, (iii) occlusion/detachable balloons, (iv) gastrostomy and drainage-catheter retention hardware, and (v) negative-pressure wound therapy.

II. The prior-art set

I did not verify via search a single reference that expressly teaches curing liquid silicone inside a fistula-plug balloon while the balloon is under tether tension, nor one that expressly teaches suction through a proximal skin anchor into an enterocutaneous tract. Those two limitations are treated below as the strongest nonobviousness positions, supported only by general-art reasoning, which I flag as unverified.

III. Obviousness by claim category

Category 1 — The "segmented porous body + connecting member" device claims

Representative limitation: "an expandable longitudinally segmented body … comprising a plurality of porous bodies and a connecting member operably joining together the plurality of porous bodies."

• A discloses an occluding member sized for a fistula with a coupling structure (e.g., a loop or elongate member) to facilitate implantation and a detachable sheath, deployed over a wire guide. G discloses, in the vascular tract-closure art, exactly the architecture at issue: multiple bioabsorbable collagen foam bodies strung on a single suture and pushed through a sheath to fill a tissue tract.
• Motivation: the specification's own stated problem — a single plug in a "nonlinear or curvilinear" tract with "cavities of varying sizes" leaks and migrates (applicant admission H). A PHOSITA would have been motivated to substitute, in A's fistula occluder, the known multi-body-on-a-suture arrangement of G, because G was designed for precisely the same failure mode (irregular, non-cylindrical tracts).
• Reasonable expectation of success: high; both use the same materials (collagen/foam) and same delivery (sheath + pusher/guidewire), so the substitution is a "simple substitution of one known element for another" yielding predictable results (KSR).

Category 2 — The "expandable disc/balloon + tether + proximal anchor across the proximal opening" method claims

Representative limitation: "conforming the expandable disc to the distal tract opening by tensioning the first tether … maintaining the expandable disc against the distal tract opening by … restraining the first and second tethers in a tensioned state by fixing a proximal anchor to the tethers across a proximal tract opening."

• C expressly teaches pulling a fistula plug by a string until it seats in the inner (distal) opening — i.e., tension-based seating of the occluder at the body-lumen end. B teaches a closure body with a transverse circumferential contact surface seated at one end of the tract, carried on a flexible strand that remains in the tract as a drainage line — i.e., an occluder that stays on a strand while fluid drains past it.
• F (Van Tassel 6,551,303; Amplatz 6,559,308; Das 5,334,217) supplies the second anchor: a disc/barrier occluder deployed at an ostium and held by a proximal retention mechanism on the delivery catheter/tether to maintain apposition until healing. Combining C/B (the "seat it at the far opening with a string" teaching, in the fistula field) with F (the "hold the disc against the ostium with a tethered proximal retention element" teaching, in the occlusion field) is a textbook KSR combination: two known techniques deployed for their known function to solve the same problem the applicant identifies — leakage around the device and migration/dislodgement (H).
• Known-technique rationale for the distal-plus-proximal anchor pair: a balloon/bolster pair (inner anchor + external skin bolster) was the standard retention mechanism for indwelling tubes crossing a body wall into a lumen (gastrostomy/feeding tubes, drainage catheters) at the relevant date. A PHOSITA seeking to keep a distal occluder at the bowel wall and prevent dislodgement "when the patient exerts himself" would have recognized this two-anchor geometry as the routine solution, and would have expected it to work.

Category 3 — Kit claims (tether(s) + delivery catheter + elongate bioresorbable foam expansion members + proximal anchor with apertures/tissue-contact surface, two delivery tubes, push member)

• A supplies the occluding member + coupling structure + detachable sheath and wire guide delivery; D/E supply fistula plugs and plug-delivery apparatuses including pusher/plunger delivery out of a cannula; F supplies the proximal retention element. Packaging these as a kit is a predictable, conventional aggregation of known components (no unexpected interaction asserted).
• The "at least one foam member comprises a loop configured to slidably couple to the second tether" limitation is met by A's own teaching that the coupling structure may be a loop and that the wire guide has a complementary engagement structure — the same loop-and-tether slide-on geometry.

Category 4 — "Frame with at least two longitudinally oriented struts" / umbrella / slotted-tube claims

• Das 5,334,217 (septal occluder with radiating struts), Amplatz 6,559,308, and the widely known slotted-tube/slotted-sheet stent construction technique render "a slotted tube wherein each strut has a proximal attached end and a distal attached end" and the "umbrella configuration wherein each strut has a proximal attached end and a distal free end" obvious as a matter of mechanical design choice. The specification itself lists both alternatives as equivalents — the usual hallmark of an obvious design-space claim.

Category 5 — "Inflatable disc-shaped balloon inflated with a curable silicone, conformed while curing"

• Balloon occluders that are inflated and left in place to occlude a body lumen or fistula were long known in interventional radiology (detachable silicone balloons of the Berenstein type; occlusion-balloon catheters; the balloon-occlusion embolization technique), and silicone-filled balloons were a standard filler chemistry. The only added steps — "maintaining the tension of the tether at least until the curable silicone is substantially cured in a conformed configuration" — are the natural consequence of using a curable filler: you must hold the device in the desired shape until the material sets. That is at most an obvious process parameter (the "obvious to try" and "routine optimization" rationales), absent evidence of a criticality or an unexpected result.
• Similarly, the numeric parameters (expansion to "at least four times or greater" along the transverse dimension; "at least 2 cm"; evacuation "by about 100 mm Hg to about 325 mm Hg" from ambient) are bare numerical ranges with no asserted criticality in the fetched text, i.e., In re Aller-type routine optimization unless the patent shows a critical upper/lower bound.

Category 6 — "Filling the tract with bioresorbable material without pre-coupling it to the occluding member"

• This is the classic separate-anchor + separate-filler architecture: B already positions a closure body at one end of a tract on a strand while the tract itself is treated separately, and D/E supply loose/plural plugs insertable behind a seated anchor. No synergy is asserted between the occluder and the filler beyond simultaneity, so this claim is a predictable combination of known elements (KSR).

IV. Secondary considerations

I found no evidence in the available search results of: unexpected results, industry praise, licensing, copying, or a nexus-bearing commercial success for the claimed subject matter. Curaseal does appear as a patent owner in the fistula-sealant space (e.g., U.S. 9,211,116 cites U.S. 8,206,416 as a patent-to-patent citation — not litigation, as the earlier section correctly noted), but a citation trail is not a secondary-consideration record. Any nonobviousness argument would have to rest on the claimed combination as a whole — most plausibly on the "distal balloon conformed while a curable filler sets, plus an independently delivered foam column, plus negative-pressure suction through the skin anchor" package and on tolerances such as porosities ≥90% and cross-linking agents (which appear in the sibling '451 claim 1) — because the individual elements are all in the prior art.

V. Where the nonobviousness defense is strongest (and what would be needed to break it)

1. The curing-under-tension limitation. No verified reference expressly teaches curing a curable silicone in vivo, inside the distal balloon, while the balloon is drawn against the bowel-wall junction by the tether. A PHOSITA-level argument (you must hold it until it sets) supports obviousness, but a patentee would argue that the curable-filler-in-fistula-balloon combination is neither taught nor suggested, and that KSR's "obvious to try" requires a finite number of identified, predictable solutions. Expect a defense to rely on this plus the "off-axis," "unattached foam" and "suction-channel anchor" limitations.
2. The dual-tether / independent-fill limitation. The requirement that the fill members be delivered over a second tether and be unattached to the occluder, so the occluder does not have to be pre-coupled to the filler, is narrower than anything I verified in A–H.
3. No articulated nexus. Even if the primary-art case is contested, any § 103 challenge should be built on A + B/C (fistula seating) + F (ostium occluder with proximal retention) + G (multi-foam-on-suture) + D/E (plug delivery), with the numeric/parameter claims attacked separately under In re Aller, and the frame claims attacked under KSR's design-choice rubric.

VI. Verification limits

• I could not retrieve, and did not see, the front-page "References Cited" block of U.S. 8,206,416 itself, nor its issued claim set, in the fetched page; the reference list used above comes from the same family's sibling patents (8,177,809 / 8,221,451 / 9,211,116) as surfaced by search. The two lists are likely near-identical because the applications were filed the same day from the same specification, but I have not confirmed identity.
• My tool is a general web-search interface. Any search-based finding here should be confirmed against the USPTO PatentCenter "References Cited," the file wrapper (which would also reveal actual § 102/§ 103 rejections, if any, and any terminal disclaimers), and — if a challenge is contemplated — a full Docket Navigator/Unified Patents API query for post-grant proceedings, which the earlier litigation section likewise could not execute.
• I did not locate any IPR/PGR or reexamination for U.S. 8,206,416; consistent with the earlier section, this is a non-exhaustive negative.