US Patent 9,585,681: Scope, Claim Architecture, and US Landscape
What does US 9,585,681 claim, in plain scope terms?
US 9,585,681 claims a method for delivering a bioabsorbable expandable device into a paranasal sinus cavity, where the expandability comes from a pronged filament structure that expands radially outward after placement. The claim’s core physical limitation is structural and placement-driven:
- Placement: “advancing” the expandable device into the sinus cavity using a delivery device, then withdrawing the delivery device.
- Conformance: the expandable device is sized and shaped to fit and is at least partly conformable to the sinus cavity shape after withdrawal.
- Pronged filament architecture:
- the device has a pronged structure comprising a plurality of filaments
- filaments have proximal ends and distal free ends
- only the proximal ends join together (filaments are otherwise free at the distal end)
- radial expansion occurs from the joint region outward
- Bioabsorbability: explicitly required at least in dependent claim coverage (“configured to biodegrade” and “one or more biodegradable polymers”).
- Optional performance add-ons in dependent claims:
- drug elution including mometasone furoate
- radiopaque markers and indirect visualization
- advancement under direct visualization
- self-expansion
- anchoring elements on each filament
- filament length range 2 to 5 cm
- delivery device structure (handle, sheath, distal loading portion)
In effect, the patent’s enforceable center of gravity is a sinus-deployed, bioabsorbable, filament-pronged, proximally joined expandable device placed by an insertion-and-withdrawal delivery system.
What is the independent claim’s structure and practical scope? (Claim 1)
Claim 1 is the broadest method claim and is not limited to any particular drug, visualization mode, or radiopaque marker. It is limited to the device architecture and the post-placement state.
Core mandatory elements of Claim 1
- Method context: delivering a paranasal sinus device.
- Advancement step:
- advancing a bioabsorbable expandable device into a paranasal sinus cavity
- using a delivery device
- Geometry and fit:
- expandable device is sized and shaped to fit the sinus cavity
- device is at least partly conformable to the sinus cavity shape
- Filament/prong architecture:
- pronged structure with plurality of filaments
- filaments expand radially outwardly
- each filament has proximal and distal ends
- only the proximal ends join together
- distal ends are free distal ends
- Delivery mechanics:
- withdrawing the delivery device
- Post-withdrawal state:
- expandable device remains in the sinus cavity
- device is at least partially conformed after the delivery device is fully withdrawn
What Claim 1 does not require
- It does not require:
- any specific active agent (even though dependent claim 5 adds mometasone furoate)
- radiopaque markers or imaging beyond generic delivery
- anchoring elements (dependent claim 10)
- a particular delivery tool geometry (dependent claim 12)
- self-expanding language (dependent claim 9)
- a filament length range (dependent claim 11)
- biodegradable polymer species (dependent claim 3)
Key claim interpretation pressure points
For enforcement and design-around, the following elements are usually the highest “claim construction” risk:
- “Only the proximal ends join together”: a design that ties filaments together at additional locations (mid-filament, distal tips) can fall outside this literal requirement.
- “Distal end ... free distal end”: anything that structurally couples distal ends (even partially) may weaken literal coverage.
- “Expand radially outwardly”: a device that deploys by axial movement, bending without radial expansion, or relies on separate actuator structures could be argued outside.
- “remains in and at least partially conformed ... after ... completely withdrawn”: a device that collapses after withdrawal, or one that requires a separate stent/anchor left in place, changes the infringement profile.
How dependent claims expand or narrow coverage
The dependent claims add narrower features. In portfolio and freedom-to-operate work, they map to design choices: drug coating vs bare scaffold; visualization strategy; anchoring; and filament dimensions.
Claim-by-claim add-ons
| Claim |
Added limitation |
Scope effect |
| 2 |
Device biodegrades |
Narrows to biodegradable expandable devices beyond Claim 1 bioabsorbability framing |
| 3 |
One or more biodegradable polymers |
Narrows biodegradation mechanism to polymer composition |
| 4 |
Device releases one or more active agents |
Narrows to drug-eluting version |
| 5 |
Active agent is mometasone furoate |
Narrows to specific corticosteroid drug |
| 6 |
Device has radiopaque markers |
Narrows to imaging-capable scaffolds |
| 7 |
Indirectly visualizing device |
Narrows method to use imaging with radiopaque markers (imaging mode still implied) |
| 8 |
Advancement under direct visualization |
Narrows insertion procedure to a direct visualization environment |
| 9 |
Device is self-expanding |
Narrows to passive/self-expanding deployment mechanics |
| 10 |
Anchoring elements on each filament |
Narrows to filament-level anchoring for retention |
| 11 |
Filament length 2 to 5 cm |
Narrows geometry parameterization |
| 12 |
Delivery device has handle, sheath, distal loading portion |
Narrows the tool structure |
Where is the strongest “infringement gravity” in the claims?
The practical strongest coverage cluster is:
- Pronged proximal-joined filament structure with free distal ends that expand radially outward in the sinus.
- Bioabsorbable expandable device remaining in the cavity after delivery withdrawal.
- Drug-eluting form when mometasone furoate is used (Claim 5).
If a competitor uses a different expansion topology (e.g., woven mesh, balloon, umbrella with fully connected ribs, or a device that expands via separate expansion members rather than filament radial outward expansion), it is the first place to look for clean non-infringing designs.
What product and procedural variants still fit the claim’s wording?
Within the wording of Claim 1, a broad range of implementation details can still fall inside if they keep the same mechanical and anatomical placement features.
Still potentially covered (typical design permutations)
- Material set: any bioabsorbable body that can function as a filament-pronged radial deployer.
- Drug payload:
- drug can be embedded in polymer matrix, coated, or otherwise configured to release (Claim 4) while still being compatible with the expandable structure.
- Imaging:
- radiopaque markers are optional in Claim 1, but if present, they add dependent coverage (Claims 6-7).
- Delivery device:
- the independent claim only requires a delivery device that is withdrawn after placement; Claim 12 adds specific structural features of handle/sheath/distal portion only for that dependent coverage.
What breaks fit and likely design-out
- Filament structures where distal ends are not “free” (for example, distal interconnects or end-bonds that connect filaments at or near the tips).
- Expansion patterns that do not meet “expand radially outwardly.”
- Devices that rely on an external scaffold or require leaving the delivery tool components behind as support.
US patent landscape: how to map likely competitive risk
You provided only the claims of US 9,585,681, not the patent assignee, filing date, priority, or prosecution history. Without those bibliographic inputs, the only defensible landscape analysis is a claim-based landscape map that focuses on patent families likely to intersect the same solution space in the US: expandable, bioabsorbable sinus implants, sinus local drug delivery, and filament/pronged expandable scaffolds.
Landscape clusters that typically collide with this claim set
-
Bioabsorbable sinus implants for local corticosteroid delivery
- Typical overlap: drug-eluting biodegradable implants designed for post-operative sinus conditions or sinus inflammation management.
- Highest collision with dependent claims 4-5 (active agent; mometasone furoate).
-
Insertable expandable devices that self-deploy in sinonasal cavities
- Typical overlap: devices that deploy after catheter/sheath withdrawal.
- Collision with Claim 1’s “withdrawing the delivery device” and “remains ... after ... completely withdrawn.”
- Collision with Claim 9 if self-expanding mechanics are used.
-
Mechanical retention and anchoring in sinus cavities
- Typical overlap: anchoring fins, barbs, mesh textures, or filament-level retention elements.
- Collision with Claim 10 (anchoring elements on each filament).
-
Conformable expandable structures tailored to sinus anatomy
- Typical overlap: conformable scaffolds that press against irregular cavities after deployment.
- Collision with Claim 1’s “at least partly conformable” language.
-
Imaging aids in implantable devices
- Typical overlap: radiopaque markers enabling X-ray/fluoroscopy, with methods referencing indirect visualization.
- Collision with Claims 6-7.
How to use this landscape map for competitive diligence
- FTO priority: identify competitors using expandable bioabsorbable sinus inserts that are drug-eluting and that deploy via sheath withdrawal.
- Claim-1-specific diligence:
- inspect whether competitors use filaments with proximal joining and free distal ends
- inspect whether distal tips are connected to each other or to a distal hub
- confirm whether expansion is radial outward versus axial/translation or balloon-style expansion
- Dependent-claim triggers:
- drug identity (mometasone furoate) drives Claim 5 risk
- anchoring element location drives Claim 10 risk
- filament length targets Claim 11 risk
- radiopaque marker strategy targets Claims 6-7 risk
- delivery catheter design targets Claim 12 risk (less likely to affect overall freedom if only the tool differs)
What does the claim set imply for design-around strategy?
A design-around that aims to avoid Claim 1 generally needs to disrupt one of the claim’s mandatory structural/functional anchors:
Design-around levers
- Change the filament connectivity topology
- avoid having “only proximal ends join together”
- or ensure distal ends are not “free distal ends” (e.g., introduce distal linkage)
- Change expansion mechanics
- avoid “expand radially outwardly” deployment profile
- use a different deployment mechanism that does not create radial outward expansion from the proximal join region
- Change post-withdrawal behavior
- ensure the device does not remain and conform after delivery device withdrawal (for example, it collapses and is supported by another component left in place)
- Change biodegradability
- if the product is not bioabsorbable/biodegradable, dependent claims fall out, and Claim 1 can be targeted (but Claim 1 explicitly requires bioabsorbability, so a non-biodegradable product would likely escape)
Dependent-claim avoidance is narrower:
- don’t elute mometasone (Claim 5)
- remove radiopaque markers (Claims 6-7)
- avoid anchoring elements on each filament (Claim 10)
- adjust filament lengths outside 2 to 5 cm (Claim 11)
- change delivery tool structure away from handle/sheath/distal loading arrangement if Claim 12 matters
Key Takeaways
- US 9,585,681 is centered on a method of placing a bioabsorbable, expandable sinus device that expands radially outward using a pronged filament architecture where only proximal ends join and distal ends remain free, then stays in and conforms after sheath withdrawal.
- Dependent claims attach major commercial risks: biodegradability (2-3), drug elution with mometasone furoate (4-5), radiopaque markers and indirect visualization (6-7), self-expansion (9), filament-level anchoring (10), filament length band (11), and specific delivery tool structure (12).
- Claim-1 topology is the highest leverage for infringement and design-around: filament connectivity, free distal ends, and radial outward expansion are the most discriminating limitations.
FAQs
1. Is mometasone furoate required to infringe Claim 1?
No. Claim 1 does not require a specific active agent. Mometasone furoate is in dependent Claim 5.
2. If a device is bioabsorbable but expands differently, does it still fall under Claim 1?
Not if it cannot meet the “expand radially outwardly” requirement tied to the pronged filament structure.
3. What is the most design-sensitive phrase in Claim 1?
“Only the proximal ends of each filament join together” and “distal end ... is a free distal end.”
4. Are radiopaque markers required?
No for Claim 1. Radiopaque markers are added in dependent Claim 6.
5. Does Claim 12 broaden the independent claim’s tool requirements?
No. Claim 12 narrows method coverage to a delivery device with a handle, sheath, and distal loading portion. It does not change Claim 1.
References
- United States Patent and Trademark Office. US 9,585,681. (Patent text and claims as provided in prompt).
