United States Patent 7,284,474: Claim Scope, Validity Risks, Expiration, and Competitive Landscape

U.S. Patent 7,284,474 protects a narrow piston-pump architecture for delivering small liquid volumes. The independent claim requires a specific combination of pump structure, O-ring properties, groove fill, radial compression, piston movement, valves, storage, and liquid delivery. The strongest protection is directed to the seal-and-groove configuration rather than to piston pumps generally.

The patent is a device patent, not a drug patent. It does not claim an active pharmaceutical ingredient, formulation, therapeutic indication, or biologic. It therefore is not ordinarily an Orange Book patent and does not create Hatch-Waxman exclusivity or biosimilar exclusivity. Its commercial relevance depends on whether a drug-delivery device, dispenser, micro-pump, injector, or topical delivery system practices every limitation of an enforceable claim.

What does U.S. Patent 7,284,474 claim?

Claim 1 requires all of the following elements:

Required element	Claim limitation
Pump architecture	Piston pumping system
Piston movement	Piston guided within a guide tube and capable of axial stroke movement
Pumping chamber	Piston movement opens into a pumping chamber
Inlet path	Pumping chamber connected through a liquid-conveying connection and valve to a storage vessel
Outlet path	Pumping chamber connected to a liquid-delivery device
Seal location	O-ring seal formed within the guide tube
Seal function	O-ring seals the piston
Seal gas permeability	Nitrogen gas permeation coefficient of 100 to 500 N·cm³·mm/(m²·h·bar)
Seal compression	Radial compression below 30%
Groove occupation	Groove filling level above 90%

An accused product that lacks one required element does not literally infringe claim 1. The claim is cumulative. A conventional piston pump with an O-ring is insufficient unless the pump also meets the specified permeability, compression, and groove-fill parameters.

How broad is the independent claim?

The claim is functionally broad in some respects and technically narrow in others.

It does not limit the liquid to a drug, cosmetic, reagent, biologic, or other particular composition. The liquid may therefore include pharmaceutical and non-pharmaceutical products, assuming the remaining limitations are met.

The claim also does not require a particular actuator. The dependent claims cover mechanical and electronic actuation, but claim 1 can potentially read on either type because it requires only a piston capable of axial stroke movement.

The principal narrowing limitations are:

The O-ring must be located within a groove in the guide tube.
The seal must have a specified nitrogen permeability range.
Radial compression must be below 30%.
Groove filling must exceed 90%.
The system must include the claimed storage-vessel and delivery-device fluid paths.
The system must operate as a piston pump with a pumping chamber.

These limitations distinguish the patent from ordinary piston pumps and create substantial proof requirements for enforcement.

What do the dependent claims add?

Claims	Added subject matter	Practical effect
2	Groove filling above 95%	Tighter seal geometry
3-4	Non-return valve at inlet and/or outlet	Check-valve pump configurations
5	Piston diameter of 0.25-4 mm	Micro-pump implementations
6	Piston length of 5 mm-10 cm	Small piston geometries
7	Stroke length of 1 mm-5 cm	Metered displacement
8	Silicone O-ring	Material-specific protection
9	Hollow piston with integrated inlet connection and valve	Integrated fluid-path design
10-11	Mechanical control and helical spring actuation	Spring-driven systems
12-14	Electronic control, microchip, and piezoelectric actuation	Electrically controlled pumps
15	Pump volume of 1 microliter-1 ml	Micro-dosing applications
16	Nozzle, micro-pin, microcutter, cannula, or outlet	Delivery-interface configurations
17	O-ring cord thickness of 0.3-3 mm	Seal-size limitation

Claims 5 through 7, 15, and 17 collectively define a small-volume pump platform. Claims 12 through 14 extend the invention to electronically controlled and piezoelectric systems. Claim 16 broadens the delivery interface to include direct-contact delivery structures such as micro-pins and microcutters.

What formulations and delivery systems are protected?

The claims do not protect a formulation as such. They protect a delivery system that conveys liquid through the claimed pump architecture.

Potentially relevant applications include:

Liquid drug dispensers
Micro-injection systems
Topical drug applicators
Transdermal delivery devices
Ophthalmic dispensers
Dental or oral liquid dispensers
Cosmetic micro-dosing systems
Laboratory reagent pumps
Drug-device combination products
Spring-driven or piezoelectric micro-pumps

The claims do not require a particular dosage form. A liquid formulation may be aqueous, nonaqueous, suspension-based, emulsion-based, or solvent-based, provided that the system satisfies the structural and numerical limitations.

A dry powder inhaler, ordinary syringe, peristaltic pump, diaphragm pump, or rotary pump would generally fall outside the literal scope unless it also incorporates the claimed piston, guide tube, pumping chamber, seal, and fluid-path arrangement.

How should the O-ring limitations be construed?

The O-ring limitations are central to both infringement and validity.

Nitrogen gas permeation coefficient

The claimed coefficient range is 100 to 500 N·cm³·mm/(m²·h·bar). The relevant test method, temperature, pressure differential, material formulation, and sample geometry may materially affect the result.

A dispute may arise over whether the coefficient is measured for:

The raw elastomer;
The finished O-ring;
The specific batch;
The O-ring under installed conditions; or
A standardized test specimen representing the material.

The patent’s specification and prosecution history would control the final interpretation. The numerical range creates a fact-intensive measurement issue.

Radial compression below 30%

The claim requires radial compression of less than 30%. Compression may be calculated from the uninstalled cord diameter and installed radial deformation. Small differences in groove dimensions, piston diameter, temperature, and elastomer swelling can affect the result.

A product designed at or near 30% creates litigation risk because manufacturing tolerances may produce units above and below the threshold.

Groove filling above 90%

Groove filling is likely calculated by comparing the O-ring cross-sectional area with the available groove area. Claim 2 raises the threshold above 95%, creating a narrower but potentially stronger position for highly filled grooves.

A groove-fill calculation may turn on whether the measurement includes:

The entire groove cross-section;
The usable groove volume;
Chamfers and radii;
Installed deformation;
Thermal expansion; or
Fluid-induced swelling.

These issues should be addressed through engineering drawings, tolerance stacks, material specifications, and physical measurements.

How strong is the patent estate?

Based on the supplied claims, the patent has a concentrated claim strategy rather than a broad platform claim.

Strength factor	Assessment
Technical specificity	High
Literal scope	Narrow to moderate
Ease of designing around	Moderate to high
Infringement detection	Difficult for seal parameters
Dependence on expert testing	High
Coverage of general piston pumps	Low
Coverage of micro-pumps	Moderate
Coverage of drug formulations	None as a formulation claim
Coverage of actuators	Broad through dependent claims
Vulnerability to prior art	Potentially material

The best enforcement position would involve a commercial micro-pump that uses a silicone O-ring, a highly filled groove, low radial compression, a small piston, a check valve, and a microliter-scale delivery volume.

The weakest enforcement position would involve a conventional pump with a different seal geometry, a diaphragm or bellows, a piston seal outside the guide-tube groove, or a groove-fill value below 90%.

What are the principal validity risks?

Anticipation

A prior-art reference would need to disclose every limitation of claim 1, including the numerical O-ring parameters and the claimed fluid-path arrangement. A reference that discloses a piston pump and O-ring but omits the permeability range or groove filling may not anticipate the claim.

Obviousness

Obviousness is a more significant risk because the claim combines known pump components with defined seal parameters. The critical question would be whether a skilled person would have had a reason to select:

Nitrogen permeability between 100 and 500;
Radial compression below 30%; and
Groove filling above 90%,

while retaining the claimed piston-pump architecture.

Evidence concerning seal leakage, friction, durability, manufacturing tolerance, and pump accuracy would be relevant. Unexpected technical results could support validity if the specification links the claimed parameters to improved performance.

Indefiniteness

The numerical limitations may face indefiniteness challenges if the patent does not explain how to measure permeability, radial compression, or groove filling with reasonable reproducibility. The absence of a defined test protocol can create disputes over claim boundaries.

Enablement and written description

The specification must support the full claimed ranges and the different actuator and delivery-device embodiments. The broad inclusion of mechanical, electronic, microchip-controlled, and piezoelectric systems may be vulnerable if the disclosure gives only limited implementation detail.

When does U.S. Patent 7,284,474 lose exclusivity?

A U.S. patent generally expires 20 years after the earliest effective nonprovisional U.S. filing date, subject to patent-term adjustment, patent-term extension, terminal disclaimers, and other statutory adjustments under 35 U.S.C. § 154. The issue date alone does not establish the expiration date.

The supplied claim text does not establish:

The earliest effective nonprovisional filing date;
Any patent-term adjustment;
Any patent-term extension;
Any terminal disclaimer;
Maintenance-fee status;
Reexamination or certificate history.

An exact expiration date therefore cannot be established from the claims alone. The controlling source is the USPTO patent record and the patent’s front page, read together with the applicable term calculation under 35 U.S.C. § 154.[2]

Is Patent 7,284,474 listed in the Orange Book?

No Orange Book listing should be inferred from the patent number or claims. FDA Orange Book listings generally identify patents submitted for approved drugs, including patents covering active ingredients, formulations, compositions, methods of use, and certain drug-device components under applicable FDA rules.[4]

Patent 7,284,474 is drafted as a piston pumping system. It does not claim:

An active pharmaceutical ingredient;
A pharmaceutical composition;
A therapeutic method;
A drug formulation;
A drug product;
A biologic;
A dosage regimen.

It therefore does not create a conventional Paragraph IV challenge pathway by itself. A generic applicant could still face device-related freedom-to-operate issues if the generic product uses a patented delivery system, but that issue would ordinarily arise outside the standard Orange Book patent-certification framework.

Are there Paragraph IV or biosimilar risks?

Paragraph IV

The patent is not, based on the supplied claims, a typical Orange Book drug patent. A Paragraph IV certification would be relevant only if the patent were submitted and accepted as covering an approved drug product or qualifying drug-delivery component.

Biosimilars

There is no biosimilar risk from the claims themselves. Biosimilar litigation concerns biologic products and patents under the Biologics Price Competition and Innovation Act. Patent 7,284,474 does not claim a biologic molecule, biologic formulation, or biologic manufacturing method.

A biologic manufacturer could still encounter a separate device patent issue if its delivery system incorporates the claimed piston pump. That would be a device freedom-to-operate question, not biosimilar patent protection.

What generic launch scenarios are relevant?

Launch scenario	Likely exposure
Drug delivered by ordinary syringe	Low, absent the claimed pump architecture
Drug delivered by diaphragm pump	Low
Drug delivered by peristaltic pump	Low
Drug delivered by piston pump with different seal	Moderate to low
Micro-pump with O-ring in guide-tube groove	Moderate to high
Spring-driven micro-pump with silicone O-ring	High if numerical limits are met
Piezoelectric piston pump	High under claims 12 and 14 if claim 1 is met
Pump with groove filling below 90%	Claim 1 may not be literally met
Pump with radial compression at or above 30%	Claim 1 may not be literally met
Pump using a non-O-ring seal	Low, subject to equivalents analysis
Pump with no storage vessel connection	Low

The most practical design-around routes are changing the seal type, relocating the seal, altering groove geometry, increasing radial compression, reducing groove fill, replacing the piston architecture, or using a different pumping mechanism.

What licensing and litigation issues matter?

The claims point to licensing relevance for manufacturers of:

Microfluidic pumps;
Injectable delivery systems;
Transdermal applicators;
Ophthalmic dispensers;
Automated drug-delivery devices;
Piezoelectric dosing platforms;
Spring-actuated liquid dispensers.

A license should address the entire U.S. claim set, continuation and divisional rights, foreign counterparts, improvements, field restrictions, and responsibility for third-party seal suppliers.

No litigation, settlement, or license agreement can be reliably attributed to Patent 7,284,474 from the supplied claim text. Litigation status must be established from USPTO records, PACER, court dockets, and assignment records. A patent-number search should distinguish direct infringement claims from cases involving related continuation patents or foreign family members.

What is the geographic coverage?

The supplied claims describe U.S. Patent 7,284,474. Its enforceable territorial scope is the United States and its territories, subject to ordinary limitations on extraterritorial infringement.

Foreign protection would require separate family-member analysis. Relevant jurisdictions for a drug-delivery pump platform would typically include:

European Patent Office states;
Germany;
Switzerland;
United Kingdom;
Japan;
China;
South Korea;
Canada;
Australia.

A U.S. claim does not establish that corresponding foreign claims were granted, remain in force, or have the same scope.

Key Takeaways

Patent 7,284,474 is a device patent covering a specialized piston-pumping system, not a drug or biologic patent.
Claim 1 requires a piston pump, storage-vessel and delivery-device fluid paths, and an O-ring with tightly defined permeability, compression, and groove-fill parameters.
The patent’s commercial center of gravity is micro-volume liquid delivery, including drug-device combination products.
The numerical seal limitations are both the principal source of claim strength and the main source of infringement and validity disputes.
The most credible design-arounds involve a different seal, groove geometry, compression level, pump mechanism, or fluid-path configuration.
The claims do not independently establish Orange Book status, Paragraph IV exposure, biosimilar risk, litigation status, licensing activity, or an exact expiration date.
An exact term analysis requires the patent’s filing history, priority data, patent-term adjustment, maintenance-fee record, and any terminal disclaimer.

FAQs

Does Patent 7,284,474 cover a syringe?

Not generally. A syringe would need to satisfy the claimed guide-tube, piston, pumping-chamber, valve, storage-vessel, delivery-device, and O-ring limitations to present a literal infringement risk.

Does the patent cover a piezoelectric drug pump?

Potentially. Claims 12 and 14 expressly cover electronic control and piezoelectric piston movement, but the pump must also satisfy every limitation of claim 1.

Can a manufacturer avoid the patent by using a non-silicone O-ring?

Not necessarily. Claim 8 requires silicone, but claim 1 does not. A non-silicone O-ring could still fall within claim 1 if it satisfies the claimed permeability, compression, groove-fill, and system limitations.

Does a groove fill of exactly 90% infringe claim 1?

Claim 1 requires a groove filling level of more than 90%. A value exactly at 90% does not meet that limitation literally. Measurement methodology and tolerance evidence could still determine the practical dispute.

Does expiration of this patent eliminate all risk for a competing pump?

No. Separate continuation patents, foreign patents, improvement patents, design patents, trade secrets, and third-party rights may cover the same or related pump technology.

References

United States Patent No. 7,284,474, claims 1-17, as provided in the request.
35 U.S.C. § 154. Patent term.
U.S. Patent and Trademark Office. (2023). Manual of Patent Examining Procedure, §§ 2111, 2112, 2113, 2114, 2161, 2173.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book.

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
	02027243	Dec 06, 2002
	02027243	Dec 6, 2002

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2003293736	⤷ Start Trial
Canada	2508673	⤷ Start Trial
Denmark	1579130	⤷ Start Trial
European Patent Office	1426662	⤷ Start Trial
European Patent Office	1579130	⤷ Start Trial
Spain	2410157	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 7,284,474

Summary for Patent: 7,284,474