United States Patent 4,907,583: A Detailed Analysis of Scope, Claims, and Patent Landscape
Introduction
United States Patent 4,907,583, assigned to Wetterlin, is a significant patent in the field of medical devices, specifically focusing on inhalation devices for delivering powdered medications. This patent is part of a series of inventions by Wetterlin that aimed to improve the design and functionality of inhalers.
Background
The patent landscape in the early 1990s saw a surge in innovations related to inhalation devices, driven by the need for more efficient and reliable delivery systems for powdered medications. Wetterlin's patents, including U.S. Patent 4,907,583, were pivotal in this development.
Scope of the Patent
Device Overview
The patent describes a dosage device designed for delivering a precise amount of powdered medicament to a patient. The device includes a storage chamber for holding the active compound, a perforated membrane, and a mechanism for introducing the active compound into the perforations of the membrane[1].
Key Components
- Storage Chamber: This is where the powdered medicament is stored.
- Perforated Membrane: This membrane is rotatably positioned under the storage chamber and has perforations where the active compound is introduced.
- Scrapers and Spring Mechanism: Elastic, spring-loaded scrapers are used to introduce the active compound into the perforations of the membrane. A coil spring biases the scrapers into engagement with the membrane[1].
Claims
The patent claims are centered around the specific design and operation of the inhalation device. Here are some key claims:
Claim 1
The patent claims a dosage device that includes a storage chamber, a perforated membrane, and a scraper assembly. The membrane is movable between two positions: one where the active compound is introduced by the scrapers and another where the loaded membrane is inserted into the air conduit of the inhalator[1].
Claim 2
The device includes a ratchet mechanism to provide distinct positions for the perforated membrane when it is advanced by the base or maneuvering unit. This mechanism involves spring-loaded pins engaging the ratcheted bottom of the membrane[1].
Patent Landscape
Prior Art
The Wetterlin patents, including U.S. Patent 4,907,583, built upon existing designs but introduced significant improvements. Prior art, such as U.S. Patents 4,534,345 and 4,667,668, also by Wetterlin, involved more complex arrangements with multiple openings in a metering plate that required separate rotation from the main housing and a ratchet mechanism for indexing[1].
Comparison with Other Patents
- Simplicity and Reliability: Unlike the prior art, the device described in U.S. Patent 4,907,583 is simpler in construction and assembly. It eliminates the need for a complex ratchet assembly by integrating the metering disk portion with the stationary body[1].
- Innovation by Virtanen: U.S. Patent 4,668,218 by Virtanen, while similar to Wetterlin's designs, includes an indicating assembly to show the number of medicament dosages administered, adding an additional layer of functionality[1].
Impact on the Industry
The innovations presented in U.S. Patent 4,907,583 have had a lasting impact on the design of inhalation devices. Here are a few key points:
Simplified Design
The integration of the metering disk with the stationary body and the use of a single receptacle in the metering disk portion simplified the construction and assembly of the device, making it more reliable and less prone to breakage[1].
Cost Efficiency
By reducing the complexity of the indexing mechanism and eliminating the need for multiple openings in the metering plate, the device became less costly to manufacture and maintain[1].
User Experience
The design improvements made the device easier to use for patients, ensuring a more consistent and reliable delivery of powdered medications.
Criticisms and Limitations
Despite the innovations, the Wetterlin patents, including U.S. Patent 4,907,583, have been criticized for their complexity relative to some later designs. For example, later patents described simpler and more robust mechanisms that did not require a ratchet assembly or multiple openings in the metering plate[1].
Legacy and Current Status
Expiration and Public Domain
The patent has expired, and the technology is now in the public domain. This has allowed other manufacturers to build upon and improve the design without the need for licensing or royalties.
Influence on Modern Designs
The principles outlined in U.S. Patent 4,907,583 continue to influence modern inhalation device designs. Manufacturers have refined these concepts to create even more efficient and user-friendly devices.
Key Takeaways
- Simplified Design: The patent introduced a simpler and more reliable design for inhalation devices.
- Cost Efficiency: The device was less costly to manufacture and maintain compared to prior art.
- Impact on Industry: The innovations had a lasting impact on the design of inhalation devices.
- Legacy: The patent has expired, and its technology is now in the public domain.
FAQs
What is the main innovation of U.S. Patent 4,907,583?
The main innovation is the simplified design of the inhalation device, which integrates the metering disk with the stationary body and eliminates the need for a complex ratchet assembly.
How does the device deliver the powdered medicament?
The device uses elastic, spring-loaded scrapers to introduce the active compound into the perforations of a rotatable membrane, which is then inserted into the air conduit of the inhalator.
What are the key components of the device?
The key components include a storage chamber, a perforated membrane, and a scraper assembly with a spring mechanism.
How does the ratchet mechanism work?
The ratchet mechanism involves spring-loaded pins engaging the ratcheted bottom of the membrane to provide distinct positions for the perforated membrane.
Is the patent still in effect?
No, the patent has expired, and the technology is now in the public domain.
Cited Sources
- EP0520440B1 - Dispositif d'inhalation pour ... - Google Patents
- U.S. Patent and Trademark Office (USPTO) | USAGov
- Patent Claims Research Dataset - USPTO
- Search for patents - USPTO
- Patent 2152088 Summary - Canadian Patents Database
