Self-lubricating medical syringes
Inventors
Gertz, Frederick Talley • Noolandi, Jaan • Schultheis, Robert James • Wilcox, Daniel Alden
Assignees
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Publication Number
US-9999731-B2
Publication Date
2018-06-19
Expiration Date
Abstract
A self-lubricating medical syringe is provided for self-lubricating the inner surface of a prefilled syringe barrel. The syringe has a plunger distinguishing a compressible porous cylinder, which can be infused with a lubricant and is sandwiched in between a proximal and distal rubber tip. The self-lubricating medical syringe will be able to compensate for any missing lubricant along the inner surface of the syringe barrel and will also be able to provide for a uniform motion of the plunger.
Core Innovation
The invention relates to a self-lubricating prefilled medical syringe having a cylindrical barrel and a plunger that fits in the cylindrical barrel and can be moved along the cylindrical barrel. The plunger distinguishes a compressible porous cylinder sandwiched between a proximal rubber tip at the proximal end and a distal rubber tip at the distal end. The compressible porous cylinder has a hole in axial direction of the cylindrical barrel and can be infused with a lubricant.
The proximal rubber tip includes a proximal protuberance on the side facing the compressible porous cylinder, and the proximal protuberance fits within the hole of the compressible porous cylinder. The distal rubber tip includes a distal protuberance on the side facing the compressible porous cylinder, and the distal protuberance fits within the hole of the compressible porous cylinder. The proximal protuberance and distal protuberance are aligned in the axial direction and are at a distance from each other within the hole of the compressible porous cylinder when the compressible porous cylinder is in a non-compressed state, and the distance gets smaller when the compressible porous cylinder is compressed when the plunger is pushed along the cylindrical barrel.
When the compressible porous cylinder is compressed, it forces out the lubricant onto the inner surface of the cylindrical barrel, thereby self-lubricating the inner surface of the cylindrical barrel. The disclosed embodiments include porous foam or porous rubber as the compressible porous cylinder, with optional ribbed rubber tips and optional angled striations on the compressible foam. Glide-force testing reports break-loose force (PBF) and dynamic glide force (DGF) on an oil-infused foam cylinder with and without two rubber stoppers, showing similar glide forces, indicating the stoppers do not significantly affect lubrication.
Claims Coverage
The independent claim identifies a single self-lubricating medical syringe architecture with multiple structural and functional requirements, namely lubricant-in-porous-cylinder construction and lubricant release to the barrel inner surface during compression-driven plunger movement. Dependent claims further specify material and optional structural rib details of the rubber tips.
Self-lubricating medical syringe with compressible porous cylinder between rubber tips and coaxial protuberances
A self-lubricating medical syringe with a cylindrical barrel and a plunger movable along the cylindrical barrel; the plunger distinguishes a compressible porous cylinder sandwiched between a proximal rubber tip and a distal rubber tip; the porous cylinder has a hole in axial direction; the porous cylinder can be infused with a lubricant; proximal and distal rubber tips include protuberances that fit within the hole, aligned axially and separated in the non-compressed state; the distance between the protuberances decreases when the porous cylinder is compressed during plunger pushing; and compression forces out the lubricant onto the inner surface to self-lubricate the inner surface.
Across the disclosed independent claim, the core inventive coverage is the compression-driven forcing out of lubricant from an infused compressible porous cylinder located between proximal and distal rubber tips, where aligned protuberances interact with an axial hole so that lubricant is delivered onto the inner barrel surface during plunger movement.
Stated Advantages
Provides self-lubrication of the inner surface of the cylindrical barrel by forcing out lubricant when the compressible porous cylinder is compressed.
Glide-force testing shows similar break-loose force (PBF) and dynamic glide force (DGF) with and without two rubber stoppers, indicating the stoppers do not significantly affect lubrication.
Documented Applications
Prefilled medical syringe application context for use of a self-lubricating plunger mechanism in a cylindrical barrel.
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