PMMA Bone Cement Mixing With Self-Sealing Puncture Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fully prepackaged mixing systems for PMMA bone cement face challenges in safely and reproducibly transferring monomer liquid without conduit blockage and uncontrolled mixing during storage and transport, which can lead to air inclusions affecting mechanical properties.
Innovation Solution
A device comprising a base part with a container for monomer liquid and a cartridge for PMMA bone cement powder, featuring a movable piston and a hollow mandrel to pump monomer liquid into the cartridge through a self-sealing septum, ensuring controlled mixing and preventing conduit blockage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If monomer liquid is transferred through a conduit in fully prepackaged mixing systems, then mixing can be performed, but the conduit may become blocked by swollen and sticky bone cement particles
Solution Approach 1:
The invention extracts the harmful interaction between monomer liquid and cement powder by eliminating the conduit that connects them during storage. The monomer liquid is transferred directly into the cartridge containing the powder through a puncture connection, removing the conduit blockage risk while maintaining mixing capability.
Solution Approach 2:
The puncture connection acts as an intermediary mechanism that allows monomer liquid transfer without requiring a permanent conduit. The liquid passes through the puncture point directly into the powder, mediating the mixing process while avoiding conduit blockage issues.
2Stability of the object's composition
If monomer liquid and powder are packaged separately in fully prepackaged systems, then storage stability is improved, but uncontrolled mixing may occur during transport
Solution Approach 1:
The invention uses a nested structure where the inner tube containing monomer liquid is inserted into the outer cartridge containing powder. The puncture connection allows controlled access while maintaining separation during storage, preventing uncontrolled mixing while ensuring stability.
Solution Approach 2:
The components are pre-packaged in a nested configuration with the puncture connection already in place, but the actual mixing is controlled to occur only when needed. The system is prepared in advance for mixing while maintaining separation during storage and transport.
3Reliability
If cement powder penetrates the monomer liquid transfer conduit during transport, then the conduit becomes blocked, but preventing penetration requires additional protective structures
Solution Approach 1:
The invention removes the conduit entirely from the storage configuration, extracting the source of blockage problems. Without a conduit, there is no structure for powder to penetrate and block, eliminating the need for protective structures while maintaining reliability.
Solution Approach 2:
Instead of protecting the conduit from powder penetration, the invention inverts the approach by eliminating the conduit and allowing direct transfer. The protective function is achieved by removal rather than protection, simplifying the overall structure.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables simple, reliable, and safe mixing of monomer liquid with powder components, preventing air inclusions and conduit blockage, resulting in a ready-to-use PMMA bone cement dough.
Implementation Method 1
the hollow mandrel is configured to pierce the septum, so that a fluid-conducting connection is formed between the collection area and the cartridge
Implementation Method 2
the septum is configured to seal the puncture site in the septum in a liquid-tight manner after removal of the hollow mandrel
Implementation Method 3
to pump a monomer liquid released from the vessel from the collection area through the hollow mandrel into the cartridge by moving the piston
Implementation Method 4
When the powder component is mixed with the monomer component, swelling of the polymers of the powder component in the methyl methacrylate can produce a plastically deformable dough
Implementation Method 5
the activator N,N-dimethyl-p-toluidine reacts with dibenzoyl peroxide to form radicals. The resulting radicals can initiate the radical polymerization of the methyl methacrylate
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a device for producing bone cement, comprising a base part (100) which has a container (101) with a carrier (118) for receiving a vessel containing monomer liquid, a bottom part (103) with a collection area (104), a hollow mandrel (105) with a tip (106), and a piston (107) with a passage (108) for receiving the hollow mandrel (105), and a cartridge (200) for receiving a PMMA bone cement powder (201), wherein the cartridge has a septum (202) which delimits the cartridge to the outside; wherein the device further comprises an operating element (124), and wherein the operating element (124) is configured to open a vessel containing monomer liquid and subsequently to pump a monomer liquid released from the vessel from the collection area through the hollow mandrel into the cartridge by moving the piston.