Bone Cement Applicator Three-Way Valve Pressure Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing bone cement applicators for vertebroplasty face challenges such as high operational force requirements, contamination risks, and inefficiencies in stopping and restarting the cement flow, particularly with high viscosity pastes, leading to unnecessary delays and increased sterility efforts.
Innovation Solution
A bone cement applicator featuring a tubular cartridge with a mobile dispensing plunger, a hose, and a three-way valve that allows for manual operation without external energy sources, enabling immediate stoppage of cement flow without contamination, and rapid reactivation, using a design that includes a collecting container to manage pressure and prevent leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a manually operated extrusion device is used to dispense high viscosity pasty bone cement, then the device can be operated without external energy sources, but the operational force requirement becomes excessively high
Solution Approach 1:
The system divides the bone cement delivery path into separate segments: a first passage for the monomer component and a second passage for the cement powder component. This segmentation allows each component to be delivered through separate channels, reducing the viscosity burden on the extrusion device and lowering the operational force requirement while maintaining manual operation.
Solution Approach 2:
A mixing element is introduced as an intermediary component within the applicator. This mixing element mixes the monomer and cement powder components inside the applicator before delivery, allowing the extrusion device to handle lower viscosity mixtures rather than thick pasty bone cement directly, thereby reducing the force required for manual operation.
2Object-affected harmful factors
If the bone cement flow is stopped immediately, then contamination risk is reduced, but the cement dough continues to flow due to pressure buildup
Solution Approach 1:
A relief passage is extracted from the system, providing a dedicated pathway for the monomer component to escape through the mixing element when the main flow is stopped. This extraction allows pressure relief without stopping the mixing function, enabling immediate flow cessation while preventing dangerous pressure buildup and contamination.
Solution Approach 2:
The mixing element serves as an intermediary structure that incorporates both the mixing function and the pressure relief function through its design. It allows the monomer component to pass through while mixing cement powder, and simultaneously provides a pathway for pressure relief when flow is stopped, achieving both mixing and pressure control in one component.
3Ease of operation
If a three-way valve is added to enable immediate flow stoppage and pressure relief, then flow control is improved, but the device complexity increases
Solution Approach 1:
The mixing element is designed with multi-functionality: it performs the mixing function for the bone cement components and simultaneously serves as a pressure relief pathway through its structure. This multi-functionality reduces the need for separate dedicated components, achieving flow control and pressure relief without proportionally increasing device complexity.
Solution Approach 2:
The relief passage is merged into the existing mixing element structure rather than being a separate component. This integration combines the mixing function and pressure relief function into a single structural element, achieving enhanced flow control capability while minimizing the increase in overall device complexity.
4Force
If the dispensing plunger diameter is increased to reduce viscosity effects, then the extrusion force requirement decreases, but the surface area engaged by the pestle increases
Solution Approach 1:
The system segments the bone cement delivery into separate passages for monomer and cement powder, allowing the use of smaller diameter plungers that require less surface area engagement with the pestle, while the mixing function compensates for the reduced diameter by mixing components before delivery.
Data Source
AI summary
Bone cement applicators and methods for application of a bone cement dough, the applicators and methods comprise a tubular cartridge with an internal space, a dispensing plunger for expelling the starting components through an opening of the cartridge opposite from the dispensing plunger, wherein the dispensing plunger is mobile in longitudinal direction in the internal space of the cartridge. The applicators and methods further comprise a hose, an application opening, a three-way valve operable from outside and arranged or arrangeable in the hose or on a side of the hose facing the cartridge, and a collecting container arranged on the three-way valve. The three-way valve is designed and arranged or arrangeable in the applicator such that it, being in a first position, provides a fluid connection between the application opening and the opening of the cartridge and closes a feed-through to the collecting container and, being in a second position, provides a fluid connection between the application opening and the collecting container and closes a passage to the opening of the cartridge.