Bone Cement Injection Device with Self-Locking Drive System
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Solution Overview
Problem
Existing devices for injecting bone cement lack mechanisms to prevent overpressure within the syringe, leading to potential rupture and irregular cement flow, which can be hazardous during medical procedures.
Innovation Solution
A device with a self-locking drive system using male and female discs and a compression spring to regulate pressure, preventing piston progression when overpressure is reached, ensuring controlled and homogeneous cement injection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the operator performs many rotations at the screw level to evacuate bone cement, then the cement flow increases, but overpressure is generated leading to syringe rupture or uncontrolled cement flow
Solution Approach 1:
The compression spring provides continuous feedback about the pressure state inside the syringe. When pressure increases, the spring compresses and eventually disengages the male-female disc coupling, automatically stopping further piston advancement. This feedback mechanism prevents overpressure while allowing high-speed evacuation when pressure is normal.
Solution Approach 2:
The system uses its own operational parameters (pressure buildup during cement evacuation) to automatically trigger the locking mechanism. The compression spring and disc coupling system self-regulate the injection process without external intervention, preventing overpressure conditions that would compromise syringe integrity.
2Reliability
If a self-locking mechanism is implemented to prevent overpressure, then syringe integrity is protected, but the injection process becomes more complex
Solution Approach 1:
The system changes the mechanical parameter of the drive coupling from always-engaged to disengageable based on pressure conditions. The compression spring modifies the engagement parameter of the male-female disc coupling dynamically, allowing the system to transition between locked and unlocked states based on operational needs.
Solution Approach 2:
The drive system is segmented into distinct functional components: the compression spring for force application, the male disc and female disc for power transmission and locking, and the piston for cement evacuation. This segmentation allows each component to perform its specific function while maintaining overall system simplicity.
3Manufacturing precision
If the piston is allowed to move freely to maintain homogeneous cement flow, then injection precision is improved, but overpressure cannot be prevented
Solution Approach 1:
The compression spring is pre-compressed to store potential energy that will be released when pressure conditions require locking. The male and female discs are preliminarily positioned to engage only when the spring force is sufficient, ensuring that locking occurs at the appropriate pressure threshold before overpressure conditions develop.
Solution Approach 2:
The drive system transitions from a static always-engaged coupling to a dynamic condition-based coupling. The male-female disc engagement is dynamic, allowing free piston movement for homogeneous flow when pressure is normal, and automatic locking when pressure approaches dangerous levels.
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
The device allows for precise and controlled bone cement injection, preventing overpressure and equipment rupture, ensuring safe and regular cement flow during medical procedures.
Implementation Method 1
The two discs come into contact with each other by means of a compression spring having one end in abutment at the distal part of the injection screw, the other end of the spring coming into contact, directly or indirectly, with the driving disc
Implementation Method 2
the drive disk coming into contact with the driven disk under the effect of a compression force exerted in the distal part of the injection screw
Data Source
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AI summary
The invention relates to a device for the injection of a bone cement. The invention comprises a container (1) provided with one end (17) including an outlet and a second end (18) that receives a piston (2). The piston is moved by means of an injection screw (5) that projects from the container body and engages with gripping means (6) comprising injection screw (5) rotation means that can self-lock depending on the pressure exerted inside the container body, said rotation means comprising a handle (13) which is provided with a passage that receives the injection screw (5) and which is hinged thereto by means of a pair of male/female disks. One disk is known as the drive disk (12) and moves integrally with the rotation movements of the handle (13), while the other disk is known as the driven disk (11), said drive disk (12) coming into contact with the driven disk (11) in response to a compressive force exerted on the distal part (19) of the injection screw (5).