Medical Injector Coupled Body Portions Plunger Activation
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Solution Overview
Problem
Medical injectors face issues with premature or failed trigger activations during automated plunger advancement, which can lead to inefficient or incomplete medication administration.
Innovation Solution
A medical injector design featuring first and second body portions that couple via a hinged connection, an axially-displaceable plunger, and a releasable retainer that retains the plunger against a biasing element, allowing automated plunger advancement upon assembly, minimizing premature or failed activations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If automated plunger advancement is implemented, then productivity is improved, but reliability deteriorates due to premature or failed trigger activation
Solution Approach 1:
The plunger is pre-loaded against the biasing element in a retained position before assembly. The coupling of body portions triggers the advancement action, ensuring automated plunger movement occurs at the precise moment of assembly rather than prematurely during handling or storage.
Solution Approach 2:
The injector is divided into separable body portions that are assembled together. This segmentation allows the plunger to be retained in a first position during manufacturing and assembly, then automatically advanced when the body portions are coupled, resolving the contradiction between automation and reliability.
2Reliability
If a releasable retainer is used to control plunger advancement, then reliability is improved, but device complexity increases
Solution Approach 1:
The releasable retainer mechanism is integrated into the coupling structure of the body portions. The act of coupling the body portions simultaneously advances the plunger and triggers the retainer release, combining multiple functions into a single structural feature rather than adding separate complex control mechanisms.
Solution Approach 2:
The biasing element provides the force for plunger advancement automatically once the retainer releases. The system uses its own internal components (biasing element, retainer, coupling structure) to accomplish the advancement without requiring external actuators, motors, or complex control systems.
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 solution ensures reliable and automated plunger drive activation upon assembly, reducing the risk of premature or failed injections and enhancing the consistency of medication administration.
Implementation Method 1
biasing element for advancing the plunger a predetermined distance
Data Source
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AI summary
A medical injector is provided herein which includes first and second body portions each having a longitudinal axis and configured to couple at a coupling. The first and second body portions are complementarily formed so as to be movable about the coupling. The medical injector also includes an axially-displaceable plunger; biasing element for advancing the plunger a predetermined distance; and, a releasable retainer for releasably retaining the plunger in a first state against the force of the biasing element. In an initial state, the axes of the first and second body portions are not aligned and the plunger is in the first state. In a coupled state, the axes of the first and second body portions are axially aligned, and the releasable retainer releases the plunger, thereby allowing the biasing element to advance the plunger the predetermined distance. Advantageously, the subject invention provides a medical injector having an automated plunger drive which is triggered upon assembly of the pen injector, thereby minimizing premature or failed activations.