Autoinjector Spring Drive and Telescopic Shroud for Complete Doses
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Solution Overview
Problem
Conventional injection devices, both manual and autoinjectors, pose challenges for users lacking dexterity, such as the elderly or children, due to the need for continuous force application and alignment during injections, which can lead to incomplete doses if the button is released prematurely.
Innovation Solution
An autoinjector design featuring a telescopic needle shroud, a carrier with a plunger, and a rotatable collar mechanism, utilizing springs for automated dose delivery, ensuring consistent injection without requiring continuous user force and facilitating easy alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If manual force is used to drive medicament through a needle, then the injection can be administered, but the force required may be too high for elderly or child users
Solution Approach 1:
The patent replaces the manual mechanical pushing system with a spring-driven automated injection system. The spring mechanism automatically provides the force needed to drive the medicament through the needle, eliminating the need for users to manually press a button or plunger with excessive force.
Solution Approach 2:
The injection device performs the injection action automatically through the spring mechanism without requiring continuous user force application. The device serves itself by automatically advancing the medicament delivery process, reducing the physical effort required from users with limited strength.
2Reliability
If continuous force application is required during injection, then the injection can be maintained, but releasing the button prematurely stops the injection and may not deliver the intended dose
Solution Approach 1:
The spring-driven mechanism automatically maintains injection pressure and flow without requiring the user to continuously hold or press any component. The device self-regulates the injection process, ensuring complete dose delivery even if the user releases the device prematurely.
Solution Approach 2:
The spring is pre-loaded before injection, storing the energy needed to drive the entire injection process. This preliminary energy storage ensures that once activated, the injection proceeds automatically to completion without requiring sustained user input or force application.
3Manufacturing precision
If alignment and stillness during injection are required, then accurate injection can be achieved, but users lacking dexterity such as elderly or arthritic patients may struggle
Solution Approach 1:
The patent incorporates a telescopic needle shroud with a collar mechanism that dynamically adjusts during the injection process. The collar can rotate and move axially to automatically align the needle with the injection site and maintain proper positioning, reducing the need for manual alignment by the user.
Solution Approach 2:
The alignment and positioning functions are performed automatically by the device's mechanical mechanisms rather than requiring manual dexterity from the user. The telescopic shroud and collar system self-aligns the needle, making the device usable by patients with limited hand coordination or dexterity.
4Ease of operation
If a telescopic needle shroud with rotatable collar is used, then alignment is facilitated and ease of operation is improved, but the device complexity increases
Solution Approach 1:
The patent combines multiple functions into the collar component: it serves as both the alignment mechanism and the activation trigger. The collar's rotation and axial movement simultaneously handle needle alignment and initiate the spring-driven injection, reducing the need for separate control mechanisms and simplifying the overall device architecture.
Solution Approach 2:
The collar mechanism performs multiple functions: alignment, positioning, and injection activation. This multi-functional design consolidates what could be separate components into a single element, managing device complexity while maintaining improved ease of operation.
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 autoinjector provides a user-friendly, reliable injection process by automating the delivery of the medicament, ensuring complete doses and providing feedback, suitable for users with limited dexterity.
Implementation Method 1
a drive spring biasing the plunger relative to the carrier
Implementation Method 2
a control spring biasing the needle shroud in the extended position
Implementation Method 3
The carrier includes a compliant beam having a boss adapted to engage an opening in the plunger
Data Source
AI summary
An autoinjector includes a case, a needle shroud telescopically coupled to the case, a carrier slidably arranged in the case, a collar rotatably and slidably disposed in the case and coupled to the needle shroud and the carrier, and a trigger button operably coupled to the carrier. The case includes a rib. The needle shroud is movable between a first extended position, a retracted position, and a locked second extended position. The carrier is adapted to hold a medicament container and movable from a first axial position to a second axial position relative to the case. The carrier abuts the rib in the first axial position and the needle shroud is in the first extended position and disengages the rib when the needle shroud is in the retracted position and the trigger button is pressed to advance the carrier to the second axial position.