Drug Delivery Feedback Mechanism for Complete Dose Delivery
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Solution Overview
Problem
Existing injection devices, both manual and autoinjectors, face challenges such as the need for manual force application, potential premature dose interruption, difficulty in aligning and keeping the device still during injection, and dexterity requirements that may be beyond the capabilities of certain users, particularly the elderly or children.
Innovation Solution
A drug delivery device with a feedback mechanism featuring a collar and needle shroud that decouples during the injection process, providing audible and tactile feedback upon completion of the medicament delivery, and a plunger release mechanism to ensure full dose administration, facilitated by a spring-driven system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a manual plunger device is used for injection, then the device structure is simple, but the user requires manual force application and dexterity which may be beyond the capabilities of elderly or children
Solution Approach 1:
The injection device is designed as an autoinjector that performs the injection process automatically without requiring manual plunger manipulation. The spring mechanism self-activates to push the plunger, and the needle shroud automatically engages and disengages during the process, making the device serve itself rather than requiring continuous user intervention.
Solution Approach 2:
The needle shroud is pre-positioned in an engaged state with the collar before injection begins. The spring is pre-compressed and ready to drive the plunger. This preliminary preparation eliminates the need for manual alignment and positioning during the actual injection process, improving ease of operation.
2Ease of operation
If a conventional autoinjector with spring-driven plunger is used, then ease of operation is improved, but there is risk of premature dose interruption if the plunger is released
Solution Approach 1:
The needle shroud and collar assembly provides mechanical feedback during the injection process. The shroud remains engaged with the collar throughout the plunger movement, and its predetermined disengagement position provides a tactile and visual indication that the full dose has been delivered, preventing premature interruption.
Solution Approach 2:
The collar acts as an intermediary mechanism between the spring-driven plunger and the needle shroud. It translates the linear motion of the plunger into the controlled engagement and disengagement of the needle shroud, ensuring that the shroud only disengages when the plunger reaches its predetermined position, thus guaranteeing complete dose delivery.
3Device complexity
If manual alignment and stabilization of the injection device is required, then device complexity is low, but the user requires dexterity to align and keep the device still during injection
Solution Approach 1:
The needle shroud is pre-positioned in an engaged state with the collar before injection begins. This preliminary engagement automatically aligns the needle with the injection site and stabilizes the device during the injection process, eliminating the need for manual alignment and stabilization by the user.
4Device complexity
If the needle shroud remains continuously engaged with the collar during injection, then structural simplicity is maintained, but feedback on dose completion cannot be provided
Solution Approach 1:
The needle shroud is designed to disengage from the collar at a predetermined position that corresponds to the completion of the full dose. This disengagement provides clear tactile and visual feedback to the user that the injection is complete, while maintaining structural simplicity through the use of a spring-loaded mechanism that automatically controls the engagement and disengagement.
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
Ensures complete medicament delivery with user-friendly operation, reducing the risk of dose interruption and aligning issues, and providing clear feedback on dose completion, suitable for a wide range of users including the elderly and children.
Implementation Method 1
a control spring biasing the collar in a distal direction
Implementation Method 2
the first snap-fit joints adapted to inwardly deflect due to this ramp engagement
Data Source
AI summary
A drug delivery device includes a case adapted to hold a medicament container, a plunger disposed within the case and slidable from a proximal position into a distal position for delivering a medicament from the medicament container, at least one feedback mechanism that is in operative connection with the plunger. The feedback mechanism comprises a collar, a control spring biasing the collar in a distal direction, a needle shroud, operatively axially abutting the collar in a first coupled state and prevented from axially decoupling the collar by the plunger in its proximal position The plunger, when approaching the distal position during movement from the proximal position towards the distal position, is adapted to allow axial decoupling of the needle shroud from the collar, allowing for a limited axial movement of the collar relative to the needle shroud until the collar axially abuts the needle shroud in a second coupled state.