Fixed-Dose Injection Shield Locking for Multi-Dose Delivery
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Solution Overview
Problem
Existing drug delivery devices for fixed doses are complex, prone to user error, and inefficient in terms of material usage, with a need for simpler, safer, and more robust devices that prevent unintentional activation and double dosing.
Innovation Solution
A shield-activated drug delivery device with a locking-and-resetting mechanism that ensures each dose is delivered intentionally, using a drive element with a release structure to prevent accidental activation, and a return spring for rotational movement to reset the shield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a shield-activated device is used for single dose delivery, then simplicity and ease of use is improved, but the device cannot deliver multiple doses and requires disposal after one injection
Solution Approach 1:
The shield is made rotatable relative to the drive element, allowing dynamic repositioning between blocked and unblocked positions. This enables the same physical shield structure to control multiple doses sequentially, transforming a single-use static shield into a multi-dose dynamic component without complicating the overall device architecture
2Adaptability or versatility
If a multi-dose device allows dose adjustment, then versatility is improved, but the risk of user error and unintentional activation increases
Solution Approach 1:
The dose adjustment functionality is extracted from the shield activation mechanism. The shield is designed with fixed angular positions that correspond to predetermined doses, separating the simple activation function from the dose selection function. This extraction prevents unintentional activation while maintaining versatility through pre-configured dose options
Solution Approach 2:
The shield is pre-positioned at specific angular orientations corresponding to predetermined doses before each injection. This preliminary positioning eliminates the need for user adjustment during activation, preventing unintentional dosing while maintaining adaptability through pre-set dose options
3Manufacturing precision
If a ratchet tube is locked to prevent insufficient dosing, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The dose precision control function is merged into the shield's rotational positioning mechanism. The shield's angular positions are mechanically coupled to the drive element's rotation, combining the locking function with the activation mechanism. This integration achieves precise dose delivery without adding separate complex locking subsystems
4Ease of operation
If a return spring is used to reset the shield, then ease of operation is improved, but the device complexity increases
Solution Approach 1:
The return spring creates a periodic automatic resetting action that occurs with each dose delivery cycle. The shield is held in the blocked position during injection, then automatically returns to the unblocked position for the next dose. This periodic action simplifies operation by eliminating manual resetting while the spring mechanism remains integrated within the existing rotational drive system
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 provides a user-friendly, safe, and robust mechanism for delivering multiple fixed doses, preventing unintentional activation and double dosing, while optimizing material usage and reducing complexity.
Implementation Method 1
a return spring, a locking-and-resetting structure biased in the distal direction by the return spring
Data Source
Figure 1A
Figure 1B~1F
Figure 2A~2D
AI summary
A shield activated drug delivery device for delivering a plurality of fixed doses comprising a housing, a drive mechanism comprising a drive element (180, 280) adapted to rotate and thereby rotate and axially advance a piston rod (109, 209), wherein the drive mechanism is adapted to expel a dose of the plurality of fixed doses, in response to activation. The injection device further comprises an activation mechanism, and a locking-and-resetting mechanism for releasably locking the shield in an activation position, in response to rotating the shield, and for inducing a rotational movement of the shield, in response to the drive element releasing a releasable lock.