Drug Delivery Device Axial Retraction End-of-Content Indication
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Solution Overview
Problem
Existing drug delivery devices, particularly pen-type injectors, often confuse users with complex end-of-content mechanisms, leading to unexpected cartridge depletion and lack of intuitive indication of remaining medicament levels, which can result in inconvenient or unnecessary cartridge replacements.
Innovation Solution
A drug delivery device design that integrates an end-of-content mechanism through the axial displacement of the cartridge holder into the body, eliminating the need for a separate last dose limiting member, providing a clear and intuitive visual or haptic indication of the cartridge's filling level by altering the device's length.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate last dose limiting member is used to indicate end of content, then the end of content indication is provided, but the device complexity increases
Solution Approach 1:
The patent combines the end of content indication function with the existing cartridge holder and dose setting mechanism. The cartridge holder itself serves as the indication mechanism through its axial displacement relative to the housing, eliminating the need for a separate last dose limiting member. This merging of functions reduces device complexity while maintaining reliable end of content indication.
2Reliability
If a separate last dose limiting member is used, then the end of content mechanism is provided, but the number of parts increases
Solution Approach 1:
The patent integrates the end of content indication function into the existing cartridge holder component. The cartridge holder's axial displacement relative to the housing during dose setting serves as the visual indication mechanism, eliminating the need for additional separate parts. This reduces the total number of components while maintaining the end of content mechanism's reliability.
3Loss of information
If the cartridge holder is fixed in position, then the structure is simple, but the filling level indication is not provided
Solution Approach 1:
The patent makes the cartridge holder dynamically movable in the axial direction during dose setting operations. This axial displacement of the cartridge holder relative to the housing provides real-time visual feedback on the filling level. The dynamic positioning of the cartridge holder allows users to intuitively assess remaining medicament without adding complex indication mechanisms.
Data Source
AI summary
A drug delivery device for dispensing of a dose of a medicament includes an elongated body extending in an axial direction, a cartridge holder to accommodate a cartridge at least partially filled with the medicament and having an axially displaceable piston, and a piston rod to operably engage with the piston of the cartridge to displace the piston in axial distal direction. The drug delivery device further includes a coupling member connected with the cartridge holder and being axially displaceably arranged in the body for retracting the cartridge holder into the body during setting of a dose.