Axially Expandable Drive Ribbon for Compact Medication Delivery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional injection devices are elongate and thin, making them awkward to carry due to their length being more than twice that of the medicament cartridge, which is undesirable for self-administration by patients who need to carry them throughout the day.
Innovation Solution
The use of an axially expandable drive ribbon that can be incrementally shifted between retracted and extended configurations, allowing for a compact design without rotational movement, or configurations that allow for rotational movement while expanding, to advance the piston within the medicament container.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional rod-based driving mechanism is used, then the device can reliably advance the piston throughout the injection process, but the device length becomes more than twice the length of the cartridge barrel, making it awkward to carry
Solution Approach 1:
The drive ribbon is configured to be received within the cartridge barrel when retracted, similar to a nested doll structure. The ribbon can be incrementally extended from the cartridge to engage the piston, and then retracted back inside after use. This nesting approach allows the driving mechanism to be compact during storage and transport while still providing full functionality during operation, resolving the contradiction between reliability and portability.
Solution Approach 2:
The drive ribbon transitions from a static, permanently extended rod to a dynamic, incrementally extendable structure. The ribbon can be extended step-by-step as needed to advance the piston, and then retracted back into the cartridge. This dynamic configuration allows the device to adapt its length based on operational requirements, maintaining reliability during injection while minimizing length during carrying.
2Length of moving object
If the drive ribbon is made extendable and retractable, then the device becomes more compact and portable, but the mechanism complexity increases with multiple components like thrust members, bearing members, and mechanical drives
Solution Approach 1:
The drive assembly integrates multiple functions into a unified mechanism. The mechanical drive, thrust member, and bearing member work together as a coordinated system to extend and retract the drive ribbon. By merging these components into a single integrated drive assembly rather than separate mechanisms, the patent reduces overall system complexity while achieving the desired compactness and retractability.
Solution Approach 2:
The drive mechanism is divided into distinct functional segments: the drive ribbon itself, the thrust member for axial force application, the bearing member for rotational support, and the mechanical drive for actuation. This segmentation allows each component to be optimized for its specific function while working together as a cohesive system, managing complexity through modular functional division.
Data Source
Figure 1~3
Figure 4
Figure 5~6
AI summary
A medication delivery device usable with a medication container wherein advancement of a piston within the container expels medication. The device includes a housing and a drive assembly. The drive assembly includes a drive ribbon having distal and proximal edge sections. The drive ribbon has a retracted configuration defining a spiral and an extended configuration defining a helix. The drive ribbon is movable from the retracted configuration to the extended configuration with such movement defining a drive axis and advancing the piston. In some embodiments, the drive ribbon may not rotate as it is advanced while in other embodiments, the ribbon does rotate. The disclosed drive assemblies include manually driven assemblies, spring driven assemblies and motor driven assemblies. The containers may be replaceable to allow for reuse of the device. In some embodiments, replaceable cartridges which includes both a medication container and a drive ribbon are employed.