Dual-Cannula Dispensing Pen for Orientation-Independent Reconstitution
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Solution Overview
Problem
Existing devices for administering pharmaceutical active ingredients, particularly those in freeze-dried form, are unwieldy and require complex handling, making them difficult to use in medical emergencies and lacking orientation-independent reconstitution capabilities.
Innovation Solution
A device with a cylindrical first container and a second container, featuring an injection device and transfer means, allows for compact, ergonomic administration with a mechanical sequence that includes an insertion cannula retracting after use and an indwelling cannula for reduced discomfort, facilitated by a control element with runners and a linear guide for predefined movements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a dual-chamber cartridge with sequential compartment arrangement is used, then reconstitution of lyophilisate is achieved, but the pen becomes comparatively unwieldy and difficult to transport
Solution Approach 1:
The patent places the second container inside the first container, creating a nested arrangement where the solvent container is housed within the lyophilisate container. This eliminates the need for sequential external compartments, significantly reducing the overall device length and improving portability while maintaining reconstitution capability.
2Reliability
If a rigid injection cannula is used for extended injection times or frequent skin penetration, then reliable substance delivery is achieved, but patient discomfort increases significantly
Solution Approach 1:
The patent employs a flexible indwelling cannula instead of a rigid needle for the actual substance delivery. The flexible material allows the cannula to conform to tissue movements and reduce mechanical irritation, thereby maintaining reliable delivery while significantly reducing patient discomfort during extended wear or frequent use.
Solution Approach 2:
The indwelling cannula is constructed from flexible material that can adapt to the injection site and surrounding tissues. This flexibility reduces mechanical stress on the patient's skin and underlying tissues, minimizing discomfort while preserving the cannula's ability to deliver substances reliably over extended periods.
3Force
If automatic injection devices with spring-loaded mechanisms are used, then injection force is sufficient for deep tissue penetration, but the device requires significant user effort and complex operation
Solution Approach 1:
The patent divides the injection function into two separate components: an insertion cannula for initial tissue penetration and an indwelling cannula for substance delivery. This segmentation allows the insertion phase to use a sharper, more penetrable structure while the delivery phase uses a softer, more comfortable structure, reducing the overall force requirement and simplifying operation.
Solution Approach 2:
The insertion cannula performs the preliminary action of penetrating the skin and tissue barriers before the indwelling cannula is deployed. By completing the difficult penetration task first with a specialized insertion element, the subsequent substance delivery requires minimal force and can be performed with simple user activation.
4Device complexity
If orientation-dependent reconstitution mechanisms are used, then simple device structure is maintained, but reconstitution cannot occur regardless of device orientation relative to gravity
Solution Approach 1:
The patent creates a fluid communication system between containers that allows liquid flow independent of gravitational orientation. The transfer means and porous partition enable solvent migration from the second container to the first container through capillary action and pressure equalization, making reconstitution effective whether the device is held upright, inverted, or at any intermediate angle.
Solution Approach 2:
The device uses pneumatic pressure equalization and hydraulic fluid transfer mechanisms that operate independently of gravity. The porous partition and fluid communication pathways allow the solvent to migrate to the lyophilisate chamber through pressure-driven flow, enabling reliable reconstitution regardless of the device's orientation relative to the gravitational field.
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 simplifies handling, reduces discomfort, and ensures reliable, orientation-independent reconstitution, making it suitable for medical emergencies with minimal user interaction.
Implementation Method 1
The porous partition (14) is permeable to the injection solution, which can thus pass through the partition (14)
Implementation Method 2
a spring element (10) which exerts a force on the piston (9) in order to displace the piston (9)
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention proposes a device (1) for dispensing a substance, in particular to a patient, comprising a cylindrical first container (2) containing the substance and a second container (3) containing a liquid. Said device further comprises an injection device (4) and transfer means (5) for transferring the liquid from the second container (3) to the first container (2) and from the first container (2) to the injection device (4). The first container (2) has, on a first end, a connection element (7) and a plunger (9) that can be moved between the first (6) and a second end (8). By moving the plunger (9) towards the first end (6) of the first container (2), a liquid contained therein can be dispensed via the injection device (4). The device is further characterised in that the injection device (4) comprises a piercing cannula (15) and an indwelling cannula (16), wherein in an initial position, a distal end region of the piercing cannula (15) extends coaxially in the interior of the indwelling cannula (16).