Medicament Delivery Device Kickback Force Absorption
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Solution Overview
Problem
Current medicament delivery devices often cause unpleasant kickback forces on the skin due to mechanical interactions between components, which can be uncomfortable for users.
Innovation Solution
A medicament delivery device design where the medicament delivery member is stationary relative to the housing, and the syringe collar is axially locked to the housing, absorbing the kickback force instead of directing it into the skin, thereby reducing discomfort for the user.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the needle cover is pushed into the housing during actuation, then the injection needle can be inserted through the skin, but the needle cover generates unpleasant kickback force on the skin due to mechanical interaction with the syringe collar
Solution Approach 1:
The harmful mechanical interaction between the needle cover and syringe collar is eliminated by extracting the needle cover from the actuation mechanism. The needle cover is made stationary relative to the housing, while the syringe collar is allowed to move independently during plunger rod actuation, thus removing the source of kickback force on the skin.
Solution Approach 2:
The device is segmented into independent functional components: the needle cover is decoupled from the syringe collar movement, allowing the syringe collar to move relative to the housing while the needle cover remains stationary. This segmentation prevents force transmission from the syringe collar to the needle cover, and thus to the skin.
2Productivity
If the syringe collar moves relative to the needle cover during actuation, then the plunger rod can force medicament out of the container, but the mechanical interaction generates kickback force that discomforts the user
Solution Approach 1:
The housing acts as an intermediary structure that absorbs the kickback force generated by the moving syringe collar. The syringe collar is axially movable within the housing, and the housing provides a stable reference frame that prevents force transmission to the needle cover and skin, while still allowing the necessary relative motion for medicament delivery.
3Device complexity
If the needle cover is mechanically coupled to the syringe collar, then the device structure is simplified, but the needle cover moves out from the housing during actuation causing user discomfort
Solution Approach 1:
The harmful mechanical coupling between the needle cover and syringe collar is removed. The needle cover is extracted from the actuation mechanism and made stationary relative to the housing, while the syringe collar operates independently, thus eliminating the problem of needle cover motion during actuation.
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 design effectively absorbs the kickback force within the housing, making the experience less unpleasant for the user by redirecting the force away from the skin, resulting in a more comfortable delivery process.
Implementation Method 1
a syringe collar at least partly enclosed by the medicament delivery member, wherein the medicament delivery member and the syringe collar are axially movable within the housing relative to each other, and a medicament delivery member spring arranged between, and in contact with, the medicament delivery member and the syringe collar
Data Source
AI summary
The present disclosure provides a medicament delivery device configured to expel a medicament from a medicament container comprising an injection needle. The medicament delivery device is configured to assume a retracted state in which an injection needle is arranged inside a medicament delivery member and prevented from external exposure, and a protracted state in which the injection needle is configured to protrude proximally from the proximal end of the medicament delivery member. When the medicament delivery device transition from the retracted state to the protracted state, the medicament delivery member is arranged stationary relative to a housing. The syringe collar is axially locked to a surface portion of the housing when the medicament delivery device assumes the protracted state such that an axial force from the syringe collar, generated during the transition from the retracted state to the protracted state, is absorbed by the surface portion of the housing.