Assisted Injection Device Lever Blocking Mechanism
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing injection devices, including autoinjectors, lack user control over the injection process, particularly for high viscosity pharmaceutical compositions, as they cannot be stopped or restarted, and the injection rate cannot be adjusted, leading to difficulties for users with reduced physical strength and potential for repetitive strain injuries.
Innovation Solution
An assisted injection device with a spring-loaded piston rod and a selective blocking system, allowing users to control the injection by pressing a lever to start or stop the injection and adjust the rate through varying the force applied, enabling easier administration of high viscosity compositions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a manual injection device is used, then the user can control the injection process, but the user needs to apply high force which causes repetitive strain injuries
Solution Approach 1:
A lever mechanism is introduced as an intermediary between the user's manual input and the piston rod. The lever pivots about an axis and translates rotational or lateral motion into linear motion of the piston rod, providing mechanical advantage that reduces the force the user must directly apply while maintaining control over the injection process.
Solution Approach 2:
The injection control is moved from a direct linear pushing motion to a rotational or lateral motion along the lever. This dimensional change allows the user to apply force in a more ergonomic direction (perpendicular to the injection axis) while the lever mechanism converts it to the required linear force on the piston rod.
2Force
If an autoinjector is used, then the user effort is reduced, but the user cannot control or stop the injection process
Solution Approach 1:
The blocking system transitions from a static locked state to a dynamic controllable state. A movable blocking element can engage with the lever to prevent motion (stopping injection) or disengage to allow motion (enabling injection). This dynamic control mechanism gives the user the ability to start, stop, and restart the injection process at will, combining the low effort of autoinjection with the control of manual injection.
3Ease of operation
If a blocking system is added to control injection, then user control is improved, but the device complexity increases
Solution Approach 1:
The blocking function is merged with the existing lever mechanism. The blocking element is integrated into the lever assembly, using the same pivot axis and structural components. This combination eliminates the need for separate blocking mechanisms and reduces overall device complexity while maintaining full control functionality.
Solution Approach 2:
The blocking system is designed to be self-actuating through the user's own lever manipulation. When the user moves the lever to position A, the blocking element automatically engages or disengages based on the lever's position, without requiring separate control inputs. This self-service approach simplifies the control interface while maintaining functionality.
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 allows for controlled and easier injection of pharmaceutical compositions, reducing user effort and minimizing the risk of repetitive strain injuries by enabling the user to manage the injection process, including stopping and restarting, and adjusting the rate as needed.
Implementation Method 1
a spring-loaded piston rod translationally movable inside the body along a spring axis, between a proximal rest position and a distal operative position wherein the piston rod engages a stopper of the medical container and pushes the stopper in the medical container
Implementation Method 2
a lever pivotably mounted on the body about a first pivot axis orthogonal to the spring axis at a first distance from the spring axis, comprising an actuation zone configured to be pressed on by a user
Implementation Method 3
a selective blocking system coupled to the lever by a second pivot axis orthogonal to the spring axis, the lever being pivotable between a rest position wherein the selective blocking system engages the piston rod to prevent any translational movement of the piston rod
Data Source
Figure 1~1B
Figure 2
Figure 3A
AI summary
The present invention relates to an assisted injection device (1) for injecting a composition contained in a medical container (30), comprising: - a body (10) configured to receive the medical container (30) in a fixed position relative to the body (10), - a spring-loaded piston rod (40) translationally movable inside the body (10) along a spring axis (A), between a proximal rest position and a distal operative position wherein the piston rod (40) engages a stopper (34) of the medical container (30) and pushes the stopper (34) in the medical container (30), - a lever (50) pivotably mounted on the body (10) about a first pivot axis (B) orthogonal to the spring axis (A) at a first distance from the spring axis (A), comprising an actuation zone (51) opposite the first pivot axis (B) relative to the spring axis (A), at a second distance from the spring axis (A), - a selective blocking system (60) coupled to the lever by a second pivot axis (C) orthogonal to the spring axis (A), the lever (50) being pivotable between a rest position wherein the selective blocking system (60) engages the piston rod (40) to prevent any translational movement of the piston rod (40) and a second position wherein the selective blocking system (60) releases the piston rod (40) to allow the piston rod (40) to move toward the distal operative position under the spring force.