Angled Trigger Injection Device for One-Handed Operation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing injection devices are difficult to operate with one hand, particularly for users with conditions like rheumatoid arthritis, as they require pressing the trigger towards the housing, which can be strenuous and awkward.
Innovation Solution
The injection device features a pivotally mounted trigger with a concave surface allowing rotation in a direction parallel to the axis, enabling operation by sliding the hand down the housing, and a second concave surface with ridges for grip, facilitating one-handed use and activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the trigger is mounted parallel to the longitudinal axis and rotated by pressing down towards the housing, then the trigger mechanism can be compactly integrated into the housing, but the device becomes difficult to operate with one hand, especially for users with mobility issues
Solution Approach 1:
The trigger is reoriented from a longitudinal mounting (parallel to the injection axis) to a transverse mounting (perpendicular to the injection axis). This dimensional change allows the trigger to be actuated by a lateral pressing motion rather than a longitudinal pressing motion, making it accessible to users gripping the device laterally and enabling one-handed operation while maintaining compact integration.
2Device complexity
If the trigger is positioned to require pressing towards the housing for activation, then the triggering mechanism can be simplified, but the operation becomes strenuous and awkward for users with conditions like rheumatoid arthritis
Solution Approach 1:
The trigger is positioned asymmetrically within the housing, with its actuation surface oriented perpendicular to the injection axis rather than parallel. This asymmetric positioning allows the trigger to be actuated by a lateral pressing motion that is more accessible to users gripping the device, reducing the strain on fingers and hands while maintaining a simple triggering mechanism.
3Length of moving object
If the trigger is mounted parallel to the longitudinal axis, then the overall device length can be minimized, but the trigger becomes inaccessible for one-handed operation
Solution Approach 1:
The trigger mounting is rotated 90 degrees from a longitudinal orientation to a transverse orientation. This repositioning places the trigger in a location and orientation that is easily accessible to the thumb or fingers of a hand gripping the device laterally, while the trigger mechanism itself remains compact and does not significantly increase the overall device length.
Data Source
Figure 1~2
Figure 3
AI summary
An injection device (110) comprises a housing (112) defining a first axis (101). A drive (120) acts upon a syringe when released by a trigger (114). The trigger is rotatable from a rest position in which the drive is retained to an active position in which it no longer causes the drive to be so retained. The trigger is pivotally mounted and has a surface (201) shaped such that a user can apply a force in a direction substantially parallel to the first axis to rotate the trigger from its rest position to its active position. Such an injection device provides improved handling and ease of operation.