Floating Trigger Mechanism for Low-Force Safe Self-Injection
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Solution Overview
Problem
Existing injection devices face issues with accidental firing due to mishandling, binding of triggering components, and constrained design, which can lead to unsafe medicament expulsion and difficulty in self-administration.
Innovation Solution
A needle-assisted jet injector with a floating trigger mechanism, including a skin-contacting member for axial rotation, a retractable needle guard, and a lock-out feature, ensuring safe and controlled medicament delivery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional trigger mechanism is used in injection devices, then the device can be activated to deliver medicament, but accidental firing may occur due to mishandling or binding of triggering components
Solution Approach 1:
The patent employs a floating trigger member that can rotate axially between a pre-firing condition (where the trigger engagement member is retained) and a firing condition (where the engagement member is released). This dynamic rotation mechanism allows the trigger to respond to user input while preventing accidental activation through controlled movement states.
Solution Approach 2:
The floating trigger member acts as an intermediary between the user's activation input and the energy source firing mechanism. It mediates the trigger action by requiring deliberate rotation to release the trigger engagement member, thereby preventing accidental firing while maintaining ease of proper use.
2Reliability
If a floating trigger mechanism with axial rotation is implemented, then accidental firing is reduced, but the device complexity increases
Solution Approach 1:
The patent combines the trigger activation function and the retention/release function into a single floating trigger member that rotates axially. This merging of functions reduces the number of separate components needed compared to traditional multi-part trigger mechanisms, thereby limiting the increase in device complexity while maintaining reliability.
3Productivity
If higher injection forces are applied to penetrate skin and deliver medicament, then injection speed increases and psychological trauma is reduced, but the risk of accidental firing increases
Solution Approach 1:
The floating trigger member provides a dynamic control mechanism that allows the device to deliver higher injection forces through controlled rotation from pre-firing to firing conditions. This dynamic control enables fast injection speeds while maintaining safety by requiring deliberate user action to initiate the high-force delivery state.
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 injector provides controlled medicament injection with reduced accidental firing risk, allowing self-administration by untrained individuals and accommodating various medicament types, including hazardous agents, with visible indicators for used status.
Implementation Method 1
the injection mechanism in needle-assisted jet injectors can be configured to pressurize the container. The pressure applied to the medicament within the injector can be less than that of a traditional jet injector, because the outer layers of the skin have already been penetrated by the needle.
Implementation Method 2
These high force injectors are button activated and administer medication as a fine, high velocity jet delivered under sufficient pressure to enable the jet to pass through the skin.
Data Source
AI summary
An exemplary embodiment of an injector includes a trigger mechanism, an energy source, and a user-operable firing-initiation member. The trigger mechanism can include a floating trigger member having a retaining portion, a ram assembly having a ram configured to pressurize a medicament container for expelling a medicament therefrom, the ram assembly further having a floating trigger engagement member configured to engage the retaining portion of the floating trigger member when the floating trigger member is in a pre-firing condition. The energy source can be associated with the ram for powering the ram to expel the medicament, and the user-operable firing-initiation member can be operable for causing an axial rotation of the floating trigger member from the pre-firing condition to a firing condition in which the floating trigger engagement member is released from the retaining portion to allow the energy source to fire the ram.