Needle-Free Injector Trigger Mechanism Recoil Restriction

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Solution Overview

Problem

Needle-free injection systems face accuracy and effectiveness limitations due to recoil of injector components, which hinder the delivery of high fluid pressures required for penetrating the skin.

Innovation Solution

The implementation of a recoil restriction system, including a restriction member and a recoil member, coupled with a trigger assembly and injection force assembly, limits recoil movement and ensures consistent delivery of a driving force to the drug delivery system, enhancing the device's accuracy and effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If high fluid pressure is generated to penetrate the skin, then injection effectiveness is improved, but recoil of injector components increases

Engineering Contradiction:

Improveinjection effectivenessVSAvoidrecoil

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The recoil member converts the harmful recoil force into a beneficial spring-loaded driving force. The spring is compressed during the injection stroke and then expands to propel the plunger, transforming the waste energy into useful work that enhances injection reliability.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The spring mechanism provides beforehand cushioning by storing energy during the compression phase and releasing it during the injection phase. This pre-charged spring system ensures consistent and reliable injection force while mitigating the harmful effects of recoil.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Measurement precision

If recoil is reduced to improve accuracy, then device accuracy is improved, but the complexity of the actuation system increases

Engineering Contradiction:

Improvedevice accuracyVSAvoidactuation system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The spring-loaded plunger mechanism is self-service, utilizing the recoil force itself to drive the injection process. The system automatically compresses and expands the spring without requiring external control mechanisms, reducing overall system complexity while maintaining accuracy.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent replaces complex electronic or mechanical control systems with a simple spring-based mechanical system. This substitution reduces the number of moving parts and control mechanisms while achieving the desired accuracy through pure mechanical principles.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If a recoil restriction system is added to limit recoil movement, then device accuracy is improved, but device complexity increases

Engineering Contradiction:

Improvedevice accuracyVSAvoidrecoil restriction system

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The recoil restriction features are merged into the existing trigger assembly and actuation mechanism. The restriction member and trigger member are integrated with the spring-loaded plunger system, combining multiple functions into a unified mechanism that limits recoil without adding separate complex subsystems.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The trigger assembly serves multiple functions: it activates the injection, restricts recoil movement, and controls the spring mechanism. This multi-functionality reduces the need for separate dedicated components, thereby limiting the increase in overall device complexity while maintaining accuracy.

Inventive Principle:

Principle #6Universality (Multi-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 recoil restriction system effectively reduces recoil effects, allowing for precise and reliable fluid penetration into the skin, improving the overall performance and accuracy of needle-free injection devices.

Implementation Method 1

The actuation system includes a spring-loaded plunger adapted to transmit a driving force to the drug delivery system

Methodology Applied

Scientific EffectSpring: Spring

Implementation Method 2

The restriction member limits movement of the recoil member once the recoil member moves a predetermined distance relative to the restriction member

Methodology Applied

Scientific EffectMechanical constraint: Mechanical Force

Data Source

PatentUS7547293B2Triggering mechanism for needle-free injector

Publication Date: 2009.06.16 BIOJECT INC

AI summary

Needle-free hypodermic jet injection devices having an actuation system to effect an injection from a drug delivery system. The actuation system includes an injection force assembly adapted to transmit a driving force to the drug delivery system. The actuation system further includes a trigger assembly adapted to alter the actuation system between a plurality of configurations including a fired configuration in which the injection force assembly transmits a driving force to the drug delivery system. In some embodiments, the device has a recoil restriction system including a restriction member adapted to couple the recoil restriction system to the trigger assembly and a recoil member coupled to the injection force assembly and movable relative to the restriction member. The restriction member limits movement of the recoil member once the recoil member moves a predetermined distance relative to the restriction member.