Collapsible Passive Needle Shield for Stable Scleral Injection

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Solution Overview

Problem

Existing injection devices require separate needle shields that need removal and replacement, increasing clinician time and risk of needle sticks, especially during ocular and other precise injections, and lack passive stabilization during administration.

Innovation Solution

Injection devices with passive needle shields that collapse upon contact with the patient's tissue, stabilizing the needle tip and preventing inadvertent contact, using collapsible structures like bellows tubes or hinge assemblies to shield and expose the needle as needed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a separate external needle shield is used, then needle tip protection is improved, but clinician time and operational complexity increase due to removal and replacement requirements

Engineering Contradiction:
Improveneedle stick riskVSAvoidclinician time
Core Design Contradiction:
Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The needle shield is merged with the syringe body to form an integrated assembly, eliminating the need for separate attachment and removal steps. The shield becomes an inherent part of the injection device structure, allowing clinicians to maintain protection without additional manual operations.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The needle shield automatically retracts or adjusts in response to injection actions, eliminating the need for clinician activation. The shield self-manages its protective function throughout the injection cycle, reducing manual intervention and time expenditure.

Inventive Principle:
Principle #25Self-service

2Object-affected harmful factors

If a separate external needle shield is used, then needle tip protection is improved, but risk of needle sterility loss increases during exposure to ambient air

Engineering Contradiction:
Improveneedle stick riskVSAvoidneedle sterility
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The integrated needle shield maintains continuous coverage of the needle tip throughout the injection process, eliminating gaps where sterility could be compromised. The unified structure ensures the shield remains properly positioned without manual reattachment.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The needle shield is pre-positioned and automatically maintains its protective function from the moment the needle is exposed, ensuring sterility is preserved without requiring manual re-shielding during the procedure.

Inventive Principle:
Principle #10Preliminary action

3Object-affected harmful factors

If an integral mechanically translatable needle shield is used, then needle protection is improved, but device complexity and alignment difficulty increase

Engineering Contradiction:
Improveneedle stick riskVSAvoidmechanical translation mechanism
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The needle shield automatically responds to injection forces by retracting or adjusting its position, eliminating complex mechanical translation mechanisms. The shield self-regulates its protective function based on the natural progression of the injection action.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The needle shield transitions from a static protective cover to a dynamic structure that automatically adjusts its position in response to injection forces, maintaining protection while simplifying the overall mechanical design.

Inventive Principle:
Principle #15Dynamics

4Stability of the object's composition

If an external forceps-type device is used for eye immobilization, then eye stability is improved, but alignment difficulty and device complexity increase

Engineering Contradiction:
Improveeye stabilityVSAvoidexternal forceps device
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The eye immobilization function is merged with the needle shield structure, creating a unified device that performs both protection and stabilization. This eliminates the need for separate forceps-type immobilization devices and simplifies the overall system.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The needle shield serves multiple functions: protecting the needle tip, stabilizing the injection site, and providing alignment guidance. This multi-functionality eliminates the need for separate specialized devices for each function.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4653029A1Injection device with stabilizing passive needle shield
Publication Date: 2025.11.26 BECTON DICKINSON & CO
  • EP4653029A1 patent drawingFigure 1~2
  • EP4653029A1 patent drawingFigure 3~4
  • EP4653029A1 patent drawingFigure 5~7

AI summary

Medical injection devices incorporate collapsible, passive needle shields for avoiding inadvertent needle tip contact with objects. The needle shield is coupled to the distal end of the syringe barrel, enveloping the needle in its relaxed, non-compressed state. When the needle shield is in a relaxed, non-collapsed state, its contact surface extends distally longer than the needle tip, so that the tip is enveloped and shielded by the contact surface. Abutment of the contact surface against a desired patient body site stabilizes the syringe orientation. Thereafter, the syringe barrel is advanced, which passively collapses the needle shield, so that the now exposed needle tip pierces the patient's body, allowing injection of medical fluids by advancement of the syringe plunger. Injection device embodiments include ocular injection devices for injecting medication through the sclera of a patient's eye.