Spring-Biased Plunger Mechanism for Low-Force Insulin Infusion

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Solution Overview

Problem

Current insulin infusion devices face challenges such as high cost, cumbersome design, patient discomfort, and potential malfunction, particularly with short and fine-gauge needles, which hinder convenient and effective insulin delivery.

Innovation Solution

A patch-like self-contained infusion device with a spring-biased plunger mechanism and microneedles that reduces the activation force required, featuring a retention plate and guide means to facilitate easy operation and minimize discomfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a spring-biased plunger mechanism is used to pressurize the reservoir, then the activation force required is reduced, but the device complexity increases due to additional components like retention plate and guide means

Engineering Contradiction:
Improveactivation forceVSAvoiddevice complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The plunger is nested within the reservoir assembly, with the spring positioned between the retention plate and plunger. The guide means are integrated into the retention plate structure, creating a compact nested arrangement that reduces overall device complexity while maintaining the spring-biased activation mechanism

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The retention plate acts as an intermediary component between the spring and the plunger, providing structural support and housing the guide means. This intermediary structure allows the spring force to be effectively transmitted to the plunger while reducing the activation force required through mechanical advantage

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If short and fine-gauge injection needles are used, then patient discomfort is reduced, but manufacturing precision and needle penetration depth control become more difficult

Engineering Contradiction:
Improvepatient discomfortVSAvoidneedle penetration depth control
Core Design Contradiction:
Object-affected harmful factorsVSManufacturing precision

Solution Approach 1:

The device enables adjustment of needle penetration depth as a variable parameter, allowing optimization for different patient needs and tissue types. This parameter control compensates for the reduced structural rigidity of fine-gauge needles while maintaining patient comfort

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The needle is pre-loaded in a protected position within the device housing, with precise positioning mechanisms already in place. This preliminary arrangement ensures accurate penetration depth control is achieved automatically upon activation, eliminating the need for manual adjustment and reducing manufacturing complexity

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If a patch-like self-contained device is used, then portability and convenience are improved, but the volume and area of the device increase

Engineering Contradiction:
Improveportability and convenienceVSAvoiddevice volume
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The device utilizes a flexible adhesive patch backing that can be conformally applied to the patient's skin. This flexible film substrate allows the self-contained device to be distributed in a thin, portable format while maintaining structural integrity and containing all necessary components (reservoir, plunger, spring, needles) within a compact form factor

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The device is segmented into functional modules (reservoir, pressurization mechanism, needle assembly, adhesive patch) that can be independently optimized for size. This segmentation allows efficient space utilization and enables the overall device to be reduced to a portable patch-like form while maintaining all necessary functions

Inventive Principle:
Principle #1Segmentation

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 provides a convenient, low-cost, and comfortable insulin delivery system with reduced activation force, enhancing patient convenience and safety while maintaining effective substance infusion.

Implementation Method 1

a spring disposed between the retention plate and the plunger and biasing the plunger

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3470100B1Self-injection device
Publication Date: 2022.08.17 BECTON DICKINSON & CO
  • EP3470100B1 patent drawingFigure 1
  • EP3470100B1 patent drawingFigure 2
  • EP3470100B1 patent drawingFigure 3

AI summary

A drug delivery device (100), including a body (104, 116) having a reservoir (160) disposed therein for containing a medicament, , the reservoir including a flexible wall (164); a plunger (144, 508, 564) movable within the body (104, 116) for causing the medicament to be expelled from the reservoir (160), the plunger (144, 508, 564) having a contact surface that is not affixed to said flexible reservoir wall (164); a spring (140) biasing the plunger (144, 508, 564) toward the reservoir (160); and means (200, 204, 216, 218, 504, 516, 520, 524, 564, 568, 572, 582, 584) for selectively maintaining the plunger (144, 508, 564) in a pre-activated position with respect to the reservoir (160) and, upon releasing the plunger (144, 508, 564) from the pre-activated position, for guiding the plunger (144, 508, 564) to move under the force of the spring (140) such that the contact surface of the plunger (144, 508, 564) contacts the flexible reservoir wall (164) to pressurize the reservoir (160) for delivery of the medicament to a patient.