Medical Insertion Device Linear Retraction Mechanism

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Solution Overview

Problem

Existing insertion devices for medical devices like analyte sensors often cause user discomfort due to rotational movements during the insertion and retraction processes, which can lead to pain and undesired deformation of the sensor.

Innovation Solution

The insertion device features a guide sleeve for skin fixation, a cap for controlled insertion and retraction, an elastic element for pre-loaded energy storage, and a retractor control element that ensures linear movement to prevent rotational displacement of the needle, thereby enhancing user comfort and stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the needle carrier is twisted during the retraction process, then the retraction mechanism can be activated, but the needle may rotate which affects user comfort

Engineering Contradiction:
Improveretraction mechanism activationVSAvoidneedle rotation causing user discomfort
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The retraction mechanism is segmented into independent rotational and longitudinal components. The needle carrier can rotate independently to activate retraction while the needle is constrained in orientation through separate guiding structures, allowing the two movements to be decoupled.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A guiding structure acts as an intermediary between the rotating needle carrier and the needle. This intermediary component translates the rotational movement into linear retraction while preventing the needle from rotating, thus mediating between the activation mechanism and the needle.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Force

If force is applied against a spring to retract the needle, then the spring provides retraction force, but the insertion process becomes more complex

Engineering Contradiction:
Improveretraction forceVSAvoidinsertion process complexity
Core Design Contradiction:
ForceVSDevice complexity

Solution Approach 1:

The spring is pre-loaded during the insertion process before retraction is needed. This preliminary action stores energy that automatically provides the retraction force when activated, eliminating the need for additional force application during the retraction phase and simplifying the user's interaction.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The spring-loaded mechanism is designed to automatically retract the needle without requiring user intervention for force application. The system serves itself by using the pre-stored elastic energy to perform the retraction action, reducing the complexity of user operation.

Inventive Principle:
Principle #25Self-service

3Stability of the object's composition

If the guide sleeve exerts force on the skin to fixate during insertion, then insertion stability is improved, but user discomfort may increase

Engineering Contradiction:
Improveinsertion stabilityVSAvoiduser discomfort
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The guide sleeve's interaction with the skin transitions from a static force application to a dynamic process. The sleeve gradually engages with the skin during insertion, adjusting the fixation force over time and allowing the tissue to adapt, thereby maintaining stability while reducing peak discomfort.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The guide sleeve incorporates cushioning elements that are positioned in advance to mitigate the force exerted on the skin. These cushioning features absorb and distribute the insertion force, providing protection before the full insertion force is applied and reducing user discomfort.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

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

This configuration allows for a safe, comfortable, and controlled insertion and retraction of medical devices, minimizing user discomfort and ensuring precise linear movement to prevent rotational issues, thus improving the overall usability and effectiveness of the insertion process.

Implementation Method 1

an elastic element which is provided to bias the retractor towards the distal end along the movement path

Methodology Applied
Scientific EffectElastic energy storage: Elasticity

Data Source

PatentEP4248860A1Insertion device, insertion system and method for inserting a medical device
Publication Date: 2023.09.27 ROCHE DIABETES CARE GMBH
  • EP4248860A1 patent drawingFigure 1a
  • EP4248860A1 patent drawingFigure 1b
  • EP4248860A1 patent drawingFigure 2a

AI summary

Insertion device for at least partially inserting a medical device such as an analyte sensor through the skin of a subject, the insertion device having a proximal end to be put in contact with the skin and a distal end opposite to the proximal end , the insertion device comprising: a guide sleeve being provided at the proximal end and to be placed in contact with the skin for an insertion process; a cap being provided at distal end, which can be pressed on to carry out at least part of the insertion process while moving in the direction of the proximal end; an inserter sleeve provided at least partially within the guide sleeve and/or the cap and being provided with a holder for the medical device and the inserter sleeve being moveable with respect to the guide sleeve; a retractor configured to retract a portion provided with the medical device, the retractor being moveable along a movement path; an elastic element such as a spring, which can bias the retractor towards the distal end along the movement path; a retractor control element which controls the movement of the retractor by blocking or freeing the movement of the retractor along the movement path and which is itself moveable such as rotatable with respect to the retractor. The invention further refers to an insertion system and an insertion method.