Pen Needle Hub Torque Feedback Mechanism

Solution Overview

Problem

Existing pen needle assemblies do not provide positive confirmation of proper connection to the pen injector, often resulting in under- or over-torquing, which can lead to inaccurate dosages and other issues.

Innovation Solution

A pen needle hub with tactile and/or audible indicia that confirms proper attachment, featuring a torque of peak value followed by a torque of lower value, ensuring correct connection and preventing under- and over-torquing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If no torque feedback mechanism is provided, then the device complexity is reduced, but the reliability of proper needle attachment is compromised

Engineering Contradiction:

Improveproper needle attachmentVSAvoidtorque feedback mechanism

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements a torque feedback mechanism where a protrusion on the needle hub interacts with a ramped surface on the cap. As the user twists the cap to attach the needle, the protrusion travels along the ramped surface, providing progressive tactile feedback. When proper attachment is achieved, the protrusion reaches a predetermined position, giving the user clear tactile and audible confirmation that the correct torque has been applied, thereby ensuring reliable needle attachment without requiring complex electronic sensors or indicators.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The feedback mechanism is entirely passive and self-service, requiring no external power source or active components. The mechanical interaction between the protrusion and ramped surface automatically generates tactile and audible feedback signals during the attachment process. The system uses the user's own twisting action to generate the feedback, eliminating the need for batteries, motors, or electronic control systems while still providing reliable attachment confirmation.

Inventive Principle:

Principle #25Self-service

2Manufacturing precision

If torque feedback indicia are added to confirm proper attachment, then the reliability of dosing accuracy is improved, but the ease of operation is reduced due to additional user education requirements

Engineering Contradiction:

Improvedosing accuracyVSAvoiduser operation simplicity

Core Design Contradiction:

Manufacturing precisionVSEase of operation

Solution Approach 1:

The feedback mechanism is entirely passive and self-service, requiring no external power source or active components. The mechanical interaction between the protrusion and ramped surface automatically generates tactile and audible feedback signals during the attachment process. The system uses the user's own twisting action to generate the feedback, eliminating the need for batteries, motors, or electronic control systems while still providing reliable attachment confirmation.

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent incorporates visual feedback through color changes or visual indicators on the cap or needle hub. As the protrusion travels along the ramped surface during attachment, visual markers or color-coded zones provide continuous feedback to the user. When proper attachment is achieved, a specific visual indicator (such as a colored ring aligning or a visual marker appearing) confirms correct positioning, enabling users to verify dosing accuracy through intuitive visual cues without requiring complex displays or electronic indicators.

Inventive Principle:

Principle #32Color changes

3Measurement precision

If a ramped surface with predetermined protrusion position is implemented, then the measurement precision of attachment torque is improved, but the device complexity increases due to additional mechanical features

Engineering Contradiction:

Improveattachment torqueVSAvoidmechanical features

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a torque feedback mechanism where a protrusion on the needle hub interacts with a ramped surface on the cap. As the user twists the cap to attach the needle, the protrusion travels along the ramped surface, providing progressive tactile feedback. When proper attachment is achieved, the protrusion reaches a predetermined position, giving the user clear tactile and audible confirmation that the correct torque has been applied, thereby ensuring reliable needle attachment without requiring complex electronic sensors or indicators.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The ramped surface is designed with specific geometric parameters (slope angle, length, and curvature) that transform the rotational torque applied by the user into linear displacement of the protrusion. By carefully controlling these geometric parameters, the system precisely maps different stages of attachment to distinct positions of the protrusion along the ramp. The predetermined position on the ramp corresponds to the optimal attachment torque, providing measurement precision through simple geometric design rather than complex sensing mechanisms.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS10220160B2Pen needle assembly for preventing under-torquing and over-torquing of pen needle

Publication Date: 2019.03.05 EMBECTA CORP

AI summary

A pen needle hub and cover for a pen needle assembly that provides tactile and/or audible indicia of proper attachment between the hub of the pen needle and the pen is provided. Such indicia substantially prevent under- and over-torquing of the pen needle. The tactile indicia may include a user sensing a wave of a torque of peak value followed by a torque of lesser value.