Syringe Barrel Stepped Inner Surface Tactile Feedback

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Solution Overview

Problem

Syringes lack a reliable method for a healthcare provider to accurately determine the amount of injected medical solution or piston insertion distance during an injection, especially in environments where visual gradations cannot be accurately used.

Innovation Solution

A syringe barrel with an inner surface featuring stepped or uneven structures that increase sliding resistance, allowing healthcare providers to feel the difference in resistance to gauge the amount injected, with specific design parameters to ensure a 1.5 to 3 times increase in resistance at certain points, facilitating accurate injection operations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If visual gradations are used on the syringe barrel, then the amount of injected solution can be measured, but the measurement cannot be accurately obtained in environments where gradations are not visible

Engineering Contradiction:

Improvemeasurement of injected solution amountVSAvoidusability in different environments

Core Design Contradiction:

Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The syringe barrel inner surface is divided into multiple sections with different sliding resistance characteristics. Steps are formed at specific positions along the axial direction, creating distinct segments with different friction properties. This segmentation allows the piston to provide tactile feedback at specific intervals, enabling measurement without visual gradations.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent replaces the visual measurement system (gradations on the barrel) with a tactile mechanical feedback system. By creating steps with different sliding resistance on the inner surface, the system translates positional information into mechanical resistance that can be felt by the operator during piston movement, substituting optical measurement with mechanical sensing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If a uniform inner diameter is used in the syringe barrel, then manufacturing is simplified, but the piston cannot provide tactile feedback for injection amount

Engineering Contradiction:

Improvesyringe barrel manufacturingVSAvoidtactile feedback during injection

Core Design Contradiction:

Ease of manufactureVSEase of operation

Solution Approach 1:

The syringe barrel inner surface is designed with local variations in geometry. Specifically, steps are formed at certain positions along the axial direction, creating localized regions with different sliding resistance. The majority of the barrel maintains a uniform diameter for ease of manufacture, while specific local areas are modified to provide tactile feedback functionality.

Inventive Principle:

Principle #3Local quality

3Ease of operation

If the piston slides smoothly without resistance changes, then injection is easy, but the operator cannot feel the injection amount or piston position

Engineering Contradiction:

Improvepiston sliding easeVSAvoidfeedback on injection amount

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The inner surface of the syringe barrel is designed with periodic variations in sliding resistance. Steps are arranged at regular intervals along the axial direction, creating a periodic pattern of resistance changes as the piston moves. This periodic action provides rhythmic tactile feedback to the operator, enabling sensing of piston position and injection amount while maintaining overall ease of operation.

Inventive Principle:

Principle #19Periodic action

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

Enables healthcare providers to accurately recognize the amount of injected medical solution and piston insertion distance through tactile feedback, even in environments where visual gradations are not visible, ensuring precise injection operations.

Implementation Method 1

an inner surface provided with a structure in which a sliding resistance is changed step by step upon sliding a piston

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS8105294B2Syringe and syringe barrel

Publication Date: 2012.01.31 DAIKYO SEIKO LTD

AI summary

To provide a syringe barrel and a syringe capable of allowing an operator to feel the amount of injected medical solution or the inserting distance of a piston by a difference in sliding resistance when an injection operation is performed. A syringe 1 includes a syringe barrel 11 which has an inner surface provided with a structure in which a sliding resistance F is changed step by step upon sliding a piston 32. The syringe barrel 11 includes steps which are formed at one or two or more positions of the inner surface in the axial direction so as to face from the rear end to the front end or from the front end to the rear end, and which include edges formed along the circumferential direction.