Two-Part Dental Suction Cannula Annular Gap Noise Reflux

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing suction cannulas for dental treatments face issues with noise generation and reflux, where noise-insulating layers increase costs and weight, and small holes to prevent reflux reduce suction power and increase noise.

Innovation Solution

A two-part suction cannula design featuring an annular gap and a funnel-shaped suction tip passage, with the annular gap depth between 20% and 60% of the suction tip length and width between 5% and 30% of the handle passage diameter, providing a fluid-tight seal and reducing noise and reflux.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If noise-insulating layers are added to reduce flow noise, then noise is reduced, but costs increase, weight increases, and sterilization capability is impaired

Engineering Contradiction:
ImprovenoiseVSAvoidcosts and weight
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The invention extracts and eliminates the need for noise-insulating layers by fundamentally changing the flow dynamics through the annular gap design. The false air suction capability is built into the basic structure rather than added as a separate insulating layer, thereby reducing complexity and cost while maintaining noise reduction.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

Instead of trying to dampen noise through insulating layers, the invention inverts the approach by intentionally creating a controlled secondary flow path (annular gap) that prevents the conditions causing noise and reflux in the first place. This structural inversion eliminates the need for additional noise-reducing components.

Inventive Principle:
Principle #13The other way round (Inversion)

2Reliability

If small holes are made on the suction cannula to prevent reflux, then reflux is prevented, but suction power is reduced and flow noise increases

Engineering Contradiction:
Improvereflux preventionVSAvoidsuction power
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention transitions from a two-dimensional surface solution (small holes on the cannula) to a three-dimensional volumetric solution (annular gap surrounding the insertion section). This dimensional change allows for significantly greater false air intake capacity without compromising the main suction flow, thereby preventing reflux while maintaining suction power.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The annular gap acts as an intermediary flow path that mediates between the need for reflux prevention and the need to maintain suction power. By providing a dedicated channel for false air suction, it allows the main suction passage to operate at full capacity without being compromised by reflux prevention requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the suction tip is tightly sealed in the handle, then fluid-tight sealing is achieved, but noise increases and reflux cannot be prevented

Engineering Contradiction:
Improvefluid-tight sealVSAvoidnoise and reflux
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention segments the sealing function into two distinct zones: a fluid-tight seal at the distal end of the insertion section, and an open annular gap at the proximal end. This segmentation allows the cannula to maintain fluid-tight sealing where needed while providing false air suction capability where it benefits noise and reflux reduction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the insertion section are given different properties: the distal end has fluid-tight sealing properties, while the proximal end has open, non-sealing properties to allow false air intake. This local differentiation of quality allows the system to achieve multiple contradictory functions simultaneously.

Inventive Principle:
Principle #3Local quality

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 combination of an annular gap and funnel-shaped passage effectively minimizes noise and prevents reflux, achieving a synergistic effect that can be achieved with either feature alone, while maintaining sufficient suction capacity.

Implementation Method 1

the air flow through the suction cannula and the suction hose comes to a standstill and a negative pressure forms in the suction tip passage and the handle passage

Methodology Applied
Scientific EffectAir flow:

Implementation Method 2

This noise is caused by the flow and in particular by turbulence in the flow

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 3

a negative pressure forms in the suction tip passage and the handle passage, which can lead to residues of fluid substances being present in the suction device, the suction hose or the suction cannula flow in the normal direction of suction

Methodology Applied
Scientific EffectNegative pressure: Pressure Gradient

Data Source

PatentEP3714837B1Two-part suction cannula for dental treatment
Publication Date: 2022.11.23 COLTENE WHALEDENT GMBH & CO KG
  • EP3714837B1 patent drawingFigure 1
  • EP3714837B1 patent drawingFigure 2
  • EP3714837B1 patent drawingFigure 3~4

AI summary

The invention relates to a two-part suction cannula for aspirating fluid substances from the oral cavity, in particular water, saliva, or blood, during dental treatment. It comprises a handle for manually handling the suction cannula and a suction tip connectable to the handle, which can be inserted into the oral cavity by means of the handle. The handle has a suction end with an intake opening and connectable to the suction tip, a suction end with an intake opening and connectable to a suction device via a suction hose, and a fluid-conducting passage in the handle connecting the intake and suction openings. The suction tip has an intake end with an intake opening, an outlet end with an outlet opening, and a fluid-conducting passage connecting the intake and outlet openings.