Laser Pulse Timing for Shock Wave Cleaning in Confined Cavities

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for cleaning and disinfecting small liquid reservoirs, such as root canals and blood vessels, are limited by the absence of shock waves due to confined geometries, leading to inadequate removal of debris and bacteria, necessitating the use of potentially toxic chemicals for effective cleaning.

Innovation Solution

A laser system delivering pulsed laser beams in sets with optimized pulse repetition times to generate secondary shock waves by leveraging the energy from subsequent bubbles to enhance the cleaning efficacy in confined spaces, even when single pulses do not produce shock waves.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If laser pulses are used to generate cavitation bubbles for cleaning, then cleaning effect is improved, but in confined geometries shock waves are not generated reducing cleaning efficacy

Engineering Contradiction:
Improvecleaning efficacyVSAvoidapplicability to confined geometries
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The invention combines multiple laser pulses into a pulse train where the cumulative energy from subsequent bubbles enhances the shock wave generation from the first bubble, enabling effective cleaning in confined geometries where single pulses fail

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

Subsequent bubbles in the pulse train perform preliminary energy deposition that accumulates in the liquid, creating conditions favorable for strong shock wave emission from the first bubble's collapse

Inventive Principle:
Principle #10Preliminary action

2Loss of time

If single laser pulses are used, then treatment time is reduced, but shock waves are not generated in confined spaces

Engineering Contradiction:
Improvetreatment timeVSAvoidshock wave generation
Core Design Contradiction:
Loss of timeVSReliability

Solution Approach 1:

The invention uses periodic laser pulse trains with optimized repetition rates that match the bubble oscillation frequency, allowing cumulative energy deposition while maintaining treatment efficiency

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The pulse train provides continuous energy deposition through multiple bubbles forming in sequence, ensuring that the cleaning action remains effective throughout the treatment duration without interruption

Inventive Principle:
Principle #20Continuity of useful action

3Device complexity

If conventional cleaning methods are used in confined geometries, then equipment complexity is reduced, but toxic chemicals are required for effective cleaning

Engineering Contradiction:
Improvesystem simplicityVSAvoidtoxic chemical exposure
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The invention replaces chemical cleaning methods with a laser-based mechanical cleaning system that uses light energy to generate cavitation bubbles and shock waves, eliminating the need for toxic chemicals

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention changes the cleaning mechanism from chemical to physical by adjusting laser parameters (pulse energy, repetition rate, duration) to optimize cavitation bubble formation and shock wave generation in confined spaces

Inventive Principle:
Principle #35Parameter changes

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 system significantly improves cleaning efficacy by generating shock waves in confined geometries, reducing the need for toxic chemicals and enhancing the removal of debris and bacteria within small liquid reservoirs.

Implementation Method 1

When energy is locally deposited within a liquid, for example with an intense focused electromagnetic radiation (e.g., laser light), locally induced boiling of the liquid leads to a creation of a cavitation bubble

Methodology Applied
Scientific EffectCavitation: Cavitation

Implementation Method 2

an intense shock wave may be emitted during the bubble's collapse. These shock waves spread through the volume at supersonic speeds, and interact disruptively with the surrounding environment

Methodology Applied
Scientific EffectShock wave: Shock Wave

Implementation Method 3

a cavitation bubble collapsing near a boundary forms a liquid jet directed at the boundary

Methodology Applied
Scientific EffectLiquid jet formation: Jet

Implementation Method 4

These violent cavitation oscillations lead to rapid streaming of liquid molecules around the cavitation bubble

Methodology Applied
Scientific EffectCavitation oscillations: Cavitation

Data Source

PatentEP3510961B1Cleaning system
Publication Date: 2021.06.09 FOTONA D O O
  • EP3510961B1 patent drawingFigure 1
  • EP3510961B1 patent drawingFigure 2a~2b
  • EP3510961B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a cleaning system being configured for cleaning, including fragmentation, debridement, material removal, irrigation, disinfection and decontamination, of cavities (2) filled with a liquid (3). The cleaning system comprises an electromagnetic radiation system and the liquid (3). A treatment handpiece (7) and its exit component (8) are configured to irradiate the liquid (3) within the cavity (2) with the radiation beam, wherein a wavelength of the radiation beam is chosen for significant absorption of the radiation beam in the liquid (3). The electromagnetic radiation system is adapted to generate a first vapor bubble (18) within the liquid (3) by means of a corresponding first pulse (pa) and a second vapor bubble (18') within the liquid (3) by means of a corresponding second pulse (pb) at a location different to the location where the first vapor bubble (18) is present at the time of generating the second vapor bubble (18'). The electromagnetic radiation system further comprises a feedback system (9) to determine a bubble oscillation intensity. Adjusting means (10) are provided for adjusting the pulse repetition time (Tp) as a function of the determined bubble oscillation intensity. The pulse repetition time (Tp) is adjusted such, that the onset time (t0b) of the second vapor bubble (18') is within the first contraction phase of the first vapor bubble (18), when the first vapor bubble (18) has contracted from its maximal Volume (Vmax) to a size in a range from about 0.7 to about 0.1 of the maximal Volume (Vmax).