Apparatus and methods for hygiene testing a medical device
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Solution Overview
Problem
Current methods for cleaning and sterilizing endoscopes are inadequate, leading to residual contamination and patient infections due to the difficulty in accessing and assessing the cleanliness of narrow, elongated passageways within these medical devices.
Innovation Solution
A sampling system utilizing a two-phase flow of liquid and gas to dislodge and recover contaminants, including a fluid supply system and a receiving container, along with a method involving a sterile aqueous composition and compressed air to flow through the endoscope channels, enhancing the removal of biofilms and bacteria like Enterococcus faecalis and Pseudomonas aeruginosa.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If manual cleaning or liquid disinfectants are used to clean endoscope channels, then the cleaning process is simple to perform, but the cleaning effectiveness is insufficient and residual contamination remains
Solution Approach 1:
The patent employs two-phase flow (combination of gas and liquid) to clean endoscope channels. Pressurized gas and liquid are introduced simultaneously through the channels, creating turbulent flow that mechanically dislodges and flushes out contaminants, biofilms, and residues from the narrow passageways, achieving reliable cleaning without complex manual procedures
Solution Approach 2:
The patent changes the physical parameters of the cleaning fluid by using two-phase flow (gas-liquid mixture) instead of single-phase liquid. This parameter change creates higher energy flow patterns including churn flow and annular flow that significantly enhance cleaning effectiveness in narrow channels while maintaining operational simplicity
2Reliability
If high temperature steam sterilization is used, then sterilization effectiveness is high, but it cannot be applied due to endoscope construction materials and narrow channel geometry
Solution Approach 1:
The patent uses pressurized two-phase flow (gas-liquid mixture) as an alternative to thermal steam sterilization. The high-velocity gas-liquid flow mechanically removes contaminants and can be combined with chemical disinfectants to achieve sterilization effectiveness without requiring high temperature steam that would damage endoscope materials or fail to reach narrow channels
Solution Approach 2:
The patent changes from thermal sterilization parameters (high temperature steam) to mechanical/chemical sterilization parameters (pressurized two-phase flow with chemical agents). This parameter change maintains sterilization effectiveness while adapting to the constraints of endoscope construction materials and narrow channel geometry
3Measurement precision
If conventional single-phase liquid flow is used for sampling, then the sampling system is simple, but it cannot effectively dislodge and recover contaminants from narrow passageways
Solution Approach 1:
The patent employs two-phase flow (gas-liquid mixture) for sampling instead of conventional single-phase liquid flow. The pressurized gas component creates turbulent flow patterns that effectively dislodge contaminants from channel walls, while the liquid component carries the dislodged contaminants to collection points, enabling accurate contaminant detection without overly complex equipment
Solution Approach 2:
The patent changes the flow regime from single-phase liquid to two-phase gas-liquid flow. This parameter change significantly enhances the ability to dislodge and recover contaminants from narrow passageways by creating high-velocity turbulent flow and churn flow patterns that mobilize adhered contaminants for accurate sampling and detection
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 effectively removes and quantifies contaminants, providing a reliable and reproducible method to assess the cleanliness of endoscopes, reducing the risk of patient infection by ensuring thorough disinfection and sterilization of endoscope channels.
Implementation Method 1
A sampling system utilizing a two-phase flow of liquid and gas to dislodge and recover contaminants
Implementation Method 2
said sampling liquid comprises an amount and selection of surfactant effective to enhance the dislodgement of Enterococcus faecalis and Pseudomonas aeruginosa bacteria from the narrow passageways
Data Source
AI summary
Provided among other things is a sampling system for determining an amount or type of contamination a narrow, elongated passageway in a medical device, said sampling system comprising: (a) a fluid supply system that supplies to said passageway a sampling liquid for flowing through said passageway and a gas for flowing through said passageway; and (b) a receiving container that receives liquid from said passageway, wherein said sampling liquid is sterile, wherein said sampling liquid is configured to allow recovery of viable pathogens from the passageway, and wherein said sampling liquid comprises an amount and selection of surfactant effective to enhance the dislodgement of Enterococcus faecalis and Pseudomonas aeruginosa bacteria from the narrow passageways.