Washer Disinfector Service Training Seminar

WD 230 •

Manual doors in stainless steel or with glass door

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Pass trough model or one door model

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Microprocessor controlled

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Electronic water level control during filling process depending of chamber loading (reduce water consumption)

WD 250 •

Automatic vertical glass door

– Door opens down •

Use the same rack as the 230.

WD 290

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15-tray washer-disinfector with automatic glass sliding doors

Accessories instrument racks

Course objectives
Discuss cleaning theory
Describe a basic wash program
Understand the fluid flow paths
Interpret electrical schematics
Identify key components
Identify normal menus
Access service mode
Troubleshoot fault codes and errors
Review maintenance procedures

Law of mass cleaning action The law of mass cleaning action expresses a relationship between time, action, concentration, and temperature in the process of removing soils. This laws states that if you decrease any one of these factors, we must increase one or more of the remaining factors in order to maintain equal cleaning ability

4 key factors for cleaning efficacy

Chemicals

Chemistry - soil
To properly clean something you need an understanding of the soil

Inorganic Soils Water spots, lime scale, rust, corrosion, oxidation, minerals, rocks USE ACID CLEANERS

Organic Soils animal fats, body oils, carbohydrates, proteins, bacteria, mold, yeast, slime USE ALKALINE CLEANERS

Combination Soils Mixtures of organic plus inorganic soils USE COMBINATION CLEANERS

Chemistry - pH

pH – This is a measure of the concentration of hydrogen ions (H+) in relation to the concentration of hydroxyl ions (OH-)

Chemistry – cleaning power
pH is a very important part of cleaning power.
The reality is many hospitals choose to use pH neutral products. These products contain some of the following to perform the cleaning task:
Solvents
Surfactants
Enzymes
Chelating agents

Chemistry - solvents
Solvent
All cleaners require some sort of liquid solvent. This solvent not only "dissolves" the soil, but also provides a medium in which soil can be suspended and carried away from the surface.
Water is the oldest, least expensive and most widely used cleaning solvent known to man. In time, water will clean or remove just about every type of soil, be it organic, inorganic, petroleum or combination.

Chemistry - surfactants Surfactant: sur·fac·tant a.k.a - detergents or soaps The word surfactant is short for "surface active agent". Surfactants work at the boundary layer (the interface) between the soil and the solvent. Each surfactant molecule has two chemical groups; one that is attracted to water (the hydrophile) and one that is attracted to soil (the hydrophobe).

http://en.wikipedia.org/wiki/Surfactant http://en.wikipedia.org/wiki/Detergent

Chemistry – Enzymes
Protease (enzymes)
Proteases can either break specific peptide bonds (limited proteolysis), depending on the amino acid sequence of a protein, or break down a complete peptide to amino acids (unlimited proteolysis). The activity can be a destructive change, abolishing a protein's function or digesting it to its principal components.

Chemistry - Enzymes For example coagulated blood protein: fibrine-network is degraded to smaller parts that can be removed easlily

There are an endless number of different enzymes with different properties (different target molecules, pH, temperature, stability etc.)

Chemistry- chelating agents
Chelating agents (che-lating)
"tie up" the hardness in water. Dissolved minerals in water are the cause of hardness. Rain and distilled water is pure and soft, but it quickly dissolves minerals (mainly calcium, magnesium, iron and silica) as it soaks into the ground and travels through rivers or lakes. As the water becomes loaded with dissolved minerals, it becomes hard.
Hardness in water will hinder the cleaning ability of a cleaning solution. This is because the detergents and other active ingredients in the cleaner see the hardness minerals as "soil". These actives are used up by the hardness, and are not available to clean the soil we want them to.

Basic wash program – pre-wash Step 1 - Pre-wash ~ 2 min
The maximum allowed temperature is 45C for all Pre-wash steps.
Cold water will help prevent coagulation of blood onto the device.
If the water temperature increases to above 45C error code 163 “Water too warm” will be flashed and the process is interrupted.
Since ~ 2009
S109 repeat option is available. In the event that excessive foam is detected in the unit during prewash, the unit will halt the process drain the washer and begin again.

Basic wash program - wash Step 2 - Wash ~ 5 min
Warm Water is mixed with the cleaning agent or detergent.
If the water temperature increases by more than 8C error code 163 “Water too warm” will be flashed and the process is interrupted. You can set temperature to 0C to prevent error code.
If there is excessive foaming in the load the unit will abort. Foam inhibits the units ability to clean instrumentation – Action from the law of mass cleaning

Basic wash program - rinse

Step 3 - Rinse ~ 1 min
Warm Water is used to rinse off the cleaning agent or detergent.
The length and number of rinse repeat steps will be determined by the detergent products rinse ability.

Basic wash program – clean rinse Step 4 - Clean Rinse ~ 1 min
DI/RO is used with instrument lubricant added (optional)
Only in models since ~2009, pre-2009 add lubricant directly to the thermal disinfect step
AAMI 7.5.4 “the final rinse should be performed with treated water that is of a quality that does not contribute to staining or contamination of the instrument.”