Transcript Cleaning solution

Care and
maintenance of
ophthalmic
equipment
Orbis International
YOU DON’T HAVE TO BE A
VICTIM OF YOUR EQUIPMENT
LOVE YOUR EQUIPMENT
AVOID DEPENDENCY &
TAKE ACTION
out of order
OPTICAL SURFACES
Care and Maintenance
Optical surfaces
Almost all ophthalmic equipment have
optical components like
glass plates
lenses
mirrors
prisms
Optical Surfaces
Surfaces of optical elements like
prisms, mirrors, bean splitters,
windows and filters used in
ophthalmic equipment are specially
prepared:
They are highly polished
Special coating of certain
materials is also present on the
surface of lenses
Coating is a thin chemical film
deposited onto the lens surface
Coatings & functions
Surfaces of lenses, prisms and windows are
antireflection coating (ARC) to prevent loss
of light due to reflection.
Mirrors have a highly reflecting coating to get
maximum reflection of light.
Beam splitters have a coating of special
thickness to have (50:50) % of reflected and
transmitted light through them.
Filters have coatings to cut out undesired
wavelengths.
In the case of lasers, the mirrors used have
coatings to give a reflectivity as high as
99.95% or better for a given wavelength.
Care of Optical surfaces
Optical surfaces should never be wiped to
removed dust especially when they are dry.
Dust must be blown off.
If wiped with a cloth, dust particles may
scratch the surface of optical components,
thereby reducing the quality of the optical
element.
Sharp instruments, even sharp fingernails,
may cause a scratch. One should be
careful in using sharp instruments near
optical surfaces when removing or refitting
the optical elements.
General care
 Objectives
Objectives of surgical microscopes always get a spray of fluid
during operation. After the end of the surgery, clean the
objective surface appropriately
 Bulbs
Bulbs should be inspected quarterly and replaced if necessary
 Cooling fans
Cooling fans should run smoothly
Replace them as necessary
 Fiber optics
Fiber optics must be handled with maximum care during
corrective and preventive maintenance procedures
Maintenance (optics)
 Normally only the outer surfaces of
the objective and the eyepieces are
cleaned
 Dust on the objective should be
removed with a rubber blower or a
grease free brush
 For cleaning the brush washing in
ether is recommended
 Fingerprints, smears etc. can be
removed with cotton wool swap
 If necessary the cotton wool can be
moistened with acetone
Cleaning the body
The varnished surfaces should
be cleaned with a mixture
consisting of 50 percent spirit
50 percent distilled water plus
a dash of surface active liquid
detergent
Cleaning Microscope parts
Mild soap
For removal of
contamination
from surfaces.
(not for optics)
Cleaning Microscope parts
Cleaning solution
(Distilled water 50%
96% Alcohol
50%)
For normal
instrument
cleaning (not for
optics)
Cleaning Microscope parts
Petroleum Benzene
For removing
greasy
contamination
(not for optics)
Cleaning Microscope parts
Distilled water with
some detergents
 For precleaning
optics where
necessary
Cleaning Microscope parts
Optics cleaning
solution
 Petroleum benzene
40%
 Ethanol
40%
 Ether
20%
Material for lens cleaning
air blowers (blower bulb, pressurized air can)
lens brush;
cotton swab *;
lens tissue;
lens cleaning solution, e.g., Kodak,
Zeiss;
lens fungicide (optional), e.g.,
Zeiss;
* use medical grade cotton swabs, which fibers have
been degreased / defatted, and don’t release lint.
Air blowers / lens brusher
Cotton swabs
Cotton swabs *
* Medical grade
Lens tissue
Lens cleaning solution
Lens fungicide
Cleaning Solutions
Cleaning Solutions
Frequent
Use
Infrequent
Use
Manufacturer's
recommendation
Yes
Yes
Ethyl
ether/alcohol
(80/20)
Yes
Yes
Alcohol
No
Yes
Benzene / petrol
No
Yes
Xylol
No
No
Microscope Maintenance-Module 3
25
Cleaning procedure for
Optical surfaces
Start by blowing away
dust particles by rubber
bulb syringe or dust
blower.
Clean the eyepieces
with a cotton swab
moistened with lens
cleaning solution
Clean in a circular
motion inside out
Cleaning optical surfaces
 If dust cannot be
removed use a soft
brush (grease free)
 Knock the brush
briefly
 If necessary
degrease the brush
with a cloth soaked
with alcohol
Cleaning optical surfaces
 Heavy contamination
(fingerprints, grease,
oil) use a cotton wool
moistened with
cleaning solution
 Begin at the center
and work outwards
by circular motion
 Don’t use old cotton
stick for next cleaning
Cleaning solution
Cleaning Contaminated
Instruments
Common sources of contamination include Hepatitis,
Herpes Simplex, Chlamydia, TB, AIDS or contagious
bacteria and viruses.
For external surfaces that do not touch the eye use
alcohol swabs if appropriate. If alcohol is damaging
then use manufacturer’s recommended solution.
For concern of AIDS transmission wipe down with a
1:10 dilution of bleach.
For instruments that come in contact with the eye
soak for 10 minutes with 3% hydrogen peroxide.
Change solution twice a day.
Cleaning optical surfaces
Cleanliness check
Breathe on the lens
and the moisture
should be
distributed evenly
Cleaning mechanical parts
Remove heavy contamination with mild
soap (never use acetone or ether)
For cleaning greasy parts use moisten
clean cloth or cotton wool with Benzene
Mechanical guide ways should be
checked for smooth operation and if
necessary cleaned and apply grease
(parts recommended by the
manufacturer)again.
Facts about Fungus
Fungi can be found everywhere
They germinate in suitable humidity and
temperature environment
They do not need any nutritive
substances which they themselves
produce
Facts about Fungus
The most important
precondition for
fungus growth is
humidity
Fungus among us…
In its first stages, fungus will not be
perceivable by the clinician.
Initially there will be a very slight loss of image
brightness.
With time the fungus covers the lens surface
in a web like manner.
In its final stages, the lens outer coatings are
etched by the fungus and image sharpness
deteriorates.
Fungus growth
The Photos are Copyright©, 1996 by Toomas Tamm
http://www.chem.helsinki.fi/~toomas/photo/life-in-camera.html
Facts about Fungus
Metabolic products
of fungus growth will
attack the polished
glass surface such
as lens, mirrors and
prisms
To avoid Fungus
Without sufficient amount of humidity
fungus can neither germinate or develop
The relative humidity for fungus growth
to become harmful is above 80%
Development of fungus is impossible if
humidity is less than 60%
Reduction of relative
humidity
Air conditioning
Dessicant
Increasing temperature
To avoid fungus growth
 Never keep in closely
fitting instrument cases
 The more air and light
are allowed on the
instrument the better
the evaporation of
moisture
 Make sure to keep in
good air circulation
 Store with dessicants
Fungus growth, some suggestions to
minimize the risks
Keep the optics in a dry place with plenty of air
circulation (air conditioners and dehumidifiers are
very helpful).
Do not cover optics with plastic drape covers
(commonly supplied by medical equipment
manufacturers) since these will retain humidity. If you
need to drape the equipment to protect against dust,
use a porous cloth cover.
If you need to keep certain optics in sealed containers,
place silica gel packs with it to absorb any humidity. It
is important, though, to check the silica for
discoloration or moisture to know when to replace it.
Fungus Removal
Removing fungus from lenses is extremely
difficult and rarely yields good results.
You can use ultraviolet radiation (sunlight or an
ultraviolet lamp) or paraldehyde to kill it.
Once killed, the fungus may be easier to
remove but the outer coatings of the lens will
most likely have irreversible damage.
Conclusion
The best microscope performance
can be obtained by proper
adjustment, daily care and regular
maintenance