Equipment
components
handle
magnifying heads
cones
assembled otoscopes
instruments
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An otoscope
consists of 3 parts:
- a handle which contains the power for the light source
- a head which contains the light bulb and magnifying lens
- a cone which is inserted into the ear canel
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The handle may contain removable batteries or may be
rechargable. Some handles are recharged by placing in a charger stand
(the bottom of the handle pictured has a contact plate on the bottom which
"connects" with the charger) or the bottom of the handle may unscrew
revealing prongs to plug into an electrical outlet. The handle connects with
the otoscope head by lining up notchs on both pieces, then rotating to
"lock" the two pieces together.
The power is turned on to the handle by depressing and then rotating the
small red button.
As the power begins to diminish, the intensity of the light will
decrease, then the light goes out altogether. Keep the handles fully charged
for maximum illumination.
Head 1 may be used both for examination and instrumentation in the ear
canel. Head 2 has a larger magnification lens but the lens must be flipped
out of the way in order to pass instruments through the otoscope, therefore
this head is best used to view, rather than to instrument. Head 3 has two
magnifying lens and is used when two individuals want to have the same view
of the ear canel (student or pet owner). top of page
Magnifying heads
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Head 1 ( see assembled otoscope)
This head may be used both for examination and instrumentation in the
ear canel but does not provide as great of magnification as does head 2.
I prefer to examine the ear first with head 2, then change to head 1 if
I need to pass an instrument into the ear canel.
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Head 2 ( see assembled otoscope)
This head provides a greater degree of magnification than head 1. The
entire magnifying lens can be piveted off the opening of the otoscope
but then all magnification is lost. The lens tends to fog with
condensation as it warms to the temperature of the animals ear. "AntiFog"
eyeglass preparations can be applied to the lens or more simply, breathe
on the lens to warm it before inserting in the ear canel. |
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Head 3 ( see assembled otoscope)
This head is used when two individuals want to have the same view of the ear
canel. It is used in a teaching setting or to show owners the ear canel of
their pet. Because the light has to travel a greater distance before
illuminating the ear canel (notice how long this head is compared to heads 1
and 2) the intensity of the light available to illuminate the ear canel is
diminshed. Therefore use a one lens head to examine the ear canel before
changing to the dual lens head. |
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Ear cones
Ear cones are made of rigid plastic. They are available in different lengths
and diameters. Use the largest cone that can be passed into the ear canel for
best visualization. The diameter of the ear canel tapers as it approaches the
tympanic membrane. You may need to use more than one size cone to examine
different depths of the ear canel. If you need to pass an instrument into the
ear canel the cone tip must be wide enough to accomedate the instrument.
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The photograph below shows the narrowest tip of the cone (the end
that is passed into the ear canel. Notice the rough edges of the wide,
short cone on the left. This cone has been cut to use as a
vaginal speculum to place a urinary
catheter in a female dog. This modified cone is too short to be of much
use in examining ears. Check ear cones periodically to assure that the
tips are smooth and not chipped or frayed (or intentionally modified).
Damaged cones can be damaging to the ear canel. |
| Cones should be cleaned of wax and debris after use and
cleaned with or stored in an antiseptic cleaning solution. |
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Assembled otoscopes
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Instruments
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There are several types of instruments that can be used
in the ear canel. Alligator forceps and an ear loop are the two I find
most useful. The forceps are used to grasp and remove formed debris
from the ear canel such as foxtails or firm "chunks" of ear wax. The
loop has a "loop" of fine gauge wire at the tip. It is very useful to
scrape debris from the ear canel, especially debris that is not well
formed which breaks up when grasped with a forceps.
A plastic "tom cat" urinary catheter is another useful tool used
during ear cleaning. |
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Before placing the otoscope into the ear canel confirm that the
instrument(s) you plan to use are of sufficient length to protrude
beyond the tip of the ear cone and that the jaws of the alligator
forceps can be opened. Make note of the distance the instrument
protrudes beyond the tip of the ear cone when the instrument is inserted
into the cone as far as it can go. One often has a poor sense of depth
perception when viewing a narrow canel like the ear canel. Knowing how
far the instruments protrude beyond the tip of the ear cone can help
reduce the chance of iatrogenic trauma to the ear drum. |
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proceed to demonstration of examination
otoscopic exam
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otoscopic exam procedures |
Diagnostic Techniques Laboratory
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