An otoscope is a hand-held device for visual examination of the auditory canal, inner ear, and tympanic membrane.
An otoscope is designed to enable the health care professional to view the auditory canal, inner ear, and tympanic membrane as part of a normal physical examination. It is also used if infection of the auditory canal is suspected, if there is a blockage due to the presence of a foreign object or build up of wax, and to inspect the tympanic membrane for signs of rupture, puncture, or hearing loss.
An otoscope consists of a handle with power source, an optical head with fiberoptic strands, a lens, specula, a small light bulb, a polished reflector, and may have pneumoscopy bellows as an option. The unit is designed to be operated by one hand, enabling the other hand to manipulate the patient's ear.
Batteries, either disposable or rechargeable, can power the unit and are often stored in the handle of the otoscope. Alternatively, the unit can be recharged using a transformer to enable it to be used from a 110V power supply mounted on a wall. Some units have other options available for the power source, including a clip-on battery unit with a two-pronged cord that can be attached to a pocket or table, and a cord with batteries that is attached to the otoscope and hangs around the health care professional's neck.
An optical head is attached to the handle and contains fiberoptic strands, a bulb, a swivel-headed magnifying lens, and the reflector, allowing the health care professional to view the patient's auditory canal via an attached speculum. The lens is constructed of scratch-resistant optical glass. Specula may be disposable or autoclavable and can range in size from 2.5–8mm. This enables the appropriate-sized speculum to be selected for the patient's ear offering comfort for the patient during the otoscopy procedure, while providing a positive ear seal for pneumoscopy. An otoscope bulb provides light that shines through the tip of the speculum while a reflector increases the amount of forward light given off by the device. The bulb is usually halogen to give off a clear light that will not affect the color of the ear canal, potentially altering the diagnosis. The illuminated canal is viewed through the magnifying lens.
Pneumoscopy bellows are made of plastic or rubber and are attached to the otoscope via a thin plastic tube. When the bellows are squeezed, a small puff of air is forced through the tubing, striking the tympanic membrane. The action of the air striking the membrane is viewed through the otoscope. Signs of oscillation are normal.
Each otoscope has different features depending on the manufacturer and the cost of each unit.
The patient will be asked to sit with the head tipped slightly toward the shoulder so that the ear to be examined is pointing up. After selecting the appropriate sized speculum for the patient's ear, the speculum is attached to the optical head of the otoscope and gently inserted into the patient's ear. The doctor or nurse may hold the ear lobe as the speculum of the otoscope is inserted into the ear. Both ears are usually examined, even if there seems to be a problem with just one ear, and the procedure takes no more than a few minutes to perform.
The otoscope should be maintained by ensuring the bulb light is bright and extends from the tip of the speculum to the eardrum. Bulbs should be replaced every six months, and rechargeable batteries changed every two years. The fiberoptic strands in the optical head may crack over prolonged use, and if the light remains dim, the unit should be repaired. The device should be checked for air leaks that prevent an adequate seal to be formed around the ear or permit air to escape from around the lens or where attachments fit the unit. A poor seal will also allow moisture to enter behind the lens and fogging will occur.
Health care team roles
The person using the scope should know how to recognize signs of inflammation and disease, including pressure behind the eardrum and be thoroughly familiar with the normal appearance and anatomy of the ear. Training hospitals may offer otoscopy programs.
Auditory canal—The ear canal.
Ear speculum—A cone or funnel-shaped attachment for an otoscope that is inserted into the ear canal to examine the eardrum.
Otoscope—A hand-held instrument with a tiny light and a funnel-shaped attachment called an ear speculum, which is used to examine the ear canal and eardrum.
Pneumoscopy—An examination using air.
Tympanic membrane—The ear drum.
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Margaret A Stockley, RGN