July 1997
ROCKVILLE, Md. — With recurrent otitis media cases on the rise among young children, a new device that detects fluid in the middle ear has been granted marketing approval by the Food and Drug Administration.
The creators of EarCheck Pro Otitis, MID Instruments Inc., hope the device will eventually replace the painful tests currently used by some doctors in detecting middle ear effusions (MEE).
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EarCheck Pro helps determine the presence of fluid in the ear.
The company said the new tool will facilitate doctors' diagnosis of otitis media by using acoustic reflectometry to measure the response of the eardrum to a sound stimulus in detecting either the presence or absence of middle ear fluid. The instrument uses an acoustic transducer consisting of 44 different frequencies at about 80 decibels. A microphone then records the sound reflected back from the eardrum. The difference in frequency spectrums between the sound emitted and its echo is analyzed by a microprocessor.
Clinical studies performed by the company show that EarCheck Pro is comparable in accuracy to a tympanometer for detecting MEE. Unlike a tympanometer, however, the EarCheck Pro is painless because it relies on an acoustic reflectometry that does not require an airtight seal or pressurization of the child's ear canal, company officials said.
In a healthy ear, a portion of sound emitted by EarCheck Pro is transmitted through the vibrating eardrum into the middle ear, as in normal hearing. Because only a small portion of the frequency spectrum is bounced back, the EarCheck Pro detects a significant difference between the sound emitted and its echo.
In a fluid filled ear, however, the fluid restricts the vibration of the eardrum. Only a small portion of the sound energy is transmitted to the middle ear, resulting in reduced hearing levels. Because most of the frequency spectrum is bounced back, the EarCheck Pro detects little difference between the sound emitted and its echo.
Otitis media is common and painful for children. There is some concern of speech delays and hearing loss from repeated episodes but studies have found conflicting results. Treating ear infections can cost $3 to $4 billion annually in the United States, according to one survey.
"About 70% of children still have fluid in the middle ear after a 10-day course of treatment with even the most potent of antimicrobial agents," said Jerome O. Klein, MD, professor of pediatrics at Boston University's School of Medicine. "Because of the impact even moderate hearing impairment can have on speech, language and cognitive development in young children, it is imperative to correctly monitor prolonged time spent with MEE."
Because of increasing pressure within managed care organizations to minimize office visits, many primary care physicians rely solely on the otoscope to diagnose acute otitis media and associated middle ear fluid. However, otoscopy is largely subjective because it is a visual exam. When used as a confirmatory tool, the EarCheck Pro can help to enhance diagnostic accuracy and limit unnecessary prescription of antibiotics that can result from overdiagnosis of acute otitis media.
"The EarCheck Pro is very user friendly," Klein said. "Compared with the tympanometer, which is a console, EarCheck Pro is very portable — it can fit right into my pocket."
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