bipolar signals
About the ear. The ear consists of three parts – the outer, middle and inner. Normally, sound waves enter the outer ear and touch the eardrum, causing the eardrum to tremble round. Immediately behind the eardrum, middle ear contains three tiny bones (they are the bones most small body!) Called the hammer, anvil and stirrup, known collectively as the ossicles. These vibrations are transmitted from the eardrum to these small middle ear bones. The bones pass the vibrations to the inner ear structure called the cochlea. The vibrations that cause special cells in the cochlea to move, generating "signals" are sent by the nerve to the brain, so "listen". Air normally fills the space in middle ear. The middle ear is connected to the throat by a structure called the eustachian tube or the Eustachian tube. The function of the eustachian tube is to normalize or equalize air pressure between the middle ear and the atmosphere. This tube is normally closed, however, occasionally, opens to allow air to enter and the liquid drain out.
Tell me more about glue ear. Glue ear is a condition where the middle ear, which normally is filled with air, filled with liquid. The liquid looks and feels like glue and hence the name of the disease. The correct medical term used to describe Glue ear is "otitis media with effusion or OME. Typically, it affects only one ear, but both ears can be affected. Since the density changes in middle ear low to high as the air is replaced by the liquid, the sound vibrations in the eardrum and keep the bones to soften. As a result of Thus, the cochlea receives low volume of the "signals". Glue ear commonly affects children, but adults can also be affected.
What are the causes of Glue ear? Researchers are still looking for cause and mechanism of glue ear. The exact cause is still uncertain. But most researchers believe it is more likely due to the Eustachian tube not working properly. The amount of air and fluid in the middle ear may change if the eustachian tube is blocked or narrowed. When the Eustachian tube is blocked, the air is absorbed by neighboring cells in the middle ear, a development vacuum, causing the fluid to seep into the middle ear by nearby cells.
Glue ear is common? Yes, affecting seven in every ten children at some stage in their life. Children are at greater risk than girls. An episode predicts another, children who have one episode are likely to have recurrent glue ear. Other risk factors include:
– Lives in the house where people smoke.
– Have a family history of ear rubber (the brothers who have ears to tail)
– Have recurrent cough and cold.
– Were not bottle-fed infants.
What are the symptoms of glue ear? Hearing dull. This is by far the most common symptom. At some point, affected children can become completely deaf. Hearing loss can range from mild to severe. If it persists, will affect children's intellectual development is normal.
Pain. This Earache is rare but can occur in mild occasionally. Affected children may pull on their ears if they have pain.
Behavioral problems. Children with adhesive otitis media tend to have behavioral problems and slow development of speech. These are commonly due to the fact that they can not hear well.
Can be treated? Yes, however, more glue ear resolve themselves. If glue ear persists, surgery may be necessary to remove the tail-like fluid in the middle ear and place a "buttonhole" (vent pipe) in the eardrum. The grommet is a tiny device that acts like a canal. It sits across the eardrum, which connects the outer and middle ear, allowing the pressure in the middle ear to normalize or equalize with the atmosphere.
Michael Russell Your Independent guide to Medicine
Module – 2 Lecture – 5 BJT Small Signal Analysis
