Eustachian Tube Function - Patulous Eustachian Tube - Interacoustics AA222 Additional Information

AA222 Additional Information Page 13
2.9 Eustachian tube function – patulous eustachian tube
The patulous Eustachian tube test is an impedance baseline test. It monitors changes in impedance over
time without applying pressure changes or acoustic stimuli. When a patulous Eustachian tube is present you
would typically expect to identify the breathing of the patient in the tympanometric curve. If the Eustachian
tube is closed and the tympanic membrane is intact, you would expect to measure small tympanometric
changes which can be caused by acoustic disturbances from around the patient, accidental displacements of
the probe, or by spontaneous movements of the eardrum. Additionally, it is possible to measure movements
due to the heartbeat as, for example, with a glomus tumor. Or the test can be used to measure reflexes
where the stimulus is presented through an external device such as a cochlear implant.
The default display of the Eustachian tube function test for the patulous Eustachian tube shows the graph for
the selected ear. Below is a real example of a measurement in which the breathing rhythm of the patient can
be recognized due to the presence of a patulous Eustachian tube.