[Measuring vibrations by laser doppler vibrometry of the human tympanic membrane after stapes fixation]. / Laserdopplervibrometrische Schwingungsmessungen am menschlichen Trommelfell nach Stapesfixierung.

At times preoperative diagnosis of otosclerosis can prove difficult. Even the objective measurement of the stapes reflex is not very conclusive in patients suffering from more severe hearing loss. Laser-Doppler vibrometry measures the velocity or amplitude of the tympanic membrane (umbo) vibrations. Laser-Doppler vibrometry has a sensitivity that is highly by the factor 10(4) than tympanometry. The herewith presented examinations show, that there is a correlation between the frequency patterns of the displacement amplitudes and experimentally simulated otosclerosis.

Middle ear transmission disorders--tympanic membrane vibration analysis by laser-Doppler-vibrometry.

Laser-Doppler-vibrometry is a useful method to measure vibrations of the tympanic membrane. It is suitable to objectively diagnose the middle ear. In comparison to tympanometry, laser-Doppler-vibrometry has greater sensitivity. Temporal bone specimens were specially prepared to simulate middle ear disorders like middle ear effusion, fixation of the malleus head, fixation of the stapes footplate and removal of the incus. A correlation between the displacement function of the umbo and the experimentally produced middle ear disorders could be demonstrated. For the first time it was possible to measure the vibration of the tympanic membrane by using a laser-Doppler-vibrometer in a healthy 25-year-old male.