Biomedical subjects

T Gundersen

Publications and source records attributed to T Gundersen.

112 records · Page 7Linked to original sources

PubMedDate not supplied

Holographic vibration analysis of the ossicular chain.

The mechanics of movement of the ossicular chain has been investigated on human temporal bone preparations by means of time average holography. The malleus and incus moved like a lever around an axis, which position was somewhat dependent upon frequency. Simulation of contraction of the muscles of the middle ear gave as result a change in the pattern of movement of the ossicular chain. The position of the rotatory axis was changed, and the amplitudes of vibration were reduced. This should be a protecting mechanism.

Autopsy↗

PubMedDate not supplied

Hearing loss resulting from perilymph fistula. A presentation of two cases.

Two cases of perilymph fistula in the oval window are presented. In such cases hearing loss may be severe and vertigo may or may not be present. Early surgical intervention is recommended, but one should not hesitate to explore a suspected ear, even if considerable time has elapsed.

Adult↗

PubMedDate not supplied

A study of the vibration of the basilar membrane in human temporal bone preparations by the use of the Mössbauer effect.

Using the Mössbauer technique, we have studied the vibration of the human basilar membrane and malleus head in the sound frequency range 0.2--9.0 kHz and at a sound pressure of 100 dB at the tympanic membrane. The displacement frequency response curves for the basilar membrane and the malleus head have similar shapes, with a maximum at about 1 kHz. Below and above 1 kHz the curves have a slope of about 10 dB/octave and--100 dB/octave, respectively. In addition, the basilar membrane has a maximum displacement at a frequency dependent distance from the stapes. A simple hydrodynamic model for the cochlea is used to interpret the experimental data. A possible mechanism for the frequency resolution of sound by the ear and noise-induced hearing loss is discussed.

Acoustic Stimulation↗

PubMedDate not supplied

Vibration measurement of the human tympanic membrane--in vivo.

The vibration patterns of the human eardrum in vivo have been recorded by time average electronic speckle pattern interferometry--ESPI. The necessary stability was achieved by shortening the exposure time of each TV frame. The amplitude--and phasedistribution was mapped across the drum by phase-modulation techniques which also could show the vibrations in slow motion. By photoelectric detection of the TV image intensity, amplitudes down to 2 nm could be measured. Preliminary results are presented.

Holography↗