Quasi-static Pressures in the Middle Ear Cleft

Dirckx, Joris J.J.; Marcusohn, Yael; Gaihede, Michael

doi:10.1007/978-1-4614-6591-1_5

Cited by 8 publications

(7 citation statements)

References 114 publications

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“…This observation corroborates with current ideas on an active function of the mucosa where the physiological regulation of the middle ear pressure is determined by the vascular congestion of the mucosa [2]. In clinical otology the overall pressure regulation is of immense importance, and hitherto, the mastoid air cell system has only been attributed a passive role [3].…”

Section: Introductionsupporting

confidence: 89%

Structural analysis of micro-channels in human temporal bone

Cros

Gaihede

Andersson

et al. 2015

2015 IEEE 12th International Symposium on Biomedical Imaging (ISBI)

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Recently, numerous micro-channels have been discovered in the human temporal bone by micro-CT-scanning. Preliminary structure of these channels has suggested they contain a new separate blood supply for the mucosa of the mastoid air cells, which may have important functional implications. This paper proposes a structural analysis of the microchannels to corroborate this role. A local structure tensor is first estimated. The eigenvalues obtained from the estimated local structure tensor were then used to build probability maps representing planar, tubular, and isotropic tensor types. Each tensor type was assigned a respective RGB color and the full structure tensor was rendered along with the original data. Such structural analysis provides new and relevant information about the micro-channels but also their connections to mastoid air cells. Before carrying a future statistical analysis, a more accurate representation of the micro-channels in terms of local structure tensor analysis using adaptive filtering is needed.

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Section: Introductionsupporting

confidence: 89%

Structural analysis of micro-channels in human temporal bone

Cros

Gaihede

Andersson

et al. 2015

2015 IEEE 12th International Symposium on Biomedical Imaging (ISBI)

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“…Also in humans the tubes are normally closed and only occasionally open to pass gas between the ME cavity and the nasal cavity (e.g. [ 34 , 35 ]). In humans, a clinical condition exists in which the Eustachian tubes are permanently open.…”

Section: Discussionmentioning

confidence: 99%

Sound attenuation in the ear of domestic chickens (Gallus gallus domesticus) as a result of beak opening

et al. 2017

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Because the quadrate and the eardrum are connected, the hypothesis was tested that birds attenuate the transmission of sound through their ears by opening the bill, which potentially serves as an additional protective mechanism for self-generated vocalizations. In domestic chickens, it was examined if a difference exists between hens and roosters, given the difference in vocalization capacity between the sexes. To test the hypothesis, vibrations of the columellar footplate were measured ex vivo with laser Doppler vibrometry (LDV) for closed and maximally opened beak conditions, with sounds introduced at the ear canal. The average attenuation was 3.5 dB in roosters and only 0.5 dB in hens. To demonstrate the importance of a putative protective mechanism, audio recordings were performed of a crowing rooster. Sound pressures levels of 133.5 dB were recorded near the ears. The frequency content of the vocalizations was in accordance with the range of highest hearing sensitivity in chickens. The results indicate a small but significant difference in sound attenuation between hens and roosters. However, the amount of attenuation as measured in the experiments on both hens and roosters is small and will provide little effective protection in addition to other mechanisms such as stapedius muscle activity.

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“…However, returning to address the question of "blocked" Eustachian tubes, it is indeed true that subjects with otitis media have pressures in the negative range (as high as -250 daPa; Tideholm [6]). Some studies in which a needle has been used to penetrate the mastoid or the tympanic membrane have confirmed this result [8], although the results are open to interpretation because of problems with leaks around the puncture site. It is difficult to say, without dedicated experiments, the extent of this misdiagnosis, but there are some useful papers that shed light on the issue, and this section looks closer at them.…”

Section: Of 'Blocked' Eustachian Tubesmentioning

confidence: 86%

“…In order to set matters straight, we will need to have a way of measuring actual middle ear pressure separately from the contractile state of the tensor tympani. Invasive measures like penetrating the middle ear space with a needle [8] are far from satisfactory, and our text suggests that careful use of wideband absorbance techniques -selecting frequency ranges which are characteristic of the impedance of the eardrum and of the tensor tympani -may provide a solution. The ranges 0.2-1 kHz and 3-6 kHz may be good starting points.…”

Section: Discussionmentioning

confidence: 99%

The Curious ‘Type C’ Tympanogram: Contraction of the Tensor Tympani Masquerades as Negative Middle Ear Pressure

Bell¹

2021

J Hear Sci

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Negative middle ear pressure presents something of a paradox. The 'Type C' tympanogram, in which the peak of the tympanogram occurs below zero pressure, seems to indicate that the air pressure in the middle ear is actually below atmospheric pressure -that there is a degree of suction -and yet the peak can remain persistently in place even if the subject swallows and opens their Eustachian tube. Negative middle ear pressure can even be measured when a subject has a permanently open (patulous) Eustachian tube, a situation that seems physically impossible. This paper reviews the paradox and concludes that in many cases of "negative middle ear pressure" the actual pressure inside the middle ear is in fact zero, but the tympanometric offset comes about because of the unappreciated action of the tensor tympani: when this muscle contracts, it pulls the eardrum inwards, and this inwards force is registered as negative middle ear pressure during tympanometry. That is, the force exerted by the muscle needs to be countered by a negative pressure in the ear canal in order to bring the eardrum back to its equilibrium position. This interpretation is reinforced by a number of findings in the literature, which are reviewed. A proposal for how tensor tympani effects might be separated from actual middle ear pressure offsets is made.

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Quasi-static Pressures in the Middle Ear Cleft

Cited by 8 publications

References 114 publications

Structural analysis of micro-channels in human temporal bone

Structural analysis of micro-channels in human temporal bone

Sound attenuation in the ear of domestic chickens (Gallus gallus domesticus) as a result of beak opening

The Curious ‘Type C’ Tympanogram: Contraction of the Tensor Tympani Masquerades as Negative Middle Ear Pressure

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