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In this first article of four the problem is displayed using experiments on humans for two kinds of gravity related positions. In each case the nystagmus depends sinusoidally on a particular orientation of the canal to the vertical. In each case, too, a dissymmetry of the response occurs. This kind of behavior confirms that the caloric stimulation induces(More)
In order to explain the mechanical effects that arise when a semi-circular canal is thermally stimulated in the horizontal position (i.e. in the absence of gravity effects) a physical model was used. The duct (corresponding to the canal) is deformable, the pressure transducer (corresponding to the ampulla) is not deformable. There is no thermal similarity(More)
The properties of the membranous wall of the semi-circular canal and of the labyrinthine fluids give as a result the inflating pressure of this inflatable structure. The difference of osmotic pressure between perilymph and endolymph, which is involved in this problem, depends on temperature. Therefore, a caloric stimulation leads to a change in the(More)
Caloric stimulation acts on the bio-accelerometer (the semi-circular canal), as on engineered ones, through second order type multiple pathways. Three temperature induced peripheral actions have been described in our previous reports. The hydrostatic mechanism induces in the endolymph a gravity dependent transcupular stationary pressure difference. The(More)
Pseudorandom binary rotatory stimulation is used to study the vestibulo-ocular reflex (VeOR) frequency response (from 0.01 to 0.64 Hz). Fifty-two normal subjects volunteered for this test. The transfer function's gain and phase, and the corresponding coherence function between slow phase eye velocity and head velocity were computed. According to the(More)
A software using a finite element method is used to study the deformation of a bidimensional model of the human cupular diaphragm and the distribution of angular shearing of the hairs of the sensory cells located on the crista ampularis. This study shows that the hairs on the top of the crista are more sensitive to the pressure difference across the cupula(More)
OBJECTIVE The authors present a case of recovery of saccular function after vestibular rehabilitation. MATERIAL AND METHOD Vestibular rehabilitation is proposed to a patient presenting a left lateral body deviation as well as postural disorders at the time of the vertical movements and in car, associated with an unilateral abolition of vestibular evoked(More)
We sought to determine whether the rotatory impulsional test was capable of exploring the canalar function with sufficient precision to replace the caloric test, as it has been recently affirmed. We first compared the observed preponderance from this test with that measured during a sinusoidal (20 and 4 s) test. We observed that, in the case of a(More)
Barany's classical hydrodynamic theory has been called into question by the zero-gravity Spacelab experiments, and several new hypotheses are put forth to explain the vestibular response to caloric stimulation. We have developed a mathematic model based on the analysis of an experimental model of the semicircular canal, incorporating observations done with(More)