A mass-spring model of the auditory system in otosclerosis

Abstract

Introduction: This paper aims to describe a model to simulate otosclerosis using a mass-spring model and to correlate the results with the clinical and audiological data on the disease. Methods: A mass-spring model was used to represent the behavior of the auditory system simulating otosclerosis. The model consisted of six masses (air volume in the external auditory canal; tympanic membrane; malleus; incus; stapes, and cochlear fl uid), springs and dashpots simulating the supporting ligaments and muscles. The parameters to simulate the disease were obtained from the literature; stapedial annular ligament stiffness was increased by 10-fold and to 100-fold and stapes mass increased by 5-fold. Results: There was a decrease in stapes displacement in the lower frequencies when the stiffness of the stapedial annular ligament was increased. It was also found a reduction in stapes displacement in the higher frequencies with increased stapes mass. Conclusions: The increased stiffness of the stapedial annular ligament can be an indication of early stage disease, whereas increased bone growth suggests disease progression. The results of the simulation are in agreement with the clinical and audiological disease and support the need for further study of the stapedial annular ligament to fi nd ways to evaluate its functioning and thus enable early detection of hearing losses caused by changes in that structure.

Anatomical and morphometric study of goat middle ear ossicles (Capra aegagrus hircus)

“…The goat malleus was lighter than the human malleus (22.40 to 30.42mg;Sim et al, 2007;Costa, 2008;Gan et al, 2010;Fragoso et al, 2014) and similar or heavier than the sheep malleus (13.4mg; Péus et al, 2020), whereas its length was similar to the human ossicle (8.11mm; Gan et al, 2007;Dai et al, 2007;Gan et al, 2010) and longer than in sheep (7.88±0.51; Péus et al, 2020). The goat incus was lighter than the human incus (24.2 to 32.0+5.9mg; Gan et al, 2007;Sim et al, 2007;Costa, 2008;Dai et al, 2007;Gan et al, 2010) and heavier than the sheep incus (7.73 mg; Péus et al, 2020), whereas its length was smaller than in humans (6.3 to 6.64 mm; Sim et al, 2007;Costa, 2008;Dai et al, 2007;Gan et al, 2010) Gan et al, 2007;Sim et al, 2007;Dai et al, 2007;Gan et al, 2010) and sheep stapes (1.75mg; Péus et al, 2020), whereas the length was similar to the human ossicle (2.4 to 3.4mm; Gan et al, 2007;Dai et al, 2007;Gan et al, 2010) and longer than in sheep (2.03±0.12mm; Péus et al, 2020).…”

“…In the middle ear, the malleus, incus, and stapes ossicles form a mobile chain limited by the tympanic membrane and the oval window (Fragoso et al, 2014), its main purpose being the transmission of sound vibrations to the liquid medium of the inner ear and entrance protection from excessive sound vibrations (Zemlin, 2005). Conductive hearing loss occurs due to outer and middle ear problems that prevent sounds from reaching the inner ear and may be caused by the presence of fluid in the middle ear (otitis media) or damaged (Thomeer et al, 2012) or malformed ossicles (Bartel-Friedrich and Wulke, 2007;Esteves et al, 2014).…”

Effects of a particle placed on the ossicles for microphoneless cochlear implant design

“…Besides, various studies have been done by using this model with its given parameters and very successful results have been obtained. For example, in the study by Fragoso et al, 15 arthritis of the ear ossicles could be examined very close to reality by changing some of the parameters in this model. Therefore, Feng and Gan’s model of the ear 14 is chosen which is quite practical and instrumental in obtaining accurate, reliable, and realistic results.…”