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- A numerical study of fenestral otosclerosisPublication . Areias, B.; Parente, M. P. L.; Gentil, Fernanda; Natal Jorge, R. M.There are three basic types of hearing loss: conductive, sensorineural and mixed. Otosclerosis is a pathology which can originate any of these types of hearing loss. Otosclerosis is a bone dysplasia, present only in the temporal bone, and consists of single or multiple absorption areas followed by healing with bone neoformation. The clinical result of this pathology is a conductive deafness when a stapes footplate fixation occurs at the oval window or a sensorineural deafness when it affects the otic capsule involving the cochlear endosteum. Otosclerosis is categorised into two types, fenestral (stapedial type) and retrofenestral (cochlear type). Cochlear otosclerosis represents a continuation of the fenestral otosclerotic process and rarely occurs without fenestral involvement. The numerical model used in this work was build based on the geometrical information obtained from “The visible ear” project. A cryosectioning procedure was applied to the temporal bone of an 85 years old woman, without hearing pathologies, to obtain anatomical data. Afterwards, the different tissues were hand-segmented and a 3D model was constructed. The aim of this study is to contribute to the understanding of the alterations introduced by the fenestral otosclerosis in the human ear and its consequences on the earing capability, using a numerical analysis. The umbo and stapes displacements with the presence of fenestral otosclerosis were carried out for a stimulation of 80 dB SPL applied on the tympanic membrane. The stimulus was applied at frequencies ranging between 100 and 10 kHz. The main conclusion of this work is that the fenestral otosclerosis affects the motion of the stapes footplate, without changing significantly the umbo response.
- Stress analysis of the tympanic membrane through imagePublication . Garbe, Carolina; Parente, M. P. L.; Martins, Pedro Alexandre Lopes de Sousa; Jorge, Renato Natal; Gentil, Fernanda; Paço, JoãoTo better understand the ear functioning, a biomechanical study of the tympanic ossicular chain of the middle ear was made. This chain consists of the tympanic membrane (which has 3 layers), three ossicles (malleus, incus and stapes), six ligaments, tendons and respective two muscles. The objective of this study was to analyze the stresses of the tympanic membrane through images, allowing a comparison of the different frequencies used. A geometric model of the tympanic membrane and ossicles was built through images of Computerized Axial Tomography (CAT). The discretization of this model was done using the finite element method, based on the ABAQUS software. The mechanical properties were obtained from previous work. The results were compared in the dynamic analysis of the tympanic ossicular chain for a frequency range between 100 Hz and 10 kHz, for a sound pressure level of 105 dB SPL, applied on the tympanic membrane. We can observe differences for each frequency in the tympanic membrane.
- Computational algorithms for the segmentation of the human earPublication . M. Barroso, E.; Ma, Zhen; Tavares, João Manuel R. S.; Gentil, FernandaThe main goal of this project is to identify an efficient segmentation algorithm for each anatomic structure of the ear. Therefore, in this paper, it is presented and analyzed computational algorithms that have been used to segment structures in images, especially of the human ear in Computed Tomography (CT) images.
- The influence of noise on the perceptions of discomfort, stress, and anoyancePublication . Monteiro, R.; Rodrigues, Matilde; Tomé, DavidThe aim of this study was to investigate the effect of different noise conditions on subjects' perceptions of discomfort, stress and annoyance: standard condition (C1), environmental noise without alert sounds (C2) and environmental noise with alert sounds (C3).
- Effects of Noise Frequency on Performance and Well-BeingPublication . Sousa, Jorge; Monteiro, Raquel; Tomé, David; Rodrigues, MatildeThe features of occupational noise, in particular sound pressure levels, the type of noise and its frequency can be related to several physiological and non-physiological effects. However, studies about the influence of occupational noise on non-physiological effects are still scarce. The aim of this study was to investigate effect of intermittent sound patterns with different frequency on subjects’ performance and well-being. Five conditions were simulated and tested through an experimental study: Standard Condition (C0); Industrial noise with alert sounds at 500 Hz (C1); Industrial noise with alert sounds at 1000 Hz (C2); Industrial noise with alert sounds at 2000 Hz (C3); Industrial noise with alert sounds at 3000 Hz (C4). The noise levels were fixed at 45 ± 0.3 dB (A) in C0, and in 68 ± 0.5 dB (A) in the other conditions. The influence of noise on participants’ attention and short-term memory was assessed with the serial recall and response inhibition tests. Discomfort, stress and annoyance were accessed using Visual Analog Scales (VAS). Sixteen undergraduate students were included in this study (8 male; age: M = 22.25 yrs; SD = 0.7 yrs). Higher discomfort, stress and annoyance perceptions were found in condition C4; however, for task performance, no significant differences were found between conditions. This study provided important insights about the influence of different noise frequencies on subject’s performance and well-being. Future research should involve workers and how they react in the field to these conditions.
- Interdisciplinaridade e AudiologiaPublication . Lopes, PaulaAs perturbações da comunicação, em particular da comunicação oral / verbal, são a principal dificuldade sentida por quem tem perda auditiva ou hipoacusia. A audição é um processo fisiológico, que permite ao ser vivo receber e analisar as vibrações das moléculas do meio exterior, numa ampla gama de frequências e intensidades.
- Computational simulation of the vestibular system using a meshless particle methodPublication . Santos, C.F.; Parente, Marco; Belinha, J.; Natal Jorge, R.M.; Gentil, FernandaVestibular rehabilitation is the most used therapy in cases of unbalance diagnosis. The vertigo symptoms are commonly related with inner ear diseases, affecting 20%-30% of the world population (von Brevern & Neuhauser, 2011). Its prevalence is higher in elders. In this work, a three-dimensional model of the semi-circular canal of the vestibular system, containing the fluids that pro-mote body balance, will be used. The Smoothed-Particle Hydrodynamics (SPH) method, a meshless particle method, will be the discrete numerical technique used to simulate the fluid behaviour. In the SPH the discretization is represented by particles with constant mass (G.R. Liu & Liu, 2003). The obtained results allow to understand the behaviour of the vestibular structures during the rehabilitation manoeuvres.
- Trigeminal nerve – interdisciplinarity between the areas of dentistry and audiologyPublication . Gentil, Fernanda; Campos, J.C. Reis; Parente, Marco; Santos, C.F.; Areias, Bruno; Natal Jorge, R.M.The trigeminal nerve is the most important nerve for the sensory and motor innervation of the oral system. A detailed knowledge of the trigeminal nerve is very important in the diagnosis and possible treatment of any type of orofacial or temporomandibular joint pain.
- Facial nerve:a clinical and anatomical reviewPublication . Gentil, Fernanda; Campos, J.C. Reis; Parente, Marco; Santos, C.F.; Areias, Bruno; Jorge, R.M. NatalThe information that pass through the facial nerve allows the expression of our smile, joy or sadness, the “facial expression”. The face is the mark of our individuality. The facial nerve is responsible for innervation of the face muscles, like the previous two-thirds of the tongue and secretion of salivary and tears glands. The aim of this work is to remember the anatomy and physiology of the facial nerve, pathology and possible treatments of facial paralysis.
- Biomechanics of the vestibular system: a numerical simulationPublication . Santos, Carla F.; Belinha, Jorge; Gentil, Fernanda; Parente, Marco; Jorge, Renato M. NatalThe vestibular system is located in the posterior portion of the inner ear. It is a key component to our sense of balance and movement. Any changes in this system can cause effects or symptoms such as dizziness, blurred vision, imbalance, and nausea, which are vertiginous syndrome indicators. Vertigo is reported as one of the most common symptoms in the world. It is considered the third most frequent complaint in medicine, transmitting a sense of inadequacy and insecurity. The aim of this work is to contribute to a better understanding of how the vestibular system works. This knowledge will help in the development of new techniques that will facilitate a more effective rehabilitation. Vestibular rehabilitation consists of a set of exercises, known as maneuvers, which can reduce and even eliminate symptoms of dizziness and imbalance associated with a vestibular disorder. In this work, a three-dimensional computational model of the vestibular system, containing the fluids promoting the body balance, will be presented. The smoothed-particle hydrodynamics (SPH) method will be used to simulate the fluid behavior. The results provide a better comprehension of the biomechanics of the vestibular system, which contribute to recover from any system disorders.