National Repository of Grey Literature 9 records found  Search took 0.01 seconds. 
Modelování vibračních vlastností lidských hlasivek
Vampola, T. ; Horáček, Jaromír ; Klepáček, I.
A 3D finite element model of the human larynx including the vocal folds was developed. The model enables to take into account phonation position (tinsion and adduction) of the vocal folds by positioning of the arythenoid and thyroid cartilages. Anisotropic properties of the three layers of the vocal fold living tissue (epitel, ligament and muscle) are modelled respecting the material nonlinearities with increasing prolongation of the tissue in longitudinal direction. The motion of the vocal folds is numerically simulated for a prescribed subglottal pressure loading the vocal folds by a periodic function in the time domain. the generated motion of the vocal folds seems to be qualitatively similar to a vibration mode known from clinical measurements.
Výpočtové modelování vztahů mezi časovou změnou glotální plochy a úrovní vyzařovaného zvuku z vibrujících hlasivek
Horáček, Jaromír ; Laukkanen, A. M. ; Šidlof, Petr
The radiated sound pressure level (SPL) during phonation is known to be mainly regulated by lung pressure and glottal resistance (adduction), at the glottal level. Few results of glottal area variation in SPL control have been presented. The present study investigated the interrelations between sound pressure level at the glottis (SPL source) and lung pressure, maximum amplitude of vocal fold vibration and maximum glottal area declinatin rate for different fundamental frequencies and prephonatory glottal widths. These data were generated by an aeroelastic model used for numerical simmulations of vocal fold self-oscillations including the vocal folds collisions. The relations of SPL source to the parameters studied were in general non-linear.
PIV měření proudění kolem samobuzeně kmitajícího modelu hlasivek
Šidlof, Petr ; Doaré, O. ; Cherfa, L. ; Lahcene, Ch. ; Chaigne, A. ; Horáček, Jaromír
A new mechanical model of vocal folds was developed in cooperation with Ecole Nationale Supérieure de Techniques Avancées, Paris. Under specific conditions, the model exhibits flow-induced vibrations, where the vocal folds collide in each cycle. The model was designed to allow dynamic, acoustic and PIV measurements synchronized with the vocal fold oscillations. The results provide interesting information about the vocal fold dynamics and about the nonstationary flow structures, developing downstream the glottis, which closes periodically.
Matematické modelování interakce tekutiny a tělesa v problematice lidských hlasivek
Šidlof, Petr
In the paper numerical results from a mathematical model of human vocal folds are compared with experimental data obtained from measurements on a maquette of vocal folds, which consisted of a silicone element vibrating in a channel conveying air.
Volumetric model of human vocal folds
Vampola, T. ; Horáček, Jaromír
The article describes the vollumetric 3D FE model of real human vocal folds in a defined phonation position. The model was developed from the CT images of the plaster casts obtained by a special procedure during experiments with the excised human larynges, when the phonatioon caused by the airflow was suddenly stopped without changing the position of the fixed larynx. The model is determined for studies of dynamical stresses in the vocal fold tissue during vocal folds collisions.
Předběžné výsledky modelování rázové napjatosti hlasivek s použitím aeroelastického modelu produkce hlasu
Horáček, Jaromír ; Laukkanen, A. M. ; Šidlof, Petr
Voice problems are kown to be common among voice professionals, e.g. teachers. More information is needed on biomechanical forces related to voice production in order to be able to set safety limits for voice use in various professions. Impact stress, defined as the impact force divided by the contact area of the vocal folds, is an important variable in quantifying the mechanical load posed on the vocal fold tissue during voice production.
3-D FE model of the human vocal folds for dynamic computations
Vampola, T. ; Horáček, Jaromír
The article describes the design of a 3D finite element (FE) model of real human vocal folds in a defined phonation position. The model was developed from the CT images of the plaster casts obtained by a special procedure during experiments with the excised human larynges. The model is determined mainly for studies of dynamical stresses in the vocal fold tissue during vocal folds collisions.
Fyziologické údaje získané z aeroelastického modelu kmitání lidských hlasivek
Horáček, Jaromír ; Laukkanen, A. M. ; Šidlof, Petr
The results of the numerical simulations show that the aeroelastic model for vocal fold self-oscillations corresponds well with the existing clinical data and it thus gives the possibility to study independently various phonation related variables that may in living subjects be obscured by the co-existence of many variables. Furthermore, the model of course naturally gives the possibility to study also such variables that are impossible to study in living subjects.

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