TY - JOUR

T1 - A biomechanical ear model to evaluate middle-ear reconstruction

AU - Mojallal, Hamidreza

AU - Stieve, Martin

AU - Krüger, Ilka

AU - Behrens, Peter

AU - Mueller, Peter P.

AU - Lenarz, Thomas

N1 - Funding information: This paper was supported by the German Research Foundation (Deutsche Forschungsgemeinschaft) as part of Collaborative Research Centre 599, ‘Biomedical Engineering’. The authors wish to thank the German Research Foundation for making this project possible.

PY - 2009/12/18

Y1 - 2009/12/18

N2 - In order to evaluate the efficiency of middle-ear prostheses in near-real conditions, an artificial model was developed that approximately simulates the actual geometrical and biomechanical properties of the ear system (excluding the ossicular chain). The sound transmission characteristics of selected commercial middle-ear prostheses and of a synthetic test material were measured using laser Doppler vibrometry (LDV) in this model. The model's realistic properties enabled clinical tympanometry to be used to control the stiffness. In addition the influences of the implant mass on transmission characteristics were investigated. With an averaged displacement between 10 and 100 nm/Pa up to 2000 Hz, the transmission characteristic of the model was comparable with data obtained from the intact middle ear in temporal bone experiments. From the acoustical point of view, no significant material-specific differences could be found. Increasing the mass of the implants to more than 50 mg results in poorer acoustic transmission. In general, changes to the stiffness involving compliance values greater than 3.5 ml and smaller than 0.2 ml led to poorer acoustic transmission. Sumario Con objeto de evaluar la eficiencia de las prtesis de odo medio en condiciones cercanas a la realidad, se desarroll un modelo artificial que simula de manera aproximada las propiedades geomtricas y biomecnicas reales del sistema auditivo (excluyendo la cadena oscicular). Se midieron las caractersticas de transmisin del sonido de prtesis comerciales seleccionadas de odo medio y de un material de prueba sinttico, usando vibrometra laser Doppler (LDV) en este modelo. Las propiedades realistas del modelo permiti-eron el uso de la timpanometra clnica para controlar la rigi-dez. Adems, se investigaron las influencias de la masa del implante en las caractersticas de transmisin. Con un despla-zamiento promedio entre 10 y 100 nm/Pa, hasta 2000 Hz, la caracterstica de transmisin del modelo fue comparable con los datos obtenidos de un odo medio intacto en experimen-tos en hueso temporal. Desde el punto de vista acstico, no se pudieron encontrar diferencias significativas relacionadas especficamente con el material. El incremento de la masa de los implantes a ms de 50 mg, determina un empobrec-imiento de la transmisin acstica. En general, los cambios en la rigidez involucran valores de compliancia mayores a 3.5 ml y menores de 0.2 ml, que llevan a una transmisin acstica ms pobre.

AB - In order to evaluate the efficiency of middle-ear prostheses in near-real conditions, an artificial model was developed that approximately simulates the actual geometrical and biomechanical properties of the ear system (excluding the ossicular chain). The sound transmission characteristics of selected commercial middle-ear prostheses and of a synthetic test material were measured using laser Doppler vibrometry (LDV) in this model. The model's realistic properties enabled clinical tympanometry to be used to control the stiffness. In addition the influences of the implant mass on transmission characteristics were investigated. With an averaged displacement between 10 and 100 nm/Pa up to 2000 Hz, the transmission characteristic of the model was comparable with data obtained from the intact middle ear in temporal bone experiments. From the acoustical point of view, no significant material-specific differences could be found. Increasing the mass of the implants to more than 50 mg results in poorer acoustic transmission. In general, changes to the stiffness involving compliance values greater than 3.5 ml and smaller than 0.2 ml led to poorer acoustic transmission. Sumario Con objeto de evaluar la eficiencia de las prtesis de odo medio en condiciones cercanas a la realidad, se desarroll un modelo artificial que simula de manera aproximada las propiedades geomtricas y biomecnicas reales del sistema auditivo (excluyendo la cadena oscicular). Se midieron las caractersticas de transmisin del sonido de prtesis comerciales seleccionadas de odo medio y de un material de prueba sinttico, usando vibrometra laser Doppler (LDV) en este modelo. Las propiedades realistas del modelo permiti-eron el uso de la timpanometra clnica para controlar la rigi-dez. Adems, se investigaron las influencias de la masa del implante en las caractersticas de transmisin. Con un despla-zamiento promedio entre 10 y 100 nm/Pa, hasta 2000 Hz, la caracterstica de transmisin del modelo fue comparable con los datos obtenidos de un odo medio intacto en experimen-tos en hueso temporal. Desde el punto de vista acstico, no se pudieron encontrar diferencias significativas relacionadas especficamente con el material. El incremento de la masa de los implantes a ms de 50 mg, determina un empobrec-imiento de la transmisin acstica. En general, los cambios en la rigidez involucran valores de compliancia mayores a 3.5 ml y menores de 0.2 ml, que llevan a una transmisin acstica ms pobre.

KW - Air-bone gap

KW - Characteristics

KW - Laser Doppler vibrometry

KW - Mechanical ear model

KW - Middle-ear

KW - Middle-ear prosthesis

KW - Reconstruction

KW - Sound transmission

KW - Static compliance

KW - Tympanometry

UR - http://www.scopus.com/inward/record.url?scp=73649124968&partnerID=8YFLogxK

U2 - 10.3109/14992020903085735

DO - 10.3109/14992020903085735

M3 - Article

C2 - 20017684

AN - SCOPUS:73649124968

VL - 48

SP - 876

EP - 884

JO - International journal of audiology

JF - International journal of audiology

SN - 1499-2027

IS - 12

ER -