The development of a whole-head human finite-element model for simulation of the transmission of bone-conducted sound

Abstract

A whole head finite element model for simulation of bone conducted (BC) sound transmission was developed. The geometry and structures were identified from cryosectional images of a female human head and eight different components were included in the model: cerebrospinal fluid, brain, three layers of bone, soft tissue, eye, and cartilage. The skull bone was modeled as a sandwich structure with an inner and outer layer of cortical bone and soft spongy bone (diploë) in between. The behavior of the finite element model was validated against experimental data of mechanical point impedance, vibration of the cochlear promontories, and transcranial BC sound transmission. The experimental data were obtained in both cadaver heads and live humans. The simulations showed multiple low-frequency resonances where the first was caused by rotation of the head and the second was close in frequency to average resonances obtained in cadaver heads. At higher frequencies, the simulation results of the impedance were within one standard deviation of the average experimental data. The acceleration response at the cochlear promontory was overall lower for the simulations compared with experiments but the overall tendencies were similar. Even if the current model cannot predict results in a specific individual, it can be used for understanding the characteristic of BC sound transmission in general.

Simulation of the power transmission of bone-conducted sound in a finite-element model of the human head

“…The details of the FE model of the whole human head, hereafter referred to as LiUHead, can be found in Chang et al (2016) and only an overview of the FE model is given here. The geometry of the LiUHead is based on an adult female and the FE model consists of 87,000 nodes and 481,000 tetrahedron elements (each with 4 nodes).…”

“…The excitation is provided at the mastoid skull bone using a triangular prism shaped mass to simulate a screw implanted through the outer layer of the cortical bone and the diploë similar to stimulations with bone anchored hearing aids (BAHA) (Berger 1976;Mudry and Tjellström 2011). The parameter values for the eight domains were obtained from the literature and are provided in Chang et al (2016).…”

“…The head is assumed symmetrical about the midline and the stimulation was only applied on one side of the LiUHead. The head model was setup as a free boundary as in Chang et al (2016).…”

“…Recently, a three-dimensional finite-element (FE) model of the whole human head was developed by Chang et al (2016). The model was reconstructed from the anatomy of an adult female head through the Visible Human Pro-ject© (http://vhnet.nlm.nih.gov/).…”

Additively manufactured porous metallic biomaterials

“…Moreover, more thorough characterization of the human tissues is required to better understand the exact properties that need to be replicated by the designer biomaterials. The natural discipline to use for this purpose is biomechanics where the properties of human tissues are studied using computational [262][263][264][265][266] and experimental [267][268][269][270][271] techniques and the musculoskeletal loads are estimated using musculoskeletal models [272][273][274][275] and massspring-damper models [276][277][278][279] of the human body.…”