Insights into the mechanical interaction between an active cranial implant and the skull subjected to moderate impact loadings

Alice Siegel (1) , Fabien Sauter , Sébastien Laporte

1 SCLIN - Clinatec - Centre de recherche biomédicale Edmond J.Safra

May it be for cochlear implants now widely used or for innovative active devices, cranial implantation of electronic devices raises new questions about the mechanical interactions between the implant and the skull.The aim of this study was to build a methodology using experimental data and numerical simulations to evaluate the mechanical interactions between the skull and the WIMAGINE® active cranial implant intended for use for tetraplegic patients.A finite element model of the implant housing and a simplified model of the three-layered skull were developed. 2.5 J-hammer impact tests were performed on implant housing and ovine cadaver heads for model calibration. The two models were then combined to analyze the interactions between the skull and the implant and compared again against impact tests.The implant dissipates a certain amount of the impact energy, which could be a parameter to include in implant design in addition to the implant integrity, tending to increase the implant stiffness. The non-implanted as well as the implanted lamb heads demonstrated an overall good resistance to the impact tests, although one skull failure was reported. The models correlated well the experimental data, which are promising results for future implant design optimizations using numerical models of the implant-skull and even implant-head complex.

Domaines: Biomécanique [physics.med-ph]; Mécanique des solides [physics.class-ph]

Alice Siegel, Fabien Sauter, Sébastien Laporte. Insights into the mechanical interaction between an active cranial implant and the skull subjected to moderate impact loadings. Journal of the mechanical behavior of biomedical materials, 2022, 126 (105048), https://doi.org/10.1016/j.jmbbm.2021.105048. ⟨10.1016/j.jmbbm.2021.105048⟩. ⟨cea-03713976⟩