Influence of blood vessel conductivity in cochlear implant stimulation using a finite element head model

It is known that the inclusion of blood vessels in finite element (FE) models can influence the current conduction results. However, there have been no studies exploring the impact of blood vessel conductivity on human head models for cochlear implant (CI) stimulation. The three-dimensional (3D) FE model presented in this paper aims to provide understanding in this regard. The electrical conductivity of blood was varied to determine the sensitivity of the 3D model. The results show that some of the current is exiting the cochlea and taking the jugular vein pathway. When compared to the case with blood vessels being omitted, the current density in the blood increased by 13.1%, 17.2% and 20.7% for low, medium and high electrical conductivity cases considered, respectively. This study suggests that blood vessels cannot be neglected from CI models as the jugular vein can provide a low impedance pathway, through which current can leave the cochlea. It also indicates the importance of using correct tissue property values for performing accurate bioelectric modeling analyses.