Towards a complete in silico assessment of the outcome of cochlear implantation surgery

Cochlear implantation (CI) surgery is a very successful technique, performed on more than 300,000 people worldwide. However, since the challenge resides in obtaining an accurate surgical planning, computational models are considered to provide such accurate tools. They allow us to plan and simulate beforehand surgical procedures in order to maximally optimize surgery outcomes, and consequently provide valuable information to guide pre-operative decisions. The aim of this work is to develop and validate computational tools to completely assess the patient-specific functional outcome of the CI surgery. A complete automatic framework was developed to create and assess computationally CI models, focusing on the neural response of the auditory nerve fibers (ANF) induced by the electrical stimulation of the implant. The framework was applied to evaluate the effects of ANF degeneration and electrode intra-cochlear position on nerve activation. Results indicate that the intra-cochlear positioning of the electrode has a strong effect on the global performance of the CI. Lateral insertion provides better neural responses in case of peripheral process degeneration, and it is recommended, together with optimized intensity levels, in order to preserve the internal structures. Overall, the developed automatic framework provides an insight into the global performance of the implant in a patient-specific way. This enables to further optimize the functional performance and helps to select the best CI configuration and treatment strategy for a given patient.This work was financially supported by the European Commission (FP7 project number 304857, HEAR-EU), Generalitat de Catalunya (PRODUCTE program, project number 2016PROD00047) and the Spanish Ministry of Economy and Competitiveness under the Maria de Maeztu Units of Excellence Programme (MDM-2015-0502)

Lifestyle, stress and cortisol response: Review II: Lifestyle

To prevent lifestyle related diseases, it is important to modify lifestyle behavior. The control of mental stress level and prevention of mental stress-related diseases have become one of the most important problems in Japan. To check mental stress level objectively during the early stage of stress-related diseases and determine appropriate coping methods, it is necessary to design a useful index for mental stress. Cortisol is a steroid hormone secreted by the adrenal cortex. This is an essential hormone to human survival, and plays a key role in adaptation to stress. In another review, we concluded that cortisol appears to be an adequate index for mental stress