1. Title of the Publication A computational model for multiobjective optimization of multipolar stimulation in cochlear implants: An enhanced focusing approach ----------------------------------------------------------------------------------------------------------------------- 2. Author Information Marcos Hernández-Gil 1 - marcosjavier.hernandez@ulpgc.es Ángel Ramos-de-Miguel 1,2 - angel.ramos@ulpgc.es David Greiner 1 - david.greiner@ulpgc.es Domingo Benítez 1 - domingo.benitez@ulpgc.es Ángel Ramos-Macías 1,2 - angelmanuel.ramos@ulpgc.es José María Escobar 1 - josem.escobar@ulpgc.es 1. Institute of Intelligent Systems and Numerical Applications in Engineering (SIANI), Universidad de Las Palmas de Gran Canaria (ULPGC), Campus Universitario de Tafira Baja, Las Palmas de Gran Canaria, 35017, Las Palmas, Spain 2. Department of Otolaryngology, Complejo Hospitalario Universitario Insular Materno Infantil de Gran Canaria, Las Palmas de Gran Canaria, 35002, Las Palmas, Spain ----------------------------------------------------------------------------------------------------------------------- 3. Corresponding Author David Greiner david.greiner@ulpgc.es ----------------------------------------------------------------------------------------------------------------------- 4. Paper Abstract Multipolar stimulation has been demonstrated to improve auditory perception in individuals with cochlear implants by generating more focused electric fields through simultaneous activation of multiple electrodes. In this study, we propose a novel approach to multipolar stimulation that aims to achieve the narrowest possible pattern of current densities at target neurons. Our goal is to find the optimal profile of currents delivered by the electrodes that maximizes the focusing for a specific power consumption, or alternatively, which minimizes the power for a given focusing. To this end, we have designed two objective functions which are optimized through multiobjective evolutionary algorithms. These objective functions are evaluated using a patient-specific finite element volume conduction model that replicates the cochlear geometry and electrical behavior of the implant. Experimental results demonstrate that this approach achieves tighter current density focusing compared to phased-array stimulation, albeit with higher power consumption. Additionally, it is possible to reach non-dominated solutions that simultaneously improve the focusing and power consumption of both monopolar and phased-array stimulation. ----------------------------------------------------------------------------------------------------------------------- 5. Criteria that the author claims that the work satisfies (A) The result was patented as an invention in the past, is an improvement over a patented invention, or would qualify today as a patentable new invention. (B) The result is equal to or better than a result that was accepted as a new scientific result at the time when it was published in a peer-reviewed scientific journal. (D) The result is publishable in its own right as a new scientific result independent of the fact that the result was mechanically created. (F) The result is equal to or better than a result that was considered an achievement in its field at the time it was first discovered. ----------------------------------------------------------------------------------------------------------------------- 6. Statement Why the Results Satisfy the Criteria In this work, evolutionary multiobjective optimization was employed to discover multipolar current stimulation patterns for cochlear implants [1]. The objective functions were to maximize focusing and minimize power consumption, and the attained non-dominated solutions are competitive with the human-designed patterns currently used in practice. The non-dominated set of solutions, each consisting of a set of weights defining multipolar current pattern associated with each electrode of the cochlear implant, improves the state-of-the-art solutions of monopolar and multipolar/phased-array solutions [5], in both objective function values (B)(F). A salient feature of our proposal is the calculation of the optimal multipolar pattern in the region of interest (cochlear nerve), a feature that distinguishes our approach from that of [5]. Furthermore, solutions with a superior value for the focusing objective function were obtained (D). The maximum focusing solution enhances a stimulation pattern that has been outlined in a recent patent application [2]. The methodology and non-dominated results applied to cochlear implants would qualify as a patentable new invention that improves state-of-the-art designs (see, for example, Figure 6 in pattent application [4]), and have been submitted as a patent application, currently under evaluation [3] (A). [1] A. Ramos-Macías, M. Manrique (2024) 17th International Conference on Cochlear Implants and other Implantable Technologies, Las Palmas de Gran Canaria, Spain. (https://ci2024spain.com/) [2] Croghan, N., Krishnamoorthi, H., & Smith, Z. (2023) Multiple sound source encoding in hearing prostheses. (US2023082528A1), URL https://worldwide.espacenet.com/patent/search/family/070463566/publication/US2023082528A1?q=pn% 3DUS2023082528A1. [3] Hernández-Gil, M., Ramos-de-Miguel, Á., Greiner, D., Benítez D., Escobar, J.M. (2024) "Method and System for Optimizing Multipolar Stimulation in Nerve Stimulation Protheses", Application Number 24382066-EP/9, January 2024. Under Review. [4] Potts W., Duran S., Smith Z. (2024) "Focusing methods for a Prosthesis", US2024073634A1, https://worldwide.espacenet.com/patent/search/family/070732122/publication/US2024073634A1?q=pn%3DUS2024073634A1 [5] Van den Honert, C., Kelsall, D. (2007) "Focused intracochlear electric stimulation with phased array channels", The Journal of the Acoustical Society of America, Vol. 121, 3703-3716. https://doi.org/10.1121/1.2722047 ----------------------------------------------------------------------------------------------------------------------- 7. Full Citation This is an open access article under the CC BY-NC-ND license, available online since 8 april 2025: Author Names: Marcos Hernández-Gil, Ángel Ramos-de-Miguel, David Greiner, Domingo Benítez, Ángel Ramos-Macías, José M. Escobar, Title: A computational model for multiobjective optimization of multipolar stimulation in cochlear implants: An enhanced focusing approach, Journal: Expert Systems with Applications, Volume: 280, Year: 2025, Article Number: 127472, ISSN: 0957-4174, Publisher name: Elsevier, DOI: https://doi.org/10.1016/j.eswa.2025.127472 ----------------------------------------------------------------------------------------------------------------------- 8. Prize Money Breakdown Any prize money, if any, is to be divided equally among the co-authors (as also agreed in the patent application). ----------------------------------------------------------------------------------------------------------------------- 9. A Statement Indicating Why this Entry Could Be the "Best" Our computational model for multiobjective optimization of multipolar stimulation in cochlear implants (CI), generates non-dominated solutions that improve both in focusing and power consumption those used in practice in CI: monopolar and multipolar (phased-array) patterns; even enhanced focusing solutions are belonging to the non-dominated front. Our approach has been peer-reviewed and published in "Expert Systems with Applications" journal, attesting to its scientific validity and potential for widespread adoption in the cochlear implant community. Our study introduces a novel multiobjective optimization framework for multipolar stimulation in CI, addressing the critical trade-off between maximizing current density focusing and minimizing power consumption. By employing patient-specific finite element models (FEMs), our approach accurately replicates the cochlear geometry and electrical properties, ensuring simulations that align closely with clinical data. Furthermore, the integration of advanced optimization techniques, such as NSGA-II and a memetic algorithm (DE+BFGS), enables the generation of extended non-dominated solutions that outperform traditional strategies like monopolar and phased-array stimulation. The resulting stimulation patterns achieve enhanced spatial selectivity and reduced current spread, directly improving auditory performance while taking into account practical energy constraints. These contributions demonstrate the clinical relevance and potential impact of our methodology on optimizing CI functionality. We believe that the advantages of our work and its broad applicability make it the best entry for the Humies. ----------------------------------------------------------------------------------------------------------------------- 10. Evolutionary Computation Type Differential Evolution (DE), Memetic Algorithm (DE + L-BFGS-B) combined with Non-dominated Sorting Genetic Algorithm (NSGA-II) ----------------------------------------------------------------------------------------------------------------------- 11. Publication Date April 8, 2025