Development of spirally coiling, force-sensing soft-robot for safe and accurate cochlear electrode implantation

Iowa State University, Ames IA

Investigators

Abstract

Cochlear implant (CI) is fast becoming the main rehabilitation aid for those who suffer from hair cell-related hearing impairments. The nation's current demography suggests that the CI adoption will increase at an accelerated pace for the foreseeable future, calling for more innovations in the CI technology. Of particular urgency is the need for safe and accurate schemes for CI electrode array insertion which is very challenging due to its stringent requirements on insertion depth, electrode-to-wall proximity, and tissue safety. The 3D-spiraling human cochlear anatomy further complicates the task. Many shape-controllable electrodes have been devised to meet the requirements but they still suffer from issues related to limited shape control, slow operation, and potential hazards of electrical actuation. This project focuses on achieving safe and accurate CI electrode insertion through joint utilization of pneumatic soft-robotic micro-tentacles and optical force sensors monolithically integrated with them. Both of them are made of soft elastomers, which greatly facilitates non-intrusive, safe insertion of the CI electrode. The high-level maneuverability of the bio-inspired micro-tentacle will also widen the scope of achievable motion and improve accuracy of the insertion process. Above all, the fusion of agile shape control and integrated sensing will eventually lead to "adaptive insertion" which has been incessantly pursued in CI. All of these will be achieved via the collaboration of two researchers with very different specialty areas, electrical engineering and structural engineering, which will contribute to the convergence in science and technology. This project also aims to strengthen cross-disciplinary training in academia through co-advising of graduate and undergraduate students in seemingly unrelated, yet highly synergistic topics such as optics, MEMS, structural engineering, and computational mechanics. It includes outreach plans to the underrepresented in based on K12 science and technology demonstrations and extra-curricular activities. This project's ultimate goal of safe and accurate insertion of CI electrode arrays through soft-robotic, sensor-integrated micro-tentacle. Accordingly, the following objectives have been lined up: (1) Development of soft-robotic tentacle capable of performing 3-dimensionally spiraling motion. This task will be carried out as a parallel effort encompassing the microfabrication and testing work by the PI and the computational design, optimization, and analysis by the co-PI. (2) Development of elastomer-based optical force sensors. The key issues of the task include the accomplishment of totally non-intrusive sensing for tissue safety and monolithic, clinically safe integration with the soft-robotic main body. (3) Development of the schemes to fix the shape of the soft-robot upon completion of the insertion process. The key issue is again achieving the goal in a clinically safe fashion. The impact of this unique collaboration will go beyond CI eventually. The importance of micro-robots and soft-robots in rehabilitation and assistive technologies has been in continuous increase in recent years. This project will expedite their fusion and add momentum to the fledgling field of "microscale soft-robotics." The plan to monolithically integrate the shape-control and force-sensing function blocks with the soft-actuator will also contribute to the field of human-friendly robotics which is attracting intense research interests from the robotics community. The resulting additive fabrication and shape-control techniques will enrich the arsenal of additive manufacturing and microscale medical robotics, respectively.