Multiscale Biomechanical Modeling and Measurement of Auditory Injury and Protection Mechanisms
Abstract
A common injury among Service members is permanent hearing loss. While this hearing loss may stem from a number of encounters on and off duty, a primary cause of hearing damage comes from exposure to high-intensity sound or blast waves. A physician can non-invasively examine the eardrum and the middle ear function for hearing loss; however, the mechanisms affecting the inner ear are challenging to quantify in humans, and evidence indicates damage in the inner ear significantly contributes to lasting auditory dysfunction. Researchers have conducted animal studies to explore the mechanisms of hearing loss in the inner ear after blast exposure and how hearing protection devices mitigate the resulting auditory injury. In addition, computational models of the human ear have been developed to predict structural damage caused by blast exposure; however, these models still fall short of a comprehensive predictive tool for predicting auditory injury in the entire ear from the external ear to the inner ear. Our multiscale computational model of the human ear developed in this project has the capability of simulating the real-time response of the entire ear during blast exposure and has this unique advantage over the existing standard models. We conducted preliminary studies to explore the blast-induced damage to the inner ear or cochlea by creating a cochlea model at the micro-scale level including the hair cells, modeling the protective function of hearing protection devices (HPDs), measuring the response of the cochlea during blast exposure with a laser device, and using the animal model of chinchilla and the 3D computational model of the chinchilla to study hearing damage induced by blast exposure. The results from our preliminary studies demonstrate the possibility of creating a comprehensive risk assessment tool for auditory dysfunction after blast exposure that is experimentally validated, and the outcomes provide the rationale for this proposed research. Here we propose to expand our 3D computational model of the human ear to a multiscale model that includes the macroscale parts of the ear (ear canal, middle, and inner ear) and the microscale cells in the inner ear. We also aim to validate the multiscale model with experimental measurements in a human ear and animal model for accurate predictions of the damage in the ear during various types of blast exposures. Studies in the human cadaver ear will utilize lasers and pressure sensors during blast exposure to measure inner ear mechanics for validating the multiscale model. Animal studies will provide validated injury criteria for the chinchilla against repetitive blast exposure for improving the development of HPDs and helmets. With validated computational models of the human and chinchilla, the proposed study will provide a critical link for the translation of animal (e.g., chinchilla) data to the human ear by using the computational models of the chinchilla and human ears to quantify auditory blast injury criteria. It is anticipated that this research’s critical link for translating animal data to humans and bridging the gap between animal and human models will be available to medical, scientific, and hearing protection device researchers soon after completion. With such a comprehensive tool, the DoD can establish new hearing safety standards for future military practice that consider many types of hazardous blasts and high-intensity environmental noise. Furthermore, our multiscale model can better inform healthcare and Veteran Affairs professionals of future treatments for patients exposed to high-intensity noise or blasts.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2024
- Source ID
- HT94252311013
Entities
People
- Rong Gan
Organizations
- United States Army
- University of Oklahoma