BRIGE: Development of an Implantable Biomimetic Angular Rotation Sensor for Overcoming Vestibular Dysfunction

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

BRIGE ECCS-0927103: Development of an Implantable Biomimetic Angular Rotation Sensor for Overcoming Vestibular Dysfunction "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)." This project seeks to develop a small, low power sensor based on the human vestibular sensor for a vestibular prosthesis. The vestibular system establishes a sense of body position, maintains balance, and helps to stabilize vision during movement. Dysfunction in the vestibular system can often lead to debilitating symptoms of postural instability, visual blurring, disorientation and falling. Some patients may benefit through conservative treatment and rehabilitation. But for those who do not, especially those suffering from vestibular dysfunction in both inner ears (bilateral), there is currently no effective alternative. The long-term goal of the work is to provide such individuals with an option-an implantable biosystem that emulates vestibular function-a vestibular prosthesis. By sensing angular head rotation and directly stimulating vestibular nerve fibers located in the inner ear, the prosthesis conveys otherwise absent head rotation cues to the central nervous system. To accomplish this goal, this effort proposes to overcome two of the most significant technical challenges faced when developing a fully implantable system-the large size and excessive power consumption of the angular rotation sensors. Thus, the objectives of this project are (1) based on a biomechanical model of the human semicircular canal, fabricate a micromachined polymeric diaphragm angular rotational sensor, (2) benchmark the sensor with existing sensor technology (gyroscopes), and (3) determine the surgical approach, site of implantation, and histologically assess the tissue response of the sensor to validate its biocompatibility and stability. Intellectual Merits: Failures in the vestibular system are especially pronounced in the elderly where falls related to balance instability are associated with high rates of mortality and morbidity, contributing significantly to today's skyrocketing healthcare costs. Past efforts toward a vestibular prosthesis have relied upon external gyroscopes. Although such an approach is potentially scalable with MEMS technology, power consumption remains a challenge. When considering a three-axis fully implantable system, a revolutionary low-power sensing mechanism is paramount. This research will be the first to assess the efficacy of a passive MEMS-based biomechanical analogue to the natural human sensor and will present a radical approach to low-power inertial sensing Broader Impacts: The proposed biosystem could greatly improve the quality of life for individuals with bilateral vestibular dysfunction. In addition, the proposed sensing mechanism may serve as an external vestibular system for wearable balance prostheses that utilize sensory substitution strategies, such as vibrotactile displays and electrotactile tongue activation. To broaden the participation of underrepresented groups, the PI pursues a strategy for integrating research with outreach, mentoring and teaching to reach students across the K-graduate continuum. For example, at the K-12 level the PI delivers science nights at the Fernbank Science Center Museum in Atlanta, GA, and plans for reaching a large underrepresented population by working with a local middle or high school science teacher to develop lectures and science modules. At the college level, the PI mentors upper-level female students participating in guided research in her lab, and is recruiting undergraduate research students nationally through an NSF-supported REU program.