This Small Business Innovation Research (SBIR) Phase I project is to develop a hidden and noninvasive assistive device that can provide in-situ sensory feedback of head movement for patients with vestibular imbalance. Loss of vestibular feedback in the sensorimotor control loop of the human body causes imbalance, which significantly increases the risk of falling, one of the leading causes of death in the elderly population. Patients with vestibular imbalance have reduced activity levels, which result in secondary problems including loss of muscle tone, decreased body strength, fatigue, and headache, leading to a significantly impaired life. The proposed device provides alternative sensory feedback to the palatal surface, a site that has been shown to possess high tactile sensitivity, but has not been explored for vestibular substitution. The objectives for Phase I of the project include: 1) development of a compact and energy-efficient electronic system that leads to a wearable battery-powered balance device; 2) development of methods for optimal electrotactile representation of the direction and range of head inclination and motion; and 3) preliminary evaluation of the wearable prototype for alternative sensory feedback and balance assistance in human subject experiments. The Phase I project is anticipated to demonstrate the enabling palate-based technology for cost-effective implementation of the device with desired dimensions and functionality, and the usefulness of the device for balance control.
The broader impact/commercial potential of this project is the improvement of balance in patients with vestibular disorders, which are prevalent worldwide due to aging, disease, ototoxicity, and surgery that cause degradation or damage of the vestibular apparatus. Data showed that in US alone several millions of American adults reported problem with balance. Currently no practical devices are available to provide in-situ sensory feedback of head movement for patients with vestibular loss. The proposed device captures this great market opportunity with its unique feature of being hidden and noninvasive while assisting vestibular patients in maintaining balance in various indoor and outdoor activities such as walking in a park, street, or shopping mall. It helps them to regain confidence in public settings, and increases their social participation, which will bring enormous benefits to their health and make their daily living more enjoyable. In addition, the device offers fresh opportunities for health professionals in the field of vestibular rehabilitation to conduct research on motion, imbalance, and treatments in uncontrolled settings. It provides a new tool for neuroscience researchers to study mechanisms of brain plasticity and perceptual learning involving use of palatal feedback in the sensorimotor control loop.
The vestibular apparatus inside our inner ears provides important feedback information about head motion that the brain uses in coordination with vision and other body senses to maintain balance of the entire body. Patients with vestibular disorders suffer from Imbalance and dizziness as a result of vestibular loss, which can have serious disabling effects far worse than what we as normal individuals might imagine. Despite of the long-felt need, no practical devices are currently available for vestibular patients to use discretely for balance assistance in various indoor and outdoor activities. In phase I of the project, Innervo Technology LLC developed and demonstrated the first generation of a new type of balance device, hidden and noninvasive, capable of providing alternative sensory feedback of head motion through stimulation on the palatal surface. Technological development in phase I has resulted in stand-alone prototypes that can be entirely worn within the oral cavity, fully operational without using any wired connection to external units outside of the mouth. The alternative sensory feedback from the device can be used to indicate the direction as well as the range of head motion. Experimental prototypes based on mouth impressions were demonstrated on vestibular patients and utilized in preliminary evaluation of alternative sensory feedback for balance control. The preliminary trials on vestibular patients in balance clinics indicated that better alignment of the center of gravity could be achieved by wearing the device, and feedback in a certain direction could provide important confirmation that may prevent body from drifting out of balance in that direction. The alternative sensory feedback also showed positive effects on balancing control strategies. In conclusion, Phase I of the project demonstrated feasibility of hidden and noninvasive balance devices for vestibular substitution and the use of palatal stimulation for alternative sensory feedback of head movement. In addition, the Phase I experimental device enabled study of the role of multisensory integration in balance. Furthermore, development of core technology in Phase I paved the way for future development of market-oriented balance devices that can potentially benefit a large number of patients with vestibular imbalance around the world.