1. Using the Tongue for Balance Gabriel Ausfresser University of Rhode Island BME 482

2. Overview Introduction – Requirements for maintaining balance – Replacing a lost sense with another Using Tongue-based Biofeedback – How it works – Why the tongue? Research Experiment – Hypothesis – Methods – Results Conclusions References

3. Introduction What sensory systems are required for balance? – Vision – Vestibular – Somatosensory

4. Introduction (cont.) Replacing one sensory system with another – Replacing a dysfunctional sense with a functioning one Types of substitutions – Tactile-Visual – Tactile-Auditory – Tactile-Vestibular – Tactile-Tactile

5. Tongue-based Biofeedback What is Tongue-based Biofeedback? – Biofeedback: using the information from the user’s own body to provide feedback to user – Using tactile sensory information from tongue to communicate with CNS Matrix of electrodes Normal: – Sensory information from vision  CNS  person adjusts body position to balance With tongue and no vision: – Sensory information (accelerometer)  device  impulse generator  tongue tactile senses  CNS  person adjusts body position to balance

6. Why the Tongue? Saliva = good electrolytic environment – Good electrode conduction Closeable mouth = protection for electrodes Tongue requires only 3% of the voltage for stimulation than a finger

7. Research Experiment 2007 - Vuillerme, N., et al. Hypothesis – Using the tongue to relay sensory information to the CNS can successfully replace one of the senses needed for good balance

8. Research Experiment (cont.) Methods – 10 healthy adults – Stand completely still with eyes opened – Measured a baseline center of foot pressure using pressure sensor insoles in shoes – Found standard deviation called “dead zones” – Stand completely still with eyes closed – Measured the subjects center of foot pressure

9. Methods (cont.) Two trials – One with tongue sensory relay When the subject’s center of foot pressure was outside the dead zone, the electrodes stimulated tongue sensors Electrode stimulation was done in the part of the matrix that corresponded with location of center of foot pressure relative to dead zone – One without tongue sensory relay

10. Research Experiment (cont.) Results – Tongue feedback = less fluctuation of center of foot pressure – Tongue feedback = more control of center of foot pressure

11. Conclusion Tongue feedback system can successfully replace the sense of vision regarding balance Future Work – Help maintain balance for person with diabetes – Help provide feedback for amputee

12. References Vuillerme, N., et al. "A plantar-pressure based tongue- placed tactile biofeedback system for balance improvement." Computer Methods in Biomechanics & Biomedical Engineering 10.(2007): 63-64. Academic Search Complete. EBSCO. http://www.newscientist.com/article/dn14058-tongue- display-helps-you-keep-your-balance.html http://en.wikipedia.org/wiki/Sensory_substitution http://www.mortonsfoot.com/badposture.html http://www.mamashealth.com/train/balance.asp http://en.wikipedia.org/wiki/Biofeedback