Daniel Merfeld, PhD

Falls (i) are common, (ii) directly injure or kill many Americans each year, and (iii) increase exponentially as we age. While many factors contribute to falls, we focus on vestibular degradation because new data show that agerelated increases in vestibular thresholds mediate (“explain”) nearly half of age-related balance declines; related findings have led to estimates that up to 150,000 Americans might die each year due to sub-optimal vestibular function, including sub-clinical age-related vestibular declines. As crucial steps to reduce age-related falls, we propose extensive human testing designed to develop: (a) targeted  vestibular screening tests by quantifying impacts of vestibular declines on age-related balance declines and falls and (b) a potential intervention designed to improve vestibular precision, which could also improve balance and reduce falls.

For both veteran and civilian populations, falls (i) are common, (ii) directly injure or kill many Americans each year, and (iii) are a leading cause of accidental death. While many factors contribute to falls, we focus on vestibular degradation because new data show that higher vestibular thresholds are correlated with failure to complete the vestibular condition of a common quiet-stance balance test, which, in turn, correlates with over a 6-fold increase in self-reported falls. Taken together, these findings have led to estimates that 50,000 Americans might die following falls each year due to sub-optimal vestibular function, including age-related vestibular declines. As a crucial step toward predicting falls related to declines in vestibular function, we propose extensive human testing to directly quantify the correlations between (a) balance, (b) vestibular function, and (c) age using: (1) portable virtual reality balance testing; and (2) vestibular threshold testing.

The goal of this project is to both understand and quantify all of the following basic science elementary subcomponents of a human cybernetic system:
• Dynamic multi-sensory Spatial Orientation 
• Multi-input multi-output Motor Control 
• Impacts of Brain Oxygenation (including vestibular oxygenation)
• Visual-Vestibular Autonomic influences
• Comprehensive closed-loop Modeling 
• Couplings & Adverse Mode signatures 

In addition, we aim to combine these subcomponents into a novel comprehensive model of a cybernetic system that will generalize to machines beyond manned aircraft.

The goal of this research is to develop a new technology for imaging the brain while the subject’s body is in motion. Moving Magnetic Resonance Imaging (mMRI) will enable imaging of the neural activity in the brain while the subject’s body is in motion and will reveal how the brain controls bodily motion, senses while in motion (active vision, vestibular function, etc.), maintains balance, and maintains homeostasis (e.g., cardiovascular regulation) during motion. The technology will likely lead to an improved understanding of brain disorders that are revealed only while the head and/or body are in motion, and will likely shed light on how the brain suffers and recovers from traumatic brain injury.

Title: Towards healthy aging: Quantifying vestibular contributors to age-related changes in balance and fall risk 
Dates: September 30, 2021 to May 31, 2026
Name of agency: NIH/NIA
Role: PI
Award number if applicable: R01AG073113

Title: Evaluating a Portable Virtual-Reality (VR) Balance Test as a Vestibular Assessment Screen
Dates: April 15, 2019 to April 15, 2023
Name of agency: DoD Congressionally Directed Medical Research Program (CDMRP)
Role: PI
Contract number: W81XWH1920003

Title: Identifying Adverse Modes via Human-Machine Cybernetic Modeling
Dates: May 1, 2020 to April 30, 2025
Name of agency: DoD Multidisciplinary University Research Initiative (MURI)
Role: PI

Title: Moving MRI: Imaging a Moving Body with a Moving MRI Magnet
Dates: September 12, 2020 to September 11, 2022
Name of agency: NIH/NIBIB
Role: Co-I

Merfeld DM (1996). Effect of spaceflight on the ability to sense and control roll tilt: Human neurovestibular studies on SLS-2. Journal of Applied Physiology 81:50-57.

Cordo P, Inglis JT, Vershuerer S, Collins J, Merfeld DM, Buckley S, Rosenblum S and Moss F (1996). Stochastic resonance in human muscle spindles, a potential fusimotor mechanism. Nature 383: 769-770.

Merfeld DM, Zupan L, Peterka RJ (1999). Humans use an internal model to estimate gravity and linear acceleration. Nature 398:615:618

Merfeld, DM, S. Park, C. Gianna-Poulin, FO Black, S. Woods, (2005) Vestibular perception and action employ qualitatively different mechanisms: II. VOR and perceptual responses during combined tilt and translation, J Neurophysiology 94:199-205.

Karmali, F, Merfeld DM (2012) A distributed, dynamic, parallel computational model: the role of noise in velocity storage. Journal of neurophysiology, 108(2):390-405.

Valko, Y, Priesol AJ, Lewis R, Merfeld DM (2012) Vestibular labyrinth contributions to human whole-body motion discrimination Journal of Neuroscience 32(39):13537-42.

Lewis RF, Haburcakova C, Gong W, Lee D, Merfeld DM (2013) Electrical stimulation of semicircular canal afferents affects the perception of head orientation. The Journal of Neuroscience 33(22):9530-5. 

Bermúdez Rey, MC, et al. (2016). "Vestibular Perceptual Thresholds Increase above the Age of 40." Frontiers in Neurology 7(162).

King, S., Priesol, AJ, Shmuel, D, Merfeld, DM, Ehtemam, F, Lewis, RF (2019). "Self-motion perception is sensitized in vestibular migraine: pathophysiologic and clinical implications." Scientific reports 9(1): 1-12.

Karmali, F., Haburcakova, C, Gong, W, Della Santina, C, Merfeld, DM, Lewis, RF. (2021). "An implanted vestibular prosthesis improves spatial orientation in animals with severe vestibular damage." Journal of Neuroscience 41(17): 3879-3888.

Wagner, AR, Kobel, MJ, Merfeld, DM (2021). "Impact of Canal-Otolith Integration on Postural Control." Frontiers in Integrative Neuroscience 15(54).

Professor
Department of Otolaryngology – Head & Neck Surgery
The Ohio State University College of Medicine

Affiliate Faculty, Biomedical Engineering
Affiliate Faculty, School of Health and Rehabilitation Sciences
Affiliate Faculty, Speech and Hearing Sciences 
The Ohio State University

1995 Biomedical Engineering Society’s “Whitaker Young Investigator”
2012 Fellow, American Institute for Medical and Biological Engineering (AIMBE)
2012-2018 Member NIH Sensorimotor Integration (SMI) Study Section
2014-2018 Associate Editor, Journal of Neurophysiology
2014 Inaugural “Champion of Vestibular Medicine” by Vestibular Disorders Association