Medical Engineering Distinguished Seminar Series, Sridevi Sarma
Quantifying neural health before irreversible decline occurs remains one of the central challenges in neuroscience and medicine. Across epilepsy, psychiatric illness, neurodevelopmental disorders, and neurodegeneration, we lack a unifying physiological standard that defines what a "healthy brain" truly is - and how it begins to fail.
In this talk, I will introduce the Neural Health Index (NHI), a physics-grounded biomarker built on two organizing principles of living neural systems: entropy maximization in spatial energy distributions and tight homeostatic regulation of neural activity. In a healthy resting brain, energy is broadly and efficiently distributed across regions, reflecting high entropy, while remaining remarkably stable and tightly controlled.
NHI operationalizes neural health through five measurable energetic properties: lognormal energy distributions, balanced regional allocation, statistical independence between regions, low variance, and temporal stability. I will present results from multimodal EEG, fMRI, and MEG datasets comprising over 800 participants across neurological, psychiatric, neurodevelopmental, and neurodegenerative conditions. NHI not only differentiates healthy and clinical populations, but scales with disease severity, modulates with treatment, and generalizes across diagnostic categories and imaging modalities.
These findings suggest the existence of a disease-agnostic, modality-invariant energetic signature of neural health. By reframing brain function through the lens of energetic organization, BEI provides a quantitative foundation for early detection, patient stratification, and real-time monitoring of therapeutic response.
Biography: Sridevi V. Sarma received her B.S. in Electrical Engineering from Cornell University and her M.S. and Ph.D. in Electrical Engineering and Computer Science from the Massachusetts Institute of Technology (MIT). She completed postdoctoral training in the Department of Brain and Cognitive Sciences at MIT. She is currently a Professor in the Institute for Computational Medicine and the Department of Biomedical Engineering at Johns Hopkins University. Her research focuses on the modeling, estimation, and control of neural systems, with particular emphasis on therapeutic electrical stimulation for neurological disorders, including epilepsy and chronic pain. She has been invited to speak at over 70 venues worldwide. Together with her undergraduate and graduate trainees, Dr. Sarma has authored over 80 journal articles, one book, two book chapters, and more than 90 peer-reviewed conference proceedings. She is an inventor on 11 patents and disclosures and has contributed to one FDA-cleared medical device. Dr. Sarma is the recipient of numerous honors, including the Burroughs Wellcome Fund Career Award at the Scientific Interface, the Krishna Kumar New Investigator Award from the North American Neuromodulation Society, the Presidential Early Career Award for Scientists and Engineers, the NIH Outstanding Investigator Award for her research in epilepsy, election as a Fellow of the American Institute for Medical and Biological Engineering (AIMBE), and the Whiting School of Engineering Robert B. Pond Award for Excellence in Teaching. https://sarmalab.icm.jhu.edu
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