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Liangyu Tao and Vineet Tiruvadi present at CNS 2017

Liangyu Tao (undergrad BME major) and Vineet Tiruvadi (BME MD/PhD student) will present at the CNS-2017 meeting in Antwerp, Belgium.  Rehman is also BME undergrad alum from the lab (now a PhD student at Stanford). Their paper info is below.

Modeling dynamic oscillations: A method of inferring neural behavior through mean field network models
Authors: Tao Liangyu, Vineet Tiruvadi, Rehman Ali, Helen Mayberg, Rob Butera

Vineet Tiruvadi receives Whitaker Scholar award!

Congratulations Vineet!  This Whitaker Scholars award will fund postdoctoral work in France after Vineet completes his PhD.

 

Yogi Patel defends PhD!

Yogi Patel defended his PhD on April 14, 2017.  Congratulations Yogi!

His PhD is titled Optimization and Application of Kilohertz Electrical Stimulation to Autonomic Neural Circuits

Advisor: Robert J. Butera, Ph.D. (Georgia Institute of Technology, School of ECE and Dept. of BME)

Thesis Committee:

  • Laura O’Farrell, DVM, Ph.D. (Georgia Institute of Technology, GTRC)
  • Arthur English, Ph.D. (Emory University, Dept. of Cell Biology)
  • Chris Rozell, Ph.D. (Georgia Institute of Technology, School of ECE)
  • Thomas Burkholder, Ph.D. (Georgia Institute of Technology, School of Biological Sciences)

Abstract

More than half a century after the first implantation of a cardiac pacemaker (1958), there is a renewed interest in the ability to electrically stimulate biological tissues, specifically peripheral nerves, to relieve clinical conditions. In their most common form, these implanted devices deliver brief bursts of electrical pulses at various frequencies (< 130 Hz) to peripheral nerves, the spinal cord, or the brain to activate nearby excitable tissues. By doing so, these therapies treat symptoms related to disorders such as epilepsy, depression, and obesity. In stark contrast to this burst of neural activation induced by low frequency stimulation is the ability to completely inhibit neural activity using continuous, kilohertz frequency electrical stimulation. When applied to peripheral nerves, kilohertz electrical stimulation creates a localized block of peripheral nerve activity, thus inhibiting propagation of activity between neural elements (e.g., ganglia, spinal circuits, the brain) and end-targets (e.g., organs, muscles).

Although implemented in a handful of clinical devices, a significant number of parameters remain to be investigated for achieving a safe and effective nerve block using kilohertz electrical stimulation. Furthermore, the application of kilohertz electrical stimulation to block propagating activity in autonomic neural circuits, specifically as it relates to maintaining homeostasis, remains an uncharted territory. The goal of this thesis was thus two-fold – i) optimize kilohertz electrical stimulation parameters for safe and effective clinical implementation and ii) investigate the utility of kilohertz electrical stimulation nerve block in autonomic neural circuits involved in homeostatic regulation.

In the first part, I briefly discuss optimized electrode geometries that increase the battery life of implanted devices, as well as the electrochemical behavior of electrodes at kilohertz frequencies. In the second part, I discuss application of kilohertz electrical stimulation nerve block to autonomic neural circuits involved in regulation of systemic inflammation and glycemia. I demonstrate the therapeutic benefits of inhibiting nerve activity in each physiological circuit and discuss potential mechanisms underlying the observed therapeutic benefits.

Liangyu Tao presents poster at Minnesota Neuromodulation Symposium

Lianyu Tao, an undergraduate BME major, presented the following poster at the Minnesota Neuromodulation Symposium Apr 13-14.  This work is in collaboration with Helen Mayberg at Emory University, and also involves Rehman Ali (now a PhD student at Stanford, formerly a GT BME undergrad), and Vineet Tiruvadi (an MD/PhD student in Biomedical Engineering at Georgia Tech and Emory University).

Modeling Dynamic Oscillations in Deep Brain Stimulation of the Subcallosal Cingulate
Liangyu Tao1, Vineet Tiruvadi1,2, Rehman Ali3, Helen Mayberg2, Robert Butera1
1. Georgia Institute of Technology, USA; 2. Emory University, USA; 3. Stanford University, USA

new publication – IEEE Transactions on Neural Systems and Rehabilitation Engineering

Our lab’s paper below was recently accepted.  You can read a copy online here.

Y. A. Patel, B. S. Kim, W. S. Rountree, and R. J. Butera. “Kilohertz Electrical Stimulation Nerve Conduction Block: Effects of Electrode Surface Area.” (2017) IEEE Transactions on Neural Systems and Rehabilitation Engineering.  Accepted February, 2017.

Abstract

Kilohertz electrical stimulation (KES) induces repeatable and reversible conduction block of nerve activity and is a potential therapeutic option for various diseases and disorders resulting from pathological or undesired neurological activity. However successful translation of KES nerve block to clinical applications is stymied by many unknowns such as the relevance of the onset response, acceptable levels of waveform contamination, and optimal electrode characteristics. We investigated the role of electrode geometric surface area on the KES nerve block threshold using 20 and 40 kHz current-controlled sinusoidal KES. Electrodes were electrochemically characterized and used to characterize typical KES waveforms and electrode charge characteristics. KES nerve block amplitudes, onset duration, and recovery of normal conduction after delivery of KES were evaluated along with power requirements for effective KES nerve block. Results from this investigation demonstrate that increasing electrode geometric surface area provides for a more power efficient KES nerve block. Reductions in block threshold by increased electrode surface area were found to be KES frequency dependent, with block thresholds and average power consumption reduced by >2x with 20 kHz KES waveforms and >3x for 40 kHz KES waveforms.