new publication — effects of electrode materials on efficacy of kHz electrical stimulation

Congrtulations to Yogi Patel (recent PhD) and Brian Kim (recent BS BME).  Their recent paper was published in the IEEE Transactions on Neural Systems and Rehabilitation Engineering.  You can read a copy online here.

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

Abstract

Kilohertz electrical stimulation (KES) has enabled a novel new paradigm for spinal cord and peripheral nerve stimulation to treat a variety of neurological diseases. KES can excite or inhibit nerve activity and is used in many clinical devices today. However, the impact of different electrode materials on the efficacy of KES is unknown. We investigated the effect of different electrode materials and their respective charge injection mechanisms on KES nerve block thresholds using 20 and 40 kHz current-controlled sinusoidal KES waveforms. We evaluated the nerve block threshold and the power requirements for achieving an effective KES nerve block. In addition, we evaluated potential effects on the onset duration and recovery of normal conduction after delivery of KES. We found that thresholds and the onset and recovery of KES nerve block are not a function of the electrode material. In contrast, the power dissipation varies among electrode materials and are a function of the materials’ properties at high frequencies. We conclude that materials with a proven track record of chronic stability, both for the tissue and electrode, are suitable for developing KES nerve block therapies.

 

RTXI paper published – congrats Yogi Patel!

Our long term collaboration developing open-source software had the latest iteration of the system published in PLOS Computational Biology.  Yogi Patel is the lead author. This is in collaboration with the labs of Dave Christini at Weill Medical College of Cornell University, Chuck Dorval at University of Utah, and John White at Boston University.

Y. A. Patel, A. George, A. Dorval, J. White, D. Christini, and R. J. Butera. “Hard real-time closed-loop electrophysiology with the Real-Time eXperiment Interface (RTXI).”  (2017) PLOS Computational Biology.  13(5):e1005430. PMC5469488

Paper link here

 

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.