Niranjan Khadka presented a poster at the Minnesota Neuromodulation Symposium

Poster Title: Principles of Within Electrode Current Steering(WECS)

KhadkaBiksonWECS

Department of Biomedical Engineering, The City College of New York, CUNY, 160 Convent Ave, New York, 10031, USA

Within Electrode Current Steering (WECS), a novel method, applies to non-invasive electrical stimulation with two or more electrodes to enhance reliability and tolerability during tDCS. The underlying assumption of WECS is steering current within electrodes (to compensate for any non-ideal conditions at the surface), but without altering current distribution in the brain target. This technology leverages our technique for independently isolating electrode impedance and over-potential during multi-channel stimulation. Through an exemplary case example of a realistic electrodes (metal-rivets embedded in an electrolyte (saline or gel)) and head geometry (FEM), we demonstrated how current flow in brain is independent of current steering at the electrode. Three current split cases (even, partially uneven, and fully uneven), keeping total current (1 mA) fixed within the electrodes are tested. At the electrode-assembly interface with the skin, the current density distribution varied only incrementally across conditions (e.g. less than would be expected) with even minor changes in electrode assembly or skin properties. There was no difference in the predicted electric filed at the brain target under all three cases. Thus, with such electrode assembly design, current steering to any functional electrode would not significantly increase current density in the skin; hence, not effecting tolerability.

Date & time: April 17, 2015 11:30-1:00 pm

Venue: University of Minnesota, Twin City, Minnesota

Niranjan Khadka presented a poster at the DMD Conference.

Poster Title: Design of Wireless Intraoperative Pulse Oximeter with Reticulated Pressure Sensitive Head

Link: KhadkaBiksonWiPOX

In order to provide a surgical tool that objectively and reliably measure tissue viability during surgery, we developed and validated a first generation compact handheld device for real time wireless monitoring of SPO2. Through the application of pressure sensor (provide feedback of real-time contact conditions of the device), reticulated shaft (facilitate flat contact with the tissue surface that are less visible), and systemic pulse rate input to signal tissue oxygenation through signal processing, this invention will enable surgeons to make treatment decision and measure the efficacy of the therapeutic interventions in real-time.

Date & time: April 15, 2015 5:30 – 7:00

Venue: McNamara Alumni Center, University of Minnesota, Minneapolis, MN

On the use of meta-analysis in neuromodulatory non-invasive brain stimulation

Brain Stimulation 2015 DOI: 10.1016/j.brs.2015.03.008

Michael A. Nitsche, MD, Marom Bikson, PhD, Sven Bestmann, PhD

Full PDF (in press version): MetaAnalysisinNeuromod105

In humans, non-invasive brain stimulation (NIBS) can modulate cortical excitability and activity. The buoyant use of this technique in basic and applied research requires further characterization of the basic mechanisms to divorce promising applications from those producing more heterogeneous outcomes. Here we outline some criteria and pitfalls for using published results to gain estimates about the effects of NIBS techniques through meta-analysis and related tools.

The Pursuit of DLPFC: Non-neuronavigated Methods to Target the Left Dorsolateral Pre-frontal Cortex With Symmetric Bicephalic Transcranial Direct Current Stimulation (tDCS)

Brain Stimulation 2015  doi: 10.1016/j.brs.2015.01.401

PDF (in press version): Bikson_Seibt_PursuitDLPFC_inpress2015        PubMED link

Ole Seibt, Andre R. Brunoni, Yu Huang, Marom Bikson

Abstract:  The dose of transcranial direct current stimulation (tDCS) is defined by electrode montage and current, while the resulting brain current flow is more complex and varies across individuals. The left dorsolateral pre-frontal cortex (lDLPFC) is a common target in neuropsychology and neuropsychiatry applications, with varied approaches used to experimentally position electrodes on subjects. Objective: To predict brain current flow intensity and distribution using conventional symmetrical bicephalic frontal 1
1 electrode montages to nominally target lDLPFC in forward modeling studies. Methods: Six high-resolution Finite Element Method (FEM) models were created from five subjects of varied head size and an MNI standard. Seven electrode positioning methods, nominally targeting lDLPFC, were investigated on each head model: the EEG 10-10 including F3-F4, F5-F6, F7-8, F9-F10, the Beam F3- System, the 5-5 cm-Rule and the developed OLE-System were evaluated as electrode positioning methods for 5
5 cm2 rectangular sponge-pad electrodes. Results: Each positioning approach resulted in distinct electrode positions on the scalp and variations in brain current flow. Variability was significant, but trends across montages and between subjects were identified. Factors enhancing electric field intensity and relative targeting in lDLPFC include increased inter-electrode distance and proximity to thinner skull structures. Conclusion: Brain current flow can be shaped, but not focused, across frontal cortex by tDCS montages, including intensity at lDLPFC. The OLE-system balances lDLPFC targeting and reduced electric field variability, along with clinical ease-of-use.

Full Press Release link

Antonios Mourdoukoutas, a junior majoring in biomedical engineering in the Grove School of Engineering and Macaulay Honors College at The City College of New York, has been awarded a Goldwater Scholarship for 2015.

Mourdoukoutas, who has a 3.91 GPA, is a member of Professor Marom Bikson’s lab at City College. The Long Island resident helps model methods of noninvasive brain stimulation using electrodes placed on the skin surface to correct neurological disorders or facilitate the recovery of lost motor functions.

Mourdoukoutas is the third Goldwater Scholar from Professor Marom Bikson’s lab.

Kevin T. Jones, Jaclyn A. Stephens, Mahtab Alam, Marom Bikson, Marian E. Berryhill

Published: April 7, 2015

DOI: 10.1371/journal.pone.0121904 FREE ONLINE

Abstract: An increasing concern affecting a growing aging population is working memory (WM) decline. Consequently, there is great interest in improving or stabilizing WM, which drives expanded use of brain training exercises. Such regimens generally result in temporary WM benefits to the trained tasks but minimal transfer of benefit to untrained tasks. Pairing training with neurostimulation may stabilize or improve WM performance by enhancing plasticity and strengthening WM-related cortical networks. We tested this possibility in healthy older adults. Participants received 10 sessions of sham (control) or active (anodal, 1.5 mA) tDCS to the right prefrontal, parietal, or prefrontal/parietal (alternating) cortices. After ten minutes of sham or active tDCS, participants performed verbal and visual WM training tasks. On the first, tenth, and follow-up sessions, participants performed transfer WM tasks including the spatial 2-back, Stroop, and digit span tasks. The results demonstrated that all groups benefited from WM training, as expected. However, at follow-up 1-month after training ended, only the participants in the active tDCS groups maintained significant improvement. Importantly, this pattern was observed for both trained and transfer tasks. These results demonstrate that tDCS-linked WM training can provide long-term benefits in maintaining cognitive training benefits and extending them to untrained tasks.

LINK

Journal of Neurorestoratology 2015:3 73–82

Transcutaneous spinal stimulation as a therapeutic strategy for spinal cord injury: state of the art 

PDF: BiksonFregniSpinalStim2015

Treatments for spinal cord injury (SCI) still have limited effects. Electrical stimu- lation might facilitate plastic changes in affected spinal circuitries that may be beneficial in improving motor function and spasticity or SCI-related neuropathic pain. Based on available animal and clinical evidence, we critically reviewed the physiological basis and therapeutic action of transcutaneous spinal cord stimulation in SCI. We analyzed the literature published on PubMed to date, looking for the role of three main noninvasive stimulation techniques in the recovery process of SCI and focusing mainly on transcutaneous spinal stimulation. This review discusses the main clinical applications, latest advances, and limitations of noninvasive electrical stimulation of the spinal cord. Although most recent research in this topic has focused on transcutaneous spinal direct current stimulation (tsDCS), we also reviewed the technique of transcutaneous electric nerve stimulation (TENS) and neuromuscular electrical stimulation (NMES) as potential methods to modulate spinal cord plasticity. We also developed a finite element method (FEM) model to predict current flow in the spinal cord when using different electrode montages. We identified gaps in our knowledge of noninvasive electrical stimulation in the modulation of spinal neuronal networks in patients with SCI. tsDCS, TENS, and NMES have a positive influence on the promotion of plasticity in SCI. Although there are no random- ized controlled studies of tsDCS in SCI, preliminary evidence is encouraging. FEMs predict that tsDCS electrode montage can be used to shape which spinal segments are modulated and what detailed areas of spinal anatomy can concentrate current density (eg, spinal roots). tsDCS is a technique that can influence conduction along ascending tracts in the spinal cord, so could modulate supraspinal activity. It may also be a promising new approach for a number of neu- ropsychiatric conditions.

Marom Bikson to be Inducted into Medical and Biological Engineering Elite

WASHINGTON, D.C.— The American Institute for Medical and Biological Engineering (AIMBE) has announced the pending induction of Marom Bikson, Ph.D., Professor of Biomedical Engineering, Department of Biomedical Engineering, City College of New York, to its College of Fellows. Dr. Bikson was nominated, reviewed, and elected by peers and members of the College of Fellows For outstanding contributions in the area of neuromodulation and the specific field of transcranial direct current stimulation of the brain.

The College of Fellows is comprised of the top two percent of medical and biological engineers in the country. The most accomplished and distinguished engineering and medical school chairs, research directors, professors, innovators, and successful entrepreneurs, comprise the College of Fellows.

AIMBE Fellows are regularly recognized for their contributions in teaching, research, and innovation. AIMBE Fellows have been awarded the Presidential Medal of Science and the Presidential Medal of Technology and Innovation and many also are members of the National Academy of Engineering, Institute of Medicine, and the National Academy of Sciences.

A formal induction ceremony will be held during AIMBE’s 2015 Annual Meeting at the National Academy of Sciences Great Hall in Washington, DC on March 16, 2015. Dr. Bikson will be inducted along with 150 colleagues who make up the AIMBE College of Fellows Class of 2015. For more information about the AIMBE Annual Meet, please visit www.aimbe.org.

AIMBE’s mission is to recognize excellence in, and advocate for, the fields of medical and biological engineering in order to advance society. Since 1991, AIMBE‘s College of Fellows has lead the way for technological growth and advancement in the fields of medical and biological engineering. Fellows have helped revolutionize medicine and related fields in order to enhance and extend the lives of people all over the world. They have also successfully advocated for public policies that have enabled researchers and business-makers to further the interests of engineers, teachers, scientists, clinical practitioners, and ultimately, patients.

Image. Dr. Marom Bikson with Dr. Gilda Barabino at the AIMBE induction ceremony at the National Academy of Science in Washington DC. Dr. Bikson is a new fellow for 2015.  Dr. Barabino is the CCNY Grove School of Engineering Dean and the rising president of AIMBE.

Khadka N, Rahman A, Sarantos C, Truong DQ, Bikson M
____________________________________
Download: PDF Published in Brain Stimulation DOI 

Abstract:

Background: Monitoring of electrode resistance during tDCS is considered important for tolerability and safety. Conventional resistance measurement methods do not isolate individual electrode resistance and for HD-tDCS devices, cross talk across electrodes makes concurrent resistance monitoring unreliable. Objective: We propose a novel method to monitor individual electrode resistance during tDCS, using a super-position of direct current with a test-signal (low intensity and low frequency sinusoids with electrodeespecific frequencies) and a sentinel electrode (not used for DC).

Methods: We developed and solved lumped-parameter models of tDCS electrodes with or without a sentinel electrode to validate this methodology. Assumptions were tested and parameterized in partic- ipants using forearm stimulation combining tDCS (2 mA) and test-signals (38 and 76 mA pk-pk at 1 Hz, 10 Hz, & 100 Hz) and an in vitro test (creating electrode failure modes). DC and AC component voltages across the electrodes were compared and participants were asked to rate subjective pain.

Results: A sentinel electrode is required to isolate electrode resistance in a two-electrode tDCS system. Cross talk aggravated with electrode proximity and resistance mismatch in multi-electrode resistance tracking could be corrected using proposed approaches. Average voltage and pain scores were not significantly different across test current intensities and frequencies.

Conclusion: Using our developed method, a test signal can predict DC electrode resistance. Since unique test frequencies can be used at each tDCS electrode, specific electrode resistance can be resolved for any number of stimulating channels – a process made still more robust by the use of a sentinel electrode.

J Neurophysiol 113: 1334–1341, 2015.  Full PDF: ReatoLastingEffectsoftDCS2

Lasting modulation of in vitro oscillatory activity with weak direct current stimulation

Davide Reato, Marom Bikson, Lucas C. Parra

Transcranial direct current stimulation (tDCS) is emerging as a versatile tool to affect brain function. While the acute neurophysiological effects of stimulation are well under- stood, little is know about the long-term effects. One hypothesis is that stimulation modulates ongoing neural activity, which then translates into lasting effects via physiological plasticity. Here we used carba- chol-induced gamma oscillations in hippocampal rat slices to establish whether prolonged constant current stimulation has a lasting effect on endogenous neural activity. During 10 min of stimulation, the power and frequency of gamma oscillations, as well as multiunit activity, were modulated in a polarity specific manner. Remarkably, the effects on power and multiunit activity persisted for more than 10 min after stimulation terminated. Using a computational model we propose that altered synaptic efficacy in excitatory and inhibitory pathways could be the source of these lasting effects. Future experimental studies using this novel in vitro preparation may be able to confirm or refute the proposed hypothesis.

March 11, Wed.  3-4:15pm in T-402 at CCNY Steinman Hall

Dr. Amy Kuceyeski: “The (dys)-connectome: quantifying brain network influences in disease and recovery“

How the human brain successfully completes varied and complex tasks is still largely unknown. In the past, brain-behavior relationships were derived from single subject studies wherein a focal lesion was linked to a corresponding impairment in a one-to-one manner. Recently developed neuroimaging methods, however, have allowed an unprecedented investigation of the workings of the human brain in health and disease. Neuroimaging methods are now able to measure the in vivo structural or functional connectivity between different brain regions. Studies of brain networks in health (the connectome) and disease (the dys-connectome) have begun to shed light on the true nature of brain-behavior relationships, which in most cases is many-to-many. This talk will present some recent work on statistical modeling of connectome-behavior relationships in disease as well as some preliminary work in mathematical modeling of network-level brain plasticity in recovery from injury. It is imperative that we understand the brain and its connectome if we aim to restore proper function after disease or injury.

Dr. Amy Kuceyeski is an assistant professor of Mathematics and Neuroscience in the Radiology Department and the Brain and Mind Research Institute at Weill Cornell Medical College.

WILL 2015 BE THE YEAR OUR SMARTPHONES LINK UP TO OUR BRAINS?

Popular Science, Feb 15, 2015, link

“Physics and neurophysiology make tDCS better”

Transcranial direct current stimulation (tDCS) is an emerging therapeutic technique under investigation for a variety of neurological and psychiatric disorders including stroke rehabilitation, addiction recovery, major depressive disorder, neuropathic pain, as well as other indications. There are encouraging results for some conditions, yet the efficacy of tDCS is mixed for others  and even for successful trials there is a need to further improve effectiveness. Moreover, it is unusual that a single approach would be effective and specific in such a diversity of application. This talk introduces the source of specificity and efficacy with tDCS, and outlines approaches to customize and optimize tDCS treatment for specific indications and individuals.  Based on computational modeling of current flow using MRI-derived models and on brain slice neurophysiology, work from the Bikson lab aims to enhance the efficacy and specify of tDCS by using physics (anatomical targeting) and electrophysiology (functional targeting).

Thursday, February 26th Harris Hall, Room 110 12:30-2:00 PM

Lunch will be provided.

Remotely-Supervised Transcranial Direct Current Stimulation (tDCS) for Clinical Trials: Guidelines for Technology and Protocols

Front. Syst. Neurosci. | doi: 10.3389/fnsys.2015.00026

Leigh E. Charvet, Margaret Kasschau, Abhishek Datta, Helena Knotkova,Michael C. Stevens, Angelo Alonzo, Colleen Loo, Kevin R. Krull and Marom Bikson

Free online here

____________________________________

The effect of transcranial direct current stimulation (tDCS) is cumulative. Treatment protocols typically require multiple consecutive sessions spanning weeks or months. However, traveling to clinic for a tDCS session can present an obstacle to subjects and their caregivers. With modified devices and headgear, tDCS treatment can be administered remotely under clinical supervision, potentially enhancing recruitment, throughput, and convenience. Here we propose standards and protocols for clinical trials utilizing remotely-supervised tDCS with the goal of providing safe, reproducible and well-tolerated stimulation therapy outside of the clinic. The recommendations include: 1) training of staff in tDCS treatment and supervision, 2) assessment of the user’s capability to participate in tDCS remotely, 3) ongoing training procedures and materials including assessments of the user and/or caregiver, 4) simple and fail-safe electrode preparation techniques and tDCS headgear, 5) strict dose control for each session, 6) ongoing monitoring to quantify compliance (device preparation, electrode saturation/placement, stimulation protocol), with corresponding corrective steps as required, 7) monitoring for treatment-emergent adverse effects, 8) guidelines for discontinuation of a session and/or study participation including emergency failsafe procedures tailored to the treatment population’s level of need. These guidelines are intended to provide a minimal level of methodological rigor for clinical trials seeking to apply tDCS outside a specialized treatment center. We outline indication-specific applications (Attention Deficit Hyperactivity Disorder, Depression, Multiple Sclerosis, Palliative Care) following these recommendations that support a standardized framework for evaluating the tolerability and reproducibility of remote-supervised tDCS that, once established, will allow for translation of tDCS clinical trials to a greater size and range of patient populations.

Special Neural Engineering speaker:  Thursday 19th at 1PM in Steinman 402.

 Fernando Fernandez 

Modulation of neuronal output by membrane voltage fluctuations

Abstract: The membrane voltage of neurons in vivo is dominated by noisy “background” fluctuations generated by network-based synaptic activity from nearby cells. It has been speculated that membrane voltage fluctuations in neurons play an important role in scaling the relationship between input amplitude and spike rate response. For this to be true, neuronal spike input-output behavior must be sensitive to physiological membrane voltage fluctuations. Using a combination of single cell recordings and modeling, we investigated the mechanisms through which voltage fluctuations modulate neuronal input-output responses. We find that neurons that express an increase in membrane input resistance with depolarization show low levels of noise-mediated modulation of input-output responses due, in part, to  voltage trajectories that suppress the likelihood of generating a spike in response to random current input fluctuations. Hence, non-linear membrane properties arising from certain types of voltage-gated conductances limit noise-based modulation of neuronal input-output responses.

In Search of Serenity: I Strapped on a Mood-Changing Device

NBC link

“The company is careful not to release too many details about these “neural pathways.” But it has tested the device on more than 3,000 people, including 100 students and staff through a Thync-funded study at the City College of New York. The company says these trials show two-thirds of wearers feel a change in their mood beyond the placebo effect.”

Thursday, Jan.29 @ 1PM in Steinman Hall Rm 402 

Rosalyn J Moran, PhD

Assistant Professor, VTC Research Institute
Assistant Professor, Bradley Department of Electrical & Computer Engineering Assistant Professor, Department of Psychiatry & Behavioral Medicine Virginia Tech Carilion School of Medicine
Virginia Tech

In this talk I will present Bayesian perspectives on the human brain, both as a methodology to assess brain activity and as an analogy of brain function more generally. In the first part of my talk, I will introduce Dynamic Causal Modeling (DCM) as a ‘mathematical microscope’ for assessing functional brain networks. Using noninvasive neuroimaging data, I will demonstrate how biologically motivated generative models can be deployed with approximate (variational) Bayesian inference techniques to infer upon the complex and latent neuronal architectures that subtend these observed time-series data. Using examples from pathological and pharmacologically-altered cortical circuits, I will show how DCM can also help elucidate the key parameters that contribute to abnormal brain function.

In the second part of my talk I will present a mathematical deconstruction of age-related changes in cortical processing motivated by the Free Energy Principle. This principle hypothesizes a simple optimization that the brain may perform and a potential implementation based on predictive coding. From this perspective, the brain itself represents a model of its environment and offers predictions about the world through a subset of cortical connections, while responding – through learning – to novel interactions and experiences. I will provide evidence for selective alterations in these predictive and updating processes over the lifespan and examine potential adaptive and maladaptive consequences. Overall, the talk will cover how the brain could ‘do inference’ on the environment, and how scientists can ‘do inference’ on the brain.

Regulatory considerations for the clinical and research use of transcranial direct current stimulation (tDCS): Review and recommendations from an expert panel

F. Fregni, M. A. Nitsche, C. K. Loo, A. R. Brunoni, P. Marangolo, J. Leite, S. Carvalho, N. Bolognini, W. Caumo, N. J. Paik, M. Simis, K. Ueda, H. Ekhtiari, P. Luu, D. M. Tucker, W. J. Tyler, J. Brunelin, A. Datta, C. H. Juan, G. Venkatasubramanian, P. S. Boggio, and M. Bikson

Clin Res Regul Aff, Early Online: 1–14 DOI: 10.3109/10601333.2015.980944 

Abstract : The field of transcranial electrical stimulation (tES) has experienced significant growth in the past 15 years. One of the tES techniques leading this increased interest is transcranial direct current stimulation (tDCS). Significant research efforts have been devoted to determining the clinical potential of tDCS in humans. Despite the promising results obtained with tDCS in basic and clinical neuroscience, further progress has been impeded by a lack of clarity on international regulatory pathways. Therefore, a group of research and clinician experts on tDCS were convened to review the research and clinical use of tDCS. This report reviews the regulatory status of tDCS and summarizes the results according to research, off-label, and compassionate use of tDCS in the following countries: Australia, Brazil, France, Germany, India, Iran, Italy, Portugal, South Korea, Taiwan, and the US. Research use, off label treatment, and compassionate use of tDCS are employed in most of the countries reviewed in this study. It is critical that a global or local effort is organized to pursue definite evidence to either approve and regulate or restrict the use of tDCS in clinical practice on the basis of adequate randomized controlled treatment trials.

Paper PDF: tDCS_Regulations_stateoftheart

Wednesday, Dec. 10@ 3PM in Steinman Hall Rm 402

DBS for Movement Disorders and other Neurological Conditions

Brian Kopell, Ph.D

DIRECTOR, CENTER FOR NEUROMODULATION . Mount Sinai

 Abstract Deep Brain Stimulation (DBS) is widely recognized as the gold-standard treatment for patients with disabling motor symptoms from idiopathic Parkinson’s disease, Essential Tremor, and Dystonia that have become refractory to medical therapy. This neurosurgical procedure is available within a fully integrated multidisciplinary program through the Mount Sinai Hospital. Biography A graduate of the NYU School of Medicine, Dr. Kopell completed his residency at NYU Medical Center. Dr. Kopell has undergone fellowship training in Functional and Restorative Neurosurgery at the Cleveland Clinic Foundation and the University of Zurich. For the past eight years, he founded and has led the Restorative Neuroscience Program at the Medical College of Wisconsin (Milwaukee, WI) where his team performed over 400 DBS cases for movement disorders. Furthermore, Dr. Kopell has participated and has been principal investigator in several clinical trials of emerging Neuromodulation technologies targeting such disorders as Parkinson’s disease, tremor, tinnitus, and Major Depression. Dr. Kopell has pioneered the use of intra-operative imaging during DBS cases to supplement the microelectrode recording typically done to make a procedure that is safer and quicker for patient