Human cochlear hydrodynamics: A high-resolution μCT-based finite element study

Annalisa De Paolis, Hirobumi Watanabe, Jeremy T. Nelson, Marom Bikson, Mark Packer, Luis Cardoso

Journal of Biomechanics 50 (2017) 209–216

PDF: Human cochlear hydrodynamics   Journal Link

Abstract: Measurements of perilymph hydrodynamics in the human cochlea are scarce, being mostly limited to the fluid pressure at the basal or apical turn of the scalae vestibuli and tympani. Indeed, measurements of fluid pressure or volumetric flow rate have only been reported in animal models. In this study we imaged the human ear at 6.7 and 3-mm resolution using mCT scanning to produce highly accurate 3D models of the entire ear and particularly the cochlea scalae. We used a contrast agent to better distinguish soft from hard tissues, including the auditory canal, tympanic membrane, malleus, incus, stapes, ligaments, oval and round window, scalae vestibule and tympani. Using a Computational Fluid Dynamics (CFD) approach and this anatomically correct 3D model of the human cochlea, we examined the pressure and perilymph flow velocity as a function of location, time and frequency within the auditory range. Perimeter, surface, hydraulic diameter, Womersley and Reynolds numbers were computed every 45° of rotation around the central axis of the cochlear spiral. CFD results showed both spatial and temporal pressure gradients along the cochlea. Small Reynolds number and large Womersley values indicate that the perilymph fluid flow at auditory frequencies is laminar and its velocity profile is plug-like. The pressure was found 102–106° out of phase with the fluid flow velocity at the scalae vestibule and tympani, respectively. The average flow velocity was found in the sub-mm/s to nm/s range at 20–100 Hz, and below the nm/s range at 1–20 kHz.

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Published in the same issue of Brain Stimulation.


—- Direct Current Stimulation Alters Neuronal Input/Output Function.

Lafon B, Rahman A, Bikson M, Parra LC. Brain Stimul. 2016 Sep 1. pii: S1935-861X(16)30248-0. doi: 10.1016/j.brs.2016.08.014.

PDF: IO_tDCS_2017


— Direct Current Stimulation Modulates LTP and LTD: Activity Dependence and Dendritic Effects

Kronberg G, Bridi M, Abel T, Bikson M, Parra LC Brain Stimul. 2016 10 (2017) 51–58

PDF: Dendrites_tDCS_2017


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Conference information

NYC Neuromodulation 2017 will focus on technologies and mechanism for advanced brain stimulation in areas that include transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), transcranial magnetic stimulation (TMS), high-definition transcranial direct current stimulation (HD-tDCS), electroconvulsive therapy (ECT), deep brain stimulation (DBS), and other emerging areas. Applications span treatment of neuropsychiatric disorders, neurorehabilitation, and performance enhancement. Interactive lectures from key opinion leaders and emerging young scientists, poster sessions with abstracts published in Brain Stimulation and extensive opportunities to network with colleagues, along with an exhibit showcase featuring the latest neuromodulation technologies are all part of the main conference agenda.

This conference is among the most forward-looking neuromodulation meetings with the goal of advancing innovation from bench-top to bedside and home. Given the increased media, public, and commercial interest in personal non-invasive brain stimulation, the 2017 meeting will emphasize emerging “consumer” technologies, and their scientific and regulatory barriers. The off-label use of new clinical protocols will be addressed from scientific, medical, and regulatory perspectives. The conference will also focus on timely and novel targets of neuromodulation including glia, as well as new waveforms including high-rate (10 kHz) stimulation. Representatives from funding agencies and journal editors will be available to discuss priorities. NYC Neuromodulation is the largest meeting focused on non-invasive neuromodulation in North America, but this year it considers the role of invasive and non-invasive techniques in the continuum of care.

Chair: Marom Bikson




Front. Hum. Neurosci., 12 January 2017 |

Cerebellar tDCS: A Novel Approach to Augment Language Treatment Post-stroke

People with post-stroke aphasia may have some degree of chronic deficit for which current rehabilitative treatments are variably effective. Accumulating evidence suggests that transcranial direct current stimulation (tDCS) may be useful for enhancing the effects of behavioral aphasia treatment. However, it remains unclear which brain regions should be stimulated to optimize effects on language recovery. Here, we report on the therapeutic potential of right cerebellar tDCS in augmenting language recovery in SMY, who sustained bilateral MCA infarct resulting in aphasia and anarthria. We investigated the effects of 15 sessions of anodal cerebellar tDCS coupled with spelling therapy using a randomized, double-blind, sham controlled within-subject crossover trial. We also investigated changes in functional connectivity using resting state functional magnetic resonance imaging before and 2 months post-treatment. Both anodal and sham treatments resulted in improved spelling to dictation for trained and untrained words immediately after and 2 months post-treatment. However, there was greater improvement with tDCS than with sham, especially for untrained words. Further, generalization to written picture naming was only noted during tDCS but not with sham. The resting state functional connectivity data indicate that improvement in spelling was accompanied by an increase in cerebro-cerebellar network connectivity. These results highlight the therapeutic potential of right cerebellar tDCS to augment spelling therapy in an individual with large bilateral chronic strokes.


Full paper: fnhum-10-00695   Journal link: Link

Microsoft Word - Sebastian-CerebellartDCS_Revision_11_30_16.docx

Fall 2016 Seminar Series Fall 2016 Seminar Series Department of Biomedical Engineering Wednesday, Nov. 30 @ 3PM in Steinman Hall Rm 402

Patient-centric innovation intersection

Dr. Hugo Caicedo

Janssen-Johnson & Johnson Pharmaceutical R&D

Abstract: The current FDA-based roadmap to drug and product development as well as regulatory decision- making and labeling, is based on four Clinical outcome assessments (COAs): Patient-reported outcome (PRO) measures, Clinician-reported outcome (ClinRO) measures, Observer-reported outcome (ObsRO) measures, and Performance outcome (PerfO) measures. In general, COAs are used to determine whether or not a therapy has demonstrated a net clinical benefit in a disease or health condition, in other words COAs assess safety and efficacy of a therapy. Under these conditions, individuals are subjected to “adequate and well-controlled studies”. The gap, however, is that in real life patients, in their natural environments, are under neither adequate nor well-controlled conditions, which limits both our capacity to understand the patient experience and our ability to develop innovated & targeted healthcare solutions. Additionally, current highly homogeneous and randomized clinical trials (RCTs) do not shed light on patient adherence to those therapies; about 50% of the patients with chronic diseases do not comply with medication therapy. During my presentation, I will talk about how three paradigms (Real World Evidence (RWE), Digital Analytics and Design Thinking) can converge and form a model that I created, the “Patient-centric innovation intersection”, to enable actionable insights for the development of targeted healthcare solutions, with particular focus in Diabetes therapy adherence.

Biosketch: Dr. Hugo Caicedo is a scientist subject matter expert in microfluidics, biomedical engineering and consumer healthcare at Janssen-Johnson & Johnson Pharmaceutical R&D in the Philadelphia area. There, he conducts preclinical research on drug discovery as well as strategic design on healthcare innovation to translate relevant science and technology into high-value partnerships that enable differentiated healthcare solutions. Currently, he is also a scholar trainee at the Corporate Sustainability and Innovation program at Harvard University. Dr. Caicedo holds a B.S in Electronics Engineering from the Universidad del Valle (Cali-Colombia) and a Ph.D. in Biomedical Engineering from the University of Illinois at Chicago (UIC). He was the recipient of MIT, Bogazicy University, Antalya University (Turkey) and UniversitéPierre and Marie Curie (France) pre-doctoral fellowships as well as one Harvard-MIT/HST post-doctoral fellowship. Dr. Caicedo has multiple publications including several peer-reviewed papers, two book chapters and a provisional patent application. Additionally, he has been awarded more than 20 recognition awards including: 2011, Ph.D student, African Colombian of the year in academia; 2012, Mayor’s Civic Merit Medal of Cali given directly by the President of Colombia; 2012, Distinguished PhD Student speaker at the 3rd US-Turkey Advanced Study Institute on Global Healthcare Challenges; 2015, BMES4SUCCESS, highlighted by the US Biomedical Engineering Society, as one of three —and the only member from industry— successful earlier career members in biomedical engineering; and 2016 Honorable Speaker invitation at the Biotechnology World Convention in Sao Paulo, Brazil.

Continue reading

Textbook of Neuromodulation
Principles, Methods and Clinical Applications

Springer. ISBN: 978-1-4939-1407-4 


Methods and Technologies for Low-Intensity Transcranial Electrical Stimulation: Waveforms, Terminology, and Historical Notes
Page 7-16. Berkan Guleyupoglu, Pedro Schestatsky, Felipe Fregni, Marom Bikson

PDF: 10-1007978-1-4939-1408-12


A Role of Computational Modeling in Customization of Transcranial Direct Current Stimulation for Susceptible Populations
Dennis Truong, Preet Minhas, Albert Mokrejs, Marom Bikson

PDF: 10-1007978-1-4939-1408-110


Direct current stimulation over the anterior temporal areas boosts semantic processing in primary progressive aphasia.

Teichmann M, Lesoil C, Godard J, Vernet M, Bertrand A, Levy R, Dubois B, Lemoine L, Truong DQ, Bikson M, Kas A, Valero-Cabré A. Ann Neurol. 2016 Nov;80(5):693-707. doi: 10.1002/ana.24766.

Download PDF: teichmann-et-al_annals-of-neurology_2016

Abstract: Objective: Noninvasive brain stimulation in primary progressive aphasia (PPA) is a promising approach. Yet, applied to single cases or insufficiently controlled small-cohort studies, it has not clarified its therapeutic value. We here address the effectiveness of transcranial direct current stimulation (tDCS) on the semantic PPA variant (sv-PPA), applying a rigorous study design to a large, homogeneous sv-PPA cohort. Methods: Using a double-blind, sham-controlled counterbalanced cross-over design, we applied three tDCS condi- tions targeting the temporal poles of 12 sv-PPA patients. Efficiency was assessed by a semantic matching task orthogonally manipulating “living”/”nonliving” categories and verbal/visual modalities. Conforming to predominantly left-lateralized damage in sv-PPA and accounts of interhemispheric inhibition, we applied left hemisphere anodal- excitatory and right hemisphere cathodal-inhibitory tDCS, compared to sham stimulation. Results: Prestimulation data, compared to 15 healthy controls, showed that patients had semantic disorders predomi- nating with living categories in the verbal modality. Stimulation selectively impacted these most impaired domains: Left- excitatory and right-inhibitory tDCS improved semantic accuracy in verbal modality, and right-inhibitory tDCS improved processing speed with living categories and accuracy and processing speed in the combined verbal 3 living condition. Interpretation: Our findings demonstrate the efficiency of tDCS in sv-PPA by generating highly specific intrasemantic effects. They provide “proof of concept” for future applications of tDCS in therapeutic multiday regimes, potentially driv- ing sustained improvement of semantic processing. Our data also support the hotly debated existence of a left temporal- pole network for verbal semantics selectively modulated through both left-excitatory and right-inhibitory brain stimulation.