42 results on '"Leon, Morales"'
Search Results
2. Comparing focused attention meditation to meditation with mobile neurofeedback for persistent symptoms after mild-moderate traumatic brain injury: a pilot study
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Duc Tran, Leon Morales-Quezada, Sarah Gray, Mel B. Glenn, and Ginger Polich
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Adult ,030506 rehabilitation ,Traumatic brain injury ,media_common.quotation_subject ,Neuroscience (miscellaneous) ,Pilot Projects ,03 medical and health sciences ,0302 clinical medicine ,Brain Injuries, Traumatic ,Developmental and Educational Psychology ,Humans ,Medicine ,Attention ,Meditation ,Depression (differential diagnoses) ,media_common ,business.industry ,Neurofeedback ,medicine.disease ,Anxiety ,Neurology (clinical) ,medicine.symptom ,0305 other medical science ,business ,030217 neurology & neurosurgery ,Clinical psychology - Abstract
This study evaluated whether a meditation practice incorporating mobile neurofeedback (mNF) offers any advantage over a more traditional form of focused attention (FA) meditation in managing persistent symptoms after traumatic brain injury (TBI) (clinicaltrials.gov NCT02615535).Pilot randomized clinical trial, exploring feasibility of mNF in TBI.Participants included adults with chronic mood and/or cognitive complaints following mild-moderate TBI. Subjects practiced either FA (n = 10) or mNF (n = 10) meditation 12 minutes daily for 6 weeks. Pre-post intervention difference on the Neurobehavioral Symptom Inventory (NSI) was the primary outcome variable. Secondary outcomes included the Beck Anxiety Inventory (BAI), Beck Depression Inventory-II (BDI-II), amongst other scales and neurocognitive tests.No significant pre-post between-group differences were found on the NSI (Meditating with neurofeedback does not appear to provide an advantage over meditating on one's own for chronic post-TBI symptoms. Further research on home-based meditation following TBI, whether self-directed or technologically facilitated, is warranted.
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- 2020
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3. Broader Implications of Progressive Liver Dysfunction and Lethal Sepsis in Two Boys following Systemic High-Dose AAV
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Hansell H. Stedman, Leon Morales, Jean Bennett, and Yuva Gambhir
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Pharmacology ,Clinical Trials as Topic ,2019-20 coronavirus outbreak ,Coronavirus disease 2019 (COVID-19) ,business.industry ,Liver Diseases ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Genetic Vectors ,Genetic Therapy ,Dependovirus ,Prognosis ,medicine.disease ,Article ,Sepsis ,Drug Discovery ,Immunology ,Genetics ,Animals ,Humans ,Molecular Medicine ,Medicine ,Liver dysfunction ,business ,Molecular Biology - Published
- 2020
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4. Non-immunogenic utrophin gene therapy for the treatment of muscular dystrophy animal models
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Kathleen J. Propert, Xiangping Lu, Margaret E Choi, Frederick J. Balzer, Shira T. Rosenblum, Daniel J VanBelzen, Leonard T. Su, Peter P. Nghiem, Joe N. Kornegay, Marilyn A. Mitchell, Mihail Petrov, Shangzhen Zhou, Benjamin W. Kozyak, Christopher D. Greer, Alock Malik, Yafeng Song, Andrew F. Mead, Ranjith K Krishnankutty, Robert A. French, Hansell H. Stedman, Emanuele Loro, Leon Morales, and Tejvir S. Khurana
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musculoskeletal diseases ,0301 basic medicine ,biology ,business.industry ,Genetic enhancement ,Transgene ,Duchenne muscular dystrophy ,Regeneration (biology) ,General Medicine ,musculoskeletal system ,medicine.disease ,General Biochemistry, Genetics and Molecular Biology ,03 medical and health sciences ,030104 developmental biology ,0302 clinical medicine ,030220 oncology & carcinogenesis ,Utrophin ,biology.protein ,Cancer research ,Medicine ,Muscular dystrophy ,business ,Dystrophin ,Immunologic Tolerance - Abstract
The essential product of the Duchenne muscular dystrophy (DMD) gene is dystrophin1, a rod-like protein2 that protects striated myocytes from contraction-induced injury3,4. Dystrophin-related protein (or utrophin) retains most of the structural and protein binding elements of dystrophin5. Importantly, normal thymic expression in DMD patients6 should protect utrophin by central immunologic tolerance. We designed a codon-optimized, synthetic transgene encoding a miniaturized utrophin (µUtro), deliverable by adeno-associated virus (AAV) vectors. Here, we show that µUtro is a highly functional, non-immunogenic substitute for dystrophin, preventing the most deleterious histological and physiological aspects of muscular dystrophy in small and large animal models. Following systemic administration of an AAV-µUtro to neonatal dystrophin-deficient mdx mice, histological and biochemical markers of myonecrosis and regeneration are completely suppressed throughout growth to adult weight. In the dystrophin-deficient golden retriever model, µUtro non-toxically prevented myonecrosis, even in the most powerful muscles. In a stringent test of immunogenicity, focal expression of µUtro in the deletional-null German shorthaired pointer model produced no evidence of cell-mediated immunity, in contrast to the robust T cell response against similarly constructed µDystrophin (µDystro). These findings support a model in which utrophin-derived therapies might be used to treat clinical dystrophin deficiency, with a favorable immunologic profile and preserved function in the face of extreme miniaturization.
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- 2019
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5. Combining Fluoxetine and rTMS in Poststroke Motor Recovery: A Placebo-Controlled Double-Blind Randomized Phase 2 Clinical Trial
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Qing Mei Wang, Faddi Ghassan Saleh Velez, Erica C.S. Camargo, Camila Bonin Pinto, Fernanda Lopes, Luiz Vicente Rizzo, Dian Zeng, David Lin, Polyana Vulcano de Toledo Piza, Dante Duarte, Felipe Fregni, Isadora Santos Ferreira, Mirret M. El-Hagrassy, Pedro Henrique Lucena, Nicole L. Mazwi, Leon Morales-Quezada, and Randie M. Black-Schaffer
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Male ,medicine.medical_treatment ,Pyramidal Tracts ,Phases of clinical research ,Motor Activity ,Placebo ,Article ,law.invention ,Upper Extremity ,03 medical and health sciences ,0302 clinical medicine ,Double-Blind Method ,Randomized controlled trial ,law ,Fluoxetine ,medicine ,Humans ,030212 general & internal medicine ,Stroke ,business.industry ,Recovery of Function ,General Medicine ,Middle Aged ,medicine.disease ,Combined Modality Therapy ,Transcranial Magnetic Stimulation ,Paresis ,Transcranial magnetic stimulation ,Treatment Outcome ,Anesthesia ,Facilitation ,Female ,Primary motor cortex ,business ,Selective Serotonin Reuptake Inhibitors ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Background. Although recent evidence has shown a new role of fluoxetine in motor rehabilitation, results are mixed. We conducted a randomized clinical trial to evaluate whether combining repetitive transcranial magnetic stimulation (rTMS) with fluoxetine increases upper limb motor function in stroke. Methods. Twenty-seven hemiparetic patients within 2 years of ischemic stroke were randomized into 3 groups: Combined (active rTMS + fluoxetine), Fluoxetine (sham rTMS + fluoxetine), or Placebo (sham rTMS + placebo fluoxetine). Participants received 18 sessions of 1-Hz rTMS in the unaffected primary motor cortex and 90 days of fluoxetine (20 mg/d). Motor function was assessed using Jebsen-Taylor Hand Function (JTHF) and Fugl-Meyer Assessment (FMA) scales. Corticospinal excitability was assessed with TMS. Results. After adjusting for time since stroke, there was significantly greater improvement in JTHF in the combined rTMS + fluoxetine group (mean improvement: −214.33 seconds) than in the placebo (−177.98 seconds, P = 0.005) and fluoxetine (−50.16 seconds, P < 0.001) groups. The fluoxetine group had less improvement than placebo on both scales (respectively, JTHF: −50.16 vs −117.98 seconds, P = 0.038; and FMA: 6.72 vs 15.55 points, P = 0.039), suggesting that fluoxetine possibly had detrimental effects. The unaffected hemisphere showed decreased intracortical inhibition in the combined and fluoxetine groups, and increased intracortical facilitation in the fluoxetine group. This facilitation was negatively correlated with motor function improvement (FMA, r2 = −0.398, P = 0.0395). Conclusion. Combined fluoxetine and rTMS treatment leads to better motor function in stroke than fluoxetine alone and placebo. Moreover, fluoxetine leads to smaller improvements than placebo, and fluoxetine’s effects on intracortical facilitation suggest a potential diffuse mechanism that may hinder beneficial plasticity on motor recovery.
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- 2019
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6. The Use of Conditioning Open-Label Placebo in Opioid Dose Reduction: A Case Report and Literature Review
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Ines Mesia-Toledo, Jeffrey C. Schneider, Leon Morales-Quezada, and Maria Anayali Estudillo‐Guerra
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Rehabilitation hospital ,medicine.medical_specialty ,Rehabilitation ,business.industry ,medicine.medical_treatment ,Placebo ,Clinical trial ,03 medical and health sciences ,0302 clinical medicine ,Opioid ,Physical therapy ,Morphine ,Medicine ,030212 general & internal medicine ,business ,Adverse effect ,Oxycodone ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Introduction: Adequate pain management for inpatients in rehabilitation units is essential for achieving therapeutic goals. Opioid treatments are commonly prescribed, but these are associated with numerous adverse effects, including the risk of addiction and decreased quality of life. Conditioning an open-label placebo is a promising approach to extend the analgesic effect of the opioid while reducing its overall dosage.Objectives: To describe a patient's experience in using conditioning open-label placebo (COLP) as a pharmaco-behavioral intervention to decrease opioid intake and its side effects after inpatient rehabilitation discharge, and to perform a literature review about the use of open-label placebo in pain.Methods: This case study has been extracted from a clinical trial initiated in 2018. A 61-year-old male was recruited at a tertiary rehabilitation hospital after suffering a traumatic sport-related injury and orthopedic surgery. Pain management included prescription of non-steroidal anti-inflammatory drugs (NSAIDs) and short-acting oxycodone. After trial participation, the patient requested off-label COLP treatment to help him decrease outpatient opioid utilization.Results: After COLP treatment, the patient could discontinue oxycodone intake (a reduction from 15 morphine equivalents/day) after rehabilitation discharge. Moreover, opioid side effects decreased from 46 to 9 points on the numerical opioid side-effects scale. A literature review identified five clinical trials using “honest” open-label placebo (OLP) or COLP as an experimental intervention for pain control. From these studies, two were in the area of chronic lower back pain, one in post spine surgery, one in irritable bowel syndrome, and another in spinal cord injury and polytrauma. Four studies reported positive outcomes related to pain control, while one study showed no significant differences in pain management between treatment-as-usual and the COLP group.Conclusion: The case report illustrates how a pharmaco-behavioral intervention can facilitate downward opioid titration safely after inpatient rehabilitation. It initiates a discussion about new approaches for opioid management using conditioning and the patient's expectation of pain relief.
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- 2021
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7. Conditioning open-label placebo: a pilot pharmacobehavioral approach for opioid dose reduction and pain control
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Douglas J. Sohn, Ted J. Kaptchuk, Leon Morales-Quezada, Ross Zafonte, Ines Mesia-Toledo, Jeffrey C. Schneider, Anayali Estudillo-Guerra, Kevin C. O’Connor, and David Crandell
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Rehabilitation hospital ,Open-label placebo ,Visual analogue scale ,medicine.medical_treatment ,Population ,Pain ,02 engineering and technology ,Placebo ,01 natural sciences ,lcsh:RD78.3-87.3 ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,010306 general physics ,education ,Pharmacology ,education.field_of_study ,Rehabilitation ,business.industry ,Brief Report ,Classical conditioning ,food and beverages ,Opioids ,Anesthesiology and Pain Medicine ,Opioid ,lcsh:Anesthesiology ,Anesthesia ,Morphine ,020201 artificial intelligence & image processing ,business ,medicine.drug ,Conditioning - Abstract
Given the complexity of pain management in rehabilitation settings, pharmaco-behavioral interventions can capitalize on the self-modulatory process to enhance the effects of a drug-based intervention., Introduction: Opioid consumption for those in comprehensive inpatient rehabilitation units is high because of the complexity of their injuries. Notably, pain in rehabilitation leads to worsened clinical outcomes because of maladaptive behaviors and poor engagement during therapies. It is critical to developing evidence-based pharmacobehavioral interventions. Based on principles of classical conditioning, conditioning open-label placebo (COLP) is a promising approach for reducing opioid use in comprehensive inpatient rehabilitation, and this technique takes advantage of the possibility of association learning and opioid pharmacology to promote evoked placebo-driven analgesia. Objectives: In this brief report, we evaluate the feasibility of COLP as a pharmacobehavioral intervention to decrease total opioid consumption in patients with pain hospitalized at Spaulding Rehabilitation Hospital. Methods: Inpatients with spinal cord injury and polytrauma (n = 20) with moderate to severe pain were randomized to receive COLP (n = 10) or treatment-as-usual for 6 consecutive days. Opioid utilization was measured by morphine equivalents using the morphine equivalent dose conversion; pain severity was assessed using the numerical visual analog scale. Results: Conditioning open-label placebo significantly reduced total opioid consumption by the end of the intervention period (P ≤ 0.001). Pain reduction was also significant for the COLP group (P = 0.005), whereas the treatment-as-usual group demonstrated a trend towards pain reduction (P = 0.05). Conclusions: This study presents the first data in the use of a pharmacobehavioral intervention that capitalize on the benefits of open-label placebo and classical drug conditioning for opioid dose reduction in a population with moderate to severe pain exposed to intensive inpatient rehabilitation.
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- 2020
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8. Brain perfusion during manic episode and at 6‐month follow‐up period in bipolar disorder patients: Correlation with cognitive functions
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Alejandra Cardenas-Rojas, Kevin Pacheco-Barrios, Gloria Adame‐Ocampo, Joan A. Camprodon, Doris Gutiérrez‐Mora, Leon Morales-Quezada, Mónica Flores‐Ramos, and Maria Anayali Estudillo‐Guerra
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Adult ,Cingulate cortex ,medicine.medical_specialty ,Prefrontal Cortex ,Perfusion scanning ,functional neuroimaging ,tomography ,Young Mania Rating Scale ,single‐photon ,050105 experimental psychology ,lcsh:RC321-571 ,03 medical and health sciences ,Behavioral Neuroscience ,Cognition ,0302 clinical medicine ,Functional neuroimaging ,Internal medicine ,medicine ,Humans ,0501 psychology and cognitive sciences ,Prospective Studies ,Bipolar disorder ,Effects of sleep deprivation on cognitive performance ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,emission‐computed ,Anterior cingulate cortex ,Original Research ,bipolar disorder ,business.industry ,05 social sciences ,medicine.disease ,Perfusion ,Mania ,medicine.anatomical_structure ,Cardiology ,Orbitofrontal cortex ,business ,030217 neurology & neurosurgery ,Follow-Up Studies - Abstract
Background Patterns of altered cerebral perfusion and cognitive dysfunction have been described in Bipolar Disorder (BD) acute episodes and euthymia. Knowledge of the relationship between cognitive function and perfusion in a manic state and status when followed up is still limited. Objective To describe brain perfusion alterations and its relationship with cognitive impairment in patients with BD during manic episodes and after 6 months. Methods Observational‐prospective study in 10 type I BD adults during moderate‐severe manic episodes. We assessed sociodemographic data and clinical variables as well as cognitive function through Screening for Cognitive Impairment in Psychiatry (SCIP‐S). Finally, we performed a Brain Perfusion SPECT using a Tc99m‐ethyl cysteine dimer. Results During manic episodes, patients showed cognitive impairment with a mean SCIP‐S score of 63.8 ± 17.16. This was positively correlated with perfusion measured as relative reuptake index (RRI) at the right temporal pole (ρ = 0.65 p = .0435) and negatively correlated with right the orbitofrontal cortex (ρ = −0.70 p = .0077) and the right subgenual cingulate cortex (ρ = −0.70 p = .0256). Episode severity measured by the Young Mania Rating Scale (YMRS) positively correlated with RRI at the right temporal pole (ρ = 0.75, p = .01). At follow‐up, six patients were taking treatment and were euthymic, we found a negative correlation with the YMRS and RRI at the bilateral orbitofrontal cortex (ρ = −0.8827, p = .019). They did not show significant improvement in cognitive performance at SCIP‐S, and there was negative correlation with the following of the SCIP‐S subscales; processing speed with the bilateral dorsolateral prefrontal, the bilateral medial prefrontal, the left temporal pole cortex RRI, and verbal fluency with the bilateral anterior cingulate cortex RRI. Conclusion Cognitive impairment was correlated with brain perfusion patterns at baseline and follow‐up. Large sample size studies with longer follow‐up are needed to describe the changes in perfusion and cognitive functions in BD., Observational‐prospective study in 10 type I BD adults during moderate‐severe manic episode that evaluates brain perfusion and cognition. Cognitive performance did not improve despite clinical improvement at follow‐up, and it was correlated to neocortical decreased perfusion. Clinical improvement was related to an increase in perfusion at orbitofrontal areas.
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- 2020
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9. Author response for 'Brain perfusion during manic episode and at 6‐month follow‐up period in bipolar disorder patients: Correlation with cognitive functions'
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Leon Morales-Quezada, Kevin Pacheco-Barrios, Doris Gutiérrez‐Mora, Gloria Adame‐Ocampo, Mónica Flores‐Ramos, Joan A. Camprodon, Maria Anayali Estudillo‐Guerra, and Alejandra Cardenas-Rojas
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Correlation ,Pediatrics ,medicine.medical_specialty ,business.industry ,Period (gene) ,medicine ,Perfusion scanning ,Cognition ,Bipolar disorder ,medicine.disease ,business ,Month follow up - Published
- 2020
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10. P181 Neurophysiological effects and behavioral outcomes after tPCS and tDCS in a patient in minimally conscious state
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Alice Barra, Leon Morales-Quezada, Yelena G. Bodien, Géraldine Martens, Joseph G. Giacino, Sepehr Mortaheb, Manon Carrière, Felipe Fregni, Steven Laureys, Aurore Thibaut, and M.L. Binda Fossati
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medicine.diagnostic_test ,business.industry ,Minimally conscious state ,Neurophysiology ,Electroencephalography ,medicine.disease ,Sensory Systems ,Neuromodulation (medicine) ,Neurology ,Physiology (medical) ,medicine ,Neurology (clinical) ,business ,Neuroscience ,Persistent vegetative state - Published
- 2020
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11. Nocebo Effects in Concussion: Is All That Is Told Beneficial?
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Ted J. Kaptchuk, Ginger Polich, Ross Zafonte, Leon Morales-Quezada, and Mary Alexis Iaccarino
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Value (ethics) ,030506 rehabilitation ,Health Knowledge, Attitudes, Practice ,Psychotherapist ,business.industry ,Rehabilitation ,Negative publicity ,MEDLINE ,Physical Therapy, Sports Therapy and Rehabilitation ,Media coverage ,Health knowledge ,Health Promotion ,medicine.disease ,Nocebo Effect ,03 medical and health sciences ,0302 clinical medicine ,Concussion ,medicine ,Humans ,Public Health ,0305 other medical science ,business ,030217 neurology & neurosurgery ,Brain Concussion - Abstract
Nocebo effects refer to new or worsening symptoms that develop in response to negative health-related information, beliefs, and/or experiences. In recent years, research on concussion pathophysiology has significantly advanced. Through health campaigns and media coverage, emerging knowledge on the risks of this injury has been quickly disseminated to the public, and nowadays, the public perceives concussions as more hazardous to health than ever before. Although advancements in concussion-related research and care are of great importance and value, we ask in this article whether the increasing negative publicity regarding concussion also carries any latent costs. Are additional nocebo effects being fostered? To do so, we will review the literature on the psychological and neurobiological processes underlying nocebo effects, present a series of clinical studies demonstrating the ways in which nocebos may impact concussion outcomes both clinically and societally, then speculate on further potential mechanisms for nocebo effects in concussion. We conclude with an outline of the specific efforts one may take to minimize nocebo effects in concussion-related care.
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- 2019
12. Laterality and Stimulation Bias in Meta-analysis of Placebo Responses
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Leon Morales-Quezada and Clas Linnman
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medicine.diagnostic_test ,business.industry ,MEDLINE ,Pain ,Stimulation ,Magnetic resonance imaging ,Placebo ,Placebo Effect ,Magnetic Resonance Imaging ,Functional Laterality ,Meta-analysis ,Anesthesia ,Laterality ,medicine ,Humans ,Neurology (clinical) ,business - Published
- 2019
13. Duration Dependent Effects of Transcranial Pulsed Current Stimulation (tPCS) Indexed by Electroencephalography
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Jorge Leite, Alejandra Malavera, Leon Morales-Quezada, Sandra Carvalho, Alejandra Vasquez, Deniz Doruk, Felipe Fregni, and Universidade do Minho
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Male ,0301 basic medicine ,Time Factors ,medicine.medical_treatment ,Stimulation ,Kaplan-Meier Estimate ,power spectrum ,Electroencephalography ,Transcranial Direct Current Stimulation ,Brain mapping ,Functional Laterality ,Interhemispheric coherence ,transcranial pulsed current stimulation ,0302 clinical medicine ,Homeostatic plasticity ,interhemispheric coherence ,Psicologia [Ciências Sociais] ,EEG ,Brain Mapping ,Transcranial direct-current stimulation ,medicine.diagnostic_test ,Brain ,General Medicine ,Healthy Volunteers ,3. Good health ,Neurology ,Duration (music) ,Ciências Sociais::Psicologia ,Cardiology ,Female ,Adult ,medicine.medical_specialty ,Alpha (ethology) ,homeostatic plasticity ,Young Adult ,03 medical and health sciences ,Double-Blind Method ,Internal medicine ,medicine ,Humans ,Science & Technology ,business.industry ,Brain Waves ,030104 developmental biology ,Anesthesiology and Pain Medicine ,Neurology (clinical) ,business ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Objective: To explore the duration of tPCS after effects given different durations of stimulation on power and interhemispheric coherence of the EEG frequency bands. Our hypothesis was that longer tPCS duration would induce a differential effect on the EEG analysis and a longer duration of after effects on the EEG frequency bands.Materials and Methods: We conducted a double blind, sham controlled study in which forty healthy subjects were randomized to receive a single session of either 10, 20, 30 min of active (2 mA, random frequency between 6 and 10 Hz, ear clip montage) or sham tPCS. EEG was recorded before and after the intervention to assess tPCS induced after effects.Results: We found that 10 and 20 min of active tPCS induced a significant increase in alpha (p = 0.004) and theta (p = 0.006) coherence in the frontal region as compared with the sham stimulation. No significant changes were found with 30 min of stimulation (p < 0.05). The Kaplan Meier analysis showed that 10 and 20 min of tPCS induced after effects that lasted 50 min.Conclusions: These results evidence the nonlinear relationship between the stimulation duration and the tPCS after effects, suggesting the presence of homeostatic mechanisms., This study was supported in part by a grant from BrainGear Inc. Dr. LMQ received funding support from an Institutional National Research Service Award from the National Center for Complementary and Integrative Health grant T32AT000051, the Ryoichi Sasakawa Fellowship Fund, and by the Program in Placebo Studies at Beth Israel Deaconess Medical Center.
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- 2016
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14. Adaptive super-twisting control of floating wind turbines with collective blade pitch control
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Susana V. Gutierrez, J. De Leon-Morales, Franck Plestan, Cheng Zhang, École Centrale de Nantes (ECN), Laboratoire des Sciences du Numérique de Nantes (LS2N), Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), and Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)
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0209 industrial biotechnology ,Wind power ,Computer science ,Oscillation ,business.industry ,Blade pitch ,020208 electrical & electronic engineering ,Control (management) ,Floating wind turbine ,02 engineering and technology ,7. Clean energy ,Sliding mode control ,020901 industrial engineering & automation ,Control and Systems Engineering ,Control theory ,[INFO.INFO-AU]Computer Science [cs]/Automatic Control Engineering ,0202 electrical engineering, electronic engineering, information engineering ,business ,Reduction (mathematics) ,ComputingMilieux_MISCELLANEOUS - Abstract
This paper proposes an adaptive super-twisting controller for floating wind turbine based on collective blade pitch control. This adaptive second order sliding mode control scheme being efficient for systems with uncertainties and external perturbations, which is compared with the traditional gain scheduled PI (GSPI) controller. It is shown that this kind of controller requires reduced knowledge about the system (only the relative degree) and the gain tuning effort is also reduced given that the operating domain is large versus GSPI controller. Simulation results show high performances of the proposed controller for rotor speed regulation and reduction of platform oscillations in Region 3 of the floating wind turbine.
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- 2019
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15. Ceftriaxone Treatment Preserves Cortical Inhibitory Interneuron Function via Transient Salvage of GLT-1 in a Rat Traumatic Brain Injury Model
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Tsung Hsun Hsieh, Paul MacMullin, Henry H.C. Lee, Alexander Rotenberg, Ugur Damar, Takao K. Hensch, Mustafa Q. Hameed, and Leon Morales-Quezada
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Male ,Traumatic brain injury ,Cognitive Neuroscience ,medicine.medical_treatment ,Excitotoxicity ,Gene Expression ,Pharmacology ,Inhibitory postsynaptic potential ,medicine.disease_cause ,050105 experimental psychology ,Rats, Sprague-Dawley ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,0302 clinical medicine ,Interneurons ,Brain Injuries, Traumatic ,medicine ,Animals ,0501 psychology and cognitive sciences ,GABAergic Neurons ,biology ,business.industry ,05 social sciences ,Ceftriaxone ,Glutamate receptor ,Motor Cortex ,Original Articles ,medicine.disease ,Anti-Bacterial Agents ,Transcranial magnetic stimulation ,Disease Models, Animal ,Parvalbumins ,nervous system ,Excitatory Amino Acid Transporter 2 ,Excitatory postsynaptic potential ,biology.protein ,GABAergic ,business ,030217 neurology & neurosurgery ,Parvalbumin - Abstract
Traumatic brain injury (TBI) results in a decrease in glutamate transporter-1 (GLT-1) expression, the major mechanism for glutamate removal from synapses. Coupled with an increase in glutamate release from dead and dying neurons, this causes an increase in extracellular glutamate. The ensuing glutamate excitotoxicity disproportionately damages vulnerable GABAergic parvalbumin-positive inhibitory interneurons, resulting in a progressively worsening cortical excitatory:inhibitory imbalance due to a loss of GABAergic inhibitory tone, as evidenced by chronic post-traumatic symptoms such as epilepsy, and supported by neuropathologic findings. This loss of intracortical inhibition can be measured and followed noninvasively using long-interval paired-pulse transcranial magnetic stimulation with mechanomyography (LI-ppTMS-MMG). Ceftriaxone, a β-lactam antibiotic, is a potent stimulator of the expression of rodent GLT-1 and would presumably decrease excitotoxic damage to GABAergic interneurons. It may thus be a viable antiepileptogenic intervention. Using a rat fluid percussion injury TBI model, we utilized LI-ppTMS-MMG, quantitative PCR, and immunohistochemistry to test whether ceftriaxone treatment preserves intracortical inhibition and cortical parvalbumin-positive inhibitory interneuron function after TBI in rat motor cortex. We show that neocortical GLT-1 gene and protein expression are significantly reduced 1 week after TBI, and this transient loss is mitigated by ceftriaxone. Importantly, whereas intracortical inhibition declines progressively after TBI, 1 week of post-TBI ceftriaxone treatment attenuates the loss of inhibition compared to saline-treated controls. This finding is accompanied by significantly higher parvalbumin gene and protein expression in ceftriaxone-treated injured rats. Our results highlight prospects for ceftriaxone as an intervention after TBI to prevent cortical inhibitory interneuron dysfunction, partly by preserving GLT-1 expression.
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- 2018
16. Placebo Effects in Traumatic Brain Injury
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Leon Morales-Quezada, Ted J. Kaptchuk, Mary Alexis Iaccarino, Ginger Polich, and Ross Zafonte
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Rehabilitation ,Traumatic brain injury ,business.industry ,medicine.medical_treatment ,Poison control ,Cognition ,Review ,medicine.disease ,Placebo ,Serotonergic ,Placebo Effect ,law.invention ,03 medical and health sciences ,0302 clinical medicine ,Randomized controlled trial ,law ,Injury prevention ,Brain Injuries, Traumatic ,medicine ,Humans ,030212 general & internal medicine ,Neurology (clinical) ,business ,030217 neurology & neurosurgery ,Clinical psychology - Abstract
In recent years, several randomized controlled trials evaluating pharmaceutical treatments for traumatic brain injury (TBI) have failed to demonstrate efficacy over placebo, with both active and placebo arms improving at comparable rates. These findings could be viewed in opposing ways, suggesting on the one hand failure of the tested outcome, but on the other, representing evidence of robust placebo effects in TBI. In this article, we examine several of the primary psychological processes driving placebo effects (verbal suggestion, cognitive re-framing, interpersonal interactions, conditioning, therapeutic alliance, anxiety reduction) as well as placebo neurobiology (top-down cortical regulation, reward system activation, dopaminergic and serotonergic neurotransmission). We then extrapolate from the literature to explore whether something inherent in TBI makes it particularly responsive to placebos. Viewed as such here, placebos may indeed represent a powerful and effective treatment for a variety of post-TBI complaints.
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- 2018
17. 416 Effects of Transcranial Direct Current Stimulation on Pain and Itch after Burn Injury
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Emily A. Ohrtman, Leon Morales-Quezada, Aurore Thibaut, Felipe Fregni, Jeffrey C. Schneider, Laura C. Simko, Ross Zafonte, and Colleen M. Ryan
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Burn injury ,Transcranial direct-current stimulation ,business.industry ,medicine.medical_treatment ,Anesthesia ,Rehabilitation ,Emergency Medicine ,medicine ,Surgery ,business - Published
- 2019
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18. Observer-based Integral Sliding Mode Approach for Bilateral Teleoperation with Unknown Time Delay
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Oscar Salas-Peña, Vicente Parra-Vega, S. Rosales, Nicolas Gonzalez, and Jesus de-Leon-Morales
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0209 industrial biotechnology ,Engineering ,General Computer Science ,Observer (quantum physics) ,business.industry ,020208 electrical & electronic engineering ,Control engineering ,02 engineering and technology ,Sliding mode control ,Integral sliding mode ,Computer Science::Robotics ,Acceleration ,020901 industrial engineering & automation ,Control and Systems Engineering ,Control theory ,Convergence (routing) ,Teleoperation ,0202 electrical engineering, electronic engineering, information engineering ,State observer ,business - Abstract
This paper deals with force-reflecting control design for teleoperation of bilateral robots under unknown constant time delay. The proposed impedance teleoperator control is based on integral sliding mode approaches, avoiding undesirable chattering effect. With the aim of implementing the proposed controller and taking into account that only position measurement is available, a Nonlinear Observer based on Super Twisting Algorithm is proposed to estimate velocity and acceleration in the slave side of the teleoperation system. Furthermore, owing to the finite-time convergence properties of the observer, the proposed control scheme guarantees robust tracking under unknown constant time delay. Experimental results illustrate the effectiveness of the proposed scheme.
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- 2016
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19. Prognostic Value of Brain Magnetic Resonance Imaging in Neonatal Hypoxic-Ischemic Encephalopathy: A Meta-analysis
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Samuel Law, Iván Sánchez Fernández, J Leon Morales-Quezada, and Paggie Kim
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medicine.medical_specialty ,Hypoxic Ischemic Encephalopathy ,03 medical and health sciences ,0302 clinical medicine ,030225 pediatrics ,Internal medicine ,medicine ,Neonatal brain ,Humans ,Brain magnetic resonance imaging ,medicine.diagnostic_test ,business.industry ,Infant, Newborn ,Brain ,Magnetic resonance imaging ,Prognosis ,Magnetic Resonance Imaging ,Neonatal Hypoxic Ischemic Encephalopathy ,Meta-analysis ,Anesthesia ,Pediatrics, Perinatology and Child Health ,Hypoxia-Ischemia, Brain ,Cardiology ,Neurology (clinical) ,business ,Value (mathematics) ,030217 neurology & neurosurgery - Abstract
Objective: To quantify the prognostic value of neonatal brain magnetic resonance imaging (MRI) in neonatal hypoxic-ischemic encephalopathy. Methods: Meta-analysis of studies with ≥35-week neonates with hypoxic-ischemic encephalopathy who underwent brain MRI within age 4 weeks and had neurodevelopmental follow-up for at least 12 months. Results: An abnormal neonatal brain MRI was more frequent among patients with unfavorable neurodevelopmental outcome: odds ratio = 18.2 (95% confidence interval: 9.4-34.9), P Conclusion: Neonatal brain MRI provides prognostic information on outcome beyond early infancy in hypoxic-ischemic encephalopathy and therapeutic hypothermia does not change its prognostic value.
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- 2017
20. Neural signature of tDCS, tPCS and their combination
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Aura Hurtado-Puerto, Cristina Russo, Aurore Thibaut, Felipe Fregni, Sandra Carvalho, Steven D. Freedman, Alícia Deitos, and Leon Morales-Quezada
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business.industry ,Computer science ,General Neuroscience ,05 social sciences ,Biophysics ,Pattern recognition ,050105 experimental psychology ,Signature (logic) ,lcsh:RC321-571 ,03 medical and health sciences ,0302 clinical medicine ,0501 psychology and cognitive sciences ,Neurology (clinical) ,Artificial intelligence ,business ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry ,030217 neurology & neurosurgery - Published
- 2017
21. Patterns of brain oscillations across different electrode montages in transcranial pulsed current stimulation
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Aurore Thibaut, Jorge Leite, Leon Morales-Quezada, Alejandra Vasquez, and Felipe Fregni
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Adult ,Male ,medicine.medical_treatment ,Alpha (ethology) ,Stimulation ,Electroencephalography ,Transcranial Direct Current Stimulation ,050105 experimental psychology ,Article ,03 medical and health sciences ,Young Adult ,0302 clinical medicine ,Neuromodulation ,Neuroplasticity ,medicine ,Humans ,0501 psychology and cognitive sciences ,Theta Rhythm ,Electrodes ,Cerebral Cortex ,medicine.diagnostic_test ,Transcranial direct-current stimulation ,business.industry ,General Neuroscience ,05 social sciences ,Alpha Rhythm ,medicine.anatomical_structure ,Cerebral cortex ,Electrode ,Female ,business ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Transcranial pulsed current stimulation (tPCS) is a neuromodulatory technique that has been studied in the last decade. Several parameters have been assessed independently to optimize the effects. Our aim was to explore the effects of tPCS using different montages on cortical brain oscillations indexed by power spectrum and interhemispheric coherence in different electroencephalography frequency bands. Twenty healthy individuals were randomized to receive either active tPCS or sham intervention using the following bilateral montages: ear clip (conventional), ear hook, or mastoid placement. Electroencephalography was recorded before and after the electroencephalography intervention to assess tPCS-induced after effects. Our results showed that active tPCS with bimastoid montage increased significantly alpha absolute power (P =0.0166) and low alpha (P =0.0014) in the frontal region, as well as in the low alpha power spectrum in the central (P =0.0001) and parieto-occipital regions (P =0.0068) compared with the other montages. For interhemispheric coherence analysis, the Kruskal–Wallis test showed a significant main effect of group for theta (P =0.0012) in the frontal region, mainly for ear-clip montage. Our findings evidenced that tPCS delivered through different electrode montages exert different effects on cortical brain oscillations and thus have a different neural signature. We discuss the implications of these findings as well as potential clinical explorations of this technique.
- Published
- 2017
22. Incidence, Predictors, and Clinical Impact of Venous Thromboembolism on Outcomes and Resource Utilization after Adult Lung Transplantation
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Dalia Larios, Clara M. Kerwin, Luis E. De Leon Morales, Sameer A. Hirji, and Gita N. Mody
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medicine.medical_specialty ,business.industry ,Incidence (epidemiology) ,medicine.medical_treatment ,Emergency medicine ,medicine ,Lung transplantation ,Surgery ,business ,Venous thromboembolism ,Resource utilization - Published
- 2018
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23. Neurofeedback impacts cognition and quality of life in pediatric focal epilepsy: An exploratory randomized double-blinded sham-controlled trial
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Ted J. Kaptchuk, Diana Martinez, Leon Morales-Quezada, Gloria Y. Yeh, Mirret M. El-Hagrassy, and M. Barry Sterman
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medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,Cognition ,Electroencephalography ,Placebo ,medicine.disease ,law.invention ,03 medical and health sciences ,Behavioral Neuroscience ,Epilepsy ,0302 clinical medicine ,Physical medicine and rehabilitation ,Neurology ,Quality of life ,Sensorimotor rhythm ,Randomized controlled trial ,law ,medicine ,030212 general & internal medicine ,Neurology (clinical) ,Neurofeedback ,business ,030217 neurology & neurosurgery - Abstract
Objective Children with epilepsy experience cognitive deficits and well-being issues that have detrimental effects on their development. Pharmacotherapy is the standard of care in epilepsy; however, few interventions exist to promote cognitive development and to mitigate disease burden. We aimed to examine the impact of two different modalities of neurofeedback (NFB) on cognitive functioning and quality-of-life (QOL) measurements in children and adolescents with controlled focal epilepsy. The study also explored the effects of NFB on clinical outcomes and electroencephalography (EEG) quantitative analysis. Methods Participants (n = 44) with controlled focal epilepsy were randomized to one of three arms: sensorimotor rhythm (SMR) NFB (n = 15), slow cortical potentials (SCP) NFB (n = 16), or sham NFB (n = 13). All participants received 25 sessions of intervention. The attention switching task (AST), Liverpool Seizure Severity Scale (LSSS), seizure frequency (SF), EEG power spectrum, and coherence were measured at baseline, postintervention, and at 3-month follow-up. Results In children and adolescents with controlled focal epilepsy, SMR training significantly reduced reaction time in the AST (p = 0.006), and this was correlated with the difference of change for theta power on EEG (p = 0.03); only the SMR group showed a significant decrease in beta coherence (p = 0.03). All groups exhibited improvement in QOL (p = Conclusions This study provides the first data on two NFB modalities (SMR and SCP) including cognitive, neurophysiological, and clinical outcomes in pediatric epilepsy. Sensorimotor rhythm NFB improved cognitive functioning, while all the interventions showed improvements in QOL, demonstrating a powerful placebo effect in the sham group.
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- 2019
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24. Abstract #111: Transcranial Direct Current Stimulation (tDCS) in Cerebral Palsy: Open-label Safety and Feasibility Study
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Camila Bonin Pinto, Leon Morales-Quezada, Mirret M. El-Hagrassy, Ana Luiza Zaninotto, Cristina Russo, and Felipe Fregni
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medicine.medical_specialty ,Transcranial direct-current stimulation ,business.industry ,General Neuroscience ,medicine.medical_treatment ,Biophysics ,medicine.disease ,lcsh:RC321-571 ,Cerebral palsy ,Physical medicine and rehabilitation ,Medicine ,Neurology (clinical) ,Open label ,business ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry - Published
- 2019
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25. Ship ballast tanks a review from microbial corrosion and electrochemical point of view
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Fraddry D’Souza, A. Heyer, C.F. Leon Morales, G.M. Ferrari, J.H.W. de Wit, and Johannes M. C. Mol
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Integral model ,Ballast ,Engineering ,Environmental Engineering ,Accident prevention ,business.industry ,Environmental engineering ,Ocean Engineering ,Electrochemical corrosion ,Corrosion ,Microbial corrosion ,Biochemical engineering ,business ,Corrosion prevention - Abstract
Microbiologically Influenced Corrosion (MIC) is the term used for the phenomenon in which corrosion is initiated and/or accelerated by the activities of microorganisms. MIC is a very serious problem for the ship industry as it reduces structural lifetime in combination with safety risks for crewmembers or inspection personal and increases maintenance costs. This review aims to focus on the importance and mechanisms of MIC in ship ballast tanks (SBTs). First section presents a literature review of general aspects of ballast tanks: structural properties including predominant environmental conditions. Second section summarizes the fundamental corrosion mechanisms within SBTs from an electrochemical point of view. Third section links microbial corrosion mechanism with electrochemical processes summarizing types of microorganisms, mechanisms of MIC and possible triggers for biofilm formation within this enclosed environment. For this an integral model, linking environmental parameters such as oxygen concentration, corrosion rate, nutrient availability and the microbial species of this environment is introduced in this paper. Fourth section gives an outlook on surface treatment and coating application in SBT. The last section considers the practical aspects of MIC detection and possible counterstrategies for engineers/operators and inspection personal. This paper gives a comprehensive overview of MIC processes in ship ballast tanks addressing engineers, equipment manufacturers and operators by offering practical solutions for an appropriate SBT management. © 2013 Elsevier Ltd.
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- 2013
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26. Corrigendum to 'Transcranial Direct Current Stimulation in Epilepsy' Brain Stimulation [8 (2015) 455–464]
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David J. Anschel, Daniel San-Juan, Adolfo Josué Orozco Garduño, Rafael Vázquez Gregorio, Dulce Anabel Espinoza López, Leon Morales-Quezada, Felipe Fregni, Maricarmen Fernández González-Aragón, and Mario Alonso-Vanegas
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Rehabilitation hospital ,medicine.medical_specialty ,Transcranial direct-current stimulation ,business.industry ,General Neuroscience ,medicine.medical_treatment ,Biophysics ,Medical school ,medicine.disease ,lcsh:RC321-571 ,Epilepsy ,Family medicine ,Brain stimulation ,Medicine ,Neurology (clinical) ,General hospital ,business ,lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry - Abstract
a Neurophysiology Department, National Institute of Neurology and Neurosurgery “Manuel Velasco Suarez”, Av. Insurgentes Sur 3877, Col. La Fama, Tlalpan, Mexico D.F. 14269, Mexico b Laboratory of Neuromodulation, Department of Physical Medicine & Rehabilitation, Spaulding Rehabilitation Hospital and Massachusetts General Hospital, Harvard Medical School, 300 1st Ave, Charlestown, MA 02129, USA c Neurosurgery Department, National Institute of Neurology and Neurosurgery “Manuel Velasco Suarez”, Av. Insurgentes Sur 3877, Col. La Fama, Tlalpan, Mexico D.F. 14269, Mexico d Comprehensive Epilepsy Center of Long Island, St. Charles Hospital, 200 Belle Terre Rd., Port Jefferson, NY 11777, USA
- Published
- 2016
27. Robust excitation control design using sliding-mode technique for multimachine power systems
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J. De Leon-Morales, Oscar Salas-Peña, Leonid Fridman, A. Colbia-Vega, and M.T. Mata-Jiménez
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Engineering ,Computer simulation ,business.industry ,Energy Engineering and Power Technology ,Control engineering ,Decentralised system ,Nonlinear system ,Differentiator ,Electric power system ,Robustness (computer science) ,Control theory ,Control system ,Electrical and Electronic Engineering ,Robust control ,business - Abstract
An output feedback controller is proposed to enhance the transient stability of nonlinear multimachine power systems considered as a classical model with flux decay dynamics. Combining high-order sliding-mode techniques with a robust high-order sliding-mode differentiator, a robust decentralized controller is obtained. Numerical results are presented to illustrate the performance of the proposed control scheme and its robustness properties.
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- 2008
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28. Paraspinous Lidocaine Injection for Chronic Nonspecific Low Back Pain: A Randomized Controlled Clinical Trial
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Satiko Tomikawa Imamura, Linamara Rizzo Battistella, Thais Raquel Martins Filippo, Fábio Marcon Alfieri, Felipe Fregni, Marta Imamura, Ivan Dias da Rocha, Raul Bolliger Neto, Luis G. Onoda Tomikawa, Rosa Alves Targino, Leon Morales-Quezada, and Luis Carlos Onoda Tomikawa
- Subjects
Adult ,Male ,medicine.medical_specialty ,Lidocaine ,ESTUDOS RANDOMIZADOS ,Article ,law.invention ,03 medical and health sciences ,Disability Evaluation ,0302 clinical medicine ,Randomized controlled trial ,law ,Threshold of pain ,medicine ,Humans ,030212 general & internal medicine ,Anesthetics, Local ,Adverse effect ,Injections, Spinal ,Pain Measurement ,Retrospective Studies ,Analysis of Variance ,business.industry ,Standard treatment ,Chronic pain ,Middle Aged ,medicine.disease ,Low back pain ,Surgery ,Exercise Therapy ,Anesthesiology and Pain Medicine ,Treatment Outcome ,Neurology ,Anesthesia ,Hyperalgesia ,Female ,Neurology (clinical) ,medicine.symptom ,Chronic Pain ,business ,Low Back Pain ,030217 neurology & neurosurgery ,medicine.drug - Abstract
In this large, sham-controlled, randomized trial, we examined the efficacy of the combination of standard treatment and paraspinous lidocaine injection compared with standard therapy alone in subjects with chronic low back pain. There is little research-based evidence for the routine clinical use of paraspinous lidocaine injection for low back pain. A total of 378 subjects with nonspecific chronic low back pain were randomized to 3 groups: paraspinous lidocaine injection, analgesics, and exercises (group 1, LID-INJ); sham paraspinous lidocaine injection, analgesics, and exercises (group 2, SH-INJ); and analgesics and exercises (group 3, STD-TTR). A blinded rater assessed the study outcomes at 3 time points: baseline, after treatment, and after 3 months of follow-up. There were increased frequency of pain responses and better low back functional scores in the LID-INJ group compared with the SH-INJ and STD-TTR groups. These effects remained at the 3-month follow-up but differed between all 3 groups. There were significant changes in pain threshold immediately after treatment, supporting the effects of this intervention in reducing central sensitization. Paraspinous lidocaine injection therapy is not associated with a higher risk of adverse effects compared with conventional treatment and sham injection. Its effects on hyperalgesia might correlate with changes in central sensitization.NCT02387567.There are few data to support paraspinous lidocaine injection use in patients with nonspecific chronic low back pain. Our results show that this therapy when combined with standard therapy significantly increases the number of responders versus standard treatment alone. Its effects on hyperalgesia might correlate with a change in central sensitization.
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- 2016
29. Observer-based controller for position regulation of stepping motor
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J. De Leon-Morales, O.H. Guevara, and Rafael Castro-Linares
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Equilibrium point ,Engineering ,Observer (quantum physics) ,Rotor (electric) ,business.industry ,Open-loop controller ,Control engineering ,Angular velocity ,law.invention ,Nonlinear system ,Exponential stability ,Control and Systems Engineering ,Control theory ,law ,Electrical and Electronic Engineering ,business ,Instrumentation - Abstract
The design of a controller-observer scheme for the exponential stabilisation of a permanent magnet stepper motor is proposed. The technique is based on sliding-mode techniques and nonlinear observers. Representing the stepper motor model as a singularly perturbed nonlinear system, a position regulation controller is obtained. Since this controller depends on the mechanical variables, load torque and equilibrium point, under the assumption that the rotor position is available for measurement, an observer design is presented to estimate the angular speed and load torque. Furthermore, a stability analysis of the closed-loop system is also made to provide sufficient conditions for the exponential stability of the full-order closed-loop system when the angular speed and load torque are estimated by means of the observer. The proposed scheme is applied to the model of a permanent-magnet stepper motor.
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- 2005
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30. Output feedback passivity-based control of facts
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Gerardo Espinosa-Pérez, J. De Leon-Morales, and Paul Maya-Ortiz
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Lyapunov function ,Engineering ,business.industry ,Passivity ,Thyristor ,Control engineering ,Nonlinear control ,Nonlinear system ,symbols.namesake ,Electric power system ,Exponential stability ,Control theory ,symbols ,business - Abstract
In this paper an output feedback controller is designed for the thyristor controlled series capacitor (TCSC) aimed at enhancing power system stability. The closed loop system is completed by considering a damping injection passivity-based controller and a non linear observer. It is shown, by using Lyapunov arguments, the asymptotic stability properties of the closed loop system.
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- 2004
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31. Observer-based control of a synchronous generator: a Hamiltonian approach
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J. De Leon-Morales, I. Macias-Cardoso, and Gerardo Espinosa-Pérez
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Equilibrium point ,Electric machine ,Engineering ,business.product_category ,business.industry ,Energy Engineering and Power Technology ,Permanent magnet synchronous generator ,Hamiltonian system ,Nonlinear system ,Control theory ,Control system ,Systems design ,Electrical and Electronic Engineering ,business ,Hamiltonian (control theory) - Abstract
In this paper, we propose a controller design for a class of nonlinear systems using Passive and Hamiltonian design techniques. The result is applied to a synchronous generator in order to synthesize an excitation control, which allows stabilization of the generator at its equilibrium position. The main characteristics of this proposition are that neither the equilibrium point of the system must be known nor the state of the generator be available for measurement. The performance of the proposed controller is validated through digital simulations.
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- 2002
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32. Intensity-dependent effects of transcranial pulsed current stimulation on interhemispheric connectivity: a high-resolution qEEG, sham-controlled study
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Lee Hadlington, Joanna Ripoll Rozisky, Leon Morales-Quezada, Laura Castillo Saavedra, and Felipe Fregni
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Adult ,medicine.diagnostic_test ,business.industry ,General Neuroscience ,Alpha (ethology) ,Electrical brain activity ,Brain ,Stimulation ,Cognition ,Electroencephalography ,Neuromodulation (medicine) ,Electric Stimulation ,Intensity (physics) ,Alpha Rhythm ,Double-Blind Method ,Surveys and Questionnaires ,medicine ,Humans ,Beta Rhythm ,Theta Rhythm ,business ,Neuroscience - Abstract
Defining optimal parameters for stimulation is a critical step in the development of noninvasive neuromodulation techniques. Transcranial pulsed current stimulation (tPCS) is emerging as another option in the field of neuromodulation; however, little is known about its mechanistic effects on electrical brain activity and how it can modulate its oscillatory patterns. The aim of this study was to identify the current intensity needed to exert an effect on quantitative electroencephalogram (qEEG) measurements. Forty healthy volunteers were randomized to receive a single session of sham or active stimulation at 0.2, 1, or 2 mA current intensity with a random frequency with an oscillatory pulsed range between 1 and 5 Hz. We conducted an exploratory frequency domain analysis to detect changes in absolute power for theta, alpha, and beta frequency bands and also interhemispheric coherence for alpha, theta, and four different sub-bands. Cognitive and nonspecific adverse effects were also recorded. Our results showed that both 1 and 2 mA can modulate interhemispheric coherence at the fronto-temporal areas for the theta band as compared with sham, while 2 mA also increased the low-beta and high-beta interhemispheric coherence at the same anatomical location. There were no group differences for adverse effects and participants could not guess correctly whether they received active versus sham stimulation. On the basis of our results, we conclude that tPCS is associated with an intensity-dependent facilitatory effect on interhemispheric connectivity. These results can guide future tPCS applications and will define its role as a neuromodulatory technique in the field.
- Published
- 2014
33. Control of a flexible joint robot manipulator via a non-linear control-observer scheme
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J. De Leon-Morales, Rafael Castro-Linares, Ja. Alvarez-Gallegos, and J.G. Alvarez-Leal
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Scheme (programming language) ,Engineering ,Observer (quantum physics) ,Scale (ratio) ,business.industry ,Stability (learning theory) ,Estimator ,Control engineering ,Nonlinear control ,Tracking (particle physics) ,Computer Science Applications ,Control and Systems Engineering ,Control theory ,Robot ,business ,computer ,computer.programming_language - Abstract
A non-linear controller-observer scheme for the output tracking of a class of non-linear singularly perturbed systems based on a two-time scale sliding-mode technique and a high gain estimator, is presented. An analysis of stability of the resultant closed-loop system is given. The proposed scheme is applied to the model of a two degrees of freedom flexible joint robot to show the controller-observer methodology proposed.
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- 2001
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34. Observer-based control for a synchronous generator
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S. Acha-Daza and J. De Leon-Morales
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Engineering ,Observer (quantum physics) ,Rotor (electric) ,business.industry ,Energy Engineering and Power Technology ,Permanent magnet synchronous generator ,Nonlinear control ,Separation principle ,law.invention ,law ,Control theory ,Control system ,Electrical and Electronic Engineering ,business ,Synchronous motor - Abstract
In this paper, a control law based on an observer for a class of nonlinear systems in a triangular form is presented. This control scheme is applied to a synchronous generator model; the performance of this controller is shown assuming that the only measurements available are those from the rotor angle. Simulation results, when the controller is modified to track a desired reference signal, are shown.
- Published
- 2000
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35. Adaptive super twisting flight control-observer for a fixed wing UAV
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Herman Castañeda, Oscar Salas-Peña, and Jesas de Leon Morales
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Attitude control ,Engineering ,Adaptive control ,Inertial frame of reference ,Robustness (computer science) ,Control theory ,business.industry ,Airspeed ,State vector ,Perturbation (astronomy) ,Control engineering ,Robust control ,business - Abstract
A flight robust control for a fixed wing Unmanned Aerial Vehicle (UAV) is addressed in this paper. Attitude and airspeed controllers are designed using an Adaptive super twisting control algorithm (ASTA). In order to implement such controller an observer based on super-twisting control algorithm (STO) provide estimation of inertial state vector despite of noisy. Furthermore, this control scheme increase robustness since it is not necessary to know the bound of perturbation. Taking into account modeling uncertainties and external disturbances, simulation tests have been done in order to illustrate performance of proposed control scheme.
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- 2013
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36. Methods to focalize noninvasive electrical brain stimulation: principles and future clinical development for the treatment of pain
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Jorge Leon Morales-Quezada, Thais Cano, Felipe Fregni, and Marom Bikson
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Neuronal Plasticity ,Transcranial direct-current stimulation ,business.industry ,General Neuroscience ,medicine.medical_treatment ,Brain ,Brain mapping ,Transcranial Magnetic Stimulation ,Clinical Practice ,Transcranial magnetic stimulation ,Brain stimulation ,Neuroplasticity ,medicine ,Humans ,Pain Management ,Pharmacology (medical) ,Neurology (clinical) ,Chronic Pain ,business ,Neuroscience ,Electrical brain stimulation - Abstract
There has been increased interest in noninvasive brain stimulation (NIBS) as a technique to investigate and treat neuropsychiatric disorders [1,2]. Usually, NIBS is targeted to specific dysfunction...
- Published
- 2013
37. A Preliminary Study on qEEG in Burn Patients With Chronic Pruritus
- Author
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Bianca Fernandes-Marcondes, Leon Morales-Quezada, Felipe Fregni, Fiorella K. Miraval, Deborah Nadler, Jeffrey C. Schneider, Vivian L. Shie, Carolina Santiago, and Colleen M. Ryan
- Subjects
Quality of life ,Burn injury ,medicine.medical_specialty ,Alpha (ethology) ,Brain waves ,Electroencephalography ,Theta power ,03 medical and health sciences ,0302 clinical medicine ,medicine ,medicine.diagnostic_test ,business.industry ,Pruritus ,Rehabilitation ,Healthy subjects ,030208 emergency & critical care medicine ,Anesthesia ,Physical therapy ,Itching ,Original Article ,medicine.symptom ,Burns ,business ,030217 neurology & neurosurgery ,Chronic pruritus - Abstract
Objective To explore and determine the reorganizational changes in the cortical neural circuits associated with pruritis, this study was undertaken to compare the electroencephalography (EEG) changes in burn patients having primary symptoms of chronic itching (pruritis) and their paired healthy subjects. Methods Eight subjects were recruited for this exploratory pilot study: 4 patients with pruritus after burn injury matched by gender and age with 4 healthy subjects. EEG recordings were analyzed for absolute alpha, low beta, high beta, and theta power for both groups. Results The mean age of the burn patients was 41.75 years; while the mean age for the matched healthy subjects was 41.5 years. All subjects were male. A decreased alpha activity was observed in the occipital channels (0.82 vs. 1.4; p=0.01) and a decreased low beta activity in the frontal area (0.22 vs. 0.4; p=0.049) in eyes closed conditions. An overall decreased theta trend was observed in both the eyes open and eyes closed conditions in burn patients, compared to healthy individuals. Conclusion This preliminary study presents initial evidence that chronic pruritus in burn subjects may be associated with brain reorganizational changes at the cortical level characterized by an EEG pattern.
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- 2017
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38. 383. Clinico-Pathological Correlation in the Earliest Stages of Muscular Dystrophy Suggests Sensitive Physiological Parameters as Novel Primary Endpoints for Systemic Gene Therapy
- Author
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Yafeng Song, Hansell H. Stedman, Andy Mead, Leon Morales, Benjamin W. Kozyak, and Joe Kornegay
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Pharmacology ,Inotrope ,medicine.medical_specialty ,biology ,business.industry ,Duchenne muscular dystrophy ,Stroke volume ,medicine.disease ,medicine.anatomical_structure ,Internal medicine ,Heart failure ,Drug Discovery ,Genetics ,medicine ,biology.protein ,Respiratory muscle ,Vascular resistance ,Cardiology ,Molecular Medicine ,Muscular dystrophy ,Dystrophin ,business ,Molecular Biology - Abstract
The clinical progression of Duchenne Muscular Dystrophy (DMD) begins with locomotive symptoms in childhood but eventually includes symptoms of severe cardiorespiratory failure. Our studies in mdx mice and GRMD dogs have reavealed surprisingly large early deficits in physiological reserve, attributable to the deficiency of dystrophin. In young GRMD dogs, the findings of diaphragmatic fibrosis and myofiber shortening correlated strongly with non-invasively measured abnormalities in respiratory muscle recruitment. In juvenile GRMD dogs without clinical signs of heart failure, detailed studies of cardiac mechanics revealed profoundly abnormal Frank-Starling and inotropic responses. Thus, submaximal exercise loading has the capactiy to reveal very early, otherwise subclinical deficits in physiological reserve. We have utilized several non-invasive systems to measure integrative cardiopulmonary mechanics in animals trained to undertake submaximal volitional exercise. Our findings demonstrate the possibility of continuous non-invasive monitoring of cardiac output, stroke volume, systemic vascular resistance, and several ventilatory parameters in young dogs and children during treadmill exercise, as well as upright and recumbent bicycling at work outputs appropriate for low risk serial testing in the earliest stages of DMD. As the field contemplates primary endpoints for use in trials of systemic gene therapy, these metrics hold promise as the most sensitive measurements of the earliest functional deficits in organ systems eventually responsible for the lethality of DMD.
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- 2016
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39. On the real time estimation of the wind speed for wind energy conversion systems
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N. Salas-Cabrera, Jonathan C. Mayo-Maldonado, J. De Leon-Morales, R. Castillo-Ibarra, Julio C. Rosas-Caro, R. Salas-Cabrera, Rafael Castillo-Gutierrez, M. Gomez-Garcia, and C. Garcia-Guendulain
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Engineering ,Emulation ,Wind power ,business.industry ,Astrophysics::High Energy Astrophysical Phenomena ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Turbine ,GeneralLiterature_MISCELLANEOUS ,Wind speed ,Wind energy conversion ,Adaptive observer ,Control theory ,Time estimation ,ComputerApplications_MISCELLANEOUS ,Physics::Space Physics ,Astrophysics::Solar and Stellar Astrophysics ,business ,Computer Science::Operating Systems ,Physics::Atmospheric and Oceanic Physics ,Simulation - Abstract
This paper presents the experimental results of the real time estimation of the wind speed for a wind turbine. In order to estimate the wind speed, an adaptive observer is employed. A wind turbine emulator was designed for validating the theoretical results. The wind turbine emulator is able to simulate the dynamics of a real wind turbine. For emulation purposes the wind speed is considered as a known input. On the other hand, for the adaptive observer the wind speed is considered as an unknown parameter. A free Linux-based real time platform was used for the experimental setup.
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- 2010
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40. A feedback control design for a class of nonlinear systems
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Mehrdad Saif, J. De Leon Morales, and K. Busawon
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Controllability ,Engineering ,Class (computer programming) ,Nonlinear system ,Exponential stability ,business.industry ,Control theory ,Control engineering ,Affine transformation ,Design methods ,business ,Adaptation (computer science) - Abstract
We propose a high gain controller design for a class of single-input control affine systems. The design methodology adopted is an adaptation of linear design techniques to solve nonlinear control design problems. Consequently, the design is simple and easy to implement. An application dealing with a flexible joint mechanism is made to show the performance of the proposed controller.
- Published
- 1999
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41. Observer-based controller for induction motors
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J.M. Dion, J. De Leon-Morales, R. Alvarez-Salas, and Luc Dugard
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Engineering ,Nonlinear system ,Observer (quantum physics) ,Control theory ,business.industry ,Cascade ,Open-loop controller ,Control engineering ,General Medicine ,Nonlinear control ,Separation principle ,business ,Induction motor - Abstract
This paper deals with the observation and control of a class of nonlinear systems. A cascade observer for a class of state affine nonlinear systems is proposed. Considering an output feedback tracking controller, a stability analysis of the resulting closed-loop system is given. The proposed observed-based controller is then shown to be closed loop stable and is applied to an induction motor industrial setup to show the proposed methodology.
42. Nonlinear control and observation of induction motors. Validation on an industrial benchmark
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R. Alvarez-Salas, Luc Dugard, J. De Leon-Morales, and J.M. Dion
- Subjects
Singular perturbation ,Engineering ,Observer (quantum physics) ,business.industry ,MathematicsofComputing_NUMERICALANALYSIS ,Control engineering ,Nonlinear control ,Tracking (particle physics) ,Quantitative Biology::Subcellular Processes ,Control theory ,Benchmark (computing) ,Rotor flux ,business ,Induction motor - Abstract
An observer-based controller for tracking rotor flux and rotor speed references of an induction motor is designed, combining the advantages of the singular perturbation methods and sliding modes techniques. This control strategy is implementing on an experimental setup where experimental results are given.
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