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Sample records for high-frequency electrical stimulation

  1. Neural correlates of heterotopic facilitation induced after high frequency electrical stimulation of nociceptive pathways

    NARCIS (Netherlands)

    Broeke, E.N. van den; Heck, C.H. van; Rijn, C.M. van; Wilder-Smith, O.H.G.

    2011-01-01

    Background High frequency electrical stimulation (HFS) of primary nociceptive afferents in humans induce a heightened sensitivity in the surrounding non-stimulated skin area. Several studies suggest that this heterotopic effect is the result of central (spinal) plasticity. The aim of this study is

  2. Neural correlates of heterotopic facilitation induced after high frequency electrical stimulation of nociceptive pathways

    NARCIS (Netherlands)

    Broeke, E.N. van den; Heck, C.H. van; Rijn, C.M. van; Wilder-Smith, O.H.G.

    2011-01-01

    BACKGROUND: High frequency electrical stimulation (HFS) of primary nociceptive afferents in humans induce a heightened sensitivity in the surrounding non-stimulated skin area. Several studies suggest that this heterotopic effect is the result of central (spinal) plasticity. The aim of this study is

  3. Differential responses to high-frequency electrical stimulation in ON and OFF retinal ganglion cells

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    Twyford, Perry; Cai, Changsi; Fried, Shelley

    2014-04-01

    Objective. The field of retinal prosthetics for artificial vision has advanced considerably in recent years, however clinical outcomes remain inconsistent. The performance of retinal prostheses is likely limited by the inability of electrical stimuli to preferentially activate different types of retinal ganglion cell (RGC). Approach. Here we examine the response of rabbit RGCs to high-frequency stimulation, using biphasic pulses applied at 2000 pulses per second. Responses were recorded using cell-attached patch clamp methods, and stimulation was applied epiretinally via a small cone electrode. Main results. When prolonged stimulus trains were applied to OFF-brisk transient (BT) RGCs, the cells exhibited a non-monotonic relationship between response strength and stimulus amplitude; this response pattern was different from those elicited previously by other electrical stimuli. When the amplitude of the stimulus was modulated transiently from a non-zero baseline amplitude, ON-BT and OFF-BT cells exhibited different activity patterns: ON cells showed an increase in activity while OFF cells exhibited a decrease in activity. Using a different envelope to modulate the amplitude of the stimulus, we observed the opposite effect: ON cells exhibited a decrease in activity while OFF cells show an increase in activity. Significance. As ON and OFF RGCs often exhibit opposing activity patterns in response to light stimulation, this work suggests that high-frequency electrical stimulation of RGCs may be able to elicit responses that are more physiological than traditional pulsatile stimuli. Additionally, the prospect of an electrical stimulus capable of cell-type specific selective activation has broad applications throughout the fields of neural stimulation and neuroprostheses.

  4. High Frequency Electrical Stimulation of Lateral Habenula Reduces Voluntary Ethanol Consumption in Rats

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    Li, Jing; Zuo, Wanhong; Fu, Rao; Xie, Guiqin; Kaur, Amandeep; Bekker, Alex

    2016-01-01

    Background: Development of new strategies that can effectively prevent and/or treat alcohol use disorders is of paramount importance, because the currently available treatments are inadequate. Increasing evidence indicates that the lateral habenula (LHb) plays an important role in aversion, drug abuse, and depression. In light of the success of high-frequency stimulation (HFS) of the LHb in improving helplessness behavior in rodents, we assessed the effects of LHb HFS on ethanol-drinking behavior in rats. Methods: We trained rats to drink ethanol under an intermittent access two-bottle choice procedure. We used c-Fos immunohistochemistry and electrophysiological approaches to examine LHb activity. We applied a HFS protocol that has proven effective for reducing helplessness behavior in rats via a bipolar electrode implanted into the LHb. Results: c-Fos protein expression and the frequency of both spontaneous action potential firings and spontaneous excitatory postsynaptic currents were higher in LHb neurons of ethanol-withdrawn rats compared to their ethanol-naïve counterparts. HFS to the LHb produced long-term reduction of intake and preference for ethanol, without altering locomotor activity. Conversely, low-frequency electrical stimulation to the LHb or HFS applied to the nearby nucleus did not affect drinking behavior. Conclusions: Our results suggest that withdrawal from chronic ethanol exposure increases glutamate release and the activity of LHb neurons, and that functional inhibition of the LHb via HFS reduces ethanol consumption. Thus, LHb HFS could be a potential new therapeutic option for alcoholics. PMID:27234303

  5. The effect of high-frequency neuromuscular electrical stimulation training on skeletal muscle properties in mice

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    Valenzuela Pedro L.

    2017-01-01

    Full Text Available The aim of this study was to analyze the effects of high-frequency neuromuscular electrical stimulation training (NMES on the structure, function and oxidative capacity of the skeletal muscle using a mice model (C57BL/6J strain, n=8. The left tibialis anterior muscle in mice was electro-stimulated (ST whereas the right muscle was maintained as an internal control (CT. The ST limb was submitted to eight surface (100 Hz NMES sessions in two weeks, with a minimum gap of 24 h between sessions. NMES training increased muscle mass (42.0±3.3 vs. 36.1±5.4 mg, p<0.05, effect size [ES] r=0.55, the mean fiber cross-sectional area (FCSA (3318±333 vs. 2577±405 μ2, p<0.001, ES=0.71, maximal force (224.7±13.8 vs. 184.5±30.9 mN, p<0.01, ES=0.64, and the rate of force development (1.63±0.14 vs. 1.34±0.20 mN/ms, p<0.05, ES=0.64, with no effects on the muscle oxidative profile. These results demonstrate that surface NMES induced muscle hypertrophy and instigated an improvement in the contractile properties of the TA muscle in mice. Therefore, this animal model appears to be suitable for the study of hypertrophic processes as it enables better control of the stimulus properties (intensity, duration, frequency, etc. than other traditionally used animal models and does not require negative reinforcements or surgical procedures.

  6. Low- and high-frequency transcutaneous electrical nerve stimulation have no deleterious or teratogenic effects on pregnant mice.

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    Yokoyama, L M; Pires, L A; Ferreira, E A Gonçalves; Casarotto, R A

    2015-06-01

    To evaluate the effects of application of transcutaneous electrical nerve stimulation (TENS) at low and high frequencies to the abdomens of Swiss mice throughout pregnancy. Experimental animal study. Research laboratory. Thirty Swiss mice received TENS throughout pregnancy. They were divided into three groups (n=10): placebo, low-frequency TENS (LF group) and high-frequency TENS (HF group). In the placebo group, the electrodes were applied to the abdominal region without any electrical current. In the LF group, the frequency was 10 Hz, pulse duration was 200 μs and intensity started at 2 mA. In the HF group, the same parameters were applied and the frequency was 150 Hz. All stimulation protocols were applied for 20 min/day from Day 0 until Day 20. The pregnant mice were weighed on Days 0, 7, 14 and 20 to verify weekly weight gain by two-way analysis of variance. The numbers of fetuses, placentas, implantations, resorptions and major external fetal malformations on Day 20 were analysed using the Kruskal-Wallis test. No significant differences were found between the placebo and TENS groups (P>0.05). Application of low- and high-frequency TENS to the abdomens of pregnant mice did not cause any deleterious or major teratogenic effects. Copyright © 2014 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

  7. Chronic Localized High Frequency Electrical Stimulation Within the Myocardial Infarct: Effects on Matrix Metalloproteinases and Regional Remodeling

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    Mukherjee, Rupak; Rivers, William T.; Ruddy, Jean Marie; Matthews, Robert G.; Koval, Christine N.; Plyler, Rebecca A.; Chang, Eileen I.; Patel, Risha K.; Kern, Christine B.; Stroud, Robert E.; Spinale, Francis G.

    2010-01-01

    Background Disruption of the balance between matrix metalloproteinases (MMP) and MMP inhibitors (TIMPs) within a myocardial infarct (MI) contribute to left ventricular (LV) wall thinning and changes in regional stiffness at the MI region. This study tested the hypothesis that a targeted regional approach through localized high frequency stimulation (LHFS) using low amplitude electrical pulses instituted within a formed MI scar would alter MMP/TIMP levels and prevent MI thinning. Methods/Results At 3 wks following MI, pigs were randomized for LHFS (n=7, 240bpm, 0.8V, 0.05ms pulses) or unstimulated (UNSTIM, n=10). At 4 wks post-MI, LV wall thickness (echo, 0.89±0.07 vs 0.67±0.08 cm, p<0.05) and regional stiffness (piezoelectric crystals, 14.70±2.08 vs 9.11±1.24, p<0.05) were higher with LHFS than UNSTIM. In vivo interstitial MMP activity (fluorescent substrate cleavage, 943±59 vs 1210±72 units, p<0.05) in the MI region was lower with LHFS than in UNSTIM. In the MI region, MMP-2 levels were lower, while TIMP-1 and collagen levels were higher with LHFS than in UNSTIM (all p<0.05). Transforming growth factor-β (TGF-β) receptor 1 and phosphorylated SMAD-2/3 levels within the MI region were higher with LHFS than in UNSTIM. Electrical stimulation (4Hz) of isolated fibroblasts resulted in a reduction of MMP-2 and MT1-MMP levels, but increased TIMP-1 levels compared to unstimulated fibroblasts. Conclusions These unique findings demonstrate that LHFS of the MI region altered LV wall thickness and material properties, likely due to reduced regional MMP activity. Thus, LHFS may provide a novel means to favorably modify LV remodeling post-MI. PMID:20566951

  8. Value of electrical stimulation and high frequency oscillations (80–500 Hz) in identifying epileptogenic areas during intracranial EEG recordings

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    Jacobs, Julia; Zijlmans, Maeike; Zelmann, Rina; Olivier, André; Hall, Jeffery; Gotman, Jean; Dubeau, François

    2013-01-01

    Summary Purpose Electrical stimulation (ES) is used during intracranial electroencephalography (EEG) investigations to delineate epileptogenic areas and seizure-onset zones (SOZs) by provoking afterdischarges (ADs) or patients’ typical seizure. High frequency oscillations (HFOs—ripples, 80–250 Hz; fast ripples, 250–500 Hz) are linked to seizure onset. This study investigates whether interictal HFOs are more frequent in areas with a low threshold to provoke ADs or seizures. Methods Intracranial EEG studies were filtered at 500 Hz and sampled at 2,000 Hz. HFOs were visually identified. Twenty patients underwent ES, with gradually increasing currents. Results were interpreted as agreeing or disagreeing with the intracranial study (clinical-EEG seizure onset defined the SOZ). Current thresholds provoking an AD or seizure were correlated with the rate of HFOs of each channel. Results ES provoked a seizure in 12 and ADs in 19 patients. Sixteen patients showed an ES response inside the SOZ, and 10 had additional areas with ADs. The response was more specific for mesiotemporal than for neocortical channels. HFO rates were negatively correlated with thresholds for ES responses; especially in neo-cortical regions; areas with low threshold and high HFO rate were colocalized even outside the SOZ. Discussion Areas showing epileptic HFOs colocalize with those reacting to ES. HFOs may represent a pathologic correlate of regions showing an ES response; both phenomena suggest a more widespread epileptogenicity. PMID:19845730

  9. High-frequency electrical stimulation can be a complementary therapy to promote nerve regeneration in diabetic rats.

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    Chia-Hong Kao

    Full Text Available The purpose of this study was to evaluate whether 1 mA of percutaneous electrical stimulation (ES at 0, 2, 20, or 200 Hz augments regeneration between the proximal and distal nerve stumps in streptozotocin diabetic rats. A10-mm gap was made in the diabetic rat sciatic nerve by suturing the stumps into silicone rubber tubes. Normal animals were used as the controls. Starting 1 week after transection, ES was applied between the cathode placed at the distal stump and the anode at the proximal stump every other day for 3 weeks. At 4 weeks after surgery, the normal controls and the groups receiving ES at 20, and 200 Hz had a higher success percentage of regeneration compared to the ES groups at 0 and 2 Hz. In addition, quantitative histology of the successfully regenerated nerves revealed that the groups receiving ES at a higher frequency, especially at 200 Hz, had a more mature structure with more myelinated fibers compared to those in the lower-frequency ES groups. Similarly, electrophysiology in the ES group at 200 Hz showed significantly shorter latency, larger amplitude, larger area of evoked muscle action potentials and faster conduction velocity compared to other groups. Immunohistochemical staining showed that ES at a higher frequency could significantly promote calcitonin gene-related peptide expression in lamina I-II regions in the dorsal horn and recruit a higher number of macrophages in the diabetic distal sciatic nerve. The macrophages were found that they could stimulate the secretion of nerve growth factor, platelet-derived growth factor, and transforming growth factor-β in dissected sciatic nerve segments. The ES at a higher frequency could also increase cutaneous blood flow in the ipsilateral hindpaw to the injury. These results indicated that a high-frequency ES could be necessary to heal severed diabetic peripheral nerve with a long gap to be repaired.

  10. High-frequency, high-intensity transcutaneous electrical nerve stimulation as treatment of pain after surgical abortion.

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    Platon, B; Andréll, P; Raner, C; Rudolph, M; Dvoretsky, A; Mannheimer, C

    2010-01-01

    The aim of the study was to compare the pain-relieving effect and the time spent in the recovery ward after treatment with high-frequency, high-intensity transcutaneous electrical nerve stimulation (TENS) or intravenous (IV) conventional pharmacological treatment after surgical abortion. Two-hundred women who underwent surgical abortion and postoperatively reported a visual analogue scale (VAS) pain score3 were included. The patients were randomised to TENS or conventional pharmacological treatment for their postoperative pain. The TENS treatment was given with a stimulus intensity between 20 and 60 mA during 1 min and repeated once if insufficient pain relief (VAS3). In the conventional pharmacological treatment group, a maximum dose of 100 microg fentanyl was given IV. There was no difference between the groups with regard to pain relief according to the VAS pain score (TENS=VAS 1.3 vs. IV opioids=VAS 1.6; p=0.09) upon discharge from the recovery ward. However, the patients in the TENS group spent shorter time (44 min) in the recovery ward than the conventional pharmacological treatment group (62 min; p<0.0001). The number of patients who needed additional analgesics in the recovery ward was comparable in both groups, as was the reported VAS pain score upon leaving the hospital (TENS=2.0 vs. conventional pharmacological treatment=1.8, NS). These results suggest that the pain-relieving effect of TENS seems to be comparable to conventional pharmacological treatment with IV opioids. Hence, TENS may be a suitable alternative to conventional pain management with IV opioids after surgical abortion. Copyright 2009 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  11. High frequency spectral changes induced by single-pulse electric stimulation: Comparison between physiologic and pathologic networks.

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    Mălîia, Mihai Dragos; Donos, Cristian; Barborica, Andrei; Mindruta, Ioana; Popa, Irina; Ene, Mirela; Beniczky, Sándor

    2017-06-01

    To investigate functional coupling between brain networks using spectral changes induced by single-pulse electric stimulation (SPES). We analyzed 20 patients with focal epilepsy, implanted with depth electrodes. SPES was applied to each pair of adjacent contacts, and responses were recorded from all other contacts. The mean response amplitude value was quantified in three time-periods after stimulation (10-60, 60-255, 255-500ms) for three frequency-ranges (Gamma, Ripples, Fast-Ripples), and compared to baseline. A total of 30,755 responses were analyzed, taking into consideration three dichotomous pairs: stimulating in primary sensory areas (S1-V1) vs. outside them, to test the interaction in physiologic networks; stimulating in seizure onset zone (SOZ) vs. non-SOZ, to test pathologic interactions; recording in default mode network (DMN) vs. non-DMN. Overall, we observed an early excitation (10-60ms) and a delayed inhibition (60-500ms). More specifically, in the delayed period, stimulation in S1-V1 produced a higher gamma-inhibition in the DMN, while stimulation in the SOZ induced a higher inhibition in the epilepsy-related higher frequencies (Ripples and Fast-Ripples). Physiologic and pathologic interactions can be assessed using spectral changes induced by SPES. This is a promising method for connectivity studies in patients with drug-resistant focal epilepsy. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.

  12. The Effects of High-Frequency Transcutaneous Electrical Nerve Stimulation for Dental Professionals with Work-Related Musculoskeletal Disorders: A Single-Blind Randomized Placebo-Controlled Trial

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    Hye Rim Suh

    2015-01-01

    Full Text Available Work-related musculoskeletal symptom disorders (WMSDs have a significant issue for dental professionals. This study investigated the effects of high-frequency transcutaneous electrical nerve stimulation (TENS on work-related pain, fatigue, and the active range of motion in dental professionals. Among recruited 47 dental professionals with WMSDs, 24 subjects received high-frequency TENS (the TENS group, while 23 subjects received placebo stimulation (the placebo group. TENS was applied to the muscle trigger points of the levator scapulae and upper trapezius, while placebo-TENS was administered without electrical stimulation during 60 min. Pain and fatigue at rest and during movement were assessed using the visual analog scale (VAS, pain pressure threshold (PPT, and active range of motion (AROM of horizontal head rotation at six time points: prelabor, postlabor, post-TENS, and at 1 h, 3 h, and 1 day after TENS application. Both groups showed significantly increased pain and fatigue and decreased PPT and AROM after completing a work task. The TENS group showed significantly greater improvements in VAS score, fatigue, PPT, and AROM at post-TENS and at 1 h and 3 h after application (all P < 0.05 as compared to the placebo group. A single session high-frequency TENS may immediately reduce symptoms related to WMSDs in dental professionals.

  13. Neuropathic pain: transcranial electric motor cortex stimulation using high frequency random noise. Case report of a novel treatment

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    Alm PA

    2013-06-01

    Full Text Available Per A Alm, Karolina DreimanisDepartment of Neuroscience, Uppsala University, Uppsala, SwedenObjectives: Electric motor cortex stimulation has been reported to be effective for many cases of neuropathic pain, in the form of epidural stimulation or transcranial direct current stimulation (tDCS. A novel technique is transcranial random noise stimulation (tRNS, which increases the cortical excitability irrespective of the orientation of the current. The aim of this study was to investigate the effect of tRNS on neuropathic pain in a small number of subjects, and in a case study explore the effects of different stimulation parameters and the long-term stability of treatment effects.Methods: The study was divided into three phases: (1 a double-blind 100–600 Hz, varying from 0.5 to 10 minutes and from 50 to 1500 µA, at intervals ranging from daily to fortnightly.crossover study, with four subjects; (2 a double-blind extended case study with one responder; and (3 open continued treatment. The motor cortex stimulation consisted of alternating current random noise (100–600 Hz, varying from 0.5 to 10 minutes and from 50 to 1500 μA, at intervals ranging from daily to fortnightly.Results: One out of four participants showed a strong positive effect (also compared with direct-current-sham, P = 0.006. Unexpectedly, this effect was shown to occur also for very weak (100 µA, P = 0.048 and brief (0.5 minutes, P = 0.028 stimulation. The effect was largest during the first month, but remained at a highly motivating level for the patient after 6 months.Discussion: The study suggests that tRNS may be an effective treatment for some cases of neuropathic pain. An important result was the indication that even low levels of stimulation may have substantial effects.Keywords: neuropathic pain, central pain, transcranial direct current stimulation, motor cortex stimulation, random noise stimulation

  14. Efficacy of the device combining high-frequency transcutaneous electrical nerve stimulation and thermotherapy for relieving primary dysmenorrhea: a randomized, single-blind, placebo-controlled trial.

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    Lee, Banghyun; Hong, Seung Hwa; Kim, Kidong; Kang, Wee Chang; No, Jae Hong; Lee, Jung Ryeol; Jee, Byung Chul; Yang, Eun Joo; Cha, Eun-Jong; Kim, Yong Beom

    2015-11-01

    To investigate the efficacy and safety of the combined therapy with high-frequency transcutaneous electrical nerve stimulation (hf-TENS) and thermotherapy in relieving primary dysmenorrheal pain. In this randomized, single-blind, placebo-controlled study, 115 women with moderate or severe primary dysmenorrhea were assigned to the study or control group at a ratio of 1:1. Subjects in the study group used an integrated hf-TENS/thermotherapy device, whereas control subjects used a sham device. A visual analog scale was used to measure pain intensity. Variables related to pain relief, including reduction rate of dysmenorrheal score, were compared between the groups. The dysmenorrheal score was significantly reduced in the study group compared to the control group following the use of the devices. The duration of pain relief was significantly increased in the study group compared to the control group. There were no differences between the groups in the brief pain inventory scores, numbers of ibuprofen tablets taken orally, and World Health Organization quality of life-BREF scores. No adverse events were observed related to the use of the study device. The combination of hf-TENS and thermotherapy was effective in relieving acute pain in women with moderate or severe primary dysmenorrhea. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Altered cortical responsiveness to pain stimuli after high frequency electrical stimulation of the skin in patients with persistent pain after inguinal hernia repair.

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    Emanuel N van den Broeke

    Full Text Available BACKGROUND: High Frequency electrical Stimulation (HFS of the skin induces enhanced brain responsiveness expressed as enhanced Event-Related Potential (ERP N1 amplitude to stimuli applied to the surrounding unconditioned skin in healthy volunteers. The aim of the present study was to investigate whether this enhanced ERP N1 amplitude could be a potential marker for altered cortical sensory processing in patients with persistent pain after surgery. MATERIALS AND METHODS: Nineteen male patients; 9 with and 10 without persistent pain after inguinal hernia repair received HFS. Before, directly after and thirty minutes after HFS evoked potentials and the subjective pain intensity were measured in response to electric pain stimuli applied to the surrounding unconditioned skin. RESULTS: The results show that, thirty minutes after HFS, the ERP N1 amplitude observed at the conditioned arm was statistically significantly larger than the amplitude at the control arm across all patients. No statistically significant differences were observed regarding ERP N1 amplitude between patients with and without persistent pain. However, thirty minutes after HFS we did observe statistically significant differences of P2 amplitude at the conditioned arm between the two groups. The P2 amplitude decreased in comparison to baseline in the group of patients with pain. CONCLUSION: The ERP N1 effect, induced after HFS, was not different between patients with vs. without persistent pain. The decreasing P2 amplitude was not observed in the patients without pain and also not in the previous healthy volunteer study and thus might be a marker for altered cortical sensory processing in patients with persistent pain after surgery.

  16. Responders to Wide-Pulse, High-Frequency Neuromuscular Electrical Stimulation Show Reduced Metabolic Demand: A 31P-MRS Study in Humans.

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    Jennifer Wegrzyk

    Full Text Available Conventional (CONV neuromuscular electrical stimulation (NMES (i.e., short pulse duration, low frequencies induces a higher energetic response as compared to voluntary contractions (VOL. In contrast, wide-pulse, high-frequency (WPHF NMES might elicit--at least in some subjects (i.e., responders--a different motor unit recruitment compared to CONV that resembles the physiological muscle activation pattern of VOL. We therefore hypothesized that for these responder subjects, the metabolic demand of WPHF would be lower than CONV and comparable to VOL. 18 healthy subjects performed isometric plantar flexions at 10% of their maximal voluntary contraction force for CONV (25 Hz, 0.05 ms, WPHF (100 Hz, 1 ms and VOL protocols. For each protocol, force time integral (FTI was quantified and subjects were classified as responders and non-responders to WPHF based on k-means clustering analysis. Furthermore, a fatigue index based on FTI loss at the end of each protocol compared with the beginning of the protocol was calculated. Phosphocreatine depletion (ΔPCr was assessed using 31P magnetic resonance spectroscopy. Responders developed four times higher FTI's during WPHF (99 ± 37 × 10(3 N.s than non-responders (26 ± 12 × 10(3 N.s. For both responders and non-responders, CONV was metabolically more demanding than VOL when ΔPCr was expressed relative to the FTI. Only for the responder group, the ∆PCr/FTI ratio of WPHF (0.74 ± 0.19 M/N.s was significantly lower compared to CONV (1.48 ± 0.46 M/N.s but similar to VOL (0.65 ± 0.21 M/N.s. Moreover, the fatigue index was not different between WPHF (-16% and CONV (-25% for the responders. WPHF could therefore be considered as the less demanding NMES modality--at least in this subgroup of subjects--by possibly exhibiting a muscle activation pattern similar to VOL contractions.

  17. Advanced waveforms and frequency with spinal cord stimulation: burst and high-frequency energy delivery.

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    Pope, Jason E; Falowski, Steven; Deer, Tim R

    2015-07-01

    In recent years, software development has been key to the next generation of neuromodulation devices. In this review, we will describe the new strategies for electrical waveform delivery for spinal cord stimulation. A systematic literature review was performed using bibliographic databases, limited to the English language and human data, between 2010 and 2014. The literature search yielded three articles on burst stimulation and four articles on high-frequency stimulation. High-frequency and burst stimulation may offer advantages over tonic stimulation, as data suggest improved patient tolerance, comparable increase in function and possible success with a subset of patients refractory to tonic spinal cord stimulation. High-frequency and burst stimulation are new ways to deliver energy to the spinal cord that may offer advantages over tonic stimulation. These may offer new salvage strategies to mitigate spinal cord stimulation failure and improve cost-effectiveness by reducing explant rate.

  18. Adjunct High Frequency Transcutaneous Electric Stimulation (TENS) for Postoperative Pain Management during Weaning from Epidural Analgesia Following Colon Surgery: Results from a Controlled Pilot Study.

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    Bjerså, Kristofer; Jildenstaal, Pether; Jakobsson, Jan; Egardt, Madelene; Fagevik Olsén, Monika

    2015-12-01

    The potential benefit of nonpharmacological adjunctive therapy is not well-studied following major abdominal surgery. The aim of the present study was to investigate transcutaneous electrical nerve stimulation (TENS) as a complementary nonpharmacological analgesia intervention during weaning from epidural analgesia (EDA) after open lower abdominal surgery. Patients were randomized to TENS and sham TENS during weaning from EDA. The effects on pain at rest, following short walk, and after deep breath were assessed by visual analog scale (VAS) grading. Number of patients assessed was lower than calculated because of change in clinical routine. Pain scores overall were low. A trend of lower pain scores was observed in the active TENS group of patients; a statistical significance between the groups was found for the pain lying prone in bed (p TENS use in postoperative pain management during weaning from EDA after open colon surgery. Further studies are warranted in order to verify the potential beneficial effects from TENS during weaning from EDA after open, lower abdominal surgery. Copyright © 2015 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

  19. Electrically stimulated high-frequency replicas of a resonant current in GaAs/AlAs resonant-tunneling double-barrier THz nanostructures

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    Aleksanyan, A. A.; Karuzskii, A. L.; Kazakov, I. P.; Mityagin, Yu. A.; Murzin, V. N.; Perestoronin, A. V.; Shmelev, S. S.; Tskhovrebov, A. M.

    2016-12-01

    The periodical-in-voltage features of the negative differential conductance (NDC) region in the current-voltage characteristics of a high-quality GaAs/AlAs terahertz resonant-tunneling diode have been detected. The found oscillations are considered taking account of the LO-phonon excitation stimulated by tunneling of electrons through the quantum active region in the resonance nanostructure where an undoped quantum well layer is sandwiched between two undoped barrier layers. Rearrangements in the I-V characteristics of the resonant-tunneling diode as a consequence of the topological transformation of a measurement circuit from the circuit with the series resistance Rs to the circuit with the shunt Rp have been experimentally studied and analyzed. The revealed substantial changes in the current-voltage characteristics of the resonant-tunneling diode are discussed schematically using Kirchhoff's voltage law.

  20. Multicompartment retinal ganglion cells response to high frequency bi-phasic pulse train stimulation: Simulation results.

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    Maturana, Matias I; Grayden, David B; Burkitt, Anthony N; Meffin, Hamish; Kameneva, Tatiana

    2013-01-01

    Retinal ganglion cells (RGCs) are the sole output neurons of the retina that carry information about a visual scene to the brain. By stimulating RGCs with electrical stimulation, it is possible to elicit a sensation of light for people with macular degeneration or retinitis pigmentosa. To investigate the responses of RGCs to high frequency bi-phasic pulse train stimulation, we use previously constrained models of multi-compartment OFF RGCs. The morphologies of mouse RGCs are taken from the Chalupa set of the NeuroMorpho database. The cell models are divided into compartments representing the dendrites, soma and axon that vary between the cells. A total of 132 cells are simulated in the NEURON environment. Results show that the cell morphology plays an important role in the response characteristics of the cell to high frequency bi-phasic pulse train stimulation.

  1. NMDA Receptor-Dependent Metaplasticity by High-Frequency Magnetic Stimulation

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    Tursonjan Tokay

    2014-01-01

    Full Text Available High-frequency magnetic stimulation (HFMS can elicit N-methyl-D-aspartate (NMDA receptor-dependent long-term potentiation (LTP at Schaffer collateral-CA1 pyramidal cell synapses. Here, we investigated the priming effect of HFMS on the subsequent magnitude of electrically induced LTP in the CA1 region of rat hippocampal slices using field excitatory postsynaptic potential (fEPSP recordings. In control slices, electrical high-frequency conditioning stimulation (CS could reliably induce LTP. In contrast, the same CS protocol resulted in long-term depression when HFMS was delivered to the slice 30 min prior to the electrical stimulation. HFMS-priming was diminished when applied in the presence of the metabotropic glutamate receptor antagonists (RS-α-methylserine-O-phosphate (MSOP and (RS-α-methyl-4-carboxyphenylglycine (MCPG. Moreover, when HFMS was delivered in the presence of the NMDA receptor-antagonist D-2-amino-5-phosphonovalerate (50 µM, CS-induced electrical LTP was again as high as under control conditions in slices without priming. These results demonstrate that HFMS significantly reduced the propensity of subsequent electrical LTP and show that both metabotropic glutamate and NMDA receptor activation were involved in this form of HFMS-induced metaplasticity.

  2. The effect of high-frequency conditioning stimulation of human skin on reported pain intensity and event-related potentials

    NARCIS (Netherlands)

    Broeke, E.N. van den; Heck, C.H. van; Ceelen, L.A.J.M.; Rijn, C.M. van; Goor, H. van; Wilder-Smith, O.H.G.

    2012-01-01

    High-frequency conditioning electrical stimulation (HFS) of human skin induces an increased pain sensitivity to mechanical stimuli in the surrounding nonconditioned skin. The aim of this study was to investigate the effect of HFS on reported pain sensitivity to single electrical stimuli applied

  3. Improving NASICON Sinterability through Crystallization under High Frequency Electrical Fields

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    Ilya eLisenker

    2016-03-01

    Full Text Available The effect of high frequency (HF electric fields on the crystallization and sintering rates of a lithium aluminum germanium phosphate (LAGP ion conducting ceramic was investigated. LAGP with the nominal composition Li1.5Al0.5Ge1.5(PO43 was crystallized and sintered, both conventionally and under effect of electrical field. Electrical field application, of 300V/cm at 1MHz, produced up to a 40% improvement in sintering rate of LAGP that was crystallized and sintered under the HF field. Heat sink effect of the electrodes appears to arrest thermal runaway and subsequent flash behavior. Sintered pellets were characterized using XRD, SEM, TEM and EIS to compare conventionally and field sintered processes. The as-sintered structure appears largely unaffected by the field as the sintering curves tend to converge beyond initial stages of sintering. Differences in densities and microstructure after 1 hour of sintering were minor with measured sintering strains of 31% vs. 26% with and without field, respectively . Ionic conductivity of the sintered pellets was evaluated and no deterioration due to the use of HF field was noted, though capacitance of grain boundaries due to secondary phases was significantly increased.

  4. High frequency stimulation of cardiac myocytes: A theoretical and computational study

    Science.gov (United States)

    Weinberg, Seth H.

    2014-12-01

    High-frequency stimulation (HFS) has recently been identified as a novel approach for terminating life-threatening cardiac arrhythmias. HFS elevates myocyte membrane potential and blocks electrical conduction for the duration of the stimulus. However, low amplitude HFS can induce rapidly firing action potentials, which may reinitiate an arrhythmia. The cellular level mechanisms underlying HFS-induced electrical activity are not well understood. Using a multiscale method, we show that a minimal myocyte model qualitatively reproduces the influence of HFS on cardiac electrical activity. Theoretical analysis and simulations suggest that persistent activation and de-inactivation of ionic currents, in particular a fast inward window current, underlie HFS-induced action potentials and membrane potential elevation, providing hypotheses for future experiments. We derive analytical expressions to describe how HFS modifies ionic current amplitude and gating dynamics. We show how fast inward current parameters influence the parameter regimes for HFS-induced electrical activity, demonstrating how the efficacy of HFS as a therapy for terminating arrhythmias may depend on the presence of pathological conditions or pharmacological treatments. Finally, we demonstrate that HFS terminates cardiac arrhythmias in a one-dimensional ring of cardiac tissue. In this study, we demonstrate a novel approach to characterize the influence of HFS on ionic current gating dynamics, provide new insight into HFS of the myocardium, and suggest mechanisms underlying HFS-induced electrical activity.

  5. Real-time CARS imaging reveals a calpain-dependent pathway for paranodal myelin retraction during high-frequency stimulation.

    Directory of Open Access Journals (Sweden)

    Terry B Huff

    2011-03-01

    Full Text Available High-frequency electrical stimulation is becoming a promising therapy for neurological disorders, however the response of the central nervous system to stimulation remains poorly understood. The current work investigates the response of myelin to electrical stimulation by laser-scanning coherent anti-Stokes Raman scattering (CARS imaging of myelin in live spinal tissues in real time. Paranodal myelin retraction at the nodes of Ranvier was observed during 200 Hz electrical stimulation. Retraction was seen to begin minutes after the onset of stimulation and continue for up to 10 min after stimulation was ceased, but was found to reverse after a 2 h recovery period. The myelin retraction resulted in exposure of Kv 1.2 potassium channels visualized by immunofluorescence. Accordingly, treating the stimulated tissue with a potassium channel blocker, 4-aminopyridine, led to the appearance of a shoulder peak in the compound action potential curve. Label-free CARS imaging of myelin coupled with multiphoton fluorescence imaging of immuno-labeled proteins at the nodes of Ranvier revealed that high-frequency stimulation induced paranodal myelin retraction via pathologic calcium influx into axons, calpain activation, and cytoskeleton degradation through spectrin break-down.

  6. Electrical stimulation in exercise training

    Science.gov (United States)

    Kroll, Walter

    1994-01-01

    muscle strength for over a century. Bigelow reported in 1894, for example, the use of electrical stimulation on a young man for the purpose of increasing muscle strength. Employing a rapidly alternating sinusoidal induced current and a dynamometer for strength testing, Bigelow reported that the total lifting capacity of a patient increased from 4328 pounds to 4639 pounds after only 25 minutes of stimulation. In 1965, Massey et al. reported on the use of an Isotron electrical stimulator that emitted a high frequency current. Interestingly enough, the frequencies used by Massey et al. and the frequencies used by Bigelow in 1894 were in the same range of frequencies reported by Kots as being the most effective in strength development. It would seem the Russian secret of high frequency electrical stimulation for strength development, then, is not a modern development at all.

  7. Intramuscular Contributions to Low-Frequency Force Potentiation Induced by a High-Frequency Conditioning Stimulation

    Directory of Open Access Journals (Sweden)

    Arthur J. Cheng

    2017-09-01

    Full Text Available Electrically-evoked low-frequency (submaximal force is increased immediately following high-frequency stimulation in human skeletal muscle. Although central mechanisms have been suggested to be the major cause of this low-frequency force potentiation, intramuscular factors might contribute. Thus, we hypothesized that two intramuscular Ca2+-dependent mechanisms can contribute to the low-frequency force potentiation: increased sarcoplasmic reticulum Ca2+ release and increased myofibrillar Ca2+ sensitivity. Experiments in humans were performed on the plantar flexor muscles at a shortened, intermediate, and long muscle length and electrically evoked contractile force and membrane excitability (i.e., M-wave amplitude were recorded during a stimulation protocol. Low-frequency force potentiation was assessed by stimulating with a low-frequency tetanus (25 Hz, 2 s duration, followed by a high-frequency tetanus (100 Hz, 2 s duration, and finally followed by another low-frequency (25 Hz, 2 s duration tetanus. Similar stimulation protocols were performed on intact mouse single fibers from flexor digitorum brevis muscle, whereby force and myoplasmic free [Ca2+] ([Ca2+]i were assessed. Our data show a low-frequency force potentiation that was not muscle length-dependent in human muscle and it was not accompanied by any increase in M-wave amplitude. A length-independent low-frequency force potentiation could be replicated in mouse single fibers, supporting an intramuscular mechanism. We show that at physiological temperature (31°C this low-frequency force potentiation in mouse fibers corresponded with an increase in sarcoplasmic reticulum (SR Ca2+ release. When mimicking the slower contractile properties of human muscle by cooling mouse single fibers to 18°C, the low-frequency force potentiation was accompanied by minimally increased SR Ca2+ release and hence it could be explained by increased myofibrillar Ca2+ sensitivity. Finally, introducing a brief 200

  8. Intramuscular Contributions to Low-Frequency Force Potentiation Induced by a High-Frequency Conditioning Stimulation.

    Science.gov (United States)

    Cheng, Arthur J; Neyroud, Daria; Kayser, Bengt; Westerblad, Håkan; Place, Nicolas

    2017-01-01

    Electrically-evoked low-frequency (submaximal) force is increased immediately following high-frequency stimulation in human skeletal muscle. Although central mechanisms have been suggested to be the major cause of this low-frequency force potentiation, intramuscular factors might contribute. Thus, we hypothesized that two intramuscular Ca2+-dependent mechanisms can contribute to the low-frequency force potentiation: increased sarcoplasmic reticulum Ca2+ release and increased myofibrillar Ca2+ sensitivity. Experiments in humans were performed on the plantar flexor muscles at a shortened, intermediate, and long muscle length and electrically evoked contractile force and membrane excitability (i.e., M-wave amplitude) were recorded during a stimulation protocol. Low-frequency force potentiation was assessed by stimulating with a low-frequency tetanus (25 Hz, 2 s duration), followed by a high-frequency tetanus (100 Hz, 2 s duration), and finally followed by another low-frequency (25 Hz, 2 s duration) tetanus. Similar stimulation protocols were performed on intact mouse single fibers from flexor digitorum brevis muscle, whereby force and myoplasmic free [Ca2+] ([Ca2+]i) were assessed. Our data show a low-frequency force potentiation that was not muscle length-dependent in human muscle and it was not accompanied by any increase in M-wave amplitude. A length-independent low-frequency force potentiation could be replicated in mouse single fibers, supporting an intramuscular mechanism. We show that at physiological temperature (31°C) this low-frequency force potentiation in mouse fibers corresponded with an increase in sarcoplasmic reticulum (SR) Ca2+ release. When mimicking the slower contractile properties of human muscle by cooling mouse single fibers to 18°C, the low-frequency force potentiation was accompanied by minimally increased SR Ca2+ release and hence it could be explained by increased myofibrillar Ca2+ sensitivity. Finally, introducing a brief 200 ms pause

  9. High frequency switched-mode stimulation can evoke postsynaptic responses in cerebellar principal neurons

    Directory of Open Access Journals (Sweden)

    Marijn Van Dongen

    2015-03-01

    Full Text Available This paper investigates the efficacy of high frequency switched-mode neural stimulation. Instead of using a constant stimulation amplitude, the stimulus is switched on and off repeatedly with a high frequency (up to 100kHz duty cycled signal. By means of tissue modeling that includes the dynamic properties of both the tissue material as well as the axon membrane, it is first shown that switched-mode stimulation depolarizes the cell membrane in a similar way as classical constant amplitude stimulation.These findings are subsequently verified using in vitro experiments in which the response of a Purkinje cell is measured due to a stimulation signal in the molecular layer of the cerebellum of a mouse. For this purpose a stimulator circuit is developed that is able to produce a monophasic high frequency switched-mode stimulation signal. The results confirm the modeling by showing that switched-mode stimulation is able to induce similar responses in the Purkinje cell as classical stimulation using a constant current source. This conclusion opens up possibilities for novel stimulation designs that can improve the performance of the stimulator circuitry. Care has to be taken to avoid losses in the system due to the higher operating frequency.

  10. Hours of high-frequency stimulations reveal intracellular neuronal trends in vivo

    Science.gov (United States)

    Brama, H.; Goldental, A.; Vardi, R.; Stern, E. A.; Kanter, I.

    2016-11-01

    The neuronal response to controlled stimulations in vivo has been classically estimated using a limited number of events. Here we show that hours of high-frequency stimulations and recordings of neurons in vivo reveal previously unknown response phases of neurons in the intact brain. Results indicate that for stimulation frequencies below a critical neuronal characteristic frequency, f c, response timings are stabilized to tens-of-microseconds accuracy. For stimulation frequencies exceeding f c the firing frequency is saturated and independent of the stimulation frequency, as a result of random neuronal response failures. This neuronal plasticity, previously shown in vitro, supports a robust mechanism for low firing rates on a network level.

  11. High frequency stimulation of the subthalamic nucleus is efficacious in Parkin disease

    NARCIS (Netherlands)

    Romito, Luigi M. A.; Contarino, Maria F.; Ghezzi, Daniele; Franzini, Angelo; Garavaglia, Barbara; Albanese, Alberto

    2005-01-01

    High frequency stimulation (HFS) of the subthalamic nucleus (STN) is an efficacious symptomatic treatment for Parkinson's disease. We have analysed the genetic status of a series of consecutive parkinsonian patients implanted for STN HFS and compared the outcome of five carrying mutations in the

  12. Bilateral high frequency subthalamic stimulation in Parkinson's disease: long-term neurological follow-up

    NARCIS (Netherlands)

    Romito, L. M.; Scerrati, M.; Contarino, M. F.; Iacoangeli, M.; Bentivoglio, A. R.; Albanese, A.

    2003-01-01

    AIM: High frequency stimulation of the subthalamic nucleus (STN) is gaining recognition as a new symptomatic treatment for Parkinson's disease (PD). The first available long-term observations show the stability of the efficacy of this procedure in time. METHODS: Quadripolar leads were implanted

  13. Accelerated high-frequency repetitive transcranial magnetic stimulation enhances motor activity in rats

    NARCIS (Netherlands)

    El Arfani, Anissa; Parthoens, Joke; Demuyser, Thomas; Servaes, Stijn; De Coninck, Mattias; De Deyn, Peter Paul; Van Dam, Debby; Wyckhuys, Tine; Baeken, Chris; Smolders, Ilse; Staelens, Steven

    2017-01-01

    High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) is currently accepted as an evidence-based treatment option for treatment-resistant depression (TRD). Additionally, HF-rTMS showed beneficial effects on psychomotor retardation in patients. The classical HF-rTMS paradigms however

  14. Effect of ischemia and cooling on the response to high frequency stimulation in rat tail nerves

    DEFF Research Database (Denmark)

    Andersen, Henning; Feldbæk Nielsen, Jørgen; Sørensen, Bodil

    2000-01-01

    In normal rat tail nerves the effect of temperature and ischemia on the response to long-term high frequency stimulation (HFS) (143 Hz) was studied. The effect of temperature was studied in two consecutive tests at 14 degrees C and 35 degrees C. Prior to the HFS the peak-to-peak amplitude (PP-amp...

  15. Evaluating Acupuncture Point and Nonacupuncture Point Stimulation with EEG: A High-Frequency Power Spectrum Analysis

    Directory of Open Access Journals (Sweden)

    Kwang-Ho Choi

    2016-01-01

    Full Text Available To identify physical and sensory responses to acupuncture point stimulation (APS, nonacupuncture point stimulation (NAPS and no stimulation (NS, changes in the high-frequency power spectrum before and after stimulation were evaluated with electroencephalography (EEG. A total of 37 healthy subjects received APS at the LI4 point, NAPS, or NS with their eyes closed. Background brain waves were measured before, during, and after stimulation using 8 channels. Changes in the power spectra of gamma waves and high beta waves before, during, and after stimulation were comparatively analyzed. After NAPS, absolute high beta power (AHBP, relative high beta power (RHBP, absolute gamma power (AGP, and relative gamma power (RGP tended to increase in all channels. But no consistent notable changes were found for APS and NS. NAPS is believed to cause temporary reactions to stress, tension, and sensory responses of the human body, while APS responds stably compared to stimulation of other parts of the body.

  16. High frequency oscillations after median nerve stimulations in healthy children and adolescents.

    Science.gov (United States)

    Zanini, Sergio; Del Piero, Ivana; Martucci, Lucia; Restuccia, Domenico

    2017-10-01

    The aim of the present research was to address somatosensory high frequency oscillations (400-800Hz) in healthy children and adolescents in comparison with healthy adults. We recorded somatosensory evoked potentials following median nerve stimulation in nineteen resting healthy children/adolescents and in nineteen resting healthy adults with eyes closed. We administered six consecutive stimulation blocks (500 sweeps each). The presynaptic component of high frequency oscillations amplitudes was smaller in healthy children/adolescents than in healthy adults (no difference between groups was found as far as the postsynaptic component was concerned). Healthy children/adolescents had smaller presynaptic component than the postsynaptic one (the postsynaptic component amplitude was 145% of the presynaptic one), while healthy adults showed the opposite (reduction of the postsynaptic component to 80% of the presynaptic one). No habituation phenomena concerning high frequency oscillation amplitudes were registered in neither healthy children/adolescents nor healthy adults. These findings suggest that healthy children/adolescents present with significantly different pattern of somatosensory high frequency oscillations compared with healthy adults' ones. This different pattern is reasonably expression of higher cortical excitability of the developing brain cortex. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

  17. High-frequency submaximal stimulation over muscle evokes centrally generated forces in human upper limb skeletal muscles.

    Science.gov (United States)

    Blouin, Jean-Sébastien; Walsh, Lee D; Nickolls, Peter; Gandevia, Simon C

    2009-02-01

    Control of posture and movement requires control of the output from motoneurons. Motoneurons of human lower limb muscles exhibit sustained, submaximal activity to high-frequency electrical trains, which has been hypothesized to be partly triggered by monosynaptic Ia afferents. The possibility to trigger such behavior in upper limb motoneurons and the potential unique role of Ia afferents to trigger such behavior remain unclear. Subjects (n = 9) received high-frequency trains of electrical stimuli over biceps brachii and flexor pollicis longus (FPL). We chose to study the FPL muscle because it has weak monosynaptic Ia afferent connectivity and it is involved in fine motor control of the thumb. Two types of stimulus trains (100-Hz bursts and triangular ramps) were tested at five intensities below painful levels. All subjects exhibited enhanced torque in biceps and FPL muscles after both types of high-frequency train. Torques also persisted after stimulation, particularly for the highest stimulus intensity. To separate the evoked torques that resulted from a peripheral mechanism (e.g., muscle potentiation) and that which resulted from a central origin, we studied FPL responses to high-frequency trains after complete combined nerve blocks of the median and radial nerves (n = 2). During the blocks, high-frequency trains over the FPL did not yield torque enhancements or persisting torques. These results suggest that enhanced contractions of central origin can be elicited in motoneurons innervating the upper limb, despite weak monosynaptic Ia connections for FPL. Their presence in a recently evolved human muscle (FPL) indicates that these enhanced contractions may have a broad role in controlling tonic postural outputs of hand muscles and that they may be available even for fine motor activities involving the thumb.

  18. Influence of high frequency electric field on the dispersion of ion-acoustic waves in plasma

    Energy Technology Data Exchange (ETDEWEB)

    Turky, A.; Cercek, M.; Tavzes, R.

    1981-01-01

    The modification of the ion-acoustic wave dispersion under the action of a high frequency electric field was studied experimentally, the wave propagating along and against the plasma stream. The frequency of the field amounted to approximately half the electron plasma frequency. It was found that the phase velocity of the ion wave and the plasma drift velocity decrease as the effective high frequency field power increases.

  19. High frequency somatosensory stimulation increases sensori-motor inhibition and leads to perceptual improvement in healthy subjects.

    Science.gov (United States)

    Rocchi, Lorenzo; Erro, Roberto; Antelmi, Elena; Berardelli, Alfredo; Tinazzi, Michele; Liguori, Rocco; Bhatia, Kailash; Rothwell, John

    2017-06-01

    High frequency repetitive somatosensory stimulation (HF-RSS), which is a patterned electric stimulation applied to the skin through surface electrodes, improves two-point discrimination, somatosensory temporal discrimination threshold (STDT) and motor performance in humans. However, the mechanisms which underlie these changes are still unknown. In particular, we hypothesize that refinement of inhibition might be responsible for the improvement in spatial and temporal perception. Fifteen healthy subjects underwent 45min of HF-RSS. Before and after the intervention several measures of inhibition in the primary somatosensory area (S1), such as paired-pulse somatosensory evoked potentials (pp-SEP), high-frequency oscillations (HFO), and STDT were tested, as well as tactile spatial acuity and short intracortical inhibition (SICI). HF-RSS increased inhibition in S1 tested by pp-SEP and HFO; these changes were correlated with improvement in STDT. HF-RSS also enhanced bumps detection, while there was no change in grating orientation test. Finally there was an increase in SICI, suggesting widespread changes in cortical sensorimotor interactions. These findings suggest that HF-RSS can improve spatial and temporal tactile abilities by increasing the effectiveness of inhibitory interactions in the somatosensory system. Moreover, HF-RSS induces changes in cortical sensorimotor interaction. HF-RSS is a repetitive electric stimulation technique able to modify the effectiveness of inhibitory circuitry in the somatosensory system and primary motor cortex. Copyright © 2017 International Federation of Clinical Neurophysiology. All rights reserved.

  20. The effect of high voltage, high frequency pulsed electric field on slain ovine cortical bone.

    Science.gov (United States)

    Asgarifar, Hajarossadat; Oloyede, Adekunle; Zare, Firuz

    2014-04-01

    High power, high frequency pulsed electric fields known as pulsed power (PP) has been applied recently in biology and medicine. However, little attention has been paid to investigate the application of pulse power in musculoskeletal system and its possible effect on functional behavior and biomechanical properties of bone tissue. This paper presents the first research investigating whether or not PP can be applied safely on bone tissue as a stimuli and what will be the possible effect of these signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to PP and in comparison with the control samples. A positive buck-boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 V and 10 kHz). The functional behavior of bone in response to pulse power excitation was elucidated by applying compressive loading until failure. The stiffness, failure stress (strength) and the total fracture energy (bone toughness) were determined as a measure of the main bone characteristics. Furthermore, an ultrasonic technique was applied to determine and comprise bone elasticity before and after pulse power stimulation. The elastic property of cortical bone samples appeared to remain unchanged following exposure to pulse power excitation for all three orthogonal directions obtained from ultrasonic technique and similarly from the compression test. Nevertheless, the compressive strength and toughness of bone samples were increased when they were exposed to 66 h of high power pulsed electromagnetic field compared to the control samples. As the toughness and the strength of the cortical bone tissue are directly associated with the quality and integrity of the collagen matrix whereas its stiffness is primarily related to bone mineral content these overall results may address that although, the pulse power stimulation can influence the arrangement or the quality of the collagen network

  1. Determining of the electric field strength using high frequency broadband measurements

    OpenAIRE

    Vulević, Branislav D.

    2017-01-01

    Exposure of humans to electromagnetic fields of high frequency (above 100 kHz), i.e. radiofrequency radiation from the modern wireless systems, today inevitable is. The purpose of this paper is to highlight the importance of broadband measurements of the electric field of high frequency in order to fast and reliable assessment of human exposure. A practical method of ‘in situ’ measurement the electric field intensity which is related to the frequency range of 3 MHz to 18 GHz, is provided.

  2. High-frequency limit of neural stimulation with ChR2.

    Science.gov (United States)

    Grossman, N; Nikolic, K; Grubb, M S; Burrone, J; Toumazou, C; Degenaar, P

    2011-01-01

    Optogenetic technology based on light activation of genetically targeted single component opsins such as Channelrhodopsin-2 (ChR2) has been changing the way neuroscience research is conducted. This technology is becoming increasingly important for neural engineering as well. The efficiency of neural stimulation with ChR2 drops at high frequencies, often before the natural limit of the neuron is reached. This study aims to investigate the underlying mechanisms that limit the efficiency of the stimulation at high frequencies. The study analyzes the dynamics of the spikes induced by ChR2 in comparison to control stimulations using patch clamp current injection. It shows that the stimulation dynamics is limited by two mechanisms: 1) a frequency independent reduction in the conductance-to-irradiance yield due to the ChR2 light adaptation process and 2) a frequency dependent reduction in the conductance-to-current yield due to a decrease in membrane re-polarization level between spikes that weakens the ionic driving force. The effect of the first mechanism can be minimized by using ChR2 mutants with lower irradiance threshold. In contrast the effect of the second mechanism is fundamentally limited by the rate the native ion channels re-polarize the membrane potential.

  3. High-frequency stimulation of nucleus accumbens changes in dopaminergic reward circuit.

    Directory of Open Access Journals (Sweden)

    Na Yan

    Full Text Available Deep brain stimulation (DBS of the nucleus accumbens (NAc is a potential remedial therapy for drug craving and relapse, but the mechanism is poorly understood. We investigated changes in neurotransmitter levels during high frequency stimulation (HFS of the unilateral NAc on morphine-induced rats. Sixty adult Wistar rats were randomized into five groups: the control group (administration of saline, the morphine-only group (systematic administration of morphine without electrode implantation, the morphine-sham-stimulation group (systematic administration of morphine with electrode implantation but not given stimulation, the morphine-stimulation group (systematic administration of morphine with electrode implantation and stimulation and the saline-stimulation group (administration of saline with electrode implantation and stimulation. The stimulation electrode was stereotaxically implanted into the core of unilateral NAc and microdialysis probes were unilaterally lowered into the ipsilateral ventral tegmental area (VTA, NAc, and ventral pallidum (VP. Samples from microdialysis probes in the ipsilateral VTA, NAc, and VP were analyzed for glutamate (Glu and γ-aminobutyric acid (GABA by high-performance liquid chromatography (HPLC. The levels of Glu were increased in the ipsilateral NAc and VP of morphine-only group versus control group, whereas Glu levels were not significantly changed in the ipsilateral VTA. Furthermore, the levels of GABA decreased significantly in the ipsilateral NAc, VP, and VTA of morphine-only group when compared with control group. The profiles of increased Glu and reduced GABA in morphine-induced rats suggest that the presence of increased excitatory neurotransmission in these brain regions. The concentrations of the Glu significantly decreased while the levels of GABA increased in ipsilateral VTA, NAc, and VP in the morphine-stimulation group compared with the morphine-only group. No significant changes were seen in the

  4. Desynchronizing effect of high-frequency stimulation in a generic cortical network model.

    Science.gov (United States)

    Schütt, Markus; Claussen, Jens Christian

    2012-08-01

    Transcranial electrical stimulation (TCES) and deep brain stimulation are two different applications of electrical current to the brain used in different areas of medicine. Both have a similar frequency dependence of their efficiency, with the most pronounced effects around 100 Hz. We apply superthreshold electrical stimulation, specifically depolarizing DC current, interrupted at different frequencies, to a simple model of a population of cortical neurons which uses phenomenological descriptions of neurons by Izhikevich and synaptic connections on a similar level of sophistication. With this model, we are able to reproduce the optimal desynchronization around 100 Hz, as well as to predict the full frequency dependence of the efficiency of desynchronization, and thereby to give a possible explanation for the action mechanism of TCES.

  5. High frequency vibration characteristics of electric wheel system under in-wheel motor torque ripple

    Science.gov (United States)

    Mao, Yu; Zuo, Shuguang; Wu, Xudong; Duan, Xianglei

    2017-07-01

    With the introduction of in-wheel motor, the electric wheel system encounters new vibration problems brought by motor torque ripple excitation. In order to analyze new vibration characteristics of electric wheel system, torque ripple of in-wheel motor based on motor module and vector control system is primarily analyzed, and frequency/order features of the torque ripple are discussed. Then quarter vehicle-electric wheel system (QV-EWS) dynamics model based on the rigid ring tire assumption is established and the main parameters of the model are identified according to tire free modal test. Modal characteristics of the model are further analyzed. The analysis indicates that torque excitation of in-wheel motor is prone to arouse horizontal vibration, in which in-phase rotational, anti-phase rotational and horizontal translational modes of electric wheel system mainly participate. Based on the model, vibration responses of the QV-EWS under torque ripple are simulated. The results show that unlike vertical low frequency (lower than 20 Hz) vibration excited by road roughness, broadband torque ripple will arouse horizontal high frequency (50-100 Hz) vibration of electric wheel system due to participation of the three aforementioned modes. To verify the theoretical analysis, the bench experiment of electric wheel system is conducted and vibration responses are acquired. The experiment demonstrates the high frequency vibration phenomenon of electric wheel system and the measured order features as well as main resonant frequencies agree with simulation results. Through theoretical modeling, analysis and experiments this paper reveals and explains the high frequency vibration characteristics of electric wheel system, providing references for the dynamic analysis, optimal design of QV-EWS.

  6. Broadband measurements of high-frequency electric field levels and exposure ratios determination

    Directory of Open Access Journals (Sweden)

    Vulević Branislav

    2017-01-01

    Full Text Available The exposure of people to high-frequency electromagnetic fields (over 100 kHz that emanate from modern wireless information transmission systems is inevitable in modern times. Due to the rapid development of new technologies, measuring devices and their connection to measuring systems, the first fifteen years of the 21st century are characterized by the appearance of different approaches to measurements. This prompts the need for the assessment of the exposure of people to these fields. The main purpose of this paper is to show how to determine the exposure ratios based on the results of broadband measurements of the high-frequency electric field in the range of 3 MHz to 18 GHz in the environment.

  7. Effects of expiratory muscle activation via high-frequency spinal cord stimulation.

    Science.gov (United States)

    Kowalski, K E; Romaniuk, J R; Kowalski, T; DiMarco, A F

    2017-12-01

    In persons with spinal cord injury, lower thoracic low-frequency spinal cord stimulation (LF-SCS; 50 Hz, 15 mA) is a useful method to restore an effective cough. Unfortunately, the high-stimulus-amplitude requirements and potential activation of pain fibers significantly limit this application in persons with intact sensation. In this study, the mechanism of the expiratory muscle activation, via high-frequency SCS (HF-SCS; 500 Hz, 1 mA) was evaluated in dogs. In group 1, the effects of electrode placement on airway pressure generation (P) was evaluated. Maximal P occurred at the T9-T10 level with progressive decrements in P at more rostral and caudal levels for both LF-SCS and HF-SCS. In group 2, electromyographic (EMG) latencies of internal intercostal muscle (II) activation were evaluated before and after spinal root section and during direct motor root stimulation. Onset time of II EMG activity during HF-SCS was significantly longer (3.84 ± 1.16 ms) than obtained during direct motor root activation (1.61 ± 0.10 ms). In group 3, P and external oblique (EO) EMG activity, before and after sequential spinal section at the T11-T12 level, were evaluated. Bilateral dorsal column section significantly reduced EO EMG activity below the section and resulted in a substantial fall in P. Subsequent lateral funiculi section completely abolished those activities and resulted in further reductions in P. We conclude that 1) activation of the expiratory muscles via HF-SCS is dependent entirely on synaptic spinal cord pathways, and 2) HF-SCS at the T9 level produces a comparable level of muscle activation with that achieved with LF-SCS but with much lower stimulus amplitudes. NEW & NOTEWORTHY The findings in the present study suggest that lower thoracic high-frequency spinal cord stimulation with low stimulus currents results in sufficient activation of the expiratory muscles via spinal circuitry to produce large positive airway pressures sufficient to generate an

  8. Synaptic dynamics regulation in response to high frequency stimulation in neuronal networks

    Science.gov (United States)

    Su, Fei; Wang, Jiang; Li, Huiyan; Wei, Xile; Yu, Haitao; Deng, Bin

    2018-02-01

    High frequency stimulation (HFS) has confirmed its ability in modulating the pathological neural activities. However its detailed mechanism is unclear. This study aims to explore the effects of HFS on neuronal networks dynamics. First, the two-neuron FitzHugh-Nagumo (FHN) networks with static coupling strength and the small-world FHN networks with spike-time-dependent plasticity (STDP) modulated synaptic coupling strength are constructed. Then, the multi-scale method is used to transform the network models into equivalent averaged models, where the HFS intensity is modeled as the ratio between stimulation amplitude and frequency. Results show that in static two-neuron networks, there is still synaptic current projected to the postsynaptic neuron even if the presynaptic neuron is blocked by the HFS. In the small-world networks, the effects of the STDP adjusting rate parameter on the inactivation ratio and synchrony degree increase with the increase of HFS intensity. However, only when the HFS intensity becomes very large can the STDP time window parameter affect the inactivation ratio and synchrony index. Both simulation and numerical analysis demonstrate that the effects of HFS on neuronal network dynamics are realized through the adjustment of synaptic variable and conductance.

  9. High frequency spinal cord stimulation-New method to restore cough.

    Science.gov (United States)

    Kowalski, K E; Romaniuk, J R; Brose, S W; Richmond, M A; Kowalski, T; DiMarco, A F

    2016-10-01

    Spinal cord stimulation (SCS, 50Hz) is a useful method to restore an effective cough in persons with spinal cord injury (SCI). However, high stimulus amplitudes and potential activation of pain fibers, significantly limits this application. It is our hypothesis that high frequency SCS (HF-SCS), with low stimulus amplitudes may provide the same level of expiratory muscle activation. In 6 dogs, the effects of SCS, with varying stimulus parameters on positive pressure (P) generation was evaluated. At any given level of stimulus current, mean P was largest at 500Hz, compared to all other stimulus frequencies. For example, with stimulation at 1mA and frequencies of 200, 500 and 600Hz, P were 25±3, 58±4, 51±6cmH2O, respectively. By comparison, P achieved with conventional SCS parameters was 61±5cmH2O. HF-SCS results in a comparable P compared to that achieved with conventional stimulus parameters but with much lower stimulus amplitudes. This method may be useful to restore cough even in subjects with intact sensation. Published by Elsevier B.V.

  10. High Frequency Deep Brain Stimulation and Neural Rhythms in Parkinson's Disease.

    Science.gov (United States)

    Blumenfeld, Zack; Brontë-Stewart, Helen

    2015-12-01

    High frequency (HF) deep brain stimulation (DBS) is an established therapy for the treatment of Parkinson's disease (PD). It effectively treats the cardinal motor signs of PD, including tremor, bradykinesia, and rigidity. The most common neural target is the subthalamic nucleus, located within the basal ganglia, the region most acutely affected by PD pathology. Using chronically-implanted DBS electrodes, researchers have been able to record underlying neural rhythms from several nodes in the PD network as well as perturb it using DBS to measure the ensuing neural and behavioral effects, both acutely and over time. In this review, we provide an overview of the PD neural network, focusing on the pathophysiological signals that have been recorded from PD patients as well as the mechanisms underlying the therapeutic benefits of HF DBS. We then discuss evidence for the relationship between specific neural oscillations and symptoms of PD, including the aberrant relationships potentially underlying functional connectivity in PD as well as the use of different frequencies of stimulation to more specifically target certain symptoms. Finally, we briefly describe several current areas of investigation and how the ability to record neural data in ecologically-valid settings may allow researchers to explore the relationship between brain and behavior in an unprecedented manner, culminating in the future automation of neurostimulation therapy for the treatment of a variety of neuropsychiatric diseases.

  11. Dynamic characteristics of non-ideal plasmas in an external high frequency electric field

    Energy Technology Data Exchange (ETDEWEB)

    Adamyan, V M [Department of Theoretical Physics, I. I. Mechnikov Odessa National University, 65026 Odessa (Ukraine); Djuric, Z [Silvaco Data System, Silvaco Technology Centre, Compass Point, St. Ives PE27 5JL (United Kingdom); Mihajlov, A A [Institute of Physics, PO Box 57, 11001 Belgrade (Serbia and Montenegro); Sakan, N M [Institute of Physics, PO Box 57, 11001 Belgrade (Serbia and Montenegro); Tkachenko, I M [Department of Applied Mathematics, ETSII, Polytechnic University of Valencia, Camino de Vera s/n, Valencia 46022 (Spain)

    2004-07-21

    The dynamic electric conductivity, dielectric permeability and refraction and reflection coefficients of a completely ionized gaseous plasma in a high frequency (HF) external electric field are calculated. These results are obtained within the self-consistent field approach developed earlier for the static conductivity determination. The plasma electron density, N{sub e}, and temperature, T, varied within the following limits: 10{sup 19} {<=} N{sub e} {<=} 10{sup 21} cm{sup -3} and 2 x 10{sup 4} {<=} T {<=} 10{sup 6} K, respectively. The external electric field frequency, f, varied in the range 3 GHz{<=} f {<=} 0.05{omicron}{sub p}, where {omicron}{sub p} is the circular plasma frequency. Thus, the upper limit for f is either in the microwave or in the far infrared frequency band. The final results are shown in a parameterized form, suitable for laboratory applications.

  12. High frequency vibration conditioning stimulation centrally reduces myoelectrical manifestation of fatigue in healthy subjects.

    Science.gov (United States)

    Casale, Roberto; Ring, Haim; Rainoldi, Alberto

    2009-10-01

    Vibration conditioning has been adopted as a tool to improve muscle force and reduce fatigue onset in various rehabilitation settings. This study was designed to asses if high frequency vibration can induce some conditioning effects detectable in surface EMG (sEMG) signal; and whether these effects are central or peripheral in origin. 300 Hz vibration was applied for 30 min during 5 consecutive days, to the right biceps brachii muscle of 10 healthy males aged from 25 to 50 years. sEMG was recorded with a 16 electrode linear array placed on the skin overlying the vibrated muscle. The test protocol consisted of 30% and 60% maximal voluntary contraction (MVC) as well as involuntary (electrically elicited) contractions before and after treatment. No statistically significant differences were found between PRE and POST vibration conditioning when involuntary stimulus-evoked contraction and 30% MVC were used. Significant differences in the initial values and rates of change of muscle fibre conduction velocity were found only at 60% MVC. 300 Hz vibration did not induce any peripheral changes as demonstrated by the lack of differences when fatigue was electrically induced. Differences were found only when the muscle was voluntarily fatigued at 60% MVC suggesting a modification in the centrally driven motor unit recruitment order, and interpreted as an adaptive response to the reiteration of the vibratory conditioning.

  13. FREQUENCY DETERMINATION OF HIGH-FREQUENCY LINK FOR PERCPECTIVE ELECTRIC ROLLING STOCK

    Directory of Open Access Journals (Sweden)

    D. O. Zabarylo

    2014-12-01

    Full Text Available Purpose. Total mileage of Ukrainian electric railways is distributed approximately equally between the areas of direct and alternating current. A double system of electric rolling stock is used to pass jointing places of different current kinds without train’s stop. Therefore introduction of such rolling stock of a new concept that is using an asynchronous traction drive is prospective for Ukrainian railways. Apart from advantages a rolling stock of similar concept has significant disadvantages, it is pulse energy consumption from the power supply, and it can affect the reliability of track automatic devices, and consequently, the train traffic safety. In addition the specific power of traction transformer is considerably inferior to the power density of other traction elements. The promising schemes using an intermediary link of increased frequency, which consist of a transformer and inverter, have been proposed for disadvantages amendments. The main task for the further introduction of prospective circuit is to determine the operating frequency for high frequency link. Methodology. The method of thermal parameters calculation of semiconductor devices has been used for determination switching transistors of maximum operating frequency. To obtain analytical expressions curves of energy, released during the IGBT (insulated-gate bipolar transistor switching from its current load approximation method is used. Findings. The permissible frequency of low-frequency link is determinated by load current of intermediate transformer. Operating frequency range of a link depending on load current has been determined. A comparative analysis of the switching characteristics of 65 class IGBT production by companies Infineon and ABB has been performed. Originality. The further determination method of the maximum operating frequency of intermediate link for circuit with high-frequency transformer has been developed. Practical value. The established operating

  14. High frequency electric field levels: An example of determination of measurement uncertainty for broadband measurements

    Directory of Open Access Journals (Sweden)

    Vulević Branislav

    2016-01-01

    Full Text Available Determining high frequency electromagnetic field levels in urban areas represents a very complex task, having in mind the exponential growth of the number of sources embodied in public cellular telephony systems in the past twenty years. The main goal of this paper is a representation of a practical solution in the evaluation of measurement uncertainty for in-situ measurements in the case of spatial averaging. An example of the estimation of the uncertainty for electric field strength broadband measurements in the frequency range from 3 MHz to 18 GHz is presented.

  15. Novel Stimulation Paradigms with Temporally-Varying Parameters to Reduce Synchronous Activity at the Onset of High Frequency Stimulation in Rat Hippocampus

    Directory of Open Access Journals (Sweden)

    Ziyan Cai

    2017-10-01

    Full Text Available Deep brain stimulation (DBS has shown wide applications for treating various disorders in the central nervous system by using high frequency stimulation (HFS sequences of electrical pulses. However, upon the onset of HFS sequences, the narrow pulses could induce synchronous firing of action potentials among large populations of neurons and cause a transient phase of “onset response” that is different from the subsequent steady state. To investigate the transient onset phase, the antidromically-evoked population spikes (APS were used as an electrophysiological marker to evaluate the synchronous neuronal reactions to axonal HFS in the hippocampal CA1 region of anesthetized rats. New stimulation paradigms with time-varying intensity and frequency were developed to suppress the “onset responses”. Results show that HFS paradigms with ramp-up intensity at the onset phase could suppress large APS potentials. In addition, an intensity ramp with a slower ramp-up rate or with a higher pulse frequency had greater suppression on APS amplitudes. Therefore, to reach a desired pulse intensity rapidly, a stimulation paradigm combining elevated frequency and ramp-up intensity was used to shorten the transition phase of initial HFS without evoking large APS potentials. The results of the study provide important clues for certain transient side effects of DBS and for development of new adaptive stimulation paradigms.

  16. Post stimulus effects of high frequency biphasic electrical current on a fibre's conductibility in isolated frog nerves

    Science.gov (United States)

    Liu, Hailong; Zhu, Linlin; Sheng, Shulei; Sun, Lifei; Zhou, Hongmin; Tang, Hong; Qiu, Tianshuang

    2013-06-01

    Objective. High frequency biphasic (HFB) electrical currents are widely used in nerve blocking studies. Their safety margins largely remain unknown and need to be investigated. Approach. This study, exploring the post stimulus effects of HFB electrical currents on a nerve's conductibility, was performed on bullfrog sciatic nerves. Both compound action potentials (CAPs) and differential CAPs (DCAPs, i.e. control CAPs subtracted by CAPs following HFB currents) were obtained, and N1 and N2 components, which were the first and second upward components of DCAPs, were used for analyses of the effects introduced by HFB electrical stimulation. Main results. First, HFB currents of 10 kHz at a completely blocking threshold were applied for 5 s. The maximum amplitudes and conducting velocities of the CAPs were significantly (P conductibility and the appearances of new delayed conductions. Decreases of N1 amplitudes along time, regarded as the recovery of the nerve's conductibility, exhibited two distinct phases: a fast one lasting several seconds and a slow one lasting longer than 5 min. Further tests showed a linear relationship between the HFB stimulation durations and recovering periods of N1 amplitudes. Supra-threshold blocking did not cause higher N1 amplitudes. Significance. This study indicates that HFB electrical currents lead to long lasting post stimulus reduction of a nerve's conductibility, which might relate to potential nerve injuries. A possible mechanism, focusing on changes in intracellular and periaxonal ionic concentrations, was proposed to underlie the reduction of the nerve's conductibility and potential nerve injuries. Greater caution and stimulation protocols with greater safety margins should be explored when utilizing HFB electrical current to block nerve conductions.

  17. High frequency deep brain stimulation attenuates subthalamic and cortical rhythms in Parkinson’s disease

    Directory of Open Access Journals (Sweden)

    Diane eWhitmer

    2012-06-01

    Full Text Available Parkinson’s disease (PD is marked by excessive synchronous activity in the beta (8-35 Hz band throughout the cortico-basal ganglia network. The optimal location of high frequency deep brain stimulation (HF DBS within the subthalamic nucleus (STN region and the location of maximal beta hypersynchrony are currently matters of debate. Additionally, the effect of STN HF DBS on neural synchrony in functionally connected regions of motor cortex is unknown and of great interest. Scalp EEG studies demonstrated that stimulation of the STN can activate motor cortex antidromically, but the spatial specificity of this effect has not been examined. The present study examined the effect of STN HF DBS on neural synchrony within the cortico-basal ganglia network in patients with PD. We measured local field potentials dorsal to and within the STN of PD patients, and additionally in the motor cortex in a subset of these patients. We used diffusion tensor imaging (DTI to guide the placement of subdural cortical surface electrodes over the DTI-identified origin of the hyperdirect pathway between motor cortex and the STN. The results demonstrated that local beta power was attenuated during HF DBS both dorsal to and within the STN. The degree of attenuation was monotonic with increased DBS voltages in both locations, but this voltage-dependent effect was greater in the central STN than dorsal to the STN (p < 0.05. Cortical signals over the estimated origin of the hyperdirect pathway also demonstrated attenuation of beta hypersynchrony during DBS dorsal to or within STN, whereas signals from non-specific regions of motor cortex were not attenuated. The spatially specific suppression of beta synchrony in the motor cortex support the hypothesis that DBS may treat Parkinsonism by reducing excessive synchrony in the functionally connected sensorimotor network.

  18. High frequency repetitive sensory stimulation as intervention to improve sensory loss in patients with complex regional pain syndrome (CRPS I

    Directory of Open Access Journals (Sweden)

    Marianne eDavid

    2015-11-01

    Full Text Available Achieving perceptual gains in healthy individuals, or facilitating rehabilitation in patients is generally considered to require intense training to engage neuronal plasticity mechanisms. Recent work, however, suggested that beneficial outcome similar to training can be effectively acquired by a complementary approach in which the learning occurs in response to mere exposure to repetitive sensory stimulation (rSS. For example, high-frequency repetitive sensory stimulation (HF-rSS enhances tactile performance and induces cortical reorganization in healthy subjects and patients after stroke. Patients with complex regional pain syndrome (CRPS show impaired tactile performance associated with shrinkage of cortical maps. We here investigated the feasibility and efficacy of HF-rSS, and low-frequency rSS (LF-rSS to enhance tactile performance and reduce pain intensity in 20 patients with CRPS type I. Intermittent high or low frequency electrical stimuli were applied for 45min/day to all fingertips of the affected hand for 5 days. Main outcome measures were spatial 2-point-discrimination thresholds and mechanical detection thresholds measured on the tip of the index finger bilaterally. Secondary endpoint was current pain intensity. All measures were assessed before and on day 5 after the last stimulation session. HF-rSS applied in 16 patients improved tactile discrimination on the affected hand significantly without changes contralaterally. Current pain intensity remained unchanged on average, but decreased in 4 patients by 30%. This limited pain relief might be due to the short stimulation period of 5 days only. In contrast, after LF-rSS, tactile discrimination was impaired in all 4 patients, while detection thresholds and pain were not affected. Our data suggest that HF-rSS could be used as a novel approach in CRPS treatment to improve sensory loss. Longer treatment periods might be required to induce consistent pain relief.

  19. LPS levels in root canals after the use of ozone gas and high frequency electrical pulses

    Directory of Open Access Journals (Sweden)

    Tiago André Fontoura de MELO

    2016-01-01

    Full Text Available Abstract The present study aims to verify the effect of ozone gas (OZY® System and high frequency electric pulse (Endox® System systems on human root canals previously contaminated with Escherichia colilipopolysaccharide (LPS. Fifty single-rooted teeth had their dental crowns removed and root lengths standardized to 16 mm. The root canals were prepared up to #60 hand K-files and sterilized using gamma radiation with cobalt 60. The specimens were divided into the following five groups (n = 10 based on the disinfection protocol used: OZY® System, one 120-second-pulse (OZY 1p; OZY® System, four 24-second-pulses (OZY 4p; and Endox® System (ENDOX. Contaminated and non-contaminated canals were exposed only to apyrogenic water and used as positive (C+ and negative (C- controls, respectively. LPS (O55:B55 was administered in all root canals except those belonging to group C-. After performing disinfection, LPS samples were collected from the canals using apyrogenic paper tips. Limulus Amoebocyte Lysate (LAL was used to quantify the LPS levels, and the data obtained was analyzed using one-way ANOVA. The disinfection protocols used were unable to reduce the LPS levels significantly (p = 0.019. The use of ozone gas and high frequency electric pulses was not effective in eliminating LPS from the root canals.

  20. Gastric Electrical Stimulation

    Science.gov (United States)

    2006-01-01

    treatment of GP, produces high-frequency GES. Most clinical studies examining GES for GP have used high-frequency (4 times the intrinsic slow wave frequency, i.e., 12 cycles per minute), low energy, short duration pulses. This type of stimulation does not alter gastric muscular contraction and has no effect on slow wave dysrhythmias. The mechanism of action is unclear but it is hypothesized that high-frequency GES may act on sensory fibers directed to the CNS. The GES device licensed by Health Canada for treatment of morbid obesity produces low-frequency GES, which is close to or just above the normal/native gastric slow wave cycle (approximately 3 cycles/min.). This pacing uses low-frequency, high-energy, long-duration pulses to induce propagated slow waves that replace the spontaneous ones. Low-frequency pacing does not invoke muscular contractions. Most studies examining the use of GES for the treatment of morbid obesity use low-frequency GES. Under normal circumstances, the gastric slow wave propagates distally and determines the frequency and propagation direction of gastric peristalsis. Low-frequency GES aims to produce abnormal gastric slow waves that can induce gastric dysrhythmia, disrupt regular propagation of slow waves, cause hypomotility of the stomach, delay gastric emptying, reduce food intake, prolong satiety, and produce weight loss. In the United States, the Enterra Therapy System is a Humanitarian Use Device (HUD), meaning it is a medical device designated by the FDA for use in the treatment of medical conditions that affect fewer than 4,000 individuals per year.2 The Enterra Therapy System is indicated for “the treatment of chronic, drug- refractory nausea and vomiting secondary to GP of diabetes or idiopathic etiology” (not postsurgical etiologies). GES for morbid obesity has not been approved by the FDA and is for investigational use only in the United States. Review Strategy The Medical Advisory Secretariat systematically reviewed the literature

  1. High frequency repetitive transcranial magnetic stimulation treatment for major depression: Dissociated effects on psychopathology and neurocognition.

    Science.gov (United States)

    Tovar-Perdomo, Santiago; McGirr, Alexander; Van den Eynde, Frederique; Rodrigues Dos Santos, Nicole; Berlim, Marcelo T

    2017-08-01

    This open-label pilot study explored the effects of a course of accelerated high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) on two neurocognitive domains (decision-making and impulse control) in patients with major depressive disorder (MDD). Participants with MDD and a treatment resistant major depressive episode (n=24) underwent twice-daily HF-rTMS targeted at the left dorsolateral prefrontal cortex (lDLPFC) over two weeks. Psychopathology was assessed by clinician-administered and self-reported measures of depression and anxiety; decision-making was assessed by the Iowa Gambling Task, the Balloon Analog Risk Task and the Game of Dice Task; impulse control was assessed by the Stroop Color-Word Task, the Continuous Performance Task and the Stop-Signal Task. Depression and anxiety scores significantly improved from pre-post HF-rTMS treatment. However, none of the decision-making or impulse control variables of interest changed significantly from pre-post HF-rTMS. Moreover, there was no correlation between changes in psychopathological symptoms and in neurocognition. This is a moderately sized open label trial, and the confounds of ongoing psychotropics and illness chronicity can not be excluded in this treatment resistant sample. There is dissociation between acute symptomatic benefit after a course of accelerated HF-rTMS applied to the lDLPFC in treatment resistant MDD and performance on tests of decision making and impulse control. Though rTMS appears cognitively safe, additional research is warranted to understand this potential dissociation and its putative clinical implications. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Trigeminal high-frequency stimulation produces short- and long-term modification of reflex blink gain.

    Science.gov (United States)

    Ryan, Michael; Kaminer, Jaime; Enmore, Patricia; Evinger, Craig

    2014-02-01

    Reflex blinks provide a model system for investigating motor learning in normal and pathological states. We investigated whether high-frequency stimulation (HFS) of the supraorbital branch of the trigeminal nerve before the R2 blink component (HFS-B) decreases reflex blink gain in alert rats. As with humans (Mao JB, Evinger C. J Neurosci 21: RC151, 2001), HFS-B significantly reduced blink size in the first hour after treatment for rats. Repeated days of HFS-B treatment produced long-term depression of blink circuits. Blink gain decreased exponentially across days, indicating a long-term depression of blink circuits. Additionally, the HFS-B protocol became more effective at depressing blink amplitude across days of treatment. This depression was not habituation, because neither long- nor short-term blink changes occurred when HFS was presented after the R2. To investigate whether gain modifications produced by HFS-B involved cerebellar networks, we trained rats in a delay eyelid conditioning paradigm using HFS-B as the unconditioned stimulus and a tone as the conditioned stimulus. As HFS-B depresses blink circuits and delay conditioning enhances blink circuit activity, occlusion should occur if they share neural networks. Rats acquiring robust eyelid conditioning did not exhibit decreases in blink gain, whereas rats developing low levels of eyelid conditioning exhibited weak, short-term reductions in blink gain. These results suggested that delay eyelid conditioning and long-term HFS-B utilize some of the same cerebellar circuits. The ability of repeated HFS-B treatment to depress trigeminal blink circuit activity long term implied that it may be a useful protocol to reduce hyperexcitable blink circuits that underlie diseases like benign essential blepharospasm.

  3. Non-contact high-frequency ultrasound microbeam stimulation for studying mechanotransduction in human umbilical vein endothelial cells.

    Science.gov (United States)

    Hwang, Jae Youn; Lim, Hae Gyun; Yoon, Chi Woo; Lam, Kwok Ho; Yoon, Sangpil; Lee, Changyang; Chiu, Chi Tat; Kang, Bong Jin; Kim, Hyung Ham; Shung, K Kirk

    2014-09-01

    We describe how contactless high-frequency ultrasound microbeam stimulation (HFUMS) is capable of eliciting cytoplasmic calcium (Ca(2+)) elevation in human umbilical vein endothelial cells. The cellular mechanotransduction process, which includes cell sensing and adaptation to the mechanical micro-environment, has been studied extensively in recent years. A variety of tools for mechanical stimulation have been developed to produce cellular responses. We developed a novel tool, a highly focused ultrasound microbeam, for non-contact cell stimulation at a microscale. This tool, at 200 MHz, was applied to human umbilical vein endothelial cells to investigate its potential to elicit an elevation in cytoplasmic Ca(2+) levels. It was found that the response was dose dependent, and moreover, extracellular Ca(2+) and cytoplasmic Ca(2+) stores were involved in the Ca(2+) elevation. These results suggest that high-frequency ultrasound microbeam stimulation is potentially a novel non-contact tool for studying cellular mechanotransduction if the acoustic pressures at such high frequencies can be quantified. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  4. A Systematic Review of Electric-Acoustic Stimulation

    Science.gov (United States)

    Ching, Teresa Y. C.; Cowan, Robert

    2013-01-01

    Cochlear implant systems that combine electric and acoustic stimulation in the same ear are now commercially available and the number of patients using these devices is steadily increasing. In particular, electric-acoustic stimulation is an option for patients with severe, high frequency sensorineural hearing impairment. There have been a range of approaches to combining electric stimulation and acoustic hearing in the same ear. To develop a better understanding of fitting practices for devices that combine electric and acoustic stimulation, we conducted a systematic review addressing three clinical questions: what is the range of acoustic hearing in the implanted ear that can be effectively preserved for an electric-acoustic fitting?; what benefits are provided by combining acoustic stimulation with electric stimulation?; and what clinical fitting practices have been developed for devices that combine electric and acoustic stimulation? A search of the literature was conducted and 27 articles that met the strict evaluation criteria adopted for the review were identified for detailed analysis. The range of auditory thresholds in the implanted ear that can be successfully used for an electric-acoustic application is quite broad. The effectiveness of combined electric and acoustic stimulation as compared with electric stimulation alone was consistently demonstrated, highlighting the potential value of preservation and utilization of low frequency hearing in the implanted ear. However, clinical procedures for best fitting of electric-acoustic devices were varied. This clearly identified a need for further investigation of fitting procedures aimed at maximizing outcomes for recipients of electric-acoustic devices. PMID:23539259

  5. A Power-Efficient Multichannel Neural Stimulator Using High-Frequency Pulsed Excitation From an Unfiltered Dynamic Supply.

    Science.gov (United States)

    van Dongen, Marijn N; Serdijn, Wouter A

    2016-02-01

    This paper presents a neural stimulator system that employs a fundamentally different way of stimulating neural tissue compared to classical constant current stimulation. A stimulation pulse is composed of a sequence of current pulses injected at a frequency of 1 MHz for which the duty cycle is used to control the stimulation intensity. The system features 8 independent channels that connect to any of the 16 electrodes at the output. A sophisticated control system allows for individual control of each channel's stimulation and timing parameters. This flexibility makes the system suitable for complex electrode configurations and current steering applications. Simultaneous multichannel stimulation is implemented using a high frequency alternating technique, which reduces the amount of electrode switches by a factor 8. The system has the advantage of requiring a single inductor as its only external component. Furthermore it offers a high power efficiency, which is nearly independent on both the voltage over the load as well as on the number of simultaneously operated channels. Measurements confirm this: in multichannel mode the power efficiency can be increased for specific cases to 40% compared to 20% that is achieved by state-of-the-art classical constant current stimulators with adaptive power supply.

  6. Defibrillation success with high frequency electric fields is related to degree and location of conduction block.

    Science.gov (United States)

    Weinberg, Seth H; Chang, Kelly C; Zhu, Renjun; Tandri, Harikrishna; Berger, Ronald D; Trayanova, Natalia A; Tung, Leslie

    2013-05-01

    We recently demonstrated that high frequency alternating current (HFAC) electric fields can reversibly block propagation in the heart by inducing an oscillating, elevated transmembrane potential (Vm) that maintains myocytes in a refractory state for the field duration and can terminate arrhythmias, including ventricular fibrillation (VF). To quantify and characterize conduction block (CB) induced by HFAC fields and to determine whether the degree of CB can be used to predict defibrillation success. Optical mapping was performed in adult guinea pig hearts (n = 14), and simulations were performed in an anatomically accurate rabbit ventricular model. HFAC fields (50-500 Hz) were applied to the ventricles. A novel power spectrum metric of CB-the loss of spectral power in the 1-30 Hz range, termed loss of conduction power (LCP)-was assessed during the HFAC field and compared with defibrillation success and VF vulnerability. LCP increased with field strength and decreased with frequency. Optical mapping experiments conducted on the epicardial surface showed that LCP and the size of CB regions were significantly correlated with VF initiation and termination. In simulations, subsurface myocardial LCP and CB sizes were more closely correlated with VF termination than surface values. Multilinear regression analysis of simulation results revealed that while CB on both the surface and the subsurface myocardium was predictive, subsurface myocardial CB was the better predictor of defibrillation success. HFAC fields induce a field-dependent state of CB, and defibrillation success is related to the degree and location of the CB. Copyright © 2013. Published by Elsevier Inc.

  7. Urotensin II stimulates high frequency-induced ANP secretion via PLC-PI 3K-PKC pathway.

    Science.gov (United States)

    Gao, Shan; Shah, Amin; Oh, Young Bin; Park, Woo Hyun; Kim, Suhn Hee

    2010-01-01

    Urotensin II (U-II) and its receptor are coexpressed in the heart and show various cardiovascular functions. However, the relationship between U-II and cardiac hormone atrial natriuretic peptide (ANP) is still unknown. The aim of the present study is to test whether U-II affects ANP secretion using in vitro perfusion experiments and in vivo studies. Human U-II (hU-II) (10(-11), 5x10(-11), 10(-10), 5x10(-10)M) stimulated ANP secretion from isolated perfused rat atria paced with high frequency (6.0Hz). However, atrial contractility and translocation of extracellular fluid (ECF) did not change. An increase in ANP secretion by rat U-II was similar to that by hU-II; however, urotensin-related peptide showed no significant effect on ANP secretion. Pretreatment with urotensin receptor antagonist and inhibitor for phospholipase C (PLC), phosphoinositide 3-kinase (PI3K), or protein kinase C (PKC) attenuated hU-II-induced ANP secretion from atria paced with high frequency, but an inhibitor for inositol triphosphate did not. Intravenous infusion of hU-II at a dose of 2.5microM for 20min increased plasma ANP level, along with increased heart rate and pulse pressure in anesthetized rats. Therefore, we suggest that U-II stimulates high stimulation frequency-induced ANP secretion partly through the urotensin receptor and the PLC/PI3K/PKC pathway.

  8. Transcranial electrical stimulation: An introduction

    CERN Document Server

    Tarazona, Carlos G; Chávez, Laura; Andrade, Sebastián

    2015-01-01

    The main objective of the electrical stimulation of the brain is to generate action potentials from the application of electromagnetic fields. Among the available techniques, transcranial electrical stimulation (TES) represents a popular method of administration that has the advantage of being non-invasive and economically more affordable. This article aims to briefly introduce the reader into the understanding of TES in terms of the physics involved as well as for some of the relevant results of studies applying this technique.

  9. Electrical power inverter having a phase modulated, twin-inverter, high frequency link and an energy storage module

    Science.gov (United States)

    Pitel, Ira J.

    1987-02-03

    The present invention provides an electrical power inverter method and apparatus, which includes a high frequency link, for converting DC power into AC power. Generally stated, the apparatus includes a first high frequency module which produces an AC voltage at a first output frequency, and a second high frequency inverter module which produces an AC voltage at a second output frequency that is substantially the same as the first output frequency. The second AC voltage is out of phase with the first AC voltage by a selected angular phase displacement. A mixer mixes the first and second output voltages to produce a high frequency carrier which has a selected base frequency impressed on the sidebands thereof. A rectifier rectifies the carrier, and a filter filters the rectified carrier. An output inverter inverts the filtered carrier to produce an AC line voltage at the selected base frequency. A phase modulator adjusts the relative angular phase displacement between the outputs of the first and second high frequency modules to control the base frequency and magnitude of the AC line voltage.

  10. Dynamic stereotypic responses of basal ganglia neurons to subthalamic nucleus high frequency stimulation in the parkinsonian primate

    Directory of Open Access Journals (Sweden)

    Anan eMoran

    2011-04-01

    Full Text Available Deep brain stimulation in the subthalamic nucleus (STN is a well-established therapy for patients with severe Parkinson‟s disease (PD; however, its mechanism of action is still unclear. In this study we explored static and dynamic activation patterns in the basal ganglia during high frequency macro-stimulation of the STN. Extracellular multi-electrode recordings were performed in primates rendered parkinsonian using 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine. Recordings were preformed simultaneously in the STN and the globus pallidus externus and internus. Single units were recorded preceding and during the stimulation. During the stimulation, STN mean firing rate dropped significantly, while pallidal mean firing rates did not change significantly. The vast majority of neurons across all three nuclei displayed stimulation driven modulations, which were stereotypic within each nucleus but differed across nuclei. The predominant response pattern of STN neurons was somatic inhibition. However, most pallidal neurons demonstrated synaptic activation patterns. A minority of neurons across all nuclei displayed axonal activation. Temporal dynamics were observed in the response to stimulation over the first 10 seconds in the STN and over the first 30 seconds in the pallidum. In both pallidal segments, the synaptic activation response patterns underwent delay and decay of the magnitude of the peak response due to short term synaptic depression. We suggest that during STN macro stimulation the STN goes through a functional ablation as its upper bound on information transmission drops significantly. This notion is further supported by the evident dissociation between the stimulation driven pre-synaptic STN somatic inhibition and the post-synaptic axonal activation of its downstream targets. Thus, basal ganglia output maintains its firing rate while losing the deleterious effect of the STN. This may be a part of the mechanism leading to the beneficial

  11. Pulse propagation and failure in the discrete FitzHugh-Nagumo model subject to high-frequency stimulation.

    Science.gov (United States)

    Ratas, Irmantas; Pyragas, Kestutis

    2012-10-01

    We investigate the effect of a homogeneous high-frequency stimulation (HFS) on a one-dimensional chain of coupled excitable elements governed by the FitzHugh-Nagumo equations. We eliminate the high-frequency term by the method of averaging and show that the averaged dynamics depends on the parameter A=a/ω equal to the ratio of the amplitude a to the frequency ω of the stimulating signal, so that for large frequencies an appreciable effect from the HFS is attained only at sufficiently large amplitudes. The averaged equations are analyzed by an asymptotic theory based on the different time scales of the recovery and excitable variables. As a result, we obtain the main characteristics of a propagating pulse as functions of the parameter A and derive an analytical criterion for the propagation failure. We show that depending on the parameter A, the HFS can either enhance or suppress pulse propagation and reveal the mechanism underlying these effects. The theoretical results are confirmed by numerical simulations of the original system with and without noise.

  12. Modulation of the Left Prefrontal Cortex with High Frequency Repetitive Transcranial Magnetic Stimulation Facilitates Gait in Multiple Sclerosis

    Directory of Open Access Journals (Sweden)

    Amer M. Burhan

    2015-01-01

    Full Text Available Multiple Sclerosis (MS is a chronic central nervous system (CNS demyelinating disease. Gait abnormalities are common and disabling in patients with MS with limited treatment options available. Emerging evidence suggests a role of prefrontal attention networks in modulating gait. High-frequency repetitive transcranial magnetic stimulation (rTMS is known to enhance cortical excitability in stimulated cortex and its correlates. We investigated the effect of high-frequency left prefrontal rTMS on gait parameters in a 51-year-old Caucasian male with chronic relapsing/remitting MS with residual disabling attention and gait symptoms. Patient received 6 Hz, rTMS at 90% motor threshold using figure of eight coil centered on F3 location (using 10-20 electroencephalography (EEG lead localization system. GAITRite gait analysis system was used to collect objective gait measures before and after one session and in another occasion three consecutive daily sessions of rTMS. Two-tailed within subject repeated measure t-test showed significant enhancement in ambulation time, gait velocity, and cadence after three consecutive daily sessions of rTMS. Modulating left prefrontal cortex excitability using rTMS resulted in significant change in gait parameters after three sessions. To our knowledge, this is the first report that demonstrates the effect of rTMS applied to the prefrontal cortex on gait in MS patients.

  13. The effects of high frequency subthalamic stimulation on balance performance and fear of falling in patients with Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Jarnlo Gun-Britt

    2009-04-01

    Full Text Available Abstract Background Balance impairment is one of the most distressing symptoms in Parkinson's disease (PD even with pharmacological treatment (levodopa. A complementary treatment is high frequency stimulation in the subthalamic nucleus (STN. Whether STN stimulation improves postural control is under debate. The aim of this study was to explore the effects of STN stimulation alone on balance performance as assessed with clinical performance tests, subjective ratings of fear of falling and posturography. Methods Ten patients (median age 66, range 59–69 years with bilateral STN stimulation for a minimum of one year, had their anti-PD medications withdrawn overnight. Assessments were done both with the STN stimulation turned OFF and ON (start randomized. In both test conditions, the following were assessed: motor symptoms (descriptive purposes, clinical performance tests, fear of falling ratings, and posturography with and without vibratory proprioceptive disturbance. Results STN stimulation alone significantly (p = 0.002 increased the scores of the Berg balance scale, and the median increase was 6 points. The results of all timed performance tests, except for sharpened Romberg, were significantly (p ≤ 0.016 improved. The patients rated their fear of falling as less severe, and the total score of the Falls-Efficacy Scale(S increased (p = 0.002 in median with 54 points. All patients completed posturography when the STN stimulation was turned ON, but three patients were unable to do so when it was turned OFF. The seven patients with complete data showed no statistical significant difference (p values ≥ 0.109 in torque variance values when comparing the two test situations. This applied both during quiet stance and during the periods with vibratory stimulation, and it was irrespective of visual input and sway direction. Conclusion In this sample, STN stimulation alone significantly improved the results of the clinical performance tests that mimic

  14. Evoked Electromyographically Controlled Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Mitsuhiro Hayashibe

    2016-07-01

    Full Text Available Time-variant muscle responses under electrical stimulation (ES are often problematic for all the applications of neuroprosthetic muscle control. This situation limits the range of ES usage in relevant areas, mainly due to muscle fatigue and also to changes in stimulation electrode contact conditions, especially in transcutaneous ES. Surface electrodes are still the most widely used in noninvasive applications.Electrical field variations caused by changes in the stimulation contact condition markedly affect the resulting total muscle activation levels. Fatigue phenomena under functional electrical stimulation (FES are also well known source of time-varying characteristics coming from muscle response under ES. Therefore it is essential to monitor the actual muscle state and assess the expected muscle response by ES so as to improve the current ES system in favour of adaptive muscle-response-aware FES control. To deal with this issue, we have been studying a novel control technique using evoked electromyography (eEMG signals to compensate for these muscle time-variances under ES for stable neuroprosthetic muscle control. In this perspective article, I overview the background of this topic and highlight important points to be aware of when using ES to induce the desired muscle activation regardless of the time-variance. I also demonstrate how to deal with the common critical problem of ES to move toward robust neuroprosthetic muscle control with the Evoked Electromyographically Controlled Electrical Stimulation paradigm.

  15. Low intensity transcranial electric stimulation

    DEFF Research Database (Denmark)

    Antal, A.; Alekseichuk, I.; Bikson, M.

    2017-01-01

    Low intensity transcranial electrical stimulation (TES) in humans, encompassing transcranial direct current (tDCS), transcutaneous spinal Direct Current Stimulation (tsDCS), transcranial alternating current (tACS), and transcranial random noise (tRNS) stimulation or their combinations, appears...... to suboptimal electrode-skin contact. Very rarely mania or hypomania was induced in patients with depression (11 documented cases), yet a causal relationship is difficult to prove because of the low incidence rate and limited numbers of subjects in controlled trials. Mild AEs (MAEs) include headache and fatigue...

  16. Effective treatment of narcolepsy-like symptoms with high-frequency repetitive transcranial magnetic stimulation: A case report.

    Science.gov (United States)

    Lai, Jian-Bo; Han, Mao-Mao; Xu, Yi; Hu, Shao-Hua

    2017-11-01

    Narcolepsy is a rare sleep disorder with disrupted sleep-architecture. Clinical management of narcolepsy lies dominantly on symptom-driven pharmacotherapy. The treatment role of repetitive transcranial magnetic stimulation (rTMS) for narcolepsy remains unexplored. In this paper, we present a case of a 14-year-old young girl with excessive daytime sleepiness (EDS), cataplexy and hypnagogic hallucinations. After excluding other possible medical conditions, this patient was primarily diagnosed with narcolepsy. The patient received 25 sessions of high-frequency rTMS over the left dorsolateral prefrontal cortex (DLPFC). The symptoms of EDS and cataplexy significantly improved after rTMS treatment. Meanwhile, her score in the Epworth sleep scale (ESS) also remarkably decreased. This case indicates that rTMS may be selected as a safe and effective alternative strategy for treating narcolepsy-like symptoms. Well-designed researches are warranted in future investigations on this topic.

  17. High-Frequency Stimulation at the Subthalamic Nucleus Suppresses Excessive Self-Grooming in Autism-Like Mouse Models.

    Science.gov (United States)

    Chang, Andrew D; Berges, Victoria A; Chung, Sunho J; Fridman, Gene Y; Baraban, Jay M; Reti, Irving M

    2016-06-01

    Approximately one quarter of individuals with an autism spectrum disorder (ASD) display self-injurious behavior (SIB) ranging from head banging to self-directed biting and punching. Sometimes, these behaviors are extreme and unresponsive to pharmacological and behavioral therapies. We have found electroconvulsive therapy (ECT) can produce life-changing results, with more than 90% suppression of SIB frequency. However, these patients typically require frequent maintenance ECT (mECT), as often as every 5 days, to sustain the improvement gained during the acute course. Long-term consequences of such frequent mECT started as early as childhood in some cases are unknown. Accordingly, there is a need for alternative forms of chronic stimulation for these patients. To explore the feasibility of deep brain stimulation (DBS) for intractable SIB seen in some patients with an ASD, we utilized two genetically distinct mouse models demonstrating excessive self-grooming, namely the Viaat-Mecp2(-/y) and Shank3B(-/-) lines, and administered high-frequency stimulation (HFS) via implanted electrodes at the subthalamic nucleus (STN-HFS). We found that STN-HFS significantly suppressed excessive self-grooming in both genetic lines. Suppression occurs both acutely when stimulation is switched on, and persists for several days after HFS is stopped. This effect was not explained by a change in locomotor activity, which was unaffected by STN-HFS. Likewise, social interaction deficits were not corrected by STN-HFS. Our data show STN-HFS suppresses excessive self-grooming in two autism-like mouse models, raising the possibility DBS might be used to treat intractable SIB associated with ASDs. Further studies are required to explore the circuitry engaged by STN-HFS, as well as other potential stimulation sites. Such studies might also yield clues about pathways, which could be modulated by non-invasive stimulatory techniques.

  18. Electrically tunable transport and high-frequency dynamics in antiferromagnetic S r3I r2O7

    Science.gov (United States)

    Seinige, Heidi; Williamson, Morgan; Shen, Shida; Wang, Cheng; Cao, Gang; Zhou, Jianshi; Goodenough, John B.; Tsoi, Maxim

    2016-12-01

    We report dc and high-frequency transport properties of antiferromagnetic S r3I r2O7 . Temperature-dependent resistivity measurements show that the activation energy of this material can be tuned by an applied dc electrical bias. The latter allows for continuous variations in the sample resistivity of as much as 50% followed by a reversible resistive switching at higher biases. Such a switching is of high interest for antiferromagnetic applications in high-speed memory devices. Interestingly, we found the switching behavior to be strongly affected by a high-frequency (microwave) current applied to the sample. The microwaves at 3-7 GHz suppress the dc switching and produce resonancelike features that we tentatively associated with the dissipationless magnonics recently predicted to occur in antiferromagnetic insulators subject to ac electric fields. We have characterized the effects of microwave irradiation on electronic transport in S r3I r2O7 as a function of microwave frequency and power, strength and direction of external magnetic field, strength and polarity of applied dc bias, and temperature. Our observations support the potential of antiferromagnetic materials for high-speed/high-frequency spintronic applications.

  19. Pitch matching psychometrics in electric acoustic stimulation.

    Science.gov (United States)

    Baumann, Uwe; Rader, Tobias; Helbig, Silke; Bahmer, Andreas

    2011-01-01

    Combined electric-acoustic stimulation (EAS) is a therapeutic option for patients with severe to profound mid- and high-frequency hearing loss while low-frequency hearing is mostly unaffected. The present study investigates bimodal pitch matching in EAS users as a function of the angular placement of electrodes. Results are compared with data obtained from previous pitch matching studies. Knowledge of electric and acoustic pitch mapping may be important for effective fitting to control the frequency range of acoustic and electric processing. Pitch adjustment experiments were conducted in eight subjects with residual hearing in the opposite ear as well as in the implanted ear. Four subjects received a standard 31.5-mm electrode array and four subjects received the shorter, more flexible 24-mm FLEX electrode array (PULSARCI100 or SONATATI100 stimulator, MED-EL, Innsbruck, Austria). The subjects' task was to listen to single-electrode stimuli presented at a fixed rate (800 pulses per second) via the cochlear implant and to adjust the frequency of the acoustic stimulus until the perceived pitch matched the perception of the electrically conveyed stimulus. Two to four of the most apical electrodes were tested depending on the range of the individual's residual hearing. Postoperative x rays (modified Stenver's view) were analyzed to compare individual pitch matching data in terms of the electrode arrays' insertion angle. The average mean frequency match for the most apical electrode 1 in EAS subjects implanted with the FLEX array was 583 Hz, while for the two subjects with a deep insertion of the 31.5-mm standard electrode array, the matches were 128 and 223 Hz. Because the residual hearing in the EAS subgroup was rather limited in the high-frequency range, a limited number of basal electrodes were assessed to determine the slope of the electric place/pitch function. A considerable variation in terms of the individual pitch function was observed. The slope of the pitch

  20. A comparative study of the impact of theta-burst and high-frequency stimulation on memory performance

    Directory of Open Access Journals (Sweden)

    Yating eZhu

    2016-02-01

    Full Text Available The transformation of the information stored in the working memory into the system of long-term memory depends on the physiological mechanism, long-term potential (LTP. In a large number of experimental studies, theta-burst stimulation (TBS and high-frequency stimulation (HFS are LTP induction protocols. However, they have not been adapted to the model related to memory. In this paper, the improved Camperi-Wang (C-W model with Ca2+ subsystem-induced bi-stability was adopted, and TBS and HFS were simulated to act as the initial stimuli of this working memory model. Evaluating the influence of stimuli properties (cycle, amplitude, duty ration on memory mechanism of the model, it is found that both TBS and HFS can be adopted to activate working memory model and produce long-term memory. Moreover, the different impacts of two types of stimuli on the formation of long-term memory were analyzed as well. Thus the importance of this study lies firstly in describing the link and interaction between working memory and long-term memory from the quantitative view, which provides a theoretical basis for the study of neural dynamics mechanism of long-term memory formation in the future.

  1. A Systematic Review of Electric-Acoustic Stimulation: Device Fitting Ranges, Outcomes, and Clinical Fitting Practices

    OpenAIRE

    Incerti, Paola V.; Ching, Teresa Y. C.; Cowan, Robert

    2013-01-01

    Cochlear implant systems that combine electric and acoustic stimulation in the same ear are now commercially available and the number of patients using these devices is steadily increasing. In particular, electric-acoustic stimulation is an option for patients with severe, high frequency sensorineural hearing impairment. There have been a range of approaches to combining electric stimulation and acoustic hearing in the same ear. To develop a better understanding of fitting practices for devic...

  2. Preliminary Evidence of the Effects of High-frequency Repetitive Transcranial Magnetic Stimulation (rTMS) on Swallowing Functions in Post-Stroke Individuals with Chronic Dysphagia

    Science.gov (United States)

    Cheng, Ivy K. Y.; Chan, Karen M. K.; Wong, C. S.; Cheung, Raymond T. F.

    2015-01-01

    Background: There is growing evidence of potential benefits of repetitive transcranial magnetic stimulation (rTMS) in the rehabilitation of dysphagia. However, the site and frequency of stimulation for optimal effects are not clear. Aims: The aim of this pilot study is to investigate the short-term effects of high-frequency 5 Hz rTMS applied to…

  3. Modulation of local field potentials by high-frequency stimulation of afferent axons in the hippocampal CA1 region.

    Science.gov (United States)

    Yu, Ying; Feng, Zhouyan; Cao, Jiayue; Guo, Zheshan; Wang, Zhaoxiang; Hu, Na; Wei, Xuefeng

    2016-03-01

    Modulation of the rhythmic activity of local field potentials (LFP) in neuronal networks could be a mechanism of deep brain stimulation (DBS). However, exact changes of LFP during the periods of high-frequency stimulation (HFS) of DBS are unclear because of the interference of dense stimulation artifacts with high amplitudes. In the present study, we investigated LFP changes induced by HFS of afferent axons in the hippocampal CA1 region of urethane-anesthetized rats by using a proper algorithm of artifact removal. Afterward, the LFP changes in the frequency bands of [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] rhythms were studied by power spectrum analysis and coherence analysis for the recorded signals collected in the pyramidal layer and in the stratum radiatum of CA1 region before, during and after 1-min long 100 and 200[Formula: see text]Hz HFS. Results showed that the power of LFP rhythms in higher-frequency band ([Formula: see text] rhythm) increased in the pyramidal layer and the power of LFP rhythms in lower-frequency bands ([Formula: see text], [Formula: see text] and [Formula: see text] rhythms) decreased in the stratum radiatum during HFS. The synchronization of [Formula: see text] rhythm decreased and the synchronization of [Formula: see text] rhythm increased during HFS in the stratum radiatum. These results suggest that axonal HFS could modulate LFP rhythms in the downstream brain areas with a plausible underlying mechanism of partial axonal blockage induced by HFS. The study provides new evidence to support the mechanism of DBS modulating rhythmic activity of neuronal populations.

  4. High frequency stimulation of the subthalamic nucleus leads to presynaptic GABA(B-dependent depression of subthalamo-nigral afferents.

    Directory of Open Access Journals (Sweden)

    Anton Dvorzhak

    Full Text Available Patients with akinesia benefit from chronic high frequency stimulation (HFS of the subthalamic nucleus (STN. Among the mechanisms contributing to the therapeutic success of HFS-STN might be a suppression of activity in the output region of the basal ganglia. Indeed, recordings in the substantia nigra pars reticulata (SNr of fully adult mice revealed that HFS-STN consistently produced a reduction of compound glutamatergic excitatory postsynaptic currents at a time when the tetrodotoxin-sensitive components of the local field potentials had already recovered after the high frequency activation. These observations suggest that HFS-STN not only alters action potential conduction on the way towards the SNr but also modifies synaptic transmission within the SNr. A classical conditioning-test paradigm was then designed to better separate the causes from the indicators of synaptic depression. A bipolar platinum-iridium macroelectrode delivered conditioning HFS trains to a larger group of fibers in the STN, while a separate high-ohmic glass micropipette in the rostral SNr provided test stimuli at minimal intensity to single fibers. The conditioning-test interval was set to 100 ms, i.e. the time required to recover the excitability of subthalamo-nigral axons after HFS-STN. The continuity of STN axons passing from the conditioning to the test sites was examined by an action potential occlusion test. About two thirds of the subthalamo-nigral afferents were occlusion-negative, i.e. they were not among the fibers directly activated by the conditioning STN stimulation. Nonetheless, occlusion-negative afferents exhibited signs of presynaptic depression that could be eliminated by blocking GABA(B receptors with CGP55845 (1 µM. Further analysis of single fiber-activated responses supported the proposal that the heterosynaptic depression of synaptic glutamate release during and after HFS-STN is mainly caused by the tonic release of GABA from co-activated striato

  5. Influence of low- and high-frequency electrical heating on biodegrading microorganisms in soil: soil respiration.

    Science.gov (United States)

    Roland, Ulf; Holzer, Frank; Kopinke, Frank-Dieter

    2013-01-01

    The influence of electrical heating on microbiological processes in soil has been studied to evaluate the potential for enhancing biodegradation of pollutants by controlling the temperature. A frequency of 50 Hz (power line frequency) was applied for resistive heating. Dielectric heating was realized using a frequency of 13.56 MHz (radio frequency). Both techniques were compared with conventional heating in a water bath. For experiments in laboratory and full scale, a model soil and a contaminated original soil were used. It was shown that under conditions capable for heating soil to 35 degrees C or even 60 degrees C, soil respiration as a measure for microbial activity was not hindered by electrical heating when temperature and moisture content were comparable with conventional heating. The variations of soil respiration were reversible upon temperature changes. Under certain conditions, periodical fluctuations of microbiological activity were observed. Several possible explanations including chronobiology are discussed without being able to provide an unambiguous interpretation for this effect.

  6. Micro- and nanostructure of a titanium surface electric-spark-doped with tantalum and modified by high-frequency currents

    Science.gov (United States)

    Fomin, A. A.; Fomina, M. A.; Koshuro, V. A.; Rodionov, I. V.; Voiko, A. V.; Zakharevich, A. M.; Aman, A.; Oseev, A.; Hirsch, S.; Majcherek, S.

    2016-09-01

    We have studied the characteristics of the porous microstructure of tantalum coatings obtained by means of electric spark spraying on the surface of commercial grade titanium. It is established that, at an electric spark current within 0.8-2.2 A, a mechanically strong tantalum coating microstructure is formed with an average protrusion size of 5.1-5.4 µm and pore sizes from 3.5 to 9.2 µm. On the nanoscale, a structurally heterogeneous state of coatings has been achieved by subsequent thermal modification at 800-830°C with the aid of high-frequency currents. A metal oxide nanostructure with grain sizes from 40 to 120 nm is formed by short-time (~30 s) thermal modification. The coating hardness reaches 9.5-10.5 GPa at an elastic modulus of 400-550 GPa.

  7. Different Mode of Afferents Determines the Frequency Range of High Frequency Activities in the Human Brain: Direct Electrocorticographic Comparison between Peripheral Nerve and Direct Cortical Stimulation.

    Directory of Open Access Journals (Sweden)

    Katsuya Kobayashi

    Full Text Available Physiological high frequency activities (HFA are related to various brain functions. Factors, however, regulating its frequency have not been well elucidated in humans. To validate the hypothesis that different propagation modes (thalamo-cortical vs. cortico-coritcal projections, or different terminal layers (layer IV vs. layer II/III affect its frequency, we, in the primary somatosensory cortex (SI, compared HFAs induced by median nerve stimulation with those induced by electrical stimulation of the cortex connecting to SI. We employed 6 patients who underwent chronic subdural electrode implantation for presurgical evaluation. We evaluated the HFA power values in reference to the baseline overriding N20 (earliest cortical response and N80 (late response of somatosensory evoked potentials (HFA(SEP(N20 and HFA(SEP(N80 and compared those overriding N1 and N2 (first and second responses of cortico-cortical evoked potentials (HFA(CCEP(N1 and HFA(CCEP(N2. HFA(SEP(N20 showed the power peak in the frequency above 200 Hz, while HFA(CCEP(N1 had its power peak in the frequency below 200 Hz. Different propagation modes and/or different terminal layers seemed to determine HFA frequency. Since HFA(CCEP(N1 and HFA induced during various brain functions share a similar broadband profile of the power spectrum, cortico-coritcal horizontal propagation seems to represent common mode of neural transmission for processing these functions.

  8. Probing whole cell currents in high-frequency electrical fields: identification of thermal effects.

    Science.gov (United States)

    Olapinski, Michael; Manus, Stephan; Fertig, Niels; Simmel, Friedrich C

    2008-01-18

    An open-end coaxial probe is combined with a planar patch-clamp system to apply electric fields with GHz frequencies during conventional patch-clamp measurements. The combination of pulsed microwave irradiation and lock-in detection allows for the separation of fast and slow effects and hence facilitates the identification of thermal effects. The setup and the influence of radiation on the patch-clamp current are thoroughly characterized. For the independent optical verification of heating effects, a temperature microscopy technique is applied with high spatial, temporal and temperature resolution. It is shown that the effect of radiation at GHz frequencies on whole cell currents is predominantly thermal in nature in the case of RBL cells with an endogenous K(ir) 2.1 channel.

  9. [Impact of the Overlap Region Between Acoustic and Electric Stimulation].

    Science.gov (United States)

    Baumann, Uwe; Mocka, Moritz

    2017-06-01

    Patients with residual hearing in the low frequencies and ski-slope hearing loss with partial deafness at medium and high frequencies receive a cochlear implant treatment with electric-acoustic stimulation (EAS, "hybrid" stimulation). In the border region between electric and acoustic stimulation a superposition of the 2 types of stimulation is expected. The area of overlap is determined by the insertion depth of the stimulating electrode and the lower starting point of signal transmission provided by the CI speech processor. The study examined the influence of the variation of the electric-acoustic overlap area on speech perception in noise, whereby the width of the "transmission gap" between the 2 different stimulus modalities was varied by 2 different methods. The results derived from 9 experienced users of the MED-EL Duet 2 speech processor show that the electric-acoustic overlapping area and with it the crossover frequency between the acoustic part and the CI should be adjusted individually. Overall, speech reception thresholds (SRT) showed a wide variation of results in between subjects. Further studies shall investigate whether generalized procedures about the setting of the overlap between electric and acoustic stimulation are reasonable, whereby an increased number of subjects and a longer period of acclimatization prior to the conduction of hearing tests deemed necessary. © Georg Thieme Verlag KG Stuttgart · New York.

  10. Braille line using electrical stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Puertas, A; Pures, P; Echenique, A M; Ensinck, J P Graffigna y G [Gabinete de TecnologIa Medica. Universidad N. de San Juan (Argentina)

    2007-11-15

    Conceived within the field of Rehabilitation Technologies for visually impaired persons, the present work aims at enabling the blind user to read written material by means of a tactile display. Once he is familiarized to operate this system, the user will be able to achieve greater performance in study, academic and job activities, thus achieving a rapid and easier social inclusion. The devise accepts any kind of text that is computer-loadable (documents, books, Internet information, and the like) which, through digital means, can be read as Braille text on the pad. This tactile display is composed of an electrodes platform that simulate, through stimulation the writing/reading Braille characters. In order to perceive said characters in similar way to the tactile feeling from paper material, the skin receptor of fingers are stimulated electrically so as to simulate the same pressure and depressions as those of the paper-based counterpart information. Once designed and developed, the display was tested with blind subjects, with relatively satisfactory results. As a continuing project, this prototype is currently being improved as regards.

  11. Braille line using electrical stimulation

    Science.gov (United States)

    Puertas, A.; Purés, P.; Echenique, A. M.; Ensinck, J. P. Graffigna y. G.

    2007-11-01

    Conceived within the field of Rehabilitation Technologies for visually impaired persons, the present work aims at enabling the blind user to read written material by means of a tactile display. Once he is familiarized to operate this system, the user will be able to achieve greater performance in study, academic and job activities, thus achieving a rapid and easier social inclusion. The devise accepts any kind of text that is computer-loadable (documents, books, Internet information, and the like) which, through digital means, can be read as Braille text on the pad. This tactile display is composed of an electrodes platform that simulate, through stimulation the writing/reading Braille characters. In order to perceive said characters in similar way to the tactile feeling from paper material, the skin receptor of fingers are stimulated electrically so as to simulate the same pressure and depressions as those of the paper-based counterpart information. Once designed and developed, the display was tested with blind subjects, with relatively satisfactory results. As a continuing project, this prototype is currently being improved as regards.

  12. When EMG contamination does not necessarily hide high-frequency EEG: scalp electrical recordings before and after Dysport injections.

    Science.gov (United States)

    Boytsova, Julia A; Danko, Sergey G; Medvedev, Svyatoslav V

    2016-11-01

    The main aim of the present study was to investigate effects of partial reductions of electromyogram (EMG) on high-frequency scalp electroencephalogram (EEG) at rest and during performance of certain cognitive tasks. Nineteen healthy women performed the same cognitive tasks before and after cosmetic injections of Dysport in certain sites of facial muscles. Scalp EEG and EMG were recorded. Impact of Dysport injections on changes of spectral power in β2 and low γ frequency ranges (18-40 Hz) in EEG and EMG derivations was investigated. Also changes of spectral power in EEG and EMG derivations during comparisons of different cognitive states were calculated before and after Dysport injections separately. Dysport injections led to EMG decreases in facial muscles around the injection zones and also led to reductions of power of electric processes in scalp derivations. Along with it results of EEG power comparisons between the pairs of the cognitive states were qualitatively similar before and after Dysport injections. These facts to all appearance demonstrate that though scalp EEGs in the range above 15-40 Hz are contaminated by EMG, in certain experimental situations EMG contamination does not preclude qualitative detections of electroencephalographic correlates of mental activities in β2 and low γ frequency ranges. Parallel EEG and EMG registrations can help not to overestimate EMG contamination in psychophysiological EEG studies.

  13. Geochemical responses of forested catchments to bark beetle infestation: Evidence from high frequency in-stream electrical conductivity monitoring

    Science.gov (United States)

    Su, Ye; Langhammer, Jakub; Jarsjö, Jerker

    2017-07-01

    Under the present conditions of climate warming, there has been an increased frequency of bark beetle-induced tree mortality in Asia, Europe, and North America. This study analyzed seven years of high frequency monitoring of in-stream electrical conductivity (EC), hydro-climatic conditions, and vegetation dynamics in four experimental catchments located in headwaters of the Sumava Mountains, Central Europe. The aim was to determine the effects of insect-induced forest disturbance on in-stream EC at multiple timescales, including annual and seasonal average conditions, daily variability, and responses to individual rainfall events. Results showed increased annual average in-stream EC values in the bark beetle-infected catchments, with particularly elevated EC values during baseflow conditions. This is likely caused by the cumulative loading of soil water and groundwater that discharge excess amounts of substances such as nitrogen and carbon, which are released via the decomposition of the needles, branches, and trunks of dead trees, into streams. Furthermore, we concluded that infestation-induced changes in event-scale dynamics may be largely responsible for the observed shifts in annual average conditions. For example, systematic EC differences between baseflow conditions and event flow conditions in relatively undisturbed catchments were essentially eliminated in catchments that were highly disturbed by bark beetles. These changes developed relatively rapidly after infestation and have long-lasting (decadal-scale) effects, implying that cumulative impacts of increasingly frequent bark beetle outbreaks may contribute to alterations of the hydrogeochemical conditions in more vulnerable mountain regions.

  14. A systematic review of electric-acoustic stimulation: device fitting ranges, outcomes, and clinical fitting practices.

    Science.gov (United States)

    Incerti, Paola V; Ching, Teresa Y C; Cowan, Robert

    2013-03-01

    Cochlear implant systems that combine electric and acoustic stimulation in the same ear are now commercially available and the number of patients using these devices is steadily increasing. In particular, electric-acoustic stimulation is an option for patients with severe, high frequency sensorineural hearing impairment. There have been a range of approaches to combining electric stimulation and acoustic hearing in the same ear. To develop a better understanding of fitting practices for devices that combine electric and acoustic stimulation, we conducted a systematic review addressing three clinical questions: what is the range of acoustic hearing in the implanted ear that can be effectively preserved for an electric-acoustic fitting?; what benefits are provided by combining acoustic stimulation with electric stimulation?; and what clinical fitting practices have been developed for devices that combine electric and acoustic stimulation? A search of the literature was conducted and 27 articles that met the strict evaluation criteria adopted for the review were identified for detailed analysis. The range of auditory thresholds in the implanted ear that can be successfully used for an electric-acoustic application is quite broad. The effectiveness of combined electric and acoustic stimulation as compared with electric stimulation alone was consistently demonstrated, highlighting the potential value of preservation and utilization of low frequency hearing in the implanted ear. However, clinical procedures for best fitting of electric-acoustic devices were varied. This clearly identified a need for further investigation of fitting procedures aimed at maximizing outcomes for recipients of electric-acoustic devices.

  15. Characterizing hyporheic exchange processes using high-frequency electrical conductivity-discharge relationships on subhourly to interannual timescales

    Science.gov (United States)

    Singley, Joel G.; Wlostowski, Adam N.; Bergstrom, Anna J.; Sokol, Eric R.; Torrens, Christa L.; Jaros, Chris; Wilson, Colleen E.; Hendrickson, Patrick J.; Gooseff, Michael N.

    2017-05-01

    Concentration-discharge (C-Q) relationships are often used to quantify source water contributions and biogeochemical processes occurring within catchments, especially during discrete hydrological events. Yet, the interpretation of C-Q hysteresis is often confounded by complexity of the critical zone, such as numerous source waters and hydrochemical nonstationarity. Consequently, researchers must often ignore important runoff pathways and geochemical sources/sinks, especially the hyporheic zone because it lacks a distinct hydrochemical signature. Such simplifications limit efforts to identify processes responsible for the transience of C-Q hysteresis over time. To address these limitations, we leverage the hydrologic simplicity and long-term, high-frequency Q and electrical conductivity (EC) data from streams in the McMurdo Dry Valleys, Antarctica. In this two end-member system, EC can serve as a proxy for the concentration of solutes derived from the hyporheic zone. We utilize a novel approach to decompose loops into subhysteretic EC-Q dynamics to identify individual mechanisms governing hysteresis across a wide range of timescales. We find that hydrologic and hydraulic processes govern EC response to diel and seasonal Q variability and that the effects of hyporheic mixing processes on C-Q transience differ in short and long streams. We also observe that variable hyporheic turnover rates govern EC-Q patterns at daily to interannual timescales. Last, subhysteretic analysis reveals a period of interannual freshening of glacial meltwater streams related to the effects of unsteady flow on hyporheic exchange. The subhysteretic analysis framework we introduce may be applied more broadly to constrain the processes controlling C-Q transience and advance understanding of catchment evolution.

  16. Effect of closed endotracheal suction in high-frequency ventilated premature infants measured with electrical impedance tomography

    NARCIS (Netherlands)

    van Veenendaal, M.B.; Miedema, M.; de Jongh, F.H.C.; van der Lee, J.H.; Frerichs, I.; van Kaam, A.H.

    2009-01-01

    Objective: To determine the global and regional changes in lung volume during and after closed endotracheal tube (ETT) suction in high-frequency ventilated preterm infants with respiratory distress syndrome (RDS). Design: Prospective observational clinical study. Setting: Neonatal intensive care

  17. [Apparatus "Stimul-1" foe electric stimulation of muscles].

    Science.gov (United States)

    Andrianova, G G; Prokopenko, G I; Shabashevich, L B; Khvostov, L N

    1977-01-01

    The apparatus "Stimul-1" has been designed and recommended for batch production, its purpose being broad application in the medical practice of electrical stimulation of the muscles. For stimulation is used sinusoidal a.c. current with frequency of 2 kHz, which produces and effective contraction of the muscles without causing any sensation of pain. The unit is constructed by using up-to-date components, including microminiature logic circuits, operational amplifiers and field-effect transistors.

  18. Mimicking muscle activity with electrical stimulation

    Science.gov (United States)

    Johnson, Lise A.; Fuglevand, Andrew J.

    2011-02-01

    Functional electrical stimulation is a rehabilitation technology that can restore some degree of motor function in individuals who have sustained a spinal cord injury or stroke. One way to identify the spatio-temporal patterns of muscle stimulation needed to elicit complex upper limb movements is to use electromyographic (EMG) activity recorded from able-bodied subjects as a template for electrical stimulation. However, this requires a transfer function to convert the recorded (or predicted) EMG signals into an appropriate pattern of electrical stimulation. Here we develop a generalized transfer function that maps EMG activity into a stimulation pattern that modulates muscle output by varying both the pulse frequency and the pulse amplitude. We show that the stimulation patterns produced by this transfer function mimic the active state measured by EMG insofar as they reproduce with good fidelity the complex patterns of joint torque and joint displacement.

  19. Neuromuscular electrical stimulation improves exercise tolerance in chronic obstructive pulmonary disease patients with better preserved fat-free mass

    Directory of Open Access Journals (Sweden)

    Lara Maris Nápolis

    2011-01-01

    Full Text Available BACKGROUND: High-frequency neuromuscular electrical stimulation increases exercise tolerance in patients with advanced chronic obstructive pulmonary disease (COPD patients. However, it is conceivable that its benefits are more prominent in patients with better-preserved peripheral muscle function and structure. OBJECTIVE: To investigate the effects of high-frequency neuromuscular electrical stimulation in COPD patients with better-preserved peripheral muscle function. Design: Prospective and cross-over study. METHODS: Thirty COPD patients were randomly assigned to either home-based, high-frequency neuromuscular electrical stimulation or sham stimulation for six weeks. The training intensity was adjusted according to each subject's tolerance. Fat-free mass, isometric strength, six-minute walking distance and time to exercise intolerance (Tlim were assessed. RESULTS: Thirteen (46.4% patients responded to high-frequency neuromuscular electrical stimulation; that is, they had a post/pre Δ Tlim >10% after stimulation (unimproved after sham stimulation. Responders had a higher baseline fat-free mass and six-minute walking distance than their seventeen (53.6% non-responding counterparts. Responders trained at higher stimulation intensities; their mean amplitude of stimulation during training was significantly related to their fat-free mass (r = 0.65; p<0.01. Logistic regression revealed that fat-free mass was the single independent predictor of Tlim improvement (odds ratio [95% CI] = 1.15 [1.04-1.26]; p<0.05. CONCLUSIONS: We conclude that high-frequency neuromuscular electrical stimulation improved the exercise capacity of COPD patients with better-preserved fat-free mass because they tolerated higher training stimulus levels. These data suggest that early training with high-frequency neuromuscular electrical stimulation before tissue wasting begins might enhance exercise tolerance in patients with less advanced COPD.

  20. High-Frequency Repetitive Transcranial Magnetic Stimulation (rTMS Improves Functional Recovery by Enhancing Neurogenesis and Activating BDNF/TrkB Signaling in Ischemic Rats

    Directory of Open Access Journals (Sweden)

    Jing Luo

    2017-02-01

    Full Text Available Repetitive transcranial magnetic stimulation (rTMS has rapidly become an attractive therapeutic approach for stroke. However, the mechanisms underlying this remain elusive. This study aimed to investigate whether high-frequency rTMS improves functional recovery mediated by enhanced neurogenesis and activation of brain-derived neurotrophic factor (BDNF/tropomyosin-related kinase B (TrkB pathway and to compare the effect of conventional 20 Hz rTMS and intermittent theta burst stimulation (iTBS on ischemic rats. Rats after rTMS were sacrificed seven and 14 days after middle cerebral artery occlusion (MCAO, following evaluation of neurological function. Neurogenesis was measured using specific markers: Ki67, Nestin, doublecortin (DCX, NeuN and glial fibrillary acidic protein (GFAP, and the expression levels of BDNF were visualized by Western blotting and RT-PCR analysis. Both high-frequency rTMS methods significantly improved neurological function and reduced infarct volume. Moreover, 20 Hz rTMS and iTBS significantly promoted neurogenesis, shown by an increase of Ki67/DCX, Ki67/Nestin, and Ki67/NeuN-positive cells in the peri-infarct striatum. These beneficial effects were accompanied by elevated protein levels of BDNF and phosphorylated-TrkB. In conclusion, high-frequency rTMS improves functional recovery possibly by enhancing neurogenesis and activating BDNF/TrkB signaling pathway and conventional 20 Hz rTMS is better than iTBS at enhancing neurogenesis in ischemic rats.

  1. High frequency stimulation alters motor maps, impairs skilled reaching performance and is accompanied by an upregulation of specific GABA, glutamate and NMDA receptor subunits.

    Science.gov (United States)

    Henderson, A K; Pittman, Q J; Teskey, G C

    2012-07-26

    High frequency stimulation (HFS) has the potential to interfere with learning and memory. HFS and motor skill training both lead to potentiation of the stimulated network and alter motor map expression. However, the extent to which HFS can interfere with the learning and performance of a skilled motor task and the resulting effect on the representation of movement has not been examined. Moreover, the molecular mechanisms associated with HFS and skilled motor training on the motor cortex are not known. We hypothesized that HFS would impair performance on a skilled reaching task, and would be associated with alterations in motor map expression and protein levels compared to non-stimulated and untrained controls. Long Evans Hooded rats were chronically implanted with stimulating and recording electrodes in the corpus callosum and frontal neocortex, respectively. High frequency theta burst stimulation or sham stimulation was applied once daily for 20 sessions. The rats were divided into five groups: control, HFS and assessed at 1 week post stimulation, HFS and assessed 3 weeks post stimulation, reach trained, and HFS and reach trained. A subset of rats from each group was assessed with either intracortical microstimulation (ICMS) to examine motor map expression or Western blot techniques to determine protein expression of several excitatory and inhibitory receptor subunits. Firstly, we found that HFS resulted in larger and reorganized motor maps, and lower movement thresholds compared to controls. This was associated with an up-regulation of the GABA(A)α1 and NR1 receptor subunits 3 weeks after the last stimulation session only. Stimulation affected skilled reaching performance in a subset of all stimulated rats. Rats that were poor performers had larger rostral forelimb areas, higher proximal and lower distal movement thresholds compared to rats that were good performers after stimulation. Reach training alone was associated with an up-regulation of GABA(A)α1, α2

  2. Neural adaptations to electrical stimulation strength training

    NARCIS (Netherlands)

    Hortobagyi, Tibor; Maffiuletti, Nicola A.

    2011-01-01

    This review provides evidence for the hypothesis that electrostimulation strength training (EST) increases the force of a maximal voluntary contraction (MVC) through neural adaptations in healthy skeletal muscle. Although electrical stimulation and voluntary effort activate muscle differently, there

  3. [Novel functional electrical stimulation for neurorehabilitation].

    Science.gov (United States)

    Hara, Yukihiro

    2010-02-01

    Our understanding of motor learning, neuroplasticity, and functional recovery after the occurrence of brain lesions has increased considerably. New findings in basic neuroscience have provided an impetus for research in motor rehabilitation. Several prospective studies have shown that repeated motor practice and motor activity in a real world environment have a favorable effect on motor recovery in stroke patients. Electrical stimulation can be applied in a variety of ways to the hemiparetic upper extremity following a stroke. In particular, electromyography (EMG)-triggered electrical muscle stimulation improves the motor function of the hemiparetic arm and hand. Triggered electrical stimulation is reported to be more effective than non-triggered electrical stimulation in facilitating upper extremity motor recovery after stroke. Power-assisted functional electrical stimulation (FES) induces greater muscle contraction by electrical stimulation that is in proportion to voluntary integrated EMG signals. Daily power-assisted FES home-program therapy with novel equipment has been shown to effectively improve wrist, finger extension, and shoulder flexion. Combined modulation of voluntary movement, proprioceptive sensory feedback, and electrical stimulation might play an important role in improving impaired sensory-motor integration by power-assisted FES therapy. A multi-channel near-infrared spectroscopy (NIRS) studies in which the hemoglobin levels in the brain were non-invasively and dynamically measured during functional activity found that the cerebral blood flow in the injured sensory-motor cortex area is greater during a power-assisted FES session than during simple active movement or simple electrical stimulation. A novel power-assisted FES sleeve (Cyberhand) has been developed for the rehabilitation of hemiplegic upper extremities.

  4. High-Frequency Stimulation of the Rat Entopeduncular Nucleus Does Not Provide Functional or Morphological Neuroprotection from 6-Hydroxydopamine.

    Directory of Open Access Journals (Sweden)

    D Luke Fischer

    Full Text Available Deep brain stimulation (DBS is the most common neurosurgical treatment for Parkinson's disease (PD. Whereas the globus pallidus interna (GPi has been less commonly targeted than the subthalamic nucleus (STN, a recent clinical trial suggests that GPi DBS may provide better outcomes for patients with psychiatric comorbidities. Several laboratories have demonstrated that DBS of the STN provides neuroprotection of substantia nigra pars compacta (SNpc dopamine neurons in preclinical neurotoxin models of PD and increases brain-derived neurotrophic factor (BDNF. However, whether DBS of the entopeduncular nucleus (EP, the homologous structure to the GPi in the rat, has similar neuroprotective potential in preclinical models has not been investigated. We investigated the impact of EP DBS on forelimb use asymmetry and SNpc degeneration induced by 6-hydroxydopamine (6-OHDA and on BDNF levels. EP DBS in male rats received unilateral, intrastriatal 6-OHDA and ACTIVE or INACTIVE stimulation continuously for two weeks. Outcome measures included quantification of contralateral forelimb use, stereological assessment of SNpc neurons and BDNF levels. EP DBS 1 did not ameliorate forelimb impairments induced by 6-OHDA, 2 did not provide neuroprotection for SNpc neurons and 3 did not significantly increase BDNF levels in any of the structures examined. These results are in sharp contrast to the functional improvement, neuroprotection and BDNF-enhancing effects of STN DBS under identical experimental parameters in the rat. The lack of functional response to EP DBS suggests that stimulation of the rat EP may not represent an accurate model of clinical GPi stimulation.

  5. Effect of closed endotracheal suction in high-frequency ventilated premature infants measured with electrical impedance tomography

    NARCIS (Netherlands)

    van Veenendaal, Mariëtte B.; Miedema, Martijn; de Jongh, Frans H. C.; van der Lee, Johanna H.; Frerichs, Inez; van Kaam, Anton H.

    2009-01-01

    To determine the global and regional changes in lung volume during and after closed endotracheal tube (ETT) suction in high-frequency ventilated preterm infants with respiratory distress syndrome (RDS). Prospective observational clinical study. Neonatal intensive care unit. Eleven non-muscle relaxed

  6. Gastric applications of electrical field stimulation.

    LENUS (Irish Health Repository)

    Hogan, Aisling M

    2012-02-01

    Advances in clinical applications of electricity have been vast since the launch of Hayman\\'s first cardiac pacemaker more than 70 years ago. Gastric electrical stimulation devices have been recently licensed for treatment of gastroparesis and preliminary studies examining their potential for use in refractory obesity yield promising results.

  7. Basal ganglia dysfunction in OCD: subthalamic neuronal activity correlates with symptoms severity and predicts high-frequency stimulation efficacy.

    Science.gov (United States)

    Welter, M-L; Burbaud, P; Fernandez-Vidal, S; Bardinet, E; Coste, J; Piallat, B; Borg, M; Besnard, S; Sauleau, P; Devaux, B; Pidoux, B; Chaynes, P; Tézenas du Montcel, S; Bastian, A; Langbour, N; Teillant, A; Haynes, W; Yelnik, J; Karachi, C; Mallet, L

    2011-05-03

    Functional and connectivity changes in corticostriatal systems have been reported in the brains of patients with obsessive-compulsive disorder (OCD); however, the relationship between basal ganglia activity and OCD severity has never been adequately established. We recently showed that deep brain stimulation of the subthalamic nucleus (STN), a central basal ganglia nucleus, improves OCD. Here, single-unit subthalamic neuronal activity was analysed in 12 OCD patients, in relation to the severity of obsessions and compulsions and response to STN stimulation, and compared with that obtained in 12 patients with Parkinson's disease (PD). STN neurons in OCD patients had lower discharge frequency than those in PD patients, with a similar proportion of burst-type activity (69 vs 67%). Oscillatory activity was present in 46 and 68% of neurons in OCD and PD patients, respectively, predominantly in the low-frequency band (1-8 Hz). In OCD patients, the bursty and oscillatory subthalamic neuronal activity was mainly located in the associative-limbic part. Both OCD severity and clinical improvement following STN stimulation were related to the STN neuronal activity. In patients with the most severe OCD, STN neurons exhibited bursts with shorter duration and interburst interval, but higher intraburst frequency, and more oscillations in the low-frequency bands. In patients with best clinical outcome with STN stimulation, STN neurons displayed higher mean discharge, burst and intraburst frequencies, and lower interburst interval. These findings are consistent with the hypothesis of a dysfunction in the associative-limbic subdivision of the basal ganglia circuitry in OCD's pathophysiology.

  8. Rapid Identification of Cortical Motor Areas in Rodents by High-Frequency Automatic Cortical Stimulation and Novel Motor Threshold Algorithm.

    Science.gov (United States)

    Takemi, Mitsuaki; Castagnola, Elisa; Ansaldo, Alberto; Ricci, Davide; Fadiga, Luciano; Taoka, Miki; Iriki, Atsushi; Ushiba, Junichi

    2017-01-01

    Cortical stimulation mapping is a valuable tool to test the functional organization of the motor cortex in both basic neurophysiology (e.g., elucidating the process of motor plasticity) and clinical practice (e.g., before resecting brain tumors involving the motor cortex). However, compilation of motor maps based on the motor threshold (MT) requires a large number of cortical stimulations and is therefore time consuming. Shortening the time for mapping may reduce stress on the subjects and unveil short-term plasticity mechanisms. In this study, we aimed to establish a cortical stimulation mapping procedure in which the time needed to identify a motor area is reduced to the order of minutes without compromising reliability. We developed an automatic motor mapping system that applies epidural cortical surface stimulations (CSSs) through one-by-one of 32 micro-electrocorticographic electrodes while examining the muscles represented in a cortical region. The next stimulus intensity was selected according to previously evoked electromyographic responses in a closed-loop fashion. CSS was repeated at 4 Hz and electromyographic responses were submitted to a newly proposed algorithm estimating the MT with smaller number of stimuli with respect to traditional approaches. The results showed that in all tested rats (n = 12) the motor area maps identified by our novel mapping procedure (novel MT algorithm and 4-Hz CSS) significantly correlated with the maps achieved by the conventional MT algorithm with 1-Hz CSS. The reliability of the both mapping methods was very high (intraclass correlation coefficients ≧0.8), while the time needed for the mapping was one-twelfth shorter with the novel method. Furthermore, the motor maps assessed by intracortical microstimulation and the novel CSS mapping procedure in two rats were compared and were also significantly correlated. Our novel mapping procedure that determined a cortical motor area within a few minutes could help to study the

  9. Cortical excitability changes following grasping exercise augmented with electrical stimulation

    DEFF Research Database (Denmark)

    Barsi, Gergely Istvan; Popovic, Dejan B.; Tarkka, Ina M.

    2008-01-01

    ) functional electrical stimulation (FES) of the finger flexors and extensors, (2) voluntary movement (VOL) with sensory stimulation, and (3) therapeutic FES (TFES) where the electrical stimulation augmented voluntary activation. TFES training produced a significant increase in MEP magnitude throughout...

  10. High-frequency epidural stimulation across the respiratory cycle evokes phrenic short-term potentiation after incomplete cervical spinal cord injury.

    Science.gov (United States)

    Gonzalez-Rothi, Elisa J; Streeter, Kristi A; Hanna, Marie H; Stamas, Anna C; Reier, Paul J; Baekey, David M; Fuller, David D

    2017-10-01

    C2 spinal hemilesion (C2Hx) paralyzes the ipsilateral diaphragm, but recovery is possible through activation of "crossed spinal" synaptic inputs to ipsilateral phrenic motoneurons. We tested the hypothesis that high-frequency epidural stimulation (HF-ES) would potentiate ipsilateral phrenic output after subacute and chronic C2Hx. HF-ES (300 Hz) was applied to the ventrolateral C4 or T2 spinal cord ipsilateral to C2Hx in anesthetized and mechanically ventilated adult rats. Stimulus duration was 60 s, and currents ranged from 100 to 1,000 µA. Bilateral phrenic nerve activity and ipsilateral hypoglossal (XII) nerve activity were recorded before and after HF-ES. Higher T2 stimulus currents potentiated ipsilateral phasic inspiratory activity at both 2 and 12 wk post-C2Hx, whereas higher stimulus currents delivered at C4 potentiated ipsilateral phasic phrenic activity only at 12 wk ( P = 0.028). Meanwhile, tonic output in the ipsilateral phrenic nerve reached 500% of baseline values at the high currents with no difference between 2 and 12 wk. HF-ES did not trigger inspiratory burst-frequency changes. Similar responses occurred following T2 HF-ES. Increases in contralateral phrenic and XII nerve output were induced by C4 and T2 HF-ES at higher currents, but the relative magnitude of these changes was small compared with the ipsilateral phrenic response. We conclude that following incomplete cervical spinal cord injury, HF-ES of the ventrolateral midcervical or thoracic spinal cord can potentiate efferent phrenic motor output with little impact on inspiratory burst frequency. However, the substantial increases in tonic output indicate that the uninterrupted 60-s stimulation paradigm used is unlikely to be useful for respiratory muscle activation after spinal injury. NEW & NOTEWORTHY Previous studies reported that high-frequency epidural stimulation (HF-ES) activates the diaphragm following acute spinal transection. This study examined HF-ES and phrenic motor output

  11. Binaural hearing with electrical stimulation.

    Science.gov (United States)

    Kan, Alan; Litovsky, Ruth Y

    2015-04-01

    Bilateral cochlear implantation is becoming a standard of care in many clinics. While much benefit has been shown through bilateral implantation, patients who have bilateral cochlear implants (CIs) still do not perform as well as normal hearing listeners in sound localization and understanding speech in noisy environments. This difference in performance can arise from a number of different factors, including the areas of hardware and engineering, surgical precision and pathology of the auditory system in deaf persons. While surgical precision and individual pathology are factors that are beyond careful control, improvements can be made in the areas of clinical practice and the engineering of binaural speech processors. These improvements should be grounded in a good understanding of the sensitivities of bilateral CI patients to the acoustic binaural cues that are important to normal hearing listeners for sound localization and speech in noise understanding. To this end, we review the current state-of-the-art in the understanding of the sensitivities of bilateral CI patients to binaural cues in electric hearing, and highlight the important issues and challenges as they relate to clinical practice and the development of new binaural processing strategies. This article is part of a Special Issue entitled . Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Binaural hearing with electrical stimulation

    Science.gov (United States)

    Kan, Alan; Litovsky, Ruth Y.

    2014-01-01

    Bilateral cochlear implantation is becoming a standard of care in many clinics. While much benefit has been shown through bilateral implantation, patients who have bilateral cochlear implants (CIs) still do not perform as well as normal hearing listeners in sound localization and understanding speech in noisy environments. This difference in performance can arise from a number of different factors, including the areas of hardware and engineering, surgical precision and pathology of the auditory system in deaf persons. While surgical precision and individual pathology are factors that are beyond careful control, improvements can be made in the areas of clinical practice and the engineering of binaural speech processors. These improvements should be grounded in a good understanding of the sensitivities of bilateral CI patients to the acoustic binaural cues that are important to normal hearing listeners for sound localization and speech in noise understanding. To this end, we review the current state-of-the-art in the understanding of the sensitivities of bilateral CI patients to binaural cues in electric hearing, and highlight the important issues and challenges as they relate to clinical practice and the development of new binaural processing strategies. PMID:25193553

  13. High-frequency measurement of depressive severity in a patient treated for severe treatment-resistant depression with deep-brain stimulation.

    Science.gov (United States)

    Sani, S; Busnello, J; Kochanski, R; Cohen, Y; Gibbons, R D

    2017-08-15

    Although there have been previous studies of deep-brain stimulation (DBS), we present, to our knowledge, the first example of high-frequency depressive severity measurement-based DBS treatment in particular and psychiatric treatment in general. Daily post-surgical e-mail prompts for a period of 6 months resulted in 93 administrations of a computerized adaptive test (CAT) of depression severity (CAT-Depression Inventory or CAT-DI) via the internet. There was an average of 3.37 weekly measurements with an average separation of 2.12 days. No additional incentive was provided to the patient for completing the adaptive tests. The patient is a 55-year-old female with six psychiatric hospitalizations for depression, two suicide attempts, marginal response to eight electroconvulsive therapy (ECT) treatments and 35 psychotropic medications. We report results after high-frequency stimulation of the superolateral branch of the medial forebrain bundle. The CAT-DI was used for daily assessments before, during and after (remotely in response to an e-mail prompt) the DBS procedure. Two follow-up Hamilton Depression Scales (HAM-Ds) were also collected. Response to treatment varied markedly, with a decrease from severe (>75) to mild (60), which is three times the size of the uncertainty level. Although the HAM-D scores decreased, they missed the more complete temporal pattern identified by CAT-DI daily monitoring. We demonstrated feasibility of daily depressive severity measurement at high levels of precision and compliance. Clinician ratings confirm the general pattern of treatment benefit, but mask the marked variability in mood and more marked periods of benefit and decline.

  14. Wireless control of functional electrical stimulation systems.

    Science.gov (United States)

    Matjacić, Z; Munih, M; Bajd, T; Kralj, A; Benko, H; Obreza, P

    1997-03-01

    With the assistance of crutches and functional electrical stimulation (FES), we are able to restore standing and simple gait in some spinal cord injured (SCI) patients. In present rehabilitative systems, the patient divides the gait cycle into stance and swing phases via pushbuttons mounted on the handles of the crutches, which are hardwired to the functional electrical stimulator. The surface-mount technology based telemetry system, which makes use of the radiofrequency medium at 40 MHz, was developed to provide wireless control of the FES system. Signals from crutch pushbuttons were coded and transferred from the transmitter to the receiver. The receiver was firmly attached to the patient's waist and was connected to the stimulator.

  15. An electrical stimulator for sensory substitution.

    Science.gov (United States)

    Pereira, Mauro C; Kassab, Fuad

    2006-01-01

    This work presents an electrical stimulator system for use in sensory substitution (SS), as a mobility aid for visually handicapped people. The whole system passes visual information via cutaneous stimulation, and consists of a webcam, a PC, dedicated hardware to generate stimuli and a 15 x 20 electrode matrix. The same system can also be used in psycophysical and somesthesic research, or even for SS of deaf people, by changing the input signal from a camera to a microphone, and adapting its control software. Circuits for pixel addressing, for signal generation and for switching are described, as well as the software involved in generating a pulse train, which configures the stimuli patterns.

  16. Spectroscopic measurement of high-frequency electric fields in the interaction of explosive debris plasma with magnetized background plasma

    Energy Technology Data Exchange (ETDEWEB)

    Bondarenko, A. S., E-mail: AntonBondarenko@ymail.com; Schaeffer, D. B.; Everson, E. T.; Clark, S. E.; Constantin, C. G.; Niemann, C. [Department of Physics and Astronomy, University of California-Los Angeles, Los Angeles, California 90095 (United States)

    2014-12-15

    The collision-less transfer of momentum and energy from explosive debris plasma to magnetized background plasma is a salient feature of various astrophysical and space environments. While much theoretical and computational work has investigated collision-less coupling mechanisms and relevant parameters, an experimental validation of the results demands the measurement of the complex, collective electric fields associated with debris-background plasma interaction. Emission spectroscopy offers a non-interfering diagnostic of electric fields via the Stark effect. A unique experiment at the University of California, Los Angeles, that combines the Large Plasma Device (LAPD) and the Phoenix laser facility has investigated the marginally super-Alfvénic, quasi-perpendicular expansion of a laser-produced carbon (C) debris plasma through a preformed, magnetized helium (He) background plasma via emission spectroscopy. Spectral profiles of the He II 468.6 nm line measured at the maximum extent of the diamagnetic cavity are observed to intensify, broaden, and develop equally spaced modulations in response to the explosive C debris, indicative of an energetic electron population and strong oscillatory electric fields. The profiles are analyzed via time-dependent Stark effect models corresponding to single-mode and multi-mode monochromatic (single frequency) electric fields, yielding temporally resolved magnitudes and frequencies. The proximity of the measured frequencies to the expected electron plasma frequency suggests the development of the electron beam-plasma instability, and a simple saturation model demonstrates that the measured magnitudes are feasible provided that a sufficiently fast electron population is generated during C debris–He background interaction. Potential sources of the fast electrons, which likely correspond to collision-less coupling mechanisms, are briefly considered.

  17. Tissue damage thresholds during therapeutic electrical stimulation

    Science.gov (United States)

    Cogan, Stuart F.; Ludwig, Kip A.; Welle, Cristin G.; Takmakov, Pavel

    2016-04-01

    Objective. Recent initiatives in bioelectronic modulation of the nervous system by the NIH (SPARC), DARPA (ElectRx, SUBNETS) and the GlaxoSmithKline Bioelectronic Medicines effort are ushering in a new era of therapeutic electrical stimulation. These novel therapies are prompting a re-evaluation of established electrical thresholds for stimulation-induced tissue damage. Approach. In this review, we explore what is known and unknown in published literature regarding tissue damage from electrical stimulation. Main results. For macroelectrodes, the potential for tissue damage is often assessed by comparing the intensity of stimulation, characterized by the charge density and charge per phase of a stimulus pulse, with a damage threshold identified through histological evidence from in vivo experiments as described by the Shannon equation. While the Shannon equation has proved useful in assessing the likely occurrence of tissue damage, the analysis is limited by the experimental parameters of the original studies. Tissue damage is influenced by factors not explicitly incorporated into the Shannon equation, including pulse frequency, duty cycle, current density, and electrode size. Microelectrodes in particular do not follow the charge per phase and charge density co-dependence reflected in the Shannon equation. The relevance of these factors to tissue damage is framed in the context of available reports from modeling and in vivo studies. Significance. It is apparent that emerging applications, especially with microelectrodes, will require clinical charge densities that exceed traditional damage thresholds. Experimental data show that stimulation at higher charge densities can be achieved without causing tissue damage, suggesting that safety parameters for microelectrodes might be distinct from those defined for macroelectrodes. However, these increased charge densities may need to be justified by bench, non-clinical or clinical testing to provide evidence of device

  18. Electric Brain Stimulation No Better Than Meds for Depression: Study

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_166920.html Electric Brain Stimulation No Better Than Meds For Depression: ... can't find relief, stimulating the brain with electric impulses may help. But a new study by ...

  19. Electrical stimulation in dysphagia treatment: a justified controversy?

    NARCIS (Netherlands)

    Bogaardt, H. C. A.

    2008-01-01

    Electrical stimulation in dysphagia treatment: a justified controversy? Neuromuscular electrostimulation (LAMES) is a method for stimulating muscles with short electrical pulses. Neuromuscular electrostimulation is frequently used in physiotherapy to strengthen healthy muscles (as in sports

  20. Turning on the central contribution to contractions evoked by neuromuscular electrical stimulation.

    Science.gov (United States)

    Dean, J C; Yates, L M; Collins, D F

    2007-07-01

    Neuromuscular electrical stimulation can generate contractions through peripheral and central mechanisms. Direct activation of motor axons (peripheral mechanism) recruits motor units in an unnatural order, with fatigable muscle fibers often activated early in contractions. The activation of sensory axons can produce contractions through a central mechanism, providing excitatory synaptic input to spinal neurons that recruit motor units in the natural order. Presently, we quantified the effect of stimulation frequency (10-100 Hz), duration (0.25-2 s of high-frequency bursts, or 20 s of constant-frequency stimulation), and intensity [1-5% maximal voluntary contraction (MVC) torque generated by a brief 100-Hz train] on the torque generated centrally. Electrical stimulation (1-ms pulses) was delivered over the triceps surae in eight subjects, and plantar flexion torque was recorded. Stimulation frequency, duration, and intensity all influenced the magnitude of the central contribution to torque. Central torque did not develop at frequencies or = 80 Hz. Increasing the duration of high-frequency stimulation increased the central contribution to torque, as central torque developed over 11 s. Central torque was greatest at a relatively low contraction intensity. The largest amount of central torque was produced by a 20-s, 100-Hz train (10.7 +/- 5.5 %MVC) and by repeated 2-s bursts of 80- or 100-Hz stimulation (9.2 +/- 4.8 and 10.2 +/- 8.1% MVC, respectively). Therefore, central torque was maximized by applying high-frequency, long-duration stimulation while avoiding antidromic block by stimulating at a relatively low intensity. If, as hypothesized, the central mechanism primarily activates fatigue-resistant muscle fibers, generating muscle contractions through this pathway may improve rehabilitation applications.

  1. Functional Electrical Stimulation in Children and Adolescents with Cerebral Palsy

    Science.gov (United States)

    van der Linden, Marietta

    2012-01-01

    In this article, the author talks about functional electrical stimulation in children and adolescents with cerebral palsy. Functional electrical stimulation (FES) is defined as the electrical stimulation of muscles that have impaired motor control, in order to produce a contraction to obtain functionally useful movement. It was first proposed in…

  2. Medical back belt with integrated neuromuscular electrical stimulation

    NARCIS (Netherlands)

    Bottenberg, E. (Eliza); Brinks, G.J. (Ger); Hesse, J. (Jenny)

    2014-01-01

    The medical back belt with integrated neuromuscular electrical stimulation is anorthopedic device, which has two main functions. The first function is to stimulate the backmuscles by using a neuromuscular electrical stimulation device that releases regular,electrical impulses. The second function of

  3. Effect of bleeding method and low voltage electrical stimulation on ...

    African Journals Online (AJOL)

    An early post mortem low voltage electrical stimulation (ES) of the carcasses also had no influence on the cooking loss, drip loss and colour of these muscles. Electrical stimulation did result in a lower pH45 in both the fillet and big drum muscles. However, after 24 h the pH of the muscles did not differ. Electrical stimulation ...

  4. Non-invasive vagus nerve stimulation for acute treatment of high-frequency and chronic migraine: an open-label study.

    Science.gov (United States)

    Barbanti, Piero; Grazzi, Licia; Egeo, Gabriella; Padovan, Anna Maria; Liebler, Eric; Bussone, Gennaro

    2015-01-01

    The treatment of migraine headache is challenging given the lack of a standardized approach to care, unsatisfactory response rates, and medication overuse. Neuromodulation therapy has gained interest as an alternative to pharmacologic therapy for primary headache disorders. This study investigated the effects of non-invasive vagus nerve stimulation (nVNS) in patients with high-frequency episodic migraine (HFEM) and chronic migraine (CM). In this open-label, single-arm, multicenter study, patients with HFEM or CM self-treated up to 3 consecutive mild or moderate migraine attacks that occurred during a 2-week period by delivering two 120-s doses of nVNS at 3-min intervals to the right cervical branch of the vagus nerve. Of the 50 migraineurs enrolled (CM/HFEM: 36/14), 48 treated 131 attacks. The proportion of patients reporting pain relief, defined as a ≥50% reduction in visual analog scale (VAS) score, was 56.3% at 1 h and 64.6% at 2 h. Of these patients, 35.4% and 39.6% achieved pain-free status (VAS = 0) at 1 and 2 h, respectively. When all attacks (N = 131) were considered, the pain-relief rate was 38.2% at 1 h and 51.1% at 2 h, whereas the pain-free rate was 17.6% at 1 h and 22.9% at 2 h. Treatment with nVNS was safe and well tolerated. Non-invasive vagus nerve stimulation may be effective as acute treatment for HFEM or CM and may help to reduce medication overuse and medication-associated adverse events.

  5. Electrical stimulation superimposed onto voluntary muscular contraction.

    Science.gov (United States)

    Paillard, Thierry; Noé, Frédéric; Passelergue, Philippe; Dupui, Philippe

    2005-01-01

    Electrical stimulation (ES) reverses the order of recruitment of motor units (MU) observed with voluntary muscular contraction (VOL) since under ES, large MU are recruited before small MU. The superimposition of ES onto VOL (superimposed technique: application of an electrical stimulus during a voluntary muscle action) can theoretically activate more motor units than VOL performed alone, which can engender an increase of the contraction force. Two superimposed techniques can be used: (i) the twitch interpolation technique (ITT), which consists of interjecting an electrical stimulus onto the muscle nerve; and (ii) the percutaneous superimposed electrical stimulation technique (PST), where the stimulation is applied to the muscle belly. These two superimposed techniques can be used to evaluate the ability to fully activate a muscle. They can thus be employed to distinguish the central or peripheral nature of fatigue after exhausting exercise. In general, whatever the technique employed, the superimposition of ES onto volitional exercise does not recruit more MU than VOL, except with eccentric actions. Nevertheless, the neuromuscular response associated with the use of the superimposed technique (ITT and PST) depends on the parameter of the superimposed current. The sex and the training level of the subjects can also modify the physiological impact of the superimposed technique. Although the motor control differs drastically between training with ES and VOL, the integration of the superimposed technique in training programmes with healthy subjects does not reveal significant benefits compared with programmes performed only with voluntary exercises. Nevertheless, in a therapeutic context, training programmes using ES superimposition compensate volume and muscle strength deficit with more efficiency than programmes using VOL or ES separately.

  6. Electrical Excitation of the Pulmonary Venous Musculature May Contribute to the Formation of the Last Component of the High Frequency Signal of the P Wave

    Directory of Open Access Journals (Sweden)

    Junko Abe, MD

    2005-01-01

    Full Text Available Pulmonary veins (PVs have been shown to play an important role in the induction and perpetuation of focal AF. Fifty-one patients with AF, and 24 patients without AF as control subjects, were enrolled in this study. Signal-averaged P-wave recording was performed, and the filtered P wave duration (FPD, the root-mean-square voltage for the last 20, 30 and 40 ms (RMS20, 30, and 40, respectively were compared. In 7 patients with AF, these parameters were compared before and after the catheter ablation. The FPD was significantly longer and the RMS20 was smaller in the patients with AF than those without AF. Because RMS30 was widely distributed between 2 and 10 µV, the AF group was sub-divided into two groups; Group 1 was comprised of the patients with an RMS30 ≧5.0 µV, and group 2, <5.0 µV. In group 1, short-coupled PACs were more frequently documented on Holter monitoring, and exercise testing more readily induced AF. After successful electrical disconnection between the LA and PVs, each micropotential parameter was significantly attenuated. These results indicate that the high frequency signal amplitude of the last component of the P wave is relatively high in patients with AF triggered by focal repetitive excitations most likely originating from the PVs. That is, attenuation by the LA-PV electrical isolation, and thus the high frequency P signals of the last component, may contain the electrical excitation of the PV musculature.

  7. Modification of behavioral responses induced by electrical stimulation of the ventral tegmental area in rats.

    Science.gov (United States)

    Watanabe, T; Morimoto, K; Nakamura, M; Suwaki, H

    1998-06-01

    To investigate the role of the ventral tegmental area (VTA), a source of the mesolimbic dopaminergic pathway, in paranoid psychosis, a detailed analysis of the behavioral responses induced by electrical stimulation of the VTA was made. Abnormal behavior induced by bilateral high-frequency stimulation of the VTA consisted of two components: forward locomotion and exploration. Similar responses were obtained when the nucleus accumbens (NAC) or prefrontal cortex (PFC) were stimulated. The expression of behavioral responses to stimulation was significantly attenuated by dopamine (DA) receptor or antagonists, such as haloperidol, YM-09151-2 and SCH23390. These results indicate that VTA stimulation causes a transient hyperdopaminergic state in the brain, that resembles psychostimulant-induced abnormal behavior. The effects of chronic administration of methamphetamine (MAP) on the behavioral responses to electrical stimulation of the VAT were also investigated. Although an acute administration of MAP did not affect the behavioral responses to electrical stimulation of the VTA, chronic treatment with MAP (for 2 weeks) caused a long-lasting reduction in the electrical threshold for the induction of abnormal behavior, compared with chronic saline-treated rats. It is suggested that a lasting enhancement in the behavioral response to stimulation of VTA neurons may contribute to the etiology of paranoid schizophrenia and amphetamine psychosis.

  8. Smart control for functional electrical stimulation with optimal pulse intensity

    Directory of Open Access Journals (Sweden)

    Reinert Aljoscha

    2016-09-01

    Full Text Available Transcutaneous electrical stimulation is a common treatment option for patients suffering from spinal cord injury or stroke. Two major difficulties arise when employing electrical stimulation in patients: Accurate stimulation electrode placement and configuration of optimal stimulation parameters. Optimizing the stimulation parameters has the advantage to reduce muscle fatigue after repetitive stimulation. Here we present a newly developed system which is able to automatically find the optimal individual stimulation intensity by varying the pulse length. The effectiveness is measured with flex sensors. By adapting the stimulation parameters, the effect of muscle fatigue can be compensated, allowing for a more stable movement upon stimulation over time.

  9. Modulation of Illusory Auditory Perception by Transcranial Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Giulia Prete

    2017-06-01

    Full Text Available The aim of the present study was to test whether transcranial electrical stimulation can modulate illusory perception in the auditory domain. In two separate experiments we applied transcranial Direct Current Stimulation (anodal/cathodal tDCS, 2 mA; N = 60 and high-frequency transcranial Random Noise Stimulation (hf-tRNS, 1.5 mA, offset 0; N = 45 on the temporal cortex during the presentation of the stimuli eliciting the Deutsch's illusion. The illusion arises when two sine tones spaced one octave apart (400 and 800 Hz are presented dichotically in alternation, one in the left and the other in the right ear, so that when the right ear receives the high tone, the left ear receives the low tone, and vice versa. The majority of the population perceives one high-pitched tone in one ear alternating with one low-pitched tone in the other ear. The results revealed that neither anodal nor cathodal tDCS applied over the left/right temporal cortex modulated the perception of the illusion, whereas hf-tRNS applied bilaterally on the temporal cortex reduced the number of times the sequence of sounds is perceived as the Deutsch's illusion with respect to the sham control condition. The stimulation time before the beginning of the task (5 or 15 min did not influence the perceptual outcome. In accordance with previous findings, we conclude that hf-tRNS can modulate auditory perception more efficiently than tDCS.

  10. Anal sphincter responses after perianal electrical stimulation

    DEFF Research Database (Denmark)

    Pedersen, Ejnar; Klemar, B; Schrøder, H D

    1982-01-01

    By perianal electrical stimulation and EMG recording from the external anal sphincter three responses were found with latencies of 2-8, 13-18 and 30-60 ms, respectively. The two first responses were recorded in most cases. They were characterised by constant latency and uniform pattern, were...... stimulation to a minimum of 30-60 ms. This response represented the clinical observable spinal reflex, "the classical anal reflex". The latencies of the two first responses were so short that they probably do not represent spinal reflexes. This was further supported by the effect of epidural anaesthesia which...... left the first responses unaffected but abolished the classical anal reflex. The origin of the two first responses is discussed and models involving antidromal impulse propagation in the efferent fibre as the afferent limbs of the responses are proposed....

  11. Functional electrical stimulation and spinal cord injury.

    Science.gov (United States)

    Ho, Chester H; Triolo, Ronald J; Elias, Anastasia L; Kilgore, Kevin L; DiMarco, Anthony F; Bogie, Kath; Vette, Albert H; Audu, Musa L; Kobetic, Rudi; Chang, Sarah R; Chan, K Ming; Dukelow, Sean; Bourbeau, Dennis J; Brose, Steven W; Gustafson, Kenneth J; Kiss, Zelma H T; Mushahwar, Vivian K

    2014-08-01

    Spinal cord injuries (SCI) can disrupt communications between the brain and the body, resulting in loss of control over otherwise intact neuromuscular systems. Functional electrical stimulation (FES) of the central and peripheral nervous system can use these intact neuromuscular systems to provide therapeutic exercise options to allow functional restoration and to manage medical complications following SCI. The use of FES for the restoration of muscular and organ functions may significantly decrease the morbidity and mortality following SCI. Many FES devices are commercially available and should be considered as part of the lifelong rehabilitation care plan for all eligible persons with SCI. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Differential effect of brief electrical stimulation on voltage-gated potassium channels.

    Science.gov (United States)

    Cameron, Morven A; Al Abed, Amr; Buskila, Yossi; Dokos, Socrates; Lovell, Nigel H; Morley, John W

    2017-05-01

    Electrical stimulation of neuronal tissue is a promising strategy to treat a variety of neurological disorders. The mechanism of neuronal activation by external electrical stimulation is governed by voltage-gated ion channels. This stimulus, typically brief in nature, leads to membrane potential depolarization, which increases ion flow across the membrane by increasing the open probability of these voltage-gated channels. In spiking neurons, it is activation of voltage-gated sodium channels (Na V channels) that leads to action potential generation. However, several other types of voltage-gated channels are expressed that also respond to electrical stimulation. In this study, we examine the response of voltage-gated potassium channels (K V channels) to brief electrical stimulation by whole cell patch-clamp electrophysiology and computational modeling. We show that nonspiking amacrine neurons of the retina exhibit a large variety of responses to stimulation, driven by different K V -channel subtypes. Computational modeling reveals substantial differences in the response of specific K V -channel subtypes that is dependent on channel kinetics. This suggests that the expression levels of different K V -channel subtypes in retinal neurons are a crucial predictor of the response that can be obtained. These data expand our knowledge of the mechanisms of neuronal activation and suggest that K V -channel expression is an important determinant of the sensitivity of neurons to electrical stimulation. NEW & NOTEWORTHY This paper describes the response of various voltage-gated potassium channels (K V channels) to brief electrical stimulation, such as is applied during prosthetic electrical stimulation. We show that the pattern of response greatly varies between K V channel subtypes depending on activation and inactivation kinetics of each channel. Our data suggest that problems encountered when artificially stimulating neurons such as cessation in firing at high frequencies, or

  13. High-frequency stimulation of the subthalamic nucleus modifies the expression of vesicular glutamate transporters in basal ganglia in a rat model of Parkinson's disease.

    Science.gov (United States)

    Favier, Mathieu; Carcenac, Carole; Drui, Guillaume; Boulet, Sabrina; El Mestikawy, Salah; Savasta, Marc

    2013-12-05

    It has been suggested that glutamatergic system hyperactivity may be related to the pathogenesis of Parkinson's disease (PD). Vesicular glutamate transporters (VGLUT1-3) import glutamate into synaptic vesicles and are key anatomical and functional markers of glutamatergic excitatory transmission. Both VGLUT1 and VGLUT2 have been identified as definitive markers of glutamatergic neurons, but VGLUT 3 is also expressed by non glutamatergic neurons. VGLUT1 and VGLUT2 are thought to be expressed in a complementary manner in the cortex and the thalamus (VL/VM), in glutamatergic neurons involved in different physiological functions. Chronic high-frequency stimulation (HFS) of the subthalamic nucleus (STN) is the neurosurgical therapy of choice for the management of motor deficits in patients with advanced PD. STN-HFS is highly effective, but its mechanisms of action remain unclear. This study examines the effect of STN-HFS on VGLUT1-3 expression in different brain nuclei involved in motor circuits, namely the basal ganglia (BG) network, in normal and 6-hydroxydopamine (6-OHDA) lesioned rats. Here we report that: 1) Dopamine(DA)-depletion did not affect VGLUT1 and VGLUT3 expression but significantly decreased that of VGLUT2 in almost all BG structures studied; 2) STN-HFS did not change VGLUT1-3 expression in the different brain areas of normal rats while, on the contrary, it systematically induced a significant increase of their expression in DA-depleted rats and 3) STN-HFS reversed the decrease in VGLUT2 expression induced by the DA-depletion. These results show for the first time a comparative analysis of changes of expression for the three VGLUTs induced by STN-HFS in the BG network of normal and hemiparkinsonian rats. They provide evidence for the involvement of VGLUT2 in the modulation of BG cicuits and in particular that of thalamostriatal and thalamocortical pathways suggesting their key role in its therapeutic effects for alleviating PD motor symptoms.

  14. Left and right High Frequency repetitive Transcranial Magnetic Stimulation of the dorsolateral prefrontal cortex does not affect mood in female volunteers.

    Science.gov (United States)

    Baeken, C; Leyman, L; De Raedt, R; Vanderhasselt, M A; D'haenen, H

    2008-03-01

    High Frequency repetitive Transcranial Magnetic Stimulation (HF-rTMS) has yielded divergent results concerning its effect on mood in normal volunteers. In a former study, we were unable to demonstrate negative mood effects after one session of HF-rTMS on the left dorsolateral prefrontal cortex (DLPFC) in a large group of healthy female volunteers: researchers had focused mainly on negative mood changes, overlooking a possible positive mood induction, while no studies had yet examined mood effects of HF-rTMS delivered on the right prefrontal cortex. In this study, we have tried to replicate our previous HF-rTMS findings on the left DLPFC in a new (large) group of healthy female subjects, and we focused especially on positive mood changes. We also extended our former research by stimulating the right DLPFC in a different but comparable (large) group of healthy female volunteers with the same HF-rTMS parameters. In this sham-controlled, single blind, crossover HF-rTMS study, stimulus parameters were an exact copy of our previous healthy volunteer study. To exclude individual anatomical differences, the left and right DLPFC were targeted under magnetic resonance (MRI) guidance. To examine subjective mood changes we used Visual Analogue Scales (VAS), the Profile of Mood States (POMS), and the Positive Affect and Negative Affect Schedule (PANAS), the latter to assure assessment of positive emotions. To detect any delayed mood changes, assessments were also re-administered 30min post-HF-rTMS. We were unable to demonstrate immediate or delayed mood changes after one single active HF-rTMS session on the left or right DLPFC. Although we took into account several methodological problems which might have confounded previous rTMS mood induction studies, the hypothesis that one single session of HF-rTMS on the left or on the right DLPFC can influence mood in healthy female volunteers was not supported. One HF-rTMS session has no effect on subjective mood in healthy female

  15. The Effect of Electrical Stimulation in Improving Muscle Tone (Clinical)

    Science.gov (United States)

    Azman, M. F.; Azman, A. W.

    2017-11-01

    Electrical stimulation (ES) and also known as neuromuscular electrical stimulation (NMES) and transcutaneous electrical stimulation (TES) involves the use of electrical current to stimulate the nerves or nerve endings that innervate muscle beneath the skin. Electrical stimulation may be applied superficially on the skin (transcutaneously) or directly into a muscle or muscles (intramuscularly) for the primary purpose of enhancing muscle function. The basic theoretical premise is that if the peripheral nerve can be stimulated, the resulting excitation impulse will be transmitted along the nerve to the motor endplates in the muscle, producing a muscle contraction. In this work, the effect of mere electrical stimulation to the muscle bulk and strength are tested. This paper explains how electrical stimulation can affect the muscle bulk, muscle size, muscle tone, muscle atrophy and muscle strength. The experiment and data collection are performed on 5 subjects and the results obtained are analyzed. This research aims to understand the full potential of electrical stimulation and identifying its possible benefits or disadvantages to the muscle properties. The results indicated that electrical stimulation alone able to improve muscle properties but with certain limits and precautions which might be useful in rehabilitation programme.

  16. Percutaneous electrical stimulation in strength training: an update.

    Science.gov (United States)

    Requena Sánchez, Bernardo; Padial Puche, Paulino; González-Badillo, Juan José

    2005-05-01

    Numerous studies have used percutaneous electrical stimulation (PES) in the context of training programs to develop strength and physical performance in healthy populations (sedentary or trained). Significant increases in muscle and fiber cross-sectional area, isokinetic peak torque, maximal isometric and dynamic strength, and motor performance skills have been found after PES training. These strength gains are explained on the basis of the characteristics of PES motor units (MUs) recruitment: (a) a continuous and exhausting contractile activity in the same pool of MUs during the entire exercise period, (b) a supramaximal temporal recruitment imposed by the high frequency chosen (up to 40 Hz), and (c) a synchronous recruitment of neighboring fibers. The PES training method is complementary to voluntary training, mainly because the application of PES causes an unconventional spatial recruitment of MUs that, depending on the muscular topography, may entail the preferential recruitment of the fast-twitch MUs. In addition, the method does not specifically develop elasticity in skeletal muscle, and it must be accompanied by a technical workout.

  17. Effect of electrical stimulation on consumer acceptance of mutton ...

    African Journals Online (AJOL)

    MarianaD

    Animal history influences meat tenderness. LVES – low-voltage electrical stimulation, HVES – high-voltage electrical stimulation, ES – electrically stimulation, .... Overall acceptance. 4.1± 0.65. 4.1 ± 0.64. 0.372. Shear force value. (Newton). 37.7 ± 10.57. 32.6 ± 5.04. 0.168. Total cooking loss (%). 20.2 ± 2.54. 18.1 ± 2.78.

  18. Noninvasive Deep Brain Stimulation via Temporally Interfering Electric Fields

    OpenAIRE

    Grossman, Nir; De Bono, David; Dedic, Nina; Kodandaramaiah, Suhasa B.; Rudenko, Andrii; Suk, Ho-Jun; Cassara, Antonio M.; Neufeld, Esra; Kuster, Niels; Tsai, Li-Huei; Pascual-Leone, Alvaro; Boyden, Edward S.

    2017-01-01

    We report a noninvasive strategy for electrically stimulating neurons at depth. By delivering to the brain multiple electric fields at frequencies too high to recruit neural firing, but which differ by a frequency within the dynamic range of neural firing, we can electrically stimulate neurons throughout a region where interference between the multiple fields results in a prominent electric field envelope modulated at the difference frequency. We validated this temporal interference (TI) conc...

  19. Wireless distributed functional electrical stimulation system

    Directory of Open Access Journals (Sweden)

    Jovičić Nenad S

    2012-08-01

    Full Text Available Abstract Background The control of movement in humans is hierarchical and distributed and uses feedback. An assistive system could be best integrated into the therapy of a human with a central nervous system lesion if the system is controlled in a similar manner. Here, we present a novel wireless architecture and routing protocol for a distributed functional electrical stimulation system that enables control of movement. Methods The new system comprises a set of miniature battery-powered devices with stimulating and sensing functionality mounted on the body of the subject. The devices communicate wirelessly with one coordinator device, which is connected to a host computer. The control algorithm runs on the computer in open- or closed-loop form. A prototype of the system was designed using commercial, off-the-shelf components. The propagation characteristics of electromagnetic waves and the distributed nature of the system were considered during the development of a two-hop routing protocol, which was implemented in the prototype’s software. Results The outcomes of this research include a novel system architecture and routing protocol and a functional prototype based on commercial, off-the-shelf components. A proof-of-concept study was performed on a hemiplegic subject with paresis of the right arm. The subject was tasked with generating a fully functional palmar grasp (closing of the fingers. One node was used to provide this movement, while a second node controlled the activation of extensor muscles to eliminate undesired wrist flexion. The system was tested with the open- and closed-loop control algorithms. Conclusions The system fulfilled technical and application requirements. The novel communication protocol enabled reliable real-time use of the system in both closed- and open-loop forms. The testing on a patient showed that the multi-node system could operate effectively to generate functional movement.

  20. Wireless distributed functional electrical stimulation system.

    Science.gov (United States)

    Jovičić, Nenad S; Saranovac, Lazar V; Popović, Dejan B

    2012-08-09

    The control of movement in humans is hierarchical and distributed and uses feedback. An assistive system could be best integrated into the therapy of a human with a central nervous system lesion if the system is controlled in a similar manner. Here, we present a novel wireless architecture and routing protocol for a distributed functional electrical stimulation system that enables control of movement. The new system comprises a set of miniature battery-powered devices with stimulating and sensing functionality mounted on the body of the subject. The devices communicate wirelessly with one coordinator device, which is connected to a host computer. The control algorithm runs on the computer in open- or closed-loop form. A prototype of the system was designed using commercial, off-the-shelf components. The propagation characteristics of electromagnetic waves and the distributed nature of the system were considered during the development of a two-hop routing protocol, which was implemented in the prototype's software. The outcomes of this research include a novel system architecture and routing protocol and a functional prototype based on commercial, off-the-shelf components. A proof-of-concept study was performed on a hemiplegic subject with paresis of the right arm. The subject was tasked with generating a fully functional palmar grasp (closing of the fingers). One node was used to provide this movement, while a second node controlled the activation of extensor muscles to eliminate undesired wrist flexion. The system was tested with the open- and closed-loop control algorithms. The system fulfilled technical and application requirements. The novel communication protocol enabled reliable real-time use of the system in both closed- and open-loop forms. The testing on a patient showed that the multi-node system could operate effectively to generate functional movement.

  1. Dynamic electrical muscle stimulation (EMS) training of the ...

    African Journals Online (AJOL)

    Previous research on muscle strengthening using electrical stimulation has mainly focused on isometric training. Thus, the aim of the study was to investigate the effect of isokinetic and isotonic electrical muscle stimulation training on the strength of the quadriceps femoris muscle group. A quantitative, experimental ...

  2. Influence of electrical stimulation on carcass and meat quality of ...

    African Journals Online (AJOL)

    In a previous study regarding the effects of Kosher and conventional slaughter techniques on carcass and meat quality of cattle, it was speculated that electrical stimulation may have affected some of the meat qualities. Therefore, the objective of this study was to investigate the effects of electrical stimulation (ES) and ...

  3. Physiological Mechanisms in Combined Electric-Acoustic Stimulation.

    Science.gov (United States)

    Sato, Mika; Baumhoff, Peter; Tillein, Jochen; Kral, Andrej

    2017-09-01

    Electrical stimulation is normally performed on ears that have no hearing function, i.e., lack functional hair cells. The properties of electrically-evoked responses in these cochleae were investigated in several previous studies. Recent clinical developments have introduced cochlear implantation (CI) in residually-hearing ears to improve speech understanding in noise. The present study documents the known physiological differences between electrical stimulation of hair cells and of spiral ganglion cells, respectively, and reviews the mechanisms of combined electric and acoustic stimulation in the hearing ears. Literature review from 1971 to 2016. Compared with pure electrical stimulation the combined electroacoustic stimulation provides additional low-frequency information and expands the dynamic range of the input. Physiological studies document a weaker synchronization of the evoked activity in electrically stimulated hearing ears compared with deaf ears that reduces the hypersynchronization of electrically-evoked activity. The findings suggest the possibility of balancing the information provided by acoustic and electric input using stimulus intensity. Absence of distorting acoustic-electric interactions allows exploiting these clinical benefits of electroacoustic stimulation.

  4. FUNCTIONAL ELECTRICAL STIMULATION FOR CONTROL OF EPILEPTIC SEIZURES

    DEFF Research Database (Denmark)

    Jiao, Jianhang

    stimulation therapies as alternative antiepileptic treatments. In spite of these developments, the antiepileptic efficacy of such electrical stimulation therapies is still relatively low. One reason for not being able to increase this efficacy is the limited knowledge about the effect of the stimulation...

  5. A model of auditory nerve responses to electrical stimulation

    DEFF Research Database (Denmark)

    Joshi, Suyash Narendra; Dau, Torsten; Epp, Bastian

    , fail to correctly predict responses to anodic stimulation. This study presents a model that simulates AN responses to anodic and cathodic stimulation. The main goal was to account for the data obtained with monophasic electrical stimulation in cat AN. The model is based on an exponential integrate...... to neutralize the charge induced during the cathodic phase. Single-neuron recordings in cat auditory nerve using monophasic electrical stimulation show, however, that both phases in isolation can generate an AP. The site of AP generation differs for both phases, being more central for the anodic phase and more...... perception of CI listeners, a model needs to incorporate the correct responsiveness of the AN to anodic and cathodic polarity. Previous models of electrical stimulation have been developed based on AN responses to symmetric biphasic stimulation or to monophasic cathodic stimulation. These models, however...

  6. Electrical stimulation for urinary incontinence in women: a systematic review.

    Science.gov (United States)

    Schreiner, Lucas; Santos, Thais Guimarães dos; Souza, Alessandra Borba Anton de; Nygaard, Christiana Campani; Silva Filho, Irenio Gomes da

    2013-01-01

    Electrical stimulation is commonly recommended to treat urinary incontinence in women. It includes several techniques that can be used to improve stress, urge, and mixed symptoms. However, the magnitude of the alleged benefits is not completely established. To determine the effects of electrical stimulation in women with symptoms or urodynamic diagnoses of stress, urge, and mixed incontinence. Our review included articles published between January 1980 and January 2012. We used the search terms ″urinary incontinence″, ″electrical stimulation ″, ″ intravaginal ″, ″ tibial nerve ″ and ″ neuromodulation ″ for studies including female patients. We evaluated randomized trials that included electrical stimulation in at least one arm of the trial, to treat women with urinary incontinence. Two reviewers independently assessed the data from the trials, for inclusion or exclusion, and methodological analysis. A total of 30 randomized clinical trials were included. Most of the trials involved intravaginal electrical stimulation. Intravaginal electrical stimulation showed effectiveness in treating urge urinary incontinence, but reported contradictory data regarding stress and mixed incontinence. Tibial-nerve stimulation showed promising results in randomized trials with a short follow-up period. Sacral-nerve stimulation yielded interesting results in refractory patients. Tibial-nerve and intravaginal stimulation have shown effectiveness in treating urge urinary incontinence. Sacral-nerve stimulation provided benefits in refractory cases. Presently available data provide no support for the use of intravaginal electrical stimulation to treat stress urinary incontinence in women. Further randomized trials are necessary to determine the magnitude of benefits, with long-term follow-up, and the effectiveness of other electrical-stimulation therapies.

  7. Electrical Stimulation for Urinary Incontinence in Women: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Lucas Schreiner

    2013-07-01

    Full Text Available Background Electrical stimulation is commonly recommended to treat urinary incontinence in women. It includes several techniques that can be used to improve stress, urge, and mixed symptoms. However, the magnitude of the alleged benefits is not completely established. Objectives To determine the effects of electrical stimulation in women with symptoms or urodynamic diagnoses of stress, urge, and mixed incontinence. Search Strategy: Our review included articles published between January 1980 and January 2012. We used the search terms “urinary incontinence”, “electrical stimulation”, “intravaginal”, “tibial nerve” and “neuromodulation” for studies including female patients. Selection Criteria We evaluated randomized trials that included electrical stimulation in at least one arm of the trial, to treat women with urinary incontinence. Data Collection and Analysis Two reviewers independently assessed the data from the trials, for inclusion or exclusion, and methodological analysis. Main Results A total of 30 randomized clinical trials were included. Most of the trials involved intravaginal electrical stimulation. Intravaginal electrical stimulation showed effectiveness in treating urge urinary incontinence, but reported contradictory data regarding stress and mixed incontinence. Tibial-nerve stimulation showed promising results in randomized trials with a short follow-up period. Sacral-nerve stimulation yielded interesting results in refractory patients. Conclusions Tibial-nerve and intravaginal stimulation have shown effectiveness in treating urge urinary incontinence. Sacral-nerve stimulation provided benefits in refractory cases. Presently available data provide no support for the use of intravaginal electrical stimulation to treat stress urinary incontinence in women. Further randomized trials are necessary to determine the magnitude of benefits, with long-term follow-up, and the effectiveness of other electrical-stimulation

  8. Transcutaneous electrical nerve stimulation in dysphonic women.

    Science.gov (United States)

    Guirro, Rinaldo Roberto de Jesus; Bigaton, Delaine Rodrigues; Silvério, Kelly Cristina Alves; Berni, Kelly Cristina dos Santos; Distéfano, Giovanna; Santos, Fernanda Lopes dos; Forti, Fabiana

    2008-01-01

    studies indicate correlation between dysphonia and muscle tension. to evaluate bilaterally the electrical activity of the suprahyoid muscles (SH), sternocleidomastoid (SCM), and trapezius (T), the presence of pain and the voice, after applying transcutaneous electrical nerve stimulation (TENS). ten (10) women with nodules or bilateral mucus thickening, and phonation fissure. Volunteers were submitted to 10 TENS sessions (200 micros and 10 Hz) for 30 minutes. Pain was evaluated using an analogical visual scale; the voice was evaluated through laryngoscopy and through a perceptive-auditory and acoustic analysis; and the myoelectric signal was converted using the Root Media Square (RMS). Voice and EMG data gathering was performed during the production of the E/vowel and during spontaneous speech (SS). Shapiro-Wilk Test followed by the Wilcoxon Test, or t Student, or Friedman Test (p readings, pre and pos treatment, for the Right T (RT) (2.80 +/- 1.36 to 1.77 +/- 0.93), the Left T (LT) (3.62 +/- 2.10 to 2.10 +/- 1.06), the Left SCM (LSCM) (2.64 +/- 0.69 to 1.94 +/- 0.95), and the SH (11.59 +/- 7.72 to 7.82 +/- 5.95) during the production of the E/vowel; and for the RT (3.56 +/- 2.77 to 1.93 +/- 1.13), the LT (4.68 +/- 2.56 to 3.09 +/- 2.31), the Right SCM (RSCM) (3.94 +/- 2.04 to 2.51 +/- 1.87), and the LSCM (3.54 +/- 1.04 to 3.12 +/- 3.00) during SS. A relieve in pain was also observed. Regarding the voice analysis, there was a decrease in level of laryngeal injuries; no difference was observed during the production of the E/vowel in the perceptive-auditory analysis; there was a decrease in the level of dysphonia and hoarseness during SS. TENS is effective in improving the clinical and functional signs of dysphonic women.

  9. Toward rational design of electrical stimulation strategies for epilepsy control

    Science.gov (United States)

    Sunderam, Sridhar; Gluckman, Bruce; Reato, Davide; Bikson, Marom

    2009-01-01

    Electrical stimulation is emerging as a viable alternative for epilepsy patients whose seizures are not alleviated by drugs or surgery. Its attractions are temporal and spatial specificity of action, flexibility of waveform parameters and timing, and the perception that its effects are reversible unlike resective surgery. However, despite significant advances in our understanding of mechanisms of neural electrical stimulation, clinical electrotherapy for seizures relies heavily on empirical tuning of parameters and protocols. We highlight concurrent treatment goals with potentially conflicting design constraints that must be resolved when formulating rational strategies for epilepsy electrotherapy: namely seizure reduction versus cognitive impairment, stimulation efficacy versus tissue safety, and mechanistic insight versus clinical pragmatism. First, treatment markers, objectives, and metrics relevant to electrical stimulation for epilepsy are discussed from a clinical perspective. Then the experimental perspective is presented, with the biophysical mechanisms and modalities of open-loop electrical stimulation, and the potential benefits of closed-loop control for epilepsy. PMID:19926525

  10. Electrical carotid sinus stimulation in treatment resistant arterial hypertension.

    Science.gov (United States)

    Jordan, Jens; Heusser, Karsten; Brinkmann, Julia; Tank, Jens

    2012-12-24

    Treatment resistant arterial hypertension is commonly defined as blood pressure that remains above goal in spite of the concurrent use of three antihypertensive agents of different classes. The sympathetic nervous system promotes arterial hypertension and cardiovascular as well as renal damage, thus, providing a logical treatment target in these patients. Recent physiological studies suggest that baroreflex mechanisms contribute to long-term control of sympathetic activity and blood pressure providing an impetus for the development of electrical carotid sinus stimulators. The concept behind electrical stimulation of baroreceptors or baroreflex afferent nerves is that the stimulus is sensed by the brain as blood pressure increase. Then, baroreflex efferent structures are adjusted to counteract the perceived blood pressure increase. Electrical stimulators directly activating afferent baroreflex nerves were developed years earlier but failed for technical reasons. Recently, a novel implantable device was developed that produces an electrical field stimulation of the carotid sinus wall. Carefully conducted experiments in dogs provided important insight in mechanisms mediating the depressor response to electrical carotid sinus stimulation. Moreover, these studies showed that the treatment success may depend on the underlying pathophysiology of the hypertension. Clinical studies suggest that electrical carotid sinus stimulation attenuates sympathetic activation of vasculature, heart, and kidney while augmenting cardiac vagal regulation, thus lowering blood pressure. Yet, not all patients respond to treatment. Additional clinical trials are required. Patients equipped with an electrical carotid sinus stimulator provide a unique opportunity gaining insight in human baroreflex physiology. Copyright © 2012. Published by Elsevier B.V.

  11. High frequency electromagnetic dosimetry

    CERN Document Server

    Sánchez-Hernández, David A

    2009-01-01

    Along with the growth of RF and microwave technology applications, there is a mounting concern about the possible adverse effects over human health from electromagnetic radiation. Addressing this issue and putting it into perspective, this groundbreaking resource provides critical details on the latest advances in high frequency electromagnetic dosimetry.

  12. Noninvasive Deep Brain Stimulation via Temporally Interfering Electric Fields.

    Science.gov (United States)

    Grossman, Nir; Bono, David; Dedic, Nina; Kodandaramaiah, Suhasa B; Rudenko, Andrii; Suk, Ho-Jun; Cassara, Antonino M; Neufeld, Esra; Kuster, Niels; Tsai, Li-Huei; Pascual-Leone, Alvaro; Boyden, Edward S

    2017-06-01

    We report a noninvasive strategy for electrically stimulating neurons at depth. By delivering to the brain multiple electric fields at frequencies too high to recruit neural firing, but which differ by a frequency within the dynamic range of neural firing, we can electrically stimulate neurons throughout a region where interference between the multiple fields results in a prominent electric field envelope modulated at the difference frequency. We validated this temporal interference (TI) concept via modeling and physics experiments, and verified that neurons in the living mouse brain could follow the electric field envelope. We demonstrate the utility of TI stimulation by stimulating neurons in the hippocampus of living mice without recruiting neurons of the overlying cortex. Finally, we show that by altering the currents delivered to a set of immobile electrodes, we can steerably evoke different motor patterns in living mice. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Electrical Stimulation for Pressure Injuries: A Health Technology Assessment

    Science.gov (United States)

    Lambrinos, Anna; Falk, Lindsey; Ali, Arshia; Holubowich, Corinne; Walter, Melissa

    2017-01-01

    Background Pressure injuries (bedsores) are common and reduce quality of life. They are also costly and difficult to treat. This health technology assessment evaluates the effectiveness, cost-effectiveness, budget impact, and lived experience of adding electrical stimulation to standard wound care for pressure injuries. Methods We conducted a systematic search for studies published to December 7, 2016, limited to randomized and non–randomized controlled trials examining the effectiveness of electrical stimulation plus standard wound care versus standard wound care alone for patients with pressure injuries. We assessed the quality of evidence through Grading of Recommendations Assessment, Development, and Evaluation (GRADE). In addition, we conducted an economic literature review and a budget impact analysis to assess the cost-effectiveness and affordability of electrical stimulation for treatment of pressure ulcers in Ontario. Given uncertainties in clinical evidence and resource use, we did not conduct a primary economic evaluation. Finally, we conducted qualitative interviews with patients and caregivers about their experiences with pressure injuries, currently available treatments, and (if applicable) electrical stimulation. Results Nine randomized controlled trials and two non–randomized controlled trials were found from the systematic search. There was no significant difference in complete pressure injury healing between adjunct electrical stimulation and standard wound care. There was a significant difference in wound surface area reduction favouring electrical stimulation compared with standard wound care. The only study on cost-effectiveness of electrical stimulation was partially applicable to the patient population of interest. Therefore, the cost-effectiveness of electrical stimulation cannot be determined. We estimate that the cost of publicly funding electrical stimulation for pressure injuries would be $0.77 to $3.85 million yearly for the next 5

  14. Electrical Stimulation of the Heart: Pacing, Arrhythmias, and Defibrillation

    Science.gov (United States)

    Roth, Bradley J.

    2000-03-01

    Electrical stimulation of the heart underlies cardiac pacing and defibrillation. The "bidomain model" describes the anisotropic electrical properties of cardiac tissue. In particular, this model predicts mechanisms by which applied electric fields change the transmembrane potential of the myocardial cells. During unipolar stimulation, the bidomain model can explain "make" and "break" stimulation. Furthermore, it elucidates the cause of the "dip" in the anodal strength-interval curve, and predicts the initiation of novel quatrefoil reentry patterns. These results are beginning to shed light on the mechanisms of arrhythmia induction and defibrillation.

  15. Design of electrical stimulation bioreactors for cardiac tissue engineering.

    Science.gov (United States)

    Tandon, N; Marsano, A; Cannizzaro, C; Voldman, J; Vunjak-Novakovic, G

    2008-01-01

    Electrical stimulation has been shown to improve functional assembly of cardiomyocytes in vitro for cardiac tissue engineering. Carbon electrodes were found in past studies to have the best current injection characteristics. The goal of this study was to develop rational experimental design principles for the electrodes and stimulation regime, in particular electrode configuration, electrode ageing, and stimulation amplitude. Carbon rod electrodes were compared via electrochemical impedance spectroscopy (EIS) and we identified a safety range of 0 to 8 V/cm by comparing excitation thresholds and maximum capture rates for neonatal rat cardiomyocytes cultured with electrical stimulation. We conclude with recommendations for studies involving carbon electrodes for cardiac tissue engineering.

  16. Effect of high-frequency repetitive transcranial magnetic stimulation on motor cortical excitability and sensory nerve conduction velocity in subacute-stage incomplete spinal cord injury patients.

    Science.gov (United States)

    Cha, Hyun Gyu; Ji, Sang-Goo; Kim, Myoung-Kwon

    2016-07-01

    [Purpose] The aim of the present study was to determine whether repetitive transcranial magnetic stimulation can improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients. [Subjects and Methods] This study was conducted on 20 subjects with diagnosed paraplegia due to spinal cord injury. These 20 subjects were allocated to an experimental group of 10 subjects that underwent active repetitive transcranial magnetic stimulation or to a control group of 10 subjects that underwent sham repetitive transcranial magnetic stimulation. The SCI patients in the experimental group underwent active repetitive transcranial magnetic stimulation and conventional rehabilitation therapy, whereas the spinal cord injury patients in the control group underwent sham repetitive transcranial magnetic stimulation and conventional rehabilitation therapy. Participants in both groups received therapy five days per week for six-weeks. Latency, amplitude, and sensory nerve conduction velocity were assessed before and after the six week therapy period. [Results] A significant intergroup difference was observed for posttreatment velocity gains, but no significant intergroup difference was observed for amplitude or latency. [Conclusion] repetitive transcranial magnetic stimulation may be improve sensory recovery of the lower extremities in subacute-stage spinal cord injury patients.

  17. Effects of different frequencies of transcutaneous electrical nerve stimulation on venous vascular reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Franco, O.S.; Paulitsch, F.S.; Pereira, A.P.C.; Teixeira, A.O. [Universidade Federal do Rio Grande, Faculdade de Medicina, Programa de Pós-Graduação em Ciências da Saúde, Rio Grande, RS, Brasil, Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, RS (Brazil); Martins, C.N. [Universidade Federal do Rio Grande, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Fisiologia Animal Comparada, Rio Grande, RS, Brasil, Programa de Pós-Graduação em Fisiologia Animal Comparada, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, RS (Brazil); Silva, A.M.V. [Universidade Federal de Santa Maria, Departamento de Fisioterapia e Reabilitação, Santa Maria, RS, Brasil, Departamento de Fisioterapia e Reabilitação, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Plentz, R.D.M. [Universidade Federal de Ciências da Saúde de Porto Alegre, Programa de Pós-Graduação em Ciências da Reabilitação, Programa de Pós-Graduação em Ciências da Saúde, Porto Alegre, RS, Brasil, Programa de Pós-Graduação em Ciências da Saúde, Programa de Pós-Graduação em Ciências da Reabilitação, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, RS (Brazil); Irigoyen, M.C. [Faculdade de Medicina, Universidade de São Paulo, Instituto do Coração, Unidade de Hipertensão, São Paulo, SP, Brasil, Unidade de Hipertensão, Instituto do Coração, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Signori, L.U. [Universidade Federal do Rio Grande, Faculdade de Medicina, Programa de Pós-Graduação em Ciências da Saúde, Rio Grande, RS, Brasil, Programa de Pós-Graduação em Ciências da Saúde, Faculdade de Medicina, Universidade Federal do Rio Grande, Rio Grande, RS (Brazil); Universidade Federal do Rio Grande, Instituto de Ciências Biológicas, Programa de Pós-Graduação em Fisiologia Animal Comparada, Rio Grande, RS, Brasil, Programa de Pós-Graduação em Fisiologia Animal Comparada, Instituto de Ciências Biológicas, Universidade Federal do Rio Grande, Rio Grande, RS (Brazil); Universidade Federal de Santa Maria, Departamento de Fisioterapia e Reabilitação, Santa Maria, RS, Brasil, Departamento de Fisioterapia e Reabilitação, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil)

    2014-04-04

    Transcutaneous electrical nerve stimulation (TENS) is a type of therapy used primarily for analgesia, but also presents changes in the cardiovascular system responses; its effects are dependent upon application parameters. Alterations to the cardiovascular system suggest that TENS may modify venous vascular response. The objective of this study was to evaluate the effects of TENS at different frequencies (10 and 100 Hz) on venous vascular reactivity in healthy subjects. Twenty-nine healthy male volunteers were randomized into three groups: placebo (n=10), low-frequency TENS (10 Hz, n=9) and high-frequency TENS (100 Hz, n=10). TENS was applied for 30 min in the nervous plexus trajectory from the superior member (from cervical to dorsal region of the fist) at low (10 Hz/200 μs) and high frequency (100 Hz/200 μs) with its intensity adjusted below the motor threshold and intensified every 5 min, intending to avoid accommodation. Venous vascular reactivity in response to phenylephrine, acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent) was assessed by the dorsal hand vein technique. The phenylephrine effective dose to achieve 70% vasoconstriction was reduced 53% (P<0.01) using low-frequency TENS (10 Hz), while in high-frequency stimulation (100 Hz), a 47% increased dose was needed (P<0.01). The endothelium-dependent (acetylcholine) and independent (sodium nitroprusside) responses were not modified by TENS, which modifies venous responsiveness, and increases the low-frequency sensitivity of α1-adrenergic receptors and shows high-frequency opposite effects. These changes represent an important vascular effect caused by TENS with implications for hemodynamics, inflammation and analgesia.

  18. Effects of different frequencies of transcutaneous electrical nerve stimulation on venous vascular reactivity

    Directory of Open Access Journals (Sweden)

    O.S. Franco

    2014-05-01

    Full Text Available Transcutaneous electrical nerve stimulation (TENS is a type of therapy used primarily for analgesia, but also presents changes in the cardiovascular system responses; its effects are dependent upon application parameters. Alterations to the cardiovascular system suggest that TENS may modify venous vascular response. The objective of this study was to evaluate the effects of TENS at different frequencies (10 and 100 Hz on venous vascular reactivity in healthy subjects. Twenty-nine healthy male volunteers were randomized into three groups: placebo (n=10, low-frequency TENS (10 Hz, n=9 and high-frequency TENS (100 Hz, n=10. TENS was applied for 30 min in the nervous plexus trajectory from the superior member (from cervical to dorsal region of the fist at low (10 Hz/200 μs and high frequency (100 Hz/200 μs with its intensity adjusted below the motor threshold and intensified every 5 min, intending to avoid accommodation. Venous vascular reactivity in response to phenylephrine, acetylcholine (endothelium-dependent and sodium nitroprusside (endothelium-independent was assessed by the dorsal hand vein technique. The phenylephrine effective dose to achieve 70% vasoconstriction was reduced 53% (P<0.01 using low-frequency TENS (10 Hz, while in high-frequency stimulation (100 Hz, a 47% increased dose was needed (P<0.01. The endothelium-dependent (acetylcholine and independent (sodium nitroprusside responses were not modified by TENS, which modifies venous responsiveness, and increases the low-frequency sensitivity of α1-adrenergic receptors and shows high-frequency opposite effects. These changes represent an important vascular effect caused by TENS with implications for hemodynamics, inflammation and analgesia.

  19. Optimization of Electrical Stimulation Parameters for Cardiac Tissue Engineering

    Science.gov (United States)

    Tandon, Nina; Marsano, Anna; Maidhof, Robert; Wan, Leo; Park, Hyoungshin; Vunjak-Novakovic, Gordana

    2010-01-01

    In vitro application of pulsatile electrical stimulation to neonatal rat cardiomyocytes cultured on polymer scaffolds has been shown to improve the functional assembly of cells into contractile cardiac tissue constrcuts. However, to date, the conditions of electrical stimulation have not been optimized. We have systematically varied the electrode material, amplitude and frequency of stimulation, to determine the conditions that are optimal for cardiac tissue engineering. Carbon electrodes, exhibiting the highest charge-injection capacity and producing cardiac tissues with the best structural and contractile properties, and were thus used in tissue engineering studies. Cardiac tissues stimulated at 3V/cm amplitude and 3Hz frequency had the highest tissue density, the highest concentrations of cardiac troponin-I and connexin-43, and the best developed contractile behavior. These findings contribute to defining bioreactor design specifications and electrical stimulation regime for cardiac tissue engineering. PMID:21604379

  20. Quadri-Pulse Theta Burst Stimulation using Ultra-High Frequency Bursts - A New Protocol to Induce Changes in Cortico-Spinal Excitability in Human Motor Cortex

    DEFF Research Database (Denmark)

    Jung, Nikolai H; Gleich, Bernhard; Gattinger, Norbert

    2016-01-01

    Patterned transcranial magnetic stimulation (TMS) such as theta burst stimulation (TBS) or quadri-pulse stimulation (QPS) can induce changes in cortico-spinal excitability, commonly referred to as long-term potentiation (LTP)-like and long-term depression (LTD)-like effects in human motor cortex ...... in cortico-spinal excitability. Induced current direction in the brain appears to be relevant when qTBS targets I-wave periodicity, corroborating that high-fidelity spike timing mechanisms are critical for inducing bi-directional plasticity in human M1....... was set to 666 Hz to mimic the rhythmicity of the descending cortico-spinal volleys that are elicited by TMS (i.e., I-wave periodicity). In a second experiment, burst frequency was set to 200 Hz to maximize postsynaptic Ca2+ influx using a temporal pattern unrelated to I-wave periodicity. The second phase...

  1. Differential stimulation of the retina with subretinally injected exogenous neurotransmitter: A biomimetic alternative to electrical stimulation

    Science.gov (United States)

    Rountree, Corey M.; Inayat, Samsoon; Troy, John B.; Saggere, Laxman

    2016-12-01

    Subretinal stimulation of the retina with neurotransmitters, the normal means of conveying visual information, is a potentially better alternative to electrical stimulation widely used in current retinal prostheses for treating blindness from photoreceptor degenerative diseases. Yet, no subretinal electrical or chemical stimulation study has stimulated the OFF and ON pathways differentially through inner retinal activation. Here, we demonstrate the feasibility of differentially stimulating retinal ganglion cells (RGCs) through the inner nuclear layer of the retina with glutamate, a primary neurotransmitter chemical, in a biomimetic way. We show that controlled pulsatile delivery of glutamate into the subsurface of explanted wild-type rat retinas elicits highly localized simultaneous inhibitory and excitatory spike rate responses in OFF and ON RGCs. We also present the spatiotemporal characteristics of RGC responses to subretinally injected glutamate and the therapeutic stimulation parameters. Our findings could pave the way for future development of a neurotransmitter-based subretinal prosthesis offering more naturalistic vision and better visual acuity than electrical prostheses.

  2. Non-invasive neuromuscular electrical stimulation in patients with central nervous system lesions: an educational review

    National Research Council Canada - National Science Library

    Schuhfried, Othmar; Crevenna, Richard; Fialka-Moser, Veronika; Paternostro-Sluga, Tatjana

    2012-01-01

    ...) functional electrical stimulation. Therapeutic electrical stimulation improves neuromuscular functional condition by strengthening muscles, increasing motor control, reducing spasticity, decreasing pain and increasing range of motion...

  3. Effect of electrical stimulation of carcasses from Dorper sheep with ...

    African Journals Online (AJOL)

    Samples of the left M. longissimus thoracis et lumborum of both groups were oven roasted and a consumer panel evaluated the acceptability of the mutton regarding ... Moreover, the variation in shear force values of meat samples from the electrically stimulated group was less compared to that of the non-stimulated group, ...

  4. Electrical muscle stimulation (EMS) training of the hamstrings ...

    African Journals Online (AJOL)

    The aim of this study was to investigate the effects of electrical muscle stimulation (EMS) training on hamstring muscle strength. The study utilised a quantitative experimental research design. The intervention was assessed using a Humac Norm 7000 Dynamometer. A Chattanooga Intelect Mobile Combo muscle stimulator ...

  5. Influence of electrical stimulation on carcass and meat quality of ...

    African Journals Online (AJOL)

    Agbeniga

    2014-08-24

    Aug 24, 2014 ... In addition to the accelerated glycolysis caused by electrical stimulation to lower the. pH of carcasses after slaughter, stress before or at slaughter could also play a part in lowering the pH and stimulating proteolysis and gluconeogenesis by the secretion of corticosteroid hormones. Carcasses from ...

  6. Design of Electrical Stimulation Bioreactors for Cardiac Tissue Engineering

    OpenAIRE

    Tandon, N.; Marsano, A.; Cannizzaro, C.; Voldman, J.; Vunjak-Novakovic, G.

    2008-01-01

    Electrical stimulation has been shown to improve functional assembly of cardiomyocytes in vitro for cardiac tissue engineering. Carbon electrodes were found in past studies to have the best current injection characteristics. The goal of this study was to develop rational experimental design principles for the electrodes and stimulation regime, in particular electrode configuration, electrode ageing, and stimulation amplitude. Carbon rod electrodes were compared via electrochemical impedance s...

  7. Therapeutic electrical stimulation for spasticity: quantitative gait analysis.

    Science.gov (United States)

    Pease, W S

    1998-01-01

    Improvement in motor function following electrical stimulation is related to strengthening of the stimulated spastic muscle and inhibition of the antagonist. A 26-year-old man with familial spastic paraparesis presented with gait dysfunction and bilateral lower limb spastic muscle tone. Clinically, muscle strength and sensation were normal. He was considered appropriate for a trial of therapeutic electrical stimulation following failed trials of physical therapy and baclofen. No other treatment was used concurrent with the electrical stimulation. Before treatment, quantitative gait analysis revealed 63% of normal velocity and a crouched gait pattern, associated with excessive electromyographic activity in the hamstrings and gastrocnemius muscles. Based on these findings, bilateral stimulation of the quadriceps and anterior compartment musculature was performed two to three times per week for three months. Repeat gait analysis was conducted three weeks after the cessation of stimulation treatment. A 27% increase in velocity was noted associated with an increase in both cadence and right step length. Right hip and bilateral knee stance motion returned to normal (rather than "crouched"). No change in the timing of dynamic electromyographic activity was seen. These findings suggest a role for the use of electrical stimulation for rehabilitation of spasticity. The specific mechanism of this improvement remains uncertain.

  8. Does electrical stimulation enhance post-exercise performance recovery?

    Science.gov (United States)

    Babault, Nicolas; Cometti, Carole; Maffiuletti, Nicola A; Deley, Gaëlle

    2011-10-01

    Elite sport requires high-volume and high-intensity training that inevitably induces neuromuscular fatigue detrimental for physical performance. Improving recovery processes is, therefore, fundamental and to this, a wide variety of recovery modalities could be proposed. Among them, neuromuscular electrical stimulation is largely adopted particularly by endurance-type and team sport athletes. This type of solicitation, when used with low stimulation frequencies, induces contractions of short duration and low intensity comparable to active recovery. This might be of interest to favour muscle blood flow and therefore metabolites washout to accelerate recovery kinetics during and after fatiguing exercises, training sessions or competition. However, although electrical stimulation is often used for recovery, limited evidence exists regarding its effects for an improvement of most physiological variables or reduced subjective rating of muscle soreness. Therefore, the main aim of this brief review is to present recent results from the literature to clarify the effectiveness of electrical stimulation as a recovery modality.

  9. Electrical stimulation promotes regeneration of injured oculomotor nerves in dogs

    Directory of Open Access Journals (Sweden)

    Lei Du

    2016-01-01

    Full Text Available Functional recovery after oculomotor nerve injury is very poor. Electrical stimulation has been shown to promote regeneration of injured nerves. We hypothesized that electrical stimulation would improve the functional recovery of injured oculomotor nerves. Oculomotor nerve injury models were created by crushing the right oculomotor nerves of adult dogs. Stimulating electrodes were positioned in both proximal and distal locations of the lesion, and non-continuous rectangular, biphasic current pulses (0.7 V, 5 Hz were administered 1 hour daily for 2 consecutive weeks. Analysis of the results showed that electrophysiological and morphological recovery of the injured oculomotor nerve was enhanced, indicating that electrical stimulation improved neural regeneration. Thus, this therapy has the potential to promote the recovery of oculomotor nerve dysfunction.

  10. Potential interests and limits of magnetic and electrical stimulation techniques to assess neuromuscular fatigue.

    Science.gov (United States)

    Millet, G Y; Bachasson, D; Temesi, J; Wuyam, B; Féasson, L; Vergès, S; Lévy, P

    2012-12-01

    Neuromuscular function can change under different conditions such as ageing, training/detraining, long-term spaceflight, environmental conditions (e.g. hypoxia, hyperthermia), disease, therapy/retraining programs and also with the appearance of fatigue. Neuromuscular fatigue can be defined as any decrease in maximal voluntary strength or power. There is no standardized method to induce fatigue and various protocols involving different contraction patterns (such as sustained or intermittent submaximal isometric or dynamic contractions on isokinetic or custom chairs) have been used. Probably due to lack of motivation/cooperation, results of fatigue resistance protocols are more variable in patients than in healthy subjects. Magnetic and electrical stimulation techniques allow non-invasive assessment of central and peripheral origins of fatigue. They also allow investigation of different types of muscle fatigue when combining various types of stimulation with force/surface EMG measurements. Since maximal electrical stimuli may be uncomfortable or even sometimes painful, several alternative methods have been recently proposed: submaximal muscle stimulation, low/high-frequency paired pulses instead of tetanic stimuli and the use of magnetic stimulation at the peripheral level. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Approximating transcranial magnetic stimulation with electric stimulation in mouse: a simulation study.

    Science.gov (United States)

    Barnes, Walter L; Lee, Won Hee; Peterchev, Angel V

    2014-01-01

    Rodent models are valuable for preclinical examination of novel therapeutic techniques, including transcranial magnetic stimulation (TMS). However, comparison of TMS effects in rodents and humans is confounded by inaccurate scaling of the spatial extent of the induced electric field in rodents. The electric field is substantially less focal in rodent models of TMS due to the technical restrictions of making very small coils that can handle the currents required for TMS. We examine the electric field distributions generated by various electrode configurations of electric stimulation in an inhomogeneous high-resolution finite element mouse model, and show that the electric field distributions produced by human TMS can be approximated by electric stimulation in mouse. Based on these results and the limits of magnetic stimulation in mice, we argue that the most practical and accurate way to model focal TMS in mice is electric stimulation through either cortical surface electrodes or electrodes implanted halfway through the mouse cranium. This approach could allow much more accurate approximation of the human TMS electric field focality and strength than that offered by TMS in mouse, enabling, for example, focal targeting of specific cortical regions, which is common in human TMS paradigms.

  12. Electrical stimulation of the upper extremity in stroke: cyclic versus EMG-triggered stimulation

    NARCIS (Netherlands)

    de Kroon, Joke R.; IJzerman, Maarten Joost

    2008-01-01

    Objective: To compare the effect of cyclic and electromyography (EMG)-triggered electrical stimulation on motor impairment and function of the affected upper extremity in chronic stroke. Design: Randomized controlled trial. Setting: Outpatient clinic of a rehabilitation centre. Subjects and

  13. Comparative Evaluation of Tactile Sensation by Electrical and Mechanical Stimulation.

    Science.gov (United States)

    Yem, Vibol; Kajimoto, Hiroyuki

    2017-01-01

    An electrotactile display is a tactile interface that provides tactile perception by passing electrical current through the surface of the skin. It is actively used instead of mechanical tactile displays for tactile feedback because of several advantages such as its small and thin size, light weight, and high responsiveness. However, the similarities and differences between these sensations is still not clear. This study directly compares the intensity sensation of electrotactile stimulation to that of mechanical stimulation, and investigates the characteristic sensation of anodic and cathodic stimulation. In the experiment, participants underwent a 30 pps electrotactile stimulus every one second to their middle finger, and were asked to match this intensity by adjusting the intensity of a mechanical tactile stimulus to an index finger. The results showed that anodic stimulation mainly produced vibration sensation, whereas cathodic sensation produced both vibration and pressure sensations. Relatively low pressure sensation was also observed for anodic stimulation but it remains low, regardless of the increasing of electrical intensity.

  14. Electric-field-stimulated protein mechanics.

    Science.gov (United States)

    Hekstra, Doeke R; White, K Ian; Socolich, Michael A; Henning, Robert W; Šrajer, Vukica; Ranganathan, Rama

    2016-12-15

    The internal mechanics of proteins-the coordinated motions of amino acids and the pattern of forces constraining these motions-connects protein structure to function. Here we describe a new method combining the application of strong electric field pulses to protein crystals with time-resolved X-ray crystallography to observe conformational changes in spatial and temporal detail. Using a human PDZ domain (LNX2PDZ2) as a model system, we show that protein crystals tolerate electric field pulses strong enough to drive concerted motions on the sub-microsecond timescale. The induced motions are subtle, involve diverse physical mechanisms, and occur throughout the protein structure. The global pattern of electric-field-induced motions is consistent with both local and allosteric conformational changes naturally induced by ligand binding, including at conserved functional sites in the PDZ domain family. This work lays the foundation for comprehensive experimental study of the mechanical basis of protein function.

  15. The effect of high frequency steep pulsed electric fields on in vitro and in vivo antitumor efficiency of ovarian cancer cell line skov3 and potential use in electrochemotherapy

    Directory of Open Access Journals (Sweden)

    Zheng Fei-Yun

    2009-04-01

    Full Text Available Abstract Background Patients received electrochemotherapy often associated with unpleasant sensations mainly result from low-frequency electric pulse induced muscle contractions. Increasing the repetition frequency of electric pulse can reduce unpleasant sensations. However, due to the specificity of SPEF, frequency related antitumor efficiency need to be further clarified. The aim of this study was to compare in vitro cytotoxic and in vivo antitumor effect on ovarian cancer cell line SKOV3 by SPEF with different repetition frequencies. Explore potential benefits of using high frequency SPEF in order to be exploitable in electrochemotherapy. Methods For in vitro experiment, SKOV3 cell suspensions were exposed to SPEF with gradient increased frequencies (1, 60, 1 000, 5 000 Hz and electric field intensity (50, 100, 150, 200, 250, 300, 350, 400 V/cm respectively. For in vivo test, SKOV3 subcutaneous implanted tumor in BALB/c nude mice (nu/nu were exposure to SPEF with gradient increased frequencies (1, 60, 1 000, 5 000 Hz and fixed electric field intensity (250 V/cm (7 mice for each frequency and 7 for control. Antitumor efficiency was performed by in vitro cytotoxic assay and in vivo tumor growth inhibition rate, supplemented by histological and TEM observations. Data were analyzed using one-way ANOVA followed by the comparisons of multiple groups. Results SPEF with a given frequency and appropriate electric field intensity could achieve similar cytotoxicity until reached a plateau of maximum cytotoxicity (approx. 100%. SPEF with different frequencies had significant antitumor efficiency in comparison to the control group (P 0.05. Histological and TEM observations demonstrated obvious cell damages in response to SPEF exposure. Furthermore, SPEF with 5 kHz could induce apoptosis under TEM observations both in vitro and in vivo. Conclusion SPEF with high frequency could also achieve similar antitumor efficiency which can be used to reduce

  16. Efficacy of Electrical Pudendal Nerve Stimulation versus Transvaginal Electrical Stimulation in Treating Female Idiopathic Urgency Urinary Incontinence.

    Science.gov (United States)

    Wang, Siyou; Lv, Jianwei; Feng, Xiaoming; Lv, Tingting

    2017-06-01

    We compared the efficacy of electrical pudendal nerve stimulation vs transvaginal electrical stimulation to treat female idiopathic urgency urinary incontinence. A total of 120 female patients with idiopathic urgency urinary incontinence refractory to medication were randomized at a ratio of 2:1 to group 1 of 80 patients and group 2 of 40. Groups 1 and 2 were treated with electrical pudendal nerve stimulation and transvaginal electrical stimulation, respectively. To perform electrical pudendal nerve stimulation long acupuncture needles were deeply inserted into 4 sacrococcygeal points and electrified to stimulate pudendal nerves. Outcome measures were the 24-hour pad test and a questionnaire to measure the severity of symptoms and quality of life in women with urgency urinary incontinence. The median severity of symptoms and quality of life score on the urgency urinary incontinence questionnaire (urgency urinary incontinence total score) was 13 (range 7 to 18.75) in group 1 and 11 (range 8 to 16) in group 2 before treatment, which decreased to 2 (range 0 to 6.75) in group 1 and 6.5 (range 3.25 to 10.75) in group 2 (both p incontinence total score was lower and the therapeutic effect was better in group 1 than in group 2 (both p incontinence. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  17. Gastric electrical stimulation: an evidence-based analysis.

    Science.gov (United States)

    2006-01-01

    related to satiety and/or appetite. Possible advantages to GES for the treatment of morbid obesity include reversibility of the procedure, less invasiveness than some bariatric procedures, e.g., gastric bypass, and less side effects (e.g., dumping syndrome). Electrical stimulation is delivered via an implanted system that consists of a neurostimulator and 2 leads. The surgical procedure can be performed via either an open or laparoscopic approach. An external programmer used by the physician can deliver instructions to the GES, i.e., adjust the rate and amplitude of stimulation (Figure 1). GES may be turned off by the physician at any time or may be removed. The battery life is approximately 4-5 years For treatment of GP, the GES leads are secured in the muscle of the lower stomach, 10 cm proximal to the pylorus (the opening from the stomach to the intestine), 1 cm apart and connected to an implantable battery-powered neurostimulator which is placed in a small pocket in the abdominal wall For treatment of morbid obesity, GES leads are implanted along the lesser curvature of the stomach where the vagal nerve branches spread, approximately 8 cm proximal to the pylorus. However, the implant positioning of the leads has been variably reported in the literature. The Enterra Therapy System and the Transcend II Implantable Gastric Stimulation System (Medtronic Inc.) are both licensed as class 3 devices by Health Canada (license numbers 60264 and 66948 respectively). The Health Canada indications for use are: ENTERRA THERAPY SYSTEM: "For use in the treatment of chronic intractable (drug-refractory) nausea and vomiting." "For use in weight reduction for obese adults with a body mass index greater than 35."The GES device that is licensed by Health Canada for treatment of GP, produces high-frequency GES. Most clinical studies examining GES for GP have used high-frequency (4 times the intrinsic slow wave frequency, i.e., 12 cycles per minute), low energy, short duration pulses. This

  18. Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Hui Zhou

    2015-07-01

    Full Text Available Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel electrode on healthy subjects. The equivalent circuit models and the finite element models of different types of electrode were built based on the measured impedance data of the electrodes to reveal the possible mechanism of electrical stimulation pain. Our results showed that the wet textile electrode could achieve similar stimulation performance as the hydrogel electrode in motor threshold and stimulation comfort. However, the dry textile electrode was found to have very low pain threshold and induced obvious cutaneous painful sensations during stimulation, in comparison to the wet and hydrogel electrodes. Indeed, the finite element modeling results showed that the activation function along the z direction at the depth of dermis epidermis junction of the dry textile electrode was significantly larger than that of the wet and hydrogel electrodes, thus resulting in stronger activation of pain sensing fibers. Future work will be done to make textile electrodes have similar stimulation performance and comfort as hydrogel electrodes.

  19. Stimulating the Comfort of Textile Electrodes in Wearable Neuromuscular Electrical Stimulation.

    Science.gov (United States)

    Zhou, Hui; Lu, Yi; Chen, Wanzhen; Wu, Zhen; Zou, Haiqing; Krundel, Ludovic; Li, Guanglin

    2015-07-16

    Textile electrodes are becoming an attractive means in the facilitation of surface electrical stimulation. However, the stimulation comfort of textile electrodes and the mechanism behind stimulation discomfort is still unknown. In this study, a textile stimulation electrode was developed using conductive fabrics and then its impedance spectroscopy, stimulation thresholds, and stimulation comfort were quantitatively assessed and compared with those of a wet textile electrode and a hydrogel electrode on healthy subjects. The equivalent circuit models and the finite element models of different types of electrode were built based on the measured impedance data of the electrodes to reveal the possible mechanism of electrical stimulation pain. Our results showed that the wet textile electrode could achieve similar stimulation performance as the hydrogel electrode in motor threshold and stimulation comfort. However, the dry textile electrode was found to have very low pain threshold and induced obvious cutaneous painful sensations during stimulation, in comparison to the wet and hydrogel electrodes. Indeed, the finite element modeling results showed that the activation function along the z direction at the depth of dermis epidermis junction of the dry textile electrode was significantly larger than that of the wet and hydrogel electrodes, thus resulting in stronger activation of pain sensing fibers. Future work will be done to make textile electrodes have similar stimulation performance and comfort as hydrogel electrodes.

  20. Gastric Electrical Stimulation with the Enterra System: A Systematic Review.

    Science.gov (United States)

    Lal, Nikhil; Livemore, Sam; Dunne, Declan; Khan, Iftikhar

    2015-01-01

    Background. Gastric electrical stimulation (GES) is a surgically implanted treatment option for refractory gastroparesis. Aim. To systematically appraise the current evidence for the use of gastric electrical stimulation and suggest a method of standardisation of assessment and follow-up in these patients. Methods. A systematic review of PubMed, Web of Science, DISCOVER, and Cochrane Library was conducted using the keywords including gastric electrical stimulation, gastroparesis, nausea, and vomiting and neuromodulation, stomach, central nervous system, gastric pacing, electrical stimulation, and gastrointestinal. Results. 1139 potentially relevant articles were identified, of which 21 met the inclusion criteria and were included. The quality of studies was variable. There was a variation in outcome measures and follow-up methodology. Included studies suggested significant reductions in symptom severity reporting over the study period, but improvements in gastric emptying time were variable and rarely correlated with symptom improvement. Conclusion. The evidence in support of gastric electrical stimulation is limited and heterogeneous in quality. While current evidence has shown a degree of efficacy in these patients, high-quality, large clinical trials are needed to establish the efficacy of this therapy and to identify the patients for whom this therapy is inappropriate. A consensus view on essential preoperative assessment and postoperative measurement is needed.

  1. Gastric Electrical Stimulation with the Enterra System: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Nikhil Lal

    2015-01-01

    Full Text Available Background. Gastric electrical stimulation (GES is a surgically implanted treatment option for refractory gastroparesis. Aim. To systematically appraise the current evidence for the use of gastric electrical stimulation and suggest a method of standardisation of assessment and follow-up in these patients. Methods. A systematic review of PubMed, Web of Science, DISCOVER, and Cochrane Library was conducted using the keywords including gastric electrical stimulation, gastroparesis, nausea, and vomiting and neuromodulation, stomach, central nervous system, gastric pacing, electrical stimulation, and gastrointestinal. Results. 1139 potentially relevant articles were identified, of which 21 met the inclusion criteria and were included. The quality of studies was variable. There was a variation in outcome measures and follow-up methodology. Included studies suggested significant reductions in symptom severity reporting over the study period, but improvements in gastric emptying time were variable and rarely correlated with symptom improvement. Conclusion. The evidence in support of gastric electrical stimulation is limited and heterogeneous in quality. While current evidence has shown a degree of efficacy in these patients, high-quality, large clinical trials are needed to establish the efficacy of this therapy and to identify the patients for whom this therapy is inappropriate. A consensus view on essential preoperative assessment and postoperative measurement is needed.

  2. Intracavitary electrical stimulation as treatment for overactive bladder: systematic review

    Directory of Open Access Journals (Sweden)

    Rafaela Fintelman Rodrigues

    Full Text Available Abstract Introduction: Overactive bladder (OAB is a clinical diagnosis of irritating urinary symptoms that influence on sufferers' life quality. There are effective treatments described in literature, but most of them present adverse effects. One way of treatment is the use of electrical stimulation, which has been widely used, but studies show varying results. Objective: To verify if intracavitary electrical stimulation can be effective in patients with OAB. Methods: online databases were searched with specific descriptors to find randomized clinical trials on overactive bladder treated with intracavitary electrical stimulation. Only articles with score equal or higher than 5 in methodological PEDro scale were used and those that described intra and / or inter-group P-value. Results: 217 articles were found, but only 6 were analyzed by the selection criteria. The studies show that electrical stimulation promotes the reduction of urinary frequency, urinary incontinence, nocturia, urgency and the number of protectors used, and improvements in maximum cystometric bladder capacity, symptoms of OAB and quality of life. Conclusion: Electrical stimulation was effective in patients with OAB and can be used before any invasive treatment due to none side effects.

  3. Non-invasive neuromuscular electrical stimulation in patients with central nervous system lesions: an educational review.

    Science.gov (United States)

    Schuhfried, Othmar; Crevenna, Richard; Fialka-Moser, Veronika; Paternostro-Sluga, Tatjana

    2012-02-01

    The aim of this educational review is to provide an overview of the clinical application of transcutaneous electrical stimulation of the extremities in patients with upper motor neurone lesions. In general two methods of electrical stimulation can be distinguished: (i) therapeutic electrical stimulation, and (ii) functional electrical stimulation. Therapeutic electrical stimulation improves neuromuscular functional condition by strengthening muscles, increasing motor control, reducing spasticity, decreasing pain and increasing range of motion. Transcutaneous electrical stimulation may be used for neuromuscular electrical stimulation inducing repetitive muscle contraction, electromyography-triggered neuromuscular electrical stimulation, position-triggered electrical stimulation and subsensory or sensory transcutaneous electric stimulation. Functional electrical stimulation provokes muscle contraction and thereby produces a functionally useful movement during stimulation. In patients with spinal cord injuries or stroke, electrical upper limb neuroprostheses are applied to enhance upper limb and hand function, and electrical lower limb neuroprostheses are applied for restoration of standing and walking. For example, a dropped foot stimulator is used to trigger ankle dorsiflexion to restore gait function. A review of the literature and clinical experience of the use of therapeutic electrical stimulation as well as of functional electrical stimulation in combination with botulinum toxin, exercise therapy and/or splinting are presented. Although the evidence is limited we conclude that neuromuscular electrical stimulation in patients with central nervous system lesions can be an effective modality to improve function, and that combination with other treatments has an additive therapeutic effect.

  4. Higher-order power harmonics of pulsed electrical stimulation modulates corticospinal contribution of peripheral nerve stimulation.

    Science.gov (United States)

    Chen, Chiun-Fan; Bikson, Marom; Chou, Li-Wei; Shan, Chunlei; Khadka, Niranjan; Chen, Wen-Shiang; Fregni, Felipe

    2017-03-03

    It is well established that electrical-stimulation frequency is crucial to determining the scale of induced neuromodulation, particularly when attempting to modulate corticospinal excitability. However, the modulatory effects of stimulation frequency are not only determined by its absolute value but also by other parameters such as power at harmonics. The stimulus pulse shape further influences parameters such as excitation threshold and fiber selectivity. The explicit role of the power in these harmonics in determining the outcome of stimulation has not previously been analyzed. In this study, we adopted an animal model of peripheral electrical stimulation that includes an amplitude-adapted pulse train which induces force enhancements with a corticospinal contribution. We report that the electrical-stimulation-induced force enhancements were correlated with the amplitude of stimulation power harmonics during the amplitude-adapted pulse train. In an exploratory analysis, different levels of correlation were observed between force enhancement and power harmonics of 20-80 Hz (r = 0.4247, p = 0.0243), 100-180 Hz (r = 0.5894, p = 0.0001), 200-280 Hz (r = 0.7002, p power harmonics. This is a pilot, but important first demonstration that power at high order harmonics in the frequency spectrum of electrical stimulation pulses may contribute to neuromodulation, thus warrant explicit attention in therapy design and analysis.

  5. Low frequencies, but not high frequencies of bi-polar spinal cord stimulation reduce cutaneous and muscle hyperalgesia induced by nerve injury.

    Science.gov (United States)

    Maeda, Y; Wacnik, P W; Sluka, K A

    2008-08-15

    Spinal cord stimulation (SCS) is an established treatment for neuropathic pain. However, SCS is not effective for all the patients and the mechanisms underlying the reduction in pain by SCS are not clearly understood. To elucidate the mechanisms of pain relief by SCS, we utilized the spared nerve injury model. Sprague-Dawley rats were anesthetized, the tibial and common peroneal nerves were tightly ligated, and an epidural SCS lead implanted in the upper lumbar spinal cord. SCS was delivered daily at one of 4 different frequencies (4Hz, 60Hz, 100Hz, and 250Hz) at approximately 85% of motor threshold 2 weeks after nerve injury for 4 days. Mechanical withdrawal threshold of the paw and compression withdrawal threshold of the hamstring muscles were measured before and after SCS on each day. All rats showed a decrease in withdrawal threshold of the paw and the muscle 2 weeks after nerve injury. Treatment with either 4Hz or 60Hz SCS significantly reversed the decreased withdrawal threshold of the paw and muscle. The effect was cumulative with a greater reversal by the fourth treatment when compared to the first treatment. Treatment with 100Hz, 250Hz or sham SCS had no significant effect on the decreased withdrawal threshold of the paw or muscle that normally occurs after nerve injury. In conclusion, SCS at 4Hz and 60Hz was more effective in reducing hyperalgesia than higher frequencies of SCS (100Hz and 250Hz); and repeated treatments result in a cumulative reduction in hyperalgesia.

  6. Soft Encapsulation of Flexible Electrical Stimulation Implant: Challenges and Innovations

    Directory of Open Access Journals (Sweden)

    Adrien Debelle

    2016-11-01

    Full Text Available In this document we discuss the main challenges encountered when producing flexible electrical stimulation implants, and present our approach to solving them for prototype production. We include a study of the optimization of the flexible PCB design, the selection of additive manufacturing materials for the mold, and the chemical compatibility of the different materials. Our approach was tested on a flexible gastro-stimulator as part of the ENDOGES research program.

  7. Prediction and control of neural responses to pulsatile electrical stimulation

    Science.gov (United States)

    Campbell, Luke J.; Sly, David James; O'Leary, Stephen John

    2012-04-01

    This paper aims to predict and control the probability of firing of a neuron in response to pulsatile electrical stimulation of the type delivered by neural prostheses such as the cochlear implant, bionic eye or in deep brain stimulation. Using the cochlear implant as a model, we developed an efficient computational model that predicts the responses of auditory nerve fibers to electrical stimulation and evaluated the model's accuracy by comparing the model output with pooled responses from a group of guinea pig auditory nerve fibers. It was found that the model accurately predicted the changes in neural firing probability over time to constant and variable amplitude electrical pulse trains, including speech-derived signals, delivered at rates up to 889 pulses s-1. A simplified version of the model that did not incorporate adaptation was used to adaptively predict, within its limitations, the pulsatile electrical stimulus required to cause a desired response from neurons up to 250 pulses s-1. Future stimulation strategies for cochlear implants and other neural prostheses may be enhanced using similar models that account for the way that neural responses are altered by previous stimulation.

  8. Ownership of an artificial limb induced by electrical brain stimulation.

    Science.gov (United States)

    Collins, Kelly L; Guterstam, Arvid; Cronin, Jeneva; Olson, Jared D; Ehrsson, H Henrik; Ojemann, Jeffrey G

    2017-01-03

    Replacing the function of a missing or paralyzed limb with a prosthetic device that acts and feels like one's own limb is a major goal in applied neuroscience. Recent studies in nonhuman primates have shown that motor control and sensory feedback can be achieved by connecting sensors in a robotic arm to electrodes implanted in the brain. However, it remains unknown whether electrical brain stimulation can be used to create a sense of ownership of an artificial limb. In this study on two human subjects, we show that ownership of an artificial hand can be induced via the electrical stimulation of the hand section of the somatosensory (SI) cortex in synchrony with touches applied to a rubber hand. Importantly, the illusion was not elicited when the electrical stimulation was delivered asynchronously or to a portion of the SI cortex representing a body part other than the hand, suggesting that multisensory integration according to basic spatial and temporal congruence rules is the underlying mechanism of the illusion. These findings show that the brain is capable of integrating "natural" visual input and direct cortical-somatosensory stimulation to create the multisensory perception that an artificial limb belongs to one's own body. Thus, they serve as a proof of concept that electrical brain stimulation can be used to "bypass" the peripheral nervous system to induce multisensory illusions and ownership of artificial body parts, which has important implications for patients who lack peripheral sensory input due to spinal cord or nerve lesions.

  9. Mapping of electrical muscle stimulation using MRI

    Science.gov (United States)

    Adams, Gregory R.; Harris, Robert T.; Woodard, Daniel; Dudley, Gary A.

    1993-01-01

    The pattern of muscle contractile activity elicited by electromyostimulation (EMS) was mapped and compared to the contractile-activity pattern produced by voluntary effort. This was done by examining the patterns and the extent of contrast shift, as indicated by T2 values, im magnetic resonance (MR) images after isometric activity of the left m. quadriceps of human subjects was elicited by EMS (1-sec train of 500-microsec sine wave pulses at 50 Hz) or voluntary effort. The results suggest that, whereas EMS stimulates the same fibers repeatedly, thereby increasing the metabolic demand and T2 values, the voluntary efforts are performed by more diffuse asynchronous activation of skeletal muscle even at forces up to 75 percent of maximal to maintain performance.

  10. The use of transcutaneous electrical nerve stimulation (tens in the treatment of the spasticity - a review

    Directory of Open Access Journals (Sweden)

    Dahyan Wagner da Silva Silveira

    2008-01-01

    Full Text Available This study it has as objective to argue the job of TENS in the spasticity, observing the main parameters, form of application and the mechanism for which TENS it acts in the spasticity. One is about a bibliographical revision based in the literature specialized selected scientific articles through search in the data base of scielo and of bireme, from the sources Medline and Lilacs. The studies found on the job of TENS in the spasticity, had pointed mainly that this chain reduces the spasticity significantly, in lower degrees. The stimulation electrical parameters had disclosed that TENS it (about 100Hz of raised frequency provides one better effect in the reduction of the spasticity. The types of TENS more used had been the conventional and the soon-intense one, however some studies had not presented the used duration of pulse, limit the determination of one better modality of TENS. Few studies had explained the mechanism of performance of the current related one. The ones that had made it, had pointed the release of opioid endogenous (Dynorphins for the central nervous system as main mechanism of performance, however this contrasts with the neurophysiologic bases of the high-frequency stimulation, that demonstrated better resulted in the joined studies. Still it is necessary more studies on the job of this modality of stimulation electrical in the spasticity, since important parameters as duration of pulse, time of application, numbers of attendance and performance mechanism remains without scientific evidence.

  11. Electrical stimulation counteracts muscle atrophy associated with aging in humans

    Directory of Open Access Journals (Sweden)

    Helmut Kern

    2013-07-01

    Full Text Available Functional and structural muscle decline is a major problem during aging. Our goal was to improve in old subjects quadriceps m. force and mobility functional performances (stair test, chair rise test, timed up and go test with neuromuscular electrical stimulation (9 weeks, 2-3times/week, 20-30 minutes per session. Furthermore we performed histological and biological molecular analyses of vastus lateralis m. biopsies. Our findings demonstrate that electrical stimulation significantly improved mobility functional performancies and muscle histological characteristics and molecular markers.

  12. Determinants of the electric field during transcranial direct current stimulation

    DEFF Research Database (Denmark)

    Opitz, Alexander; Paulus, Walter; Will, Susanne

    2015-01-01

    Transcranial direct current stimulation (tDCS) causes a complex spatial distribution of the electric current flow in the head which hampers the accurate localization of the stimulated brain areas. In this study we show how various anatomical features systematically shape the electric field...... over the motor cortex in small steps to examine the resulting changes of the electric field distribution in the underlying cortex. We examined the effect of skull thickness and composition on the passing currents showing that thinner skull regions lead to higher electric field strengths. This effect...... is counteracted by a larger proportion of higher conducting spongy bone in thicker regions leading to a more homogenous current over the skull. Using a multiple regression model we could identify key factors that determine the field distribution to a significant extent, namely the thicknesses of the cerebrospinal...

  13. Electrical and structural properties of nano-crystalline silicon intrinsic layers for nano-crystalline silicon solar cells prepared by very high frequency plasma chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P.; Zhu, F. [Department of Metallurgical and Materials Engineering, Colorado School of Mines, Colorado 80401 (United States); Madan, A. [Department of Metallurgical and Materials Engineering, Colorado School of Mines, Colorado 80401 (United States); MVSystems Inc, Golden Colorado 80401 (United States)

    2008-07-15

    Thin silicon intrinsic layers were deposited in the amorphous to nano-crystalline transition regime to investigate their structural and optoelectrical properties using the very high frequency plasma enhanced chemical vapor deposition (VHF-PECVD) technique. Optical emission spectroscopy (OES) was primarily used to monitor the plasma properties during the deposition. The ratio H{alpha}/Si{sup *}, estimated from OES spectra, is closely related to the microstructure of the films. With the increasing plasma power from 10 to 50 W, the ratio H{alpha}/Si{sup *} increases leading to nano-crystalline films. The ratio H{alpha}/Si{sup *} decreases with the increase of process gas pressure at constant power of 15 and 30 W. The films were nano-crystalline at low pressure and became amorphous at high pressure. (author)

  14. Hearing suppression induced by electrical stimulation of human auditory cortex.

    Science.gov (United States)

    Fenoy, Albert J; Severson, Meryl A; Volkov, Igor O; Brugge, John F; Howard, Matthew A

    2006-11-06

    In the course of performing electrical stimulation functional mapping (ESFM) in neurosurgery patients, we identified three subjects who experienced hearing suppression during stimulation of sites within the superior temporal gyrus (STG). One of these patients had long standing tinnitus that affected both ears. In all subjects, auditory event related potentials (ERPs) were recorded from chronically implanted intracranial electrodes and the results were used to localize auditory cortical fields within the STG. Hearing suppression sites were identified within anterior lateral Heschl's gyrus (HG) and posterior lateral STG, in what may be auditory belt and parabelt fields. Cortical stimulation suppressed hearing in both ears, which persisted beyond the period of electrical stimulation. Subjects experienced other stimulation-evoked perceptions at some of these same sites, including symptoms of vestibular activation and alteration of audio-visual speech processing. In contrast, stimulation of presumed core auditory cortex within posterior medial HG evoked sound perceptions, or in one case an increase in tinnitus intensity, that affected the contralateral ear and did not persist beyond the period of stimulation. The current results confirm a rarely reported experimental observation, and correlate the cortical sites associated with hearing suppression with physiologically identified auditory cortical fields.

  15. Investigation of electrical responses to acupuncture stimulation: the effect of electrical grounding and insulation conditions.

    Science.gov (United States)

    Lee, Yong-Heum; Ryu, Yeon-Hang; Jung, Byungjo

    2009-03-01

    Acupuncture in Oriental medicine has been widely used as a core therapeutic method due to its minimal side-effects and therapeutic efficacy. However, the electrical response to acupuncture stimulation (ERAS) has not been clearly studied under acupuncture conditions that might affect the efficacy of acupuncture therapy. In this study, the ERAS was objectively investigated by measuring meridian electric potentials (MEPs) when the electrical grounding conditions of the operator and subject were varied, and when the insulation conditions of acupuncture needle were varied. MEPs between Sang-geoheo (ST37) and Ha-geoheo (ST39) of the Stomach Meridian (ST) were measured by stimulating Jok-samni (ST36) with an acupuncture needle. For non-insulated acupuncture stimulation (NIAS), the average MEP peak was 148.6 +/- 20.6 when neither the operator nor the subject were electrically grounded, 23.1 +/- 8.8 when the subject only was electrically grounded, 348 +/- 76.8 when the operator only was electrically grounded, and 19.9 +/- 4.7 when both the operator and the subject were electrically grounded. The MEPs presented various magnitudes and patterns depending on the electrical grounding conditions. The MEP pattern was very similar to that of the charge and discharge of a capacitor. For insulated acupuncture stimulation (IAS), the average MEP peak was 20 +/- 4 in all electrical grounding conditions, which is not a significant electric response for acupuncture stimulation. In terms of electricity, this study verified that acupuncture therapy might be affected by acupuncture conditions such as (1) the electrical grounding condition of the operator and the subject and (2) the insulation condition of the acupuncture needle.

  16. Motor unit recruitment during neuromuscular electrical stimulation: a critical appraisal.

    Science.gov (United States)

    Bickel, C Scott; Gregory, Chris M; Dean, Jesse C

    2011-10-01

    Neuromuscular electrical stimulation (NMES) is commonly used in clinical settings to activate skeletal muscle in an effort to mimic voluntary contractions and enhance the rehabilitation of human skeletal muscles. It is also used as a tool in research to assess muscle performance and/or neuromuscular activation levels. However, there are fundamental differences between voluntary- and artificial-activation of motor units that need to be appreciated before NMES protocol design can be most effective. The unique effects of NMES have been attributed to several mechanisms, most notably, a reversal of the voluntary recruitment pattern that is known to occur during voluntary muscle contractions. This review outlines the assertion that electrical stimulation recruits motor units in a nonselective, spatially fixed, and temporally synchronous pattern. Additionally, it synthesizes the evidence that supports the contention that this recruitment pattern contributes to increased muscle fatigue when compared with voluntary actions and provides some commentary on the parameters of electrical stimulation as well as emerging technologies being developed to facilitate NMES implementation. A greater understanding of how electrical stimulation recruits motor units, as well as the benefits and limitations of its use, is highly relevant when using this tool for testing and training in rehabilitation, exercise, and/or research.

  17. Electrical stimulation to increase lower esophageal sphincter pressure after POEM.

    Science.gov (United States)

    Ciotola, Franco; Ditaranto, Andres; Bilder, Claudio; Badaloni, Adolfo; Lowenstein, Daniel; Riganti, Juan Martin; Hoppo, Toshitaka; Jobe, Blair; Nachman, Fabio; Nieponice, Alejandro

    2015-01-01

    Postoperative reflux remains to be a challenge for patients with achalasia undergoing Heller myotomy. Similarly, per-oral endoscopic myotomy (POEM) is gaining rapid acceptance but the impossibility of adding a fundoplication is questioned as the main pitfall to control reflux. Electrical stimulation of the lower esophageal sphincter (LES) has emerged as a new alternative for the treatment of reflux disease. The objective of this study was to evaluate the potential benefits of combining electrical stimulation with endoscopic esophageal myotomy to prevent post procedural reflux. Five pigs were subjected to POEM. After myotomy was completed, two electrical leads were implanted at the LES level and electrical stimulation was applied with the Endostim system with a regimen of 215 μs (5 mA amplitude), at 20 Hz for 25 min. LES pressures were recorded with manometry at pre and post-myotomy and after LES stimulation. Myotomy was completed successfully in all cases. Mean pre-myotomy LES pressure was 35.99 ± 8.08 mmHg. After myotomy, the LES pressure significantly dropped to 10.60 ± 3.24 mmHg (p = 0.03). Subsequent to LES-EST, LES pressure significantly increased to 21.74 ± 4.65 mmHg (p = 0.01). The findings of this study show that LES-EST in healthy animals increases LES pressure after POEM procedure, and could be useful tool to minimize gastroesophageal reflux.

  18. Spectral loudness summation for electrical stimulation in cochlear implant users

    NARCIS (Netherlands)

    Theelen-van den Hoek, Femke L.; Boymans, Monique; Dreschler, Wouter A.

    2015-01-01

    This study investigates the effect of spectral loudness summation (SLS) in the electrical domain as perceived by cochlear implant (CI) users. Analogous to SLS in the acoustical domain, SLS was defined as the effect of electrode separation at a fixed overall stimulation rate. Categorical loudness

  19. Modeling auditory-nerve responses to electrical stimulation

    DEFF Research Database (Denmark)

    Joshi, Suyash Narendra; Dau, Torsten; Epp, Bastian

    Cochlear implants (CI) directly stimulate the auditory nerve (AN), bypassing the mechano-electrical transduction in the inner ear. Trains of biphasic, charge balanced pulses (anodic and cathodic) are used as stimuli to avoid damage of the tissue. The pulses of either polarity are capable of produ......Cochlear implants (CI) directly stimulate the auditory nerve (AN), bypassing the mechano-electrical transduction in the inner ear. Trains of biphasic, charge balanced pulses (anodic and cathodic) are used as stimuli to avoid damage of the tissue. The pulses of either polarity are capable......μs, which is large enough to affect the temporal coding of sounds and hence, potentially, the communication abilities of the CI listener. In the present study, two recently proposed models of electric stimulation of the AN [1,2] were considered in terms of their efficacy to predict the spike timing...... for anodic and cathodic stimulation of the AN of cat [3]. The models’ responses to the electrical pulses of various shapes [4,5,6] were also analyzed. It was found that, while the models can account for the firing rates in response to various biphasic pulse shapes, they fail to correctly describe the timing...

  20. Pharyngeal Electrical Stimulation for Treatment of Dysphagia in Subacute Stroke

    DEFF Research Database (Denmark)

    Bath, Philip M W; Scutt, Polly; Love, Jo

    2016-01-01

    BACKGROUND AND PURPOSE: Dysphagia is common after stroke, associated with increased death and dependency, and treatment options are limited. Pharyngeal electric stimulation (PES) is a novel treatment for poststroke dysphagia that has shown promise in 3 pilot randomized controlled trials. METHODS:...

  1. Effects of Electrical Vagal Stimulation and Bilateral Vagotomy on ...

    African Journals Online (AJOL)

    Effect of electrical vagal stimulation and bilateral vagotomy on the flow and electrolyte composition of bile was studied in fasted and anaesthetized male albino Wistar Rats. Entero-hepatic circulation was maintained artificially by continuous infusion of 1% sodium teurocholate. In each experiment, bile was collected at 15 ...

  2. Electrical and mechanical stimulation of cardiac cells and tissue constructs.

    Science.gov (United States)

    Stoppel, Whitney L; Kaplan, David L; Black, Lauren D

    2016-01-15

    The field of cardiac tissue engineering has made significant strides over the last few decades, highlighted by the development of human cell derived constructs that have shown increasing functional maturity over time, particularly using bioreactor systems to stimulate the constructs. However, the functionality of these tissues is still unable to match that of native cardiac tissue and many of the stem-cell derived cardiomyocytes display an immature, fetal like phenotype. In this review, we seek to elucidate the biological underpinnings of both mechanical and electrical signaling, as identified via studies related to cardiac development and those related to an evaluation of cardiac disease progression. Next, we review the different types of bioreactors developed to individually deliver electrical and mechanical stimulation to cardiomyocytes in vitro in both two and three-dimensional tissue platforms. Reactors and culture conditions that promote functional cardiomyogenesis in vitro are also highlighted. We then cover the more recent work in the development of bioreactors that combine electrical and mechanical stimulation in order to mimic the complex signaling environment present in vivo. We conclude by offering our impressions on the important next steps for physiologically relevant mechanical and electrical stimulation of cardiac cells and engineered tissue in vitro. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Comparison of the Effect of Neuromuscular Electrical Stimulation ...

    African Journals Online (AJOL)

    Children with cerebral palsy (CP) often demonstrate poor hand function due to spasticity. Thus spasticity in the wrist and finger flexors poses a great deal of functional limitations. This study was therefore designed to compare the effectiveness of Cryotherapy and Neuromuscular Electrical Stimulation (NMES) on spasticity ...

  4. Electrical field stimulation-induced excitatory responses of ...

    African Journals Online (AJOL)

    The aim of the present study was to investigate the effect of the endothelium on electrical field stimulation (EFS)-induced excitatory responses of pulmonary artery segments from pulmonary hypertensive rats. Methods: Pulmonary hypertension was induced in rats with a single dose of monocrotaline (60 mg/kg) and 21 days ...

  5. Electrical stimulation using kilohertz-frequency alternating current.

    Science.gov (United States)

    Ward, Alex R

    2009-02-01

    Transcutaneous electrical stimulation using kilohertz-frequency alternating current (AC) became popular in the 1950s with the introduction of "interferential currents," promoted as a means of producing depth-efficient stimulation of nerve and muscle. Later, "Russian current" was adopted as a means of muscle strengthening. This article reviews some clinically relevant, laboratory-based studies that offer an insight into the mechanism of action of kilohertz-frequency AC. It provides some answers to the question: "What are the optimal stimulus parameters for eliciting forceful, yet comfortable, electrically induced muscle contractions?" It is concluded that the stimulation parameters commonly used clinically (Russian and interferential currents) are suboptimal for achieving their stated goals and that greater benefit would be obtained using short-duration (2-4 millisecond), rectangular bursts of kilohertz-frequency AC with a frequency chosen to maximize the desired outcome.

  6. Electric stimulation with sinusoids and white noise for neural prostheses

    Directory of Open Access Journals (Sweden)

    Daniel K Freeman

    2010-02-01

    Full Text Available We are investigating the use of novel stimulus waveforms in neural prostheses to determine whether they can provide more precise control over the temporal and spatial pattern of elicited activity as compared to conventional pulsatile stimulation. To study this, we measured the response of retinal ganglion cells to both sinusoidal and white noise waveforms. The use of cell-attached and whole cell patch clamp recordings allowed the responses to be observed without significant obstruction from the stimulus artifact. Electric stimulation with sinusoids elicited robust responses. White noise analysis was used to derive the linear kernel for the ganglion cell’s spiking response as well as for the underlying excitatory currents. These results suggest that in response to electric stimulation, presynaptic retinal neurons exhibit bandpass filtering characteristics with peak response that occur 25ms after onset. The experimental approach demonstrated here may be useful for studying the temporal response properties of other neurons in the CNS.

  7. Power amplifier circuits for functional electrical stimulation systems

    Directory of Open Access Journals (Sweden)

    Delmar Carvalho de Souza

    Full Text Available Abstract Introduction: Functional electrical stimulation (FES is a technique that has been successfully employed in rehabilitation treatment to mitigate problems after spinal cord injury (SCI. One of the most relevant modules in a typical FES system is the power or output amplifier stage, which is responsible for the application of voltage or current pulses of proper intensity to the biological tissue, applied noninvasively via electrodes, placed on the skin surface or inside the muscular tissue, closer to the nervous fibers. The goals of this paper are to describe and discuss about the main power output designs usually employed in transcutaneous functional electrical stimulators as well as safety precautions taken to protect patients. Methods A systematic review investigated the circuits of papers published in IEEE Xplore and ScienceDirect databases from 2000 to 2016. The query terms were “((FES or Functional electric stimulator and (circuit or design” with 274 papers retrieved from IEEE Xplore and 29 from ScienceDirect. After the application of exclusion criteria the amount of papers decreased to 9 and 2 from IEEE Xplore and ScienceDirect, respectively. One paper was inserted in the results as a technological contribution to the field. Therefore, 12 papers presented power stage circuits suitable to stimulate great muscles. Discussion The retrieved results presented relevant circuits with different electronic strategies and circuit components. Some of them considered patient safety strategies or aimed to preserve muscle homeostasis such as biphasic current application, which prevents charge accumulation in stimulated tissues as well as circuits that dealt with electrical impedance variation to keep the electrode-tissue interface within an electrochemical safe regime. The investigation revealed a predominance of design strategies using operational amplifiers in power circuits, current outputs, and safety methods to reduce risks of electrical

  8. The effects of electrical stimulation or an electrolytic lesion in the mediodorsal thalamus of the rat on survival, body weight, food intake and running activity in the activity-based anorexia model

    OpenAIRE

    Luyten, Laura; Welkenhuysen, Marleen; Van Kuyck, Kris; Fieuws, Steffen; Das, John; Sciot, Raf; Nuttin, Bart

    2009-01-01

    The glucose metabolism in the mediodorsal thalamus (MD) is increased in rats in the activity-based anorexia (ABA) model. In patients, electrical stimulation in hyperactive brain regions reduced symptoms in e.g. major depressive disorder and cluster headache. In two blinded randomised controlled experiments, we therefore examined the effects of high-frequency electrical stimulation and an electrolytic lesion in the MD in a validated rat model for anorexia nervosa. The ABA model was successfull...

  9. Electrical Stimulation of the Retina to Produce Artificial Vision.

    Science.gov (United States)

    Weiland, James D; Walston, Steven T; Humayun, Mark S

    2016-10-14

    Retinal prostheses aim to restore vision to blind individuals suffering from retinal diseases such as retinitis pigmentosa and age-related macular degeneration. These devices function by electrically stimulating surviving retinal neurons, whose activation is interpreted by the brain as a visual percept. Many prostheses are currently under development. They are categorized as epiretinal, subretinal, and suprachoroidal prostheses on the basis of the placement of the stimulating microelectrode array. Each can activate ganglion cells through direct or indirect stimulation. The response of retinal neurons to these modes of stimulation are discussed in detail and are placed in context of the visual percept they are likely to evoke. This article further reviews challenges faced by retinal prosthesis and discusses potential solutions to address them.

  10. High frequency nanotube oscillator

    Science.gov (United States)

    Peng, Haibing [Houston, TX; Zettl, Alexander K [Kensington, TX

    2012-02-21

    A tunable nanostructure such as a nanotube is used to make an electromechanical oscillator. The mechanically oscillating nanotube can be provided with inertial clamps in the form of metal beads. The metal beads serve to clamp the nanotube so that the fundamental resonance frequency is in the microwave range, i.e., greater than at least 1 GHz, and up to 4 GHz and beyond. An electric current can be run through the nanotube to cause the metal beads to move along the nanotube and changing the length of the intervening nanotube segments. The oscillator can operate at ambient temperature and in air without significant loss of resonance quality. The nanotube is can be fabricated in a semiconductor style process and the device can be provided with source, drain, and gate electrodes, which may be connected to appropriate circuitry for driving and measuring the oscillation. Novel driving and measuring circuits are also disclosed.

  11. Coherent anti-Stokes Raman scattering under electric field stimulation

    Science.gov (United States)

    Capitaine, Erwan; Ould Moussa, Nawel; Louot, Christophe; Lefort, Claire; Pagnoux, Dominique; Duclère, Jean-René; Kaneyasu, Junya F.; Kano, Hideaki; Duponchel, Ludovic; Couderc, Vincent; Leproux, Philippe

    2016-12-01

    We introduce an experiment using electro-CARS, an electro-optical method based on the combination of ultrabroadband multiplex coherent anti-Stokes Raman scattering (M-CARS) spectroscopy and electric field stimulation. We demonstrate that this method can effectively discriminate the resonant CARS signal from the nonresonant background owing to a phenomenon of molecular orientation in the sample medium. Such molecular orientation is intrinsically related to the induction of an electric dipole moment by the applied static electric field. Evidence of the electro-CARS effect is obtained with a solution of n -alkanes (CnH2 n +2 , 15 ≤n ≤40 ), for which an enhancement of the CARS signal-to-noise ratio is achieved in the case of CH2 and CH3 symmetric/asymmetric stretching vibrations. Additionally, an electric-field-induced second-harmonic generation experiment is performed in order to corroborate the orientational organization of molecules due to the electric field excitation. Finally, we use a simple mathematical approach to compare the vibrational information extracted from electro-CARS measurements with spontaneous Raman data and to highlight the impact of electric stimulation on the vibrational signal.

  12. Assessment of Neuromuscular Function Using Percutaneous Electrical Nerve Stimulation.

    Science.gov (United States)

    Rozand, Vianney; Grosprêtre, Sidney; Stapley, Paul J; Lepers, Romuald

    2015-09-13

    Percutaneous electrical nerve stimulation is a non-invasive method commonly used to evaluate neuromuscular function from brain to muscle (supra-spinal, spinal and peripheral levels). The present protocol describes how this method can be used to stimulate the posterior tibial nerve that activates plantar flexor muscles. Percutaneous electrical nerve stimulation consists of inducing an electrical stimulus to a motor nerve to evoke a muscular response. Direct (M-wave) and/or indirect (H-reflex) electrophysiological responses can be recorded at rest using surface electromyography. Mechanical (twitch torque) responses can be quantified with a force/torque ergometer. M-wave and twitch torque reflect neuromuscular transmission and excitation-contraction coupling, whereas H-reflex provides an index of spinal excitability. EMG activity and mechanical (superimposed twitch) responses can also be recorded during maximal voluntary contractions to evaluate voluntary activation level. Percutaneous nerve stimulation provides an assessment of neuromuscular function in humans, and is highly beneficial especially for studies evaluating neuromuscular plasticity following acute (fatigue) or chronic (training/detraining) exercise.

  13. Measurements and models of electric fields in the in vivo human brain during transcranial electric stimulation.

    Science.gov (United States)

    Huang, Yu; Liu, Anli A; Lafon, Belen; Friedman, Daniel; Dayan, Michael; Wang, Xiuyuan; Bikson, Marom; Doyle, Werner K; Devinsky, Orrin; Parra, Lucas C

    2017-02-07

    Transcranial electric stimulation aims to stimulate the brain by applying weak electrical currents at the scalp. However, the magnitude and spatial distribution of electric fields in the human brain are unknown. We measured electric potentials intracranially in ten epilepsy patients and estimated electric fields across the entire brain by leveraging calibrated current-flow models. When stimulating at 2 mA, cortical electric fields reach 0.4 V/m, the lower limit of effectiveness in animal studies. When individual whole-head anatomy is considered, the predicted electric field magnitudes correlate with the recorded values in cortical (r = 0.89) and depth (r = 0.84) electrodes. Accurate models require adjustment of tissue conductivity values reported in the literature, but accuracy is not improved when incorporating white matter anisotropy or different skull compartments. This is the first study to validate and calibrate current-flow models with in vivo intracranial recordings in humans, providing a solid foundation to target stimulation and interpret clinical trials.

  14. Determinants of the electric field during transcranial direct current stimulation.

    Science.gov (United States)

    Opitz, Alexander; Paulus, Walter; Will, Susanne; Antunes, Andre; Thielscher, Axel

    2015-04-01

    Transcranial direct current stimulation (tDCS) causes a complex spatial distribution of the electric current flow in the head which hampers the accurate localization of the stimulated brain areas. In this study we show how various anatomical features systematically shape the electric field distribution in the brain during tDCS. We constructed anatomically realistic finite element (FEM) models of two individual heads including conductivity anisotropy and different skull layers. We simulated a widely employed electrode montage to induce motor cortex plasticity and moved the stimulating electrode over the motor cortex in small steps to examine the resulting changes of the electric field distribution in the underlying cortex. We examined the effect of skull thickness and composition on the passing currents showing that thinner skull regions lead to higher electric field strengths. This effect is counteracted by a larger proportion of higher conducting spongy bone in thicker regions leading to a more homogenous current over the skull. Using a multiple regression model we could identify key factors that determine the field distribution to a significant extent, namely the thicknesses of the cerebrospinal fluid and the skull, the gyral depth and the distance to the anode and cathode. These factors account for up to 50% of the spatial variation of the electric field strength. Further, we demonstrate that individual anatomical factors can lead to stimulation "hotspots" which are partly resistant to electrode positioning. Our results give valuable novel insights in the biophysical foundation of tDCS and highlight the importance to account for individual anatomical factors when choosing an electrode montage. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. A distributed transducer system for functional electrical stimulation

    DEFF Research Database (Denmark)

    Gudnason, Gunnar; Nielsen, Jannik Hammel; Bruun, Erik

    2001-01-01

    Implanted transducers for functional electrical stimulation (FES) powered by inductive links are subject to conflicting requirements arising from low link efficiency, a low power budget and the need for protection of the weak signals against strong RF electromagnetic fields. We propose a solution...... to be affected by the inductive link. Neural stimulators are affected to a lesser degree, but still benefit from the partitioning. As a test case, we have designed a transceiver and a sensor chip which implement this partitioning policy. The transceiver is designed to operate in the 6.78 MHz ISM band...

  16. Modeling auditory-nerve responses to electrical stimulation

    DEFF Research Database (Denmark)

    Joshi, Suyash Narendra; Dau, Torsten; Epp, Bastian

    2014-01-01

    large enough to affect the temporal coding of sounds and hence, potentially, the communication abilities of the CI listener. In the present study, two recently proposed models of electric stimulationof the AN [1, 2, 3] were considered in terms of their efficacy to predict the spike timing for anodic...... andcathodic stimulation of the AN of cat [4]. The models' responses to the electrical pulses of variousshapes [5] were also analyzed. It was found that, while the models can account for the ring rates inresponse to various biphasic pulse shapes, they fail to correctly describe the timing of AP in response...

  17. GaN-Based High-Efficiency, High-Density, High-Frequency Battery Charger for Plug-in Hybrid Electric Vehicle

    OpenAIRE

    Xue, Lingxiao

    2015-01-01

    This work explores how GaN devices and advanced control can improve the power density of battery chargers for the plug-in hybrid electric vehicle. Gallium nitride (GaN) devices are used to increase switching frequency and shrink passive components. An innovative DC link reduction technique is proposed and several practical design issues are solved. A multi-chip-module (MCM) approach is used to integrate multiple GaN transistors into a package that enables fast, reliable, and efficient swi...

  18. The Impact of Accelerated Right Prefrontal High-Frequency Repetitive Transcranial Magnetic Stimulation (rTMS on Cue-Reactivity: An fMRI Study on Craving in Recently Detoxified Alcohol-Dependent Patients.

    Directory of Open Access Journals (Sweden)

    Sarah C Herremans

    Full Text Available In alcohol-dependent patients craving is a difficult-to-treat phenomenon. It has been suggested that high-frequency (HF repetitive transcranial magnetic stimulation (rTMS may have beneficial effects. However, exactly how this application exerts its effect on the underlying craving neurocircuit is currently unclear. In an effort to induce alcohol craving and to maximize detection of HF-rTMS effects to cue-induced alcohol craving, patients were exposed to a block and event-related alcohol cue-reactivity paradigm while being scanned with fMRI. Hence, we assessed the effect of right dorsolateral prefrontal cortex (DLPFC stimulation on cue-induced and general alcohol craving, and the related craving neurocircuit. Twenty-six recently detoxified alcohol-dependent patients were included. First, we evaluated the impact of one sham-controlled stimulation session. Second, we examined the effect of accelerated right DLPFC HF-rTMS treatment: here patients received 15 sessions in an open label accelerated design, spread over 4 consecutive days. General craving significantly decreased after 15 active HF-rTMS sessions. However, cue-induced alcohol craving was not altered. Our brain imaging results did not show that the cue-exposure affected the underlying craving neurocircuit after both one and fifteen active HF-rTMS sessions. Yet, brain activation changes after one and 15 HF-rTMS sessions, respectively, were observed in regions associated with the extended reward system and the default mode network, but only during the presentation of the event-related paradigm. Our findings indicate that accelerated HF-rTMS applied to the right DLPFC does not manifestly affect the craving neurocircuit during an alcohol-related cue-exposure, but instead it may influence the attentional network.

  19. Neuromuscular electrical stimulation for mobility support of elderly

    Directory of Open Access Journals (Sweden)

    Winfried Mayr

    2015-10-01

    Full Text Available The stimulator for neuromuscular electrical stimulation for mobility support of elderly is not very complicated, but for application within "MOBIL" we have some additional demands to fulfill. First we have specific safety issues for this user group. A powerful compliance management system is crucial not only to guide daily application, but for creating hard data for the scientific outcome. We also need to assure easy handling of the stimulator, because the subjects are generally not able to cope with too difficult and complex motor skills. So, we developed five generations of stimulators and optimizing solutions after field tests. We are already planning the sixth generation with wireless control of the stimulation units by the central main handheld control unit. In a prototype, we have implemented a newly available high capacity memory, a breakthrough in “compliance data storage” as they offer the necessary high storage capacity and fast data handling for an affordable prize. The circuit also contains a 3D accelerometer sensor which acts as a further important safety features: if the control unit drops, this event is detected automatically by the sensor and activates an emergency switch-off that disables the stimulation to avoid associated risks. Further, we have implemented a hardware emergence shutdown and other safety measures. Finally, in the last example muscle torque measurements are referenced with compliance data. In the study normalized maximum voluntary contraction (MVC and maximum stimulation induced contraction (MSC were assessed in regular check-ups along the training period. With additional consideration of adjusted stimulation intensity for training out of the compliance data records we are able to estimate the induced contraction strength, which turned out to amount in average 11% of MVC. This value may seem on a first sight rather low, and ought to be considered in relation to the results at the end of the training period

  20. Neuromuscular Electrical Stimulation for Motor Restoration in Hemiplegia.

    Science.gov (United States)

    Knutson, Jayme S; Fu, Michael J; Sheffler, Lynne R; Chae, John

    2015-11-01

    This article reviews the most common therapeutic and neuroprosthetic applications of neuromuscular electrical stimulation (NMES) for upper and lower extremity stroke rehabilitation. Fundamental NMES principles and purposes in stroke rehabilitation are explained. NMES modalities used for upper and lower limb rehabilitation are described, and efficacy studies are summarized. The evidence for peripheral and central mechanisms of action is also summarized. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. Electric field calculations in brain stimulation based on finite elements

    DEFF Research Database (Denmark)

    Windhoff, Mirko; Opitz, Alexander; Thielscher, Axel

    2013-01-01

    The need for realistic electric field calculations in human noninvasive brain stimulation is undisputed to more accurately determine the affected brain areas. However, using numerical techniques such as the finite element method (FEM) is methodologically complex, starting with the creation...... elements. The latter is crucial to guarantee the numerical robustness of the FEM calculations. The pipeline will be released as open-source, allowing for the first time to perform realistic field calculations at an acceptable methodological complexity and moderate costs....

  2. Power amplifier circuits for functional electrical stimulation systems

    OpenAIRE

    Souza, Delmar Carvalho de; Gaiotto, Marcelo do Carmo; Nogueira Neto,Guilherme Nunes; Castro,Maria Claudia Ferrari de; Nohama, Percy

    2017-01-01

    Abstract Introduction: Functional electrical stimulation (FES) is a technique that has been successfully employed in rehabilitation treatment to mitigate problems after spinal cord injury (SCI). One of the most relevant modules in a typical FES system is the power or output amplifier stage, which is responsible for the application of voltage or current pulses of proper intensity to the biological tissue, applied noninvasively via electrodes, placed on the skin surface or inside the muscular ...

  3. Multi-Scale Computational Models for Electrical Brain Stimulation

    Science.gov (United States)

    Seo, Hyeon; Jun, Sung C.

    2017-01-01

    Electrical brain stimulation (EBS) is an appealing method to treat neurological disorders. To achieve optimal stimulation effects and a better understanding of the underlying brain mechanisms, neuroscientists have proposed computational modeling studies for a decade. Recently, multi-scale models that combine a volume conductor head model and multi-compartmental models of cortical neurons have been developed to predict stimulation effects on the macroscopic and microscopic levels more precisely. As the need for better computational models continues to increase, we overview here recent multi-scale modeling studies; we focused on approaches that coupled a simplified or high-resolution volume conductor head model and multi-compartmental models of cortical neurons, and constructed realistic fiber models using diffusion tensor imaging (DTI). Further implications for achieving better precision in estimating cellular responses are discussed. PMID:29123476

  4. Right Median Nerve Electrical Stimulation for Acute Traumatic Coma Patients.

    Science.gov (United States)

    Lei, Jin; Wang, Lei; Gao, Guoyi; Cooper, Edwin; Jiang, Jiyao

    2015-10-15

    The right median nerve as a peripheral portal to the central nervous system can be electrically stimulated to help coma arousal after traumatic brain injury (TBI). The present study set out to examine the efficacy and safety of right median nerve electrical stimulation (RMNS) in a cohort of 437 comatose patients after severe TBI from August 2005 to December 2011. The patients were enrolled 2 weeks after their injury and assigned to the RMNS group (n=221) receiving electrical stimulation for 2 weeks or the control group (n = 216) treated by standard management according to the date of birth in the month. The baseline data were similar. After the 2-week treatment, the RMNS-treated patients demonstrated a more rapid increase of the mean Glasgow Coma Score, although statistical significance was not reached (8.43 ± 4.98 vs. 7.47 ± 5.37, p = 0.0532). The follow-up data at 6-month post-injury showed a significantly higher proportion of patients who regained consciousness (59.8% vs. 46.2%, p = 0.0073). There was a lower proportion of vegetative persons in the RMNS group than in the control group (17.6% vs. 22.0%, p = 0.0012). For persons regaining consciousness, the functional independence measurement (FIM) score was higher among the RMNS group patients (91.45 ± 8.65 vs. 76.23 ± 11.02, p coma in the early phase.

  5. Stimulation of Neurite Outgrowth Using an Electrically Conducting Polymer

    Science.gov (United States)

    Schmidt, Christine E.; Shastri, Venkatram R.; Vacanti, Joseph P.; Langer, Robert

    1997-08-01

    Damage to peripheral nerves often cannot be repaired by the juxtaposition of the severed nerve ends. Surgeons have typically used autologous nerve grafts, which have several drawbacks including the need for multiple surgical procedures and loss of function at the donor site. As an alternative, the use of nerve guidance channels to bridge the gap between severed nerve ends is being explored. In this paper, the electrically conductive polymer--oxidized polypyrrole (PP)--has been evaluated for use as a substrate to enhance nerve cell interactions in culture as a first step toward potentially using such polymers to stimulate in vivo nerve regeneration. Image analysis demonstrates that PC-12 cells and primary chicken sciatic nerve explants attached and extended neurites equally well on both PP films and tissue culture polystyrene in the absence of electrical stimulation. In contrast, PC-12 cells interacted poorly with indium tin oxide (ITO), poly(L-lactic acid) (PLA), and poly(lactic acid-coglycolic acid) surfaces. However, PC-12 cells cultured on PP films and subjected to an electrical stimulus through the film showed a significant increase in neurite lengths compared with ones that were not subjected to electrical stimulation through the film and tissue culture polystyrene controls. The median neurite length for PC-12 cells grown on PP and subjected to an electrical stimulus was 18.14 μ m (n = 5643) compared with 9.5 μ m (n = 4440) for controls. Furthermore, animal implantation studies reveal that PP invokes little adverse tissue response compared with poly(lactic acid-coglycolic acid).

  6. Intraoperative dorsal language network mapping by using single-pulse electrical stimulation.

    Science.gov (United States)

    Yamao, Yukihiro; Matsumoto, Riki; Kunieda, Takeharu; Arakawa, Yoshiki; Kobayashi, Katsuya; Usami, Kiyohide; Shibata, Sumiya; Kikuchi, Takayuki; Sawamoto, Nobukatsu; Mikuni, Nobuhiro; Ikeda, Akio; Fukuyama, Hidenao; Miyamoto, Susumu

    2014-09-01

    The preservation of language function during brain surgery still poses a challenge. No intraoperative methods have been established to monitor the language network reliably. We aimed to establish intraoperative language network monitoring by means of cortico-cortical evoked potentials (CCEPs). Subjects were six patients with tumors located close to the arcuate fasciculus (AF) in the language-dominant left hemisphere. Under general anesthesia, the anterior perisylvian language area (AL) was first defined by the CCEP connectivity patterns between the ventrolateral frontal and temporoparietal area, and also by presurgical neuroimaging findings. We then monitored the integrity of the language network by stimulating AL and by recording CCEPs from the posterior perisylvian language area (PL) consecutively during both general anesthesia and awake condition. High-frequency electrical stimulation (ES) performed during awake craniotomy confirmed language function at AL in all six patients. Despite an amplitude decline (≤32%) in two patients, CCEP monitoring successfully prevented persistent language impairment. After tumor removal, single-pulse ES was applied to the white matter tract beneath the floor of the removal cavity in five patients, in order to trace its connections into the language cortices. In three patients in whom high-frequency ES of the white matter produced naming impairment, this "eloquent" subcortical site directly connected AL and PL, judging from the latencies and distributions of cortico- and subcortico-cortical evoked potentials. In conclusion, this study provided the direct evidence that AL, PL, and AF constitute the dorsal language network. Intraoperative CCEP monitoring is clinically useful for evaluating the integrity of the language network. Copyright © 2014 Wiley Periodicals, Inc.

  7. High-frequency TRNS reduces BOLD activity during visuomotor learning.

    Directory of Open Access Journals (Sweden)

    Catarina Saiote

    Full Text Available Transcranial direct current stimulation (tDCS and transcranial random noise stimulation (tRNS consist in the application of electrical current of small intensity through the scalp, able to modulate perceptual and motor learning, probably by changing brain excitability. We investigated the effects of these transcranial electrical stimulation techniques in the early and later stages of visuomotor learning, as well as associated brain activity changes using functional magnetic resonance imaging (fMRI. We applied anodal and cathodal tDCS, low-frequency and high-frequency tRNS (lf-tRNS, 0.1-100 Hz; hf-tRNS 101-640 Hz, respectively and sham stimulation over the primary motor cortex (M1 during the first 10 minutes of a visuomotor learning paradigm and measured performance changes for 20 minutes after stimulation ceased. Functional imaging scans were acquired throughout the whole experiment. Cathodal tDCS and hf-tRNS showed a tendency to improve and lf-tRNS to hinder early learning during stimulation, an effect that remained for 20 minutes after cessation of stimulation in the late learning phase. Motor learning-related activity decreased in several regions as reported previously, however, there was no significant modulation of brain activity by tDCS. In opposition to this, hf-tRNS was associated with reduced motor task-related-activity bilaterally in the frontal cortex and precuneous, probably due to interaction with ongoing neuronal oscillations. This result highlights the potential of lf-tRNS and hf-tRNS to differentially modulate visuomotor learning and advances our knowledge on neuroplasticity induction approaches combined with functional imaging methods.

  8. A systematic review investigating the relationship between efficacy and stimulation parameters when using transcutaneous electrical nerve stimulation after knee arthroplasty

    Directory of Open Access Journals (Sweden)

    David Beckwée

    2014-06-01

    Full Text Available Objective: To evaluate the clinical efficacy of transcutaneous electric nerve stimulation in the treatment of postoperative knee arthroplasty pain and to relate these results to the stimulation parameters used. Data Sources: PubMed, Pedro and Web of Knowledge were systematically screened for studies investigating effects of transcutaneous electric nerve stimulation on postoperative knee arthroplasty pain. Review Methods: Studies were screened for their methodological and therapeutical quality. We appraised the influence of the stimulation settings used and indicated whether or not a neurophysiological and/or mechanistic rationale was given for these stimulation settings. Results: A total of 5 articles met the inclusion criteria. In total, 347 patients were investigated. The number of patients who received some form of transcutaneous electric nerve stimulation was 117, and 54 patients received sham transcutaneous electric nerve stimulation. Pain was the primary outcome in all studies. The stimulation settings used in the studies (n = 2 that reported significant effects differed from the others as they implemented a submaximal stimulation intensity. Stimulation parameters were heterogeneous, and only one study provided a rationale for them. Conclusion: This review reveals that an effect of transcutaneous electric nerve stimulation might have been missed due to low methodological and therapeutical quality. Justifying the choice of transcutaneous electric nerve stimulation parameters may improve therapeutical quality.

  9. Realistic Electric Field Mapping of Anisotropic Muscle During Electrical Stimulation Using a Combination of Water Diffusion Tensor and Electrical Conductivity.

    Science.gov (United States)

    Choi, Bup Kyung; Oh, Tong In; Sajib, Saurav Zk; Kim, Jin Woong; Kim, Hyung Joong; Kwon, Oh In; Woo, Eung Je

    2017-04-01

    To realistically map the electric fields of biological tissues using a diffusion tensor magnetic resonance electrical impedance tomography (DT-MREIT) method to estimate tissue response during electrical stimulation. Imaging experiments were performed using chunks of bovine muscle. Two silver wire electrodes were positioned inside the muscle tissue for electrical stimulation. Electric pulses were applied with a 100-V amplitude and 100-μs width using a voltage stimulator. During electrical stimulation, we collected DT-MREIT data from a 3T magnetic resonance imaging scanner. We adopted the projected current density method to calculate the electric field. Based on the relation between the water diffusion tensor and the conductivity tensor, we computed the position-dependent scale factor using the measured magnetic flux density data. Then, a final conductivity tensor map was reconstructed using the multiplication of the water diffusion tensor and the scale factor. The current density images from DT-MREIT data represent the internal current flows that exist not only in the electrodes but also in surrounding regions. The reconstructed electric filed map from our anisotropic conductivity tensor with the projected current density shows coverage that is more than 2 times as wide, and higher signals in both the electrodes and surrounding tissues, than the previous isotropic method owing to the consideration of tissue anisotropy. An electric field map obtained by an anisotropic reconstruction method showed different patterns from the results of the previous isotropic reconstruction method. Since accurate electric field mapping is important to correctly estimate the coverage of the electrical treatment, future studies should include more rigorous validations of the new method through in vivo and in situ experiments.

  10. The facilitation of motor actions by acoustic and electric stimulation.

    Science.gov (United States)

    Marinovic, Welber; Milford, Magdalene; Carroll, Timothy; Riek, Stephan

    2015-12-01

    The presentation of a loud acoustic stimulus during the preparation of motor actions can both speed movement initiation and increase response vigor. Several recent studies have explored this phenomenon as a means to investigate the mechanisms and neural correlates of movement preparation. Here, we sought to determine the generality of this effect across sensory modalities, and in particular whether unexpected somatosensory stimulation can facilitate movements in a manner similar to loud sounds. We show that electric and acoustic stimuli can be similarly effective in inducing the early release of motor actions, in both reaction time and anticipatory timing tasks. Consistent with recent response activation models of motor preparation, we also demonstrate that increasing the intensity of electric stimuli induces both progressive decreases in reaction time and increases in response vigor. Additionally, we show that the early release of motor actions can be induced by electric stimuli targeting predominantly either muscle afferents or skin afferents. Finally, we show that simultaneous acoustic and electric stimulation leads to earlier releases of anticipatory actions than either unimodal stimulus. These findings may lead to new avenues for experimental and clinical exploitation of the effects of accessory sensory information on movement preparation and initiation. © 2015 Society for Psychophysiological Research.

  11. High frequency pressure oscillator for microcryocoolers

    Science.gov (United States)

    Vanapalli, S.; ter Brake, H. J. M.; Jansen, H. V.; Zhao, Y.; Holland, H. J.; Burger, J. F.; Elwenspoek, M. C.

    2008-04-01

    Microminiature pulse tube cryocoolers should operate at a frequency of an order higher than the conventional macro ones because the pulse tube cryocooler operating frequency scales inversely with the square of the pulse tube diameter. In this paper, the design and experiments of a high frequency pressure oscillator is presented with the aim to power a micropulse tube cryocooler operating between 300 and 80K, delivering a cooling power of 10mW. Piezoelectric actuators operate efficiently at high frequencies and have high power density making them good candidates as drivers for high frequency pressure oscillator. The pressure oscillator described in this work consists of a membrane driven by a piezoelectric actuator. A pressure ratio of about 1.11 was achieved with a filling pressure of 2.5MPa and compression volume of about 22.6mm3 when operating the actuator with a peak-to-peak sinusoidal voltage of 100V at a frequency of 1kHz. The electrical power input was 2.73W. The high pressure ratio and low electrical input power at high frequencies would herald development of microminiature cryocoolers.

  12. The transcutaneous electrical nerve stimulation of variable frequency intensity has a longer-lasting analgesic action than the burst transcutaneous electrical nerve stimulation in cancer pain

    OpenAIRE

    Schleder, Juliana Carvalho; Verner, Fernanda Aparecida; Mauda, Loriane; Mazzo, Débora Melo; Fernandes, Luiz Cláudio

    2017-01-01

    ABSTRACT BACKGROUND AND OBJECTIVES: Pain is one of the most frequent symptoms in cancer, and physical therapy offers non-invasive methods such as the transcutaneous electrical nerve stimulation for the relief of symptoms. The objective of this study was to compare the effect of the burst transcutaneous electrical nerve stimulation with the transcutaneous electrical nerve stimulation with variable intensity frequency in cancer pain. METHODS: This study was conducted with 53 patients of the H...

  13. 10 kHz High-Frequency Spinal Cord Stimulation for Chronic Axial Low Back Pain in Patients With No History of Spinal Surgery: A Preliminary, Prospective, Open Label and Proof-of-Concept Study.

    Science.gov (United States)

    Al-Kaisy, Adnan; Palmisani, Stefano; Smith, Thomas E; Pang, David; Lam, Khai; Burgoyne, William; Houghton, Russell; Hudson, Emma; Lucas, Jonathan

    2017-01-01

    To explore the effectiveness of 10 kHz high frequency spinal cord stimulation (HF10 therapy) treatment of chronic low back pain in patients who have not had spinal surgery. Patients with chronic low back pain without prior spinal surgery were evaluated by a team of spine surgeons to rule out any spinal pathology amenable to surgical interventions and by a multidisciplinary pain team to confirm eligibility for the study. After a successful (>50% back pain reduction) trial of HF10 therapy, enrolled subjects underwent permanent system implantation and were followed-up one year post-implant. About 95% of the enrolled subjects (20/21) received the permanent system. At 12 months post-implant, both back pain VAS score and ODI were significantly reduced compared with baseline values (by 73% and 48%, respectively); an estimated quality-adjusted life year gain of 0.47 and a reduction in opioid use by 64% was observed. Four more patients among those unable to work at baseline due to back pain were employed at 12 months post-implant. There were no serious adverse events. HF10 therapy may provide significant back pain relief, reduction in disability, improvement quality of life, and reduction in opioid use in chronic low back pain not resulting from spinal surgery. © 2016 The Authors. Neuromodulation: Technology at the Neural Interface published by Wiley Periodicals, Inc. on behalf of International Neuromodulation Society.

  14. THE USE OF TRANSCUTANEOUS ELECTRICAL NERVE STIMULATION (TENS IN THE TREATMENT OF THE SPASTICITY - A REVIEW

    Directory of Open Access Journals (Sweden)

    Dahyan Wagner da Silva Silveira

    2008-01-01

    Full Text Available This study it has as objective to argue the job of TENS in the spasticity, observing the main parameters, form of application and the mechanism for which TENS it acts in the spasticity. One is about a bibliographical revision based in the literature specialized selected scientific articles through search in the data base of scielo and of bireme, from the sources Medline and Lilacs. The studies found on the job of TENS in the spasticity, had pointed mainly that this chain reduces the spasticity significantly, in lower degrees. The stimulation electrical parameters had disclosed that TENS it (about A utilização da estimulação elétrica nervosa transcutânea (tens... 100Hz of raised frequency provides one better effect in the reduction of the spasticity. The types of TENS more used had been the conventional and the soon-intense one, however some studies had not presented the used duration of pulse, limit the determination of one better modality of TENS. Few studies had explained the mechanism of performance of the current related one. The ones that had made it, had pointed the release of opioid endogenous (Dynorphins for the central nervous system as main mechanism of performance, however this contrasts with the neurophysiologic bases of the high-frequency stimulation, that demonstrated better resulted in the joined studies. Still it is necessary more studies on the job of this modality of stimulation electrical in the spasticity, since important parameters as duration of pulse, time of application, numbers of attendance and performance mechanism remains without scientific evidence.

  15. Electrical stimulation vs thermal effects in a complex electromagnetic environment.

    Science.gov (United States)

    Paniagua, Jesús M; Rufo, Montaña; Jiménez, Antonio; Antolín, Alicia; Sánchez, Miguel

    2009-08-01

    Studies linking exposure to low levels of radiofrequencies with adverse health effects, notwithstanding their present apparent inconsistency, have contributed to a steady improvement in the quality of evaluating that exposure. In complex electromagnetic environments, with a multitude of emissions of different frequencies acting simultaneously, knowledge of the spectral content is fundamental to evaluating human exposure to non-ionizing radiation. In the present work, we quantify the most significant spectral components in the frequency band 0.5-2200 MHz in an urban area. The measurements were made with a spectrum analyzer and monopole, biconical, and log-periodic antennas. Power density levels were calculated separately for the medium wave, short wave, and frequency modulation radio broadcasting bands, and for the television and GSM, DCS, and UMTS mobile telephony bands. The measured levels were compared with the ICNIRP reference levels for exposure to multiple frequency sources for thermal effects and electrical stimulation. The results showed the criterion limiting exposure on the basis of preventing electrical stimulation of peripheral nerves and muscles to be stricter (exposure quotient 24.7 10(-4)) than that based on thermal considerations (exposure quotient 0.16 10(-4)). The bands that contribute most to the latter are short wave, with 46.2%, and mobile telephony with 32.6% of the total exposure. In a complex electromagnetic environment, knowledge of the radiofrequency spectrum is essential in order to quantify the contribution of each type of emission to the public's exposure. It is also necessary to evaluate the electrical effects as well as the thermal effects because the criterion to limit exposure on the basis of the effect of the electrical stimulation of tissues is stricter than that based on thermal effects.

  16. Electrical stimulation vs thermal effects in a complex electromagnetic environment

    Energy Technology Data Exchange (ETDEWEB)

    Paniagua, Jesus M., E-mail: paniagua@unex.es [Department of Applied Physics, Polytechnic School, University of Extremadura. Avda. de la Universidad s/n, 10071 Caceres (Spain); Rufo, Montana; Jimenez, Antonio; Antolin, Alicia; Sanchez, Miguel [Department of Applied Physics, Polytechnic School, University of Extremadura. Avda. de la Universidad s/n, 10071 Caceres (Spain)

    2009-08-01

    Studies linking exposure to low levels of radiofrequencies with adverse health effects, notwithstanding their present apparent inconsistency, have contributed to a steady improvement in the quality of evaluating that exposure. In complex electromagnetic environments, with a multitude of emissions of different frequencies acting simultaneously, knowledge of the spectral content is fundamental to evaluating human exposure to non-ionizing radiation. In the present work, we quantify the most significant spectral components in the frequency band 0.5-2200 MHz in an urban area. The measurements were made with a spectrum analyzer and monopole, biconical, and log-periodic antennas. Power density levels were calculated separately for the medium wave, short wave, and frequency modulation radio broadcasting bands, and for the television and GSM, DCS, and UMTS mobile telephony bands. The measured levels were compared with the ICNIRP reference levels for exposure to multiple frequency sources for thermal effects and electrical stimulation. The results showed the criterion limiting exposure on the basis of preventing electrical stimulation of peripheral nerves and muscles to be stricter (exposure quotient 24.7 10{sup -4}) than that based on thermal considerations (exposure quotient 0.16 10{sup -4}). The bands that contribute most to the latter are short wave, with 46.2%, and mobile telephony with 32.6% of the total exposure. In a complex electromagnetic environment, knowledge of the radiofrequency spectrum is essential in order to quantify the contribution of each type of emission to the public's exposure. It is also necessary to evaluate the electrical effects as well as the thermal effects because the criterion to limit exposure on the basis of the effect of the electrical stimulation of tissues is stricter than that based on thermal effects.

  17. Achieving High-Frequency Optical Control of Synaptic Transmission

    Science.gov (United States)

    Jackman, Skyler L.; Beneduce, Brandon M.; Drew, Iain R.

    2014-01-01

    The optogenetic tool channelrhodopsin-2 (ChR2) is widely used to excite neurons to study neural circuits. Previous optogenetic studies of synapses suggest that light-evoked synaptic responses often exhibit artificial synaptic depression, which has been attributed to either the inability of ChR2 to reliably fire presynaptic axons or to ChR2 elevating the probability of release by depolarizing presynaptic boutons. Here, we compare light-evoked and electrically evoked synaptic responses for high-frequency stimulation at three synapses in the mouse brain. At synapses from Purkinje cells to deep cerebellar nuclei neurons (PC→DCN), light- and electrically evoked synaptic currents were remarkably similar for ChR2 expressed transgenically or with adeno-associated virus (AAV) expression vectors. For hippocampal CA3→CA1 synapses, AAV expression vectors of serotype 1, 5, and 8 led to light-evoked synaptic currents that depressed much more than electrically evoked currents, even though ChR2 could fire axons reliably at up to 50 Hz. The disparity between optical and electrical stimulation was eliminated when ChR2 was expressed transgenically or with AAV9. For cerebellar granule cell to stellate cell (grc→SC) synapses, AAV1 also led to artificial synaptic depression and AAV9 provided superior performance. Artificial synaptic depression also occurred when stimulating over presynaptic boutons, rather than axons, at CA3→CA1 synapses, but not at PC→DCN synapses. These findings indicate that ChR2 expression methods and light stimulation techniques influence synaptic responses in a neuron-specific manner. They also identify pitfalls associated with using ChR2 to study synapses and suggest an approach that allows optogenetics to be applied in a manner that helps to avoid potential complications. PMID:24872574

  18. Achieving high-frequency optical control of synaptic transmission.

    Science.gov (United States)

    Jackman, Skyler L; Beneduce, Brandon M; Drew, Iain R; Regehr, Wade G

    2014-05-28

    The optogenetic tool channelrhodopsin-2 (ChR2) is widely used to excite neurons to study neural circuits. Previous optogenetic studies of synapses suggest that light-evoked synaptic responses often exhibit artificial synaptic depression, which has been attributed to either the inability of ChR2 to reliably fire presynaptic axons or to ChR2 elevating the probability of release by depolarizing presynaptic boutons. Here, we compare light-evoked and electrically evoked synaptic responses for high-frequency stimulation at three synapses in the mouse brain. At synapses from Purkinje cells to deep cerebellar nuclei neurons (PC→DCN), light- and electrically evoked synaptic currents were remarkably similar for ChR2 expressed transgenically or with adeno-associated virus (AAV) expression vectors. For hippocampal CA3→CA1 synapses, AAV expression vectors of serotype 1, 5, and 8 led to light-evoked synaptic currents that depressed much more than electrically evoked currents, even though ChR2 could fire axons reliably at up to 50 Hz. The disparity between optical and electrical stimulation was eliminated when ChR2 was expressed transgenically or with AAV9. For cerebellar granule cell to stellate cell (grc→SC) synapses, AAV1 also led to artificial synaptic depression and AAV9 provided superior performance. Artificial synaptic depression also occurred when stimulating over presynaptic boutons, rather than axons, at CA3→CA1 synapses, but not at PC→DCN synapses. These findings indicate that ChR2 expression methods and light stimulation techniques influence synaptic responses in a neuron-specific manner. They also identify pitfalls associated with using ChR2 to study synapses and suggest an approach that allows optogenetics to be applied in a manner that helps to avoid potential complications. Copyright © 2014 the authors 0270-6474/14/347704-11$15.00/0.

  19. Effect of Intermittent Low-Frequency Electrical Stimulation on the Rat Gastrocnemius Muscle

    Directory of Open Access Journals (Sweden)

    Arata Tsutaki

    2013-01-01

    Full Text Available Low-frequency neuromuscular electrical stimulation (NMES has been used as an endurance exercise model. This study aimed to test whether low-frequency NMES increases the phosphorylation of anabolic signaling molecules and induces skeletal muscle hypertrophy, as seen with high-frequency NMES. Using Sprague-Dawley rats, 1 bout of exercise (with dissection done immediately (Post0 and 3 h (Post3 after exercise and another 6 sessions of training were performed. All experimental groups consisted of high- and low-frequency stimulation (HFS: 100 Hz; LFS: 10 Hz. Periodic acid-Schiff (PAS staining was conducted to investigate type II fiber activation, and western blot analysis (WB was conducted to examine whether NMES leads to anabolic intracellular signaling. At first, we examined the acute effect of exercise. PAS staining revealed that glycogen depletion occurred in both type I and type II fibers. WB results demonstrated that p70S6K phosphorylation was significantly increased by HFS, but there was no significant difference with LFS. In contrast, ERK 1/2 phosphorylation was increased by LFS at Post0. In the 6-session training, the wet weight and myofibrillar protein were significantly increased by both HFS and LFS. In conclusion, LFS has a similar anabolic effect for skeletal muscle hypertrophy as HFS, but the mediating signaling pathway might differ.

  20. Geographies of High Frequency Trading

    DEFF Research Database (Denmark)

    Grindsted, Thomas Skou

    2016-01-01

    This paper investigates the geographies of high frequency trading. Today shares shift hands within micro seconds, giving rise to a form of financial geographies termed algorithmic capitalism. This notion refers to the different spatio-temporalities produced by high frequency trading, under...... the valuation of time. As high frequency trading accelerates financial markets, the paper examines the spatio-temporalities of automated trading by the ways in which the speed of knowledge exploitation in financial markets is not only of interest, but also the expansion between different temporalities....... The paper demonstrates how the intensification of time-space compression produces radical new dynamics in the financial market and develops information rent in HFT as convertible to a time rent and a spatio-temporal rent. The final section discusses whether high frequency trading only responds to crises...

  1. Perceptual embodiment of prosthetic limbs by transcutaneous electrical nerve stimulation.

    Science.gov (United States)

    Mulvey, Matthew R; Fawkner, Helen J; Radford, Helen E; Johnson, Mark I

    2012-01-01

      In able-bodied participants, it is possible to induce a sense of perceptual embodiment in an artificial hand using a visual-tactile illusion. In amputee patients, electrical stimulation of sensory afferents using transcutaneous electrical nerve stimulation (TENS) has been shown to generate somatic sensations in an amputee's phantom limb(s). However, the effects of TENS on the perceptual embodiment of an artificial limb are not known. Our objective was to investigate the effects of TENS on the perceptual embodiment of an artificial limb in fully intact able-bodied participants.   We used a modified version of the rubber hand illusion presented to 30 able-bodied participants (16 women, 14 men) to convey TENS paresthesia to an artificial hand. TENS electrodes were located over superficial radial nerve on the lateral aspect of the right forearm (1 cm proximal to the wrist), which was hidden from view. TENS intensity was increased to a strong non-painful TENS sensation (electrical paresthesia) was felt beneath the electrodes and projecting into the fingers of the hand. The electrical characteristics of TENS were asymmetric biphasic electrical pulsed waves, continuous pulse pattern, 120 Hz pulse frequency (rate), and 80 µs pulse duration (width).   Participants reported significantly higher intensities of the rubber hand illusion during the two TENS conditions (mean = 5.8, standard deviation = 1.9) compared with the two non-TENS conditions (mean = 4.9, standard deviation = 1.7), p limb, and this can enhance the sense of perceptual embodiment of an artificial hand. Further exploratory studies involving an amputee population are warranted. © 2011 International Neuromodulation Society.

  2. Generation of Electrical Power from Stimulated Muscle Contractions Evaluated

    Science.gov (United States)

    Lewandowski, Beth; Kilgore, Kevin; Ercegovic, David B.

    2004-01-01

    This project is a collaborative effort between NASA Glenn Research Center's Revolutionary Aeropropulsion Concepts (RAC) Project, part of the NASA Aerospace Propulsion and Power Program of the Aerospace Technology Enterprise, and Case Western Reserve University's Cleveland Functional Electrical Stimulation (FES) Center. The RAC Project foresees implantable power requirements for future applications such as organically based sensor platforms and robotics that can interface with the human senses. One of the goals of the FES Center is to develop a totally implantable neural prosthesis. This goal is based on feedback from patients who would prefer a system with an internal power source over the currently used system with an external power source. The conversion system under investigation would transform the energy produced from a stimulated muscle contraction into electrical energy. We hypothesize that the output power of the system will be greater than the input power necessary to initiate, sustain, and control the electrical conversion system because of the stored potential energy of the muscle. If the system can be made biocompatible, durable, and with the potential for sustained use, then the biological power source will be a viable solution.

  3. The positive effects of high-frequency right dorsolateral prefrontal cortex repetitive transcranial magnetic stimulation on memory, correlated with increases in brain metabolites detected by proton magnetic resonance spectroscopy in recently detoxified alcohol-dependent patients

    Directory of Open Access Journals (Sweden)

    Qiao J

    2016-09-01

    Full Text Available Jun Qiao,1,2 Guixing Jin,1,2 Licun Lei,3 Lan Wang,1,2 Yaqiang Du,3 Xueyi Wang1,2 1Institute of Mental Health, The First Hospital of Hebei Medical University, 2Brain Ageing and Cognitive Neuroscience Laboratory, Hebei Medical University, 3Department of Radiology, The First Hospital of Hebei Medical University, Hebei, People’s Republic of China Objective: To explore the effect of right dorsolateral prefrontal cortex (DLPFC repetitive transcranial magnetic stimulation (rTMS on memory, and its correlation with levels of hippocampal brain metabolites detected by proton magnetic resonance spectroscopy (1H-MRS in recently detoxified alcohol-dependent patients. Materials and methods: In this randomized, double-blind sham-controlled trial, alcohol-dependent patients were enrolled and randomized into two groups: the experimental group (rTMS, 10 Hz, on right DLPFC, 20 sessions and the control group (sham stimulation. Memory function was assessed using Hopkins Verbal Learning Test-Revised (HVLT-R and Brief Visuospatial Memory Test-Revised (BVMT-R before and after treatment. 1H-MRS was used to detect the levels of N-acetyl aspartic acid (NAA, choline (Cho, and creatine (Cr in bilateral hippocampi before and after treatment. Results: Thirty-eight patients (18 in the experimental group and 20 in the control group were included in the analyses. The experimental group showed significantly greater changes in HVLT-R, BVMT-R, NAA/Cr, and Cho/Cr after rTMS from baseline than the control group. The percentage change in BVMT-R and HVLT-R correlated with the percentage change in NAA/Cr and Cho/Cr in the right brain. Conclusion: High-frequency right DLPFC rTMS was associated with improvement in memory dysfunction, which is correlated with levels of hippocampal brain metabolites detected by 1H-MRS in recently detoxified alcohol-dependent patients. Keywords: alcohol dependence, memory, repetitive transcranial magnetic stimulation, MR spectroscopy

  4. [Mechanisms and applications of transcutaneous electrical nerve stimulation in analgesia].

    Science.gov (United States)

    Tang, Zheng-Yu; Wang, Hui-Quan; Xia, Xiao-Lei; Tang, Yi; Peng, Wei-Wei; Hu, Li

    2017-06-25

    Transcutaneous electrical nerve stimulation (TENS), as a non-pharmacological and non-invasive analgesic therapy with low-cost, has been widely used to relieve pain in various clinical applications, by delivering current pulses to the skin area to activate the peripheral nerve fibers. Nevertheless, analgesia induced by TENS varied in the clinical practice, which could be caused by the fact that TENS with different stimulus parameters has different biological mechanisms in relieving pain. Therefore, to advance our understanding of TENS in various basic and clinical studies, we discussed (1) neurophysiological and biochemical mechanisms of TENS-induced analgesia; (2) relevant factors that may influence analgesic effects of TENS from the perspectives of stimulus parameters, including stimulated position, pulse parameters (current intensity, frequency, and pulse width), stimulus duration and used times in each day; and (3) applications of TENS in relieving clinical pain, including post-operative pain, chronic low back pain and labor pain. Finally, we propose that TENS may involve multiple and complex psychological neurophysiological mechanisms, and suggest that different analgesic effects of TENS with different stimulus parameters should be taken into consideration in clinical applications. In addition, to optimize analgesic effect, we recommend that individual-based TENS stimulation parameters should be designed by considering individual differences among patients, e.g., adaptively adjusting the stimulation parameters based on the dynamic ratings of patients' pain.

  5. Technical Rebuilding of Movement Function Using Functional Electrical Stimulation

    Science.gov (United States)

    Gföhler, Margit

    To rebuild lost movement functions, neuroprostheses based on functional electrical stimulation (FES) artificially activate skeletal muscles in corresponding sequences, using both residual body functions and artificial signals for control. Besides the functional gain, FES training also brings physiological and psychological benefits for spinal cord-injured subjects. In this chapter, current stimulation technology and the main components of FES-based neuroprostheses including enhanced control systems are presented. Technology and application of FES cycling and rowing, both approaches that enable spinal cord-injured subjects to participate in mainstream activities and improve their health and fitness by exercising like able-bodied subjects, are discussed in detail, and an overview of neuroprostheses that aim at restoring movement functions for daily life as walking or grasping is given.

  6. Designing electrical stimulated bioreactors for nerve tissue engineering

    Science.gov (United States)

    Sagita, Ignasius Dwi; Whulanza, Yudan; Dhelika, Radon; Nurhadi, Ibrahim

    2018-02-01

    Bioreactor provides a biomimetic ecosystem that is able to culture cells in a physically controlled system. In general, the controlled-parameters are temperature, pH, fluid flow, nutrition flow, etc. In this study, we develop a bioreactor that specifically targeted to culture neural stem cells. This bioreactor could overcome some limitations of conventional culture technology, such as petri dish, by providing specific range of observation area and a uniform treatment. Moreover, the microfluidic bioreactor, which is a small-controlled environment, is able to observe as small number of cells as possible. A perfusion flow is applied to mimic the physiological environment in human body. Additionally, this bioreactor also provides an electrical stimulation which is needed by neural stem cells. In conclusion, we found the correlation between the induced shear stress with geometric parameters of the bioreactor. Ultimately, this system shall be used to observe the interaction between stimulation and cell growth.

  7. Bio-robots automatic navigation with electrical reward stimulation.

    Science.gov (United States)

    Sun, Chao; Zhang, Xinlu; Zheng, Nenggan; Chen, Weidong; Zheng, Xiaoxiang

    2012-01-01

    Bio-robots that controlled by outer stimulation through brain computer interface (BCI) suffer from the dependence on realtime guidance of human operators. Current automatic navigation methods for bio-robots focus on the controlling rules to force animals to obey man-made commands, with animals' intelligence ignored. This paper proposes a new method to realize the automatic navigation for bio-robots with electrical micro-stimulation as real-time rewards. Due to the reward-seeking instinct and trial-and-error capability, bio-robot can be steered to keep walking along the right route with rewards and correct its direction spontaneously when rewards are deprived. In navigation experiments, rat-robots learn the controlling methods in short time. The results show that our method simplifies the controlling logic and realizes the automatic navigation for rat-robots successfully. Our work might have significant implication for the further development of bio-robots with hybrid intelligence.

  8. Photoacoustic microscopy of microvascular responses to cortical electrical stimulation

    Science.gov (United States)

    Tsytsarev, Vassiliy; Hu, Song; Yao, Junjie; Maslov, Konstantin; Barbour, Dennis L.; Wang, Lihong V.

    2011-07-01

    Advances in the functional imaging of cortical hemodynamics have greatly facilitated the understanding of neurovascular coupling. In this study, label-free optical-resolution photoacoustic microscopy (OR-PAM) was used to monitor microvascular responses to direct electrical stimulations of the mouse somatosensory cortex through a cranial opening. The responses appeared in two forms: vasoconstriction and vasodilatation. The transition between these two forms of response was observed in single vessels by varying the stimulation intensity. Marked correlation was found between the current-dependent responses of two daughter vessels bifurcating from the same parent vessel. Statistical analysis of twenty-seven vessels from three different animals further characterized the spatial-temporal features and the current dependence of the microvascular response. Our results demonstrate that OR-PAM is a valuable tool to study neurovascular coupling at the microscopic level.

  9. Preventing Ischial Pressure Ulcers: I. Review of Neuromuscular Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Hilton M. Kaplan

    2011-01-01

    Full Text Available Objective: Pressure ulcers (PUs are common and debilitating wounds that arise when immobilized patients cannot shift their weight. Treatment is expensive and recurrence rates are high. Pathophysiological mechanisms include reduced bulk and perfusion of chronically atrophic muscles as well as prolonged occlusion of blood flow to soft tissues from lack of voluntary postural shifting of body weight. This has suggested that PUs might be prevented by reanimating the paralyzed muscles using neuromuscular electrical stimulation (NMES. A review of the published literature over the past 2 decades is detailed.

  10. Gastric electrical stimulation: a report of two cases.

    LENUS (Irish Health Repository)

    Sibartie, V

    2012-02-03

    Gastroparesis refractory to prokinetic agents poses a major challenge to the physician and patient, alike. In the past 5 years, electrical methods to treat gastroparesis have emerged from animal and human experiments to a potentially valuable tool in clinical gastroenterology. One of these methods, known as gastric electrical stimulation (GES), is being increasingly used in specialized centres worldwide, but had never been tried in Ireland. We describe here our experience with the first two implantations of gastric neurostimulators performed in Ireland and the outcome with these 2 patients. Our results at 6 months show reduction in symptoms and improvement in quality of life, which is encouraging and should prompt further evaluation of GES for patients with gastroparesis refractory to medical therapy.

  11. Transcutaneous electric nerve stimulation (TENS) in dentistry- A review.

    Science.gov (United States)

    Kasat, Vikrant; Gupta, Aditi; Ladda, Ruchi; Kathariya, Mitesh; Saluja, Harish; Farooqui, Anjum-Ara

    2014-12-01

    Transcutaneous electric nerve stimulation (TENS) is a non-pharmacological method which is widely used by medical and paramedical professionals for the management of acute and chronic pain in a variety of conditions. Similarly, it can be utilized for the management of pain during various dental procedures as well as pain due to various conditions affecting maxillofacial region. This review aims to provide an insight into clinical research evidence available for the analgesic and non analgesic uses of TENS in pediatric as well as adult patients related to the field of dentistry. Also, an attempt is made to briefly discuss history of therapeutic electricity, mechanism of action of TENS, components of TENs equipment, types, techniques of administration, advantages and contradictions of TENS. With this we hope to raise awareness among dental fraternity regarding its dental applications thereby increasing its use in dentistry. Key words:Dentistry, pain, TENS.

  12. Neuromuscular Fatigue After Repeated Jumping With Concomitant Electrical Stimulation.

    Science.gov (United States)

    Neyroud, Daria; Samararatne, Jimmy; Kayser, Bengt; Place, Nicolas

    2017-12-18

    To evaluate the etiology and extent of neuromuscular fatigue induced by 50 squat jumps performed with and without neuromuscular electrical stimulation (NMES) of the knee extensors. Nine healthy, recreationally active men (24 ± 2 y) took part in 2 experiments. These consisted of 50 squat jumps performed with stimulation (NMES) or without (CON). Maximal voluntary contraction (MVC) force, maximal voluntary activation level (VAL), and forces evoked by single and double (10 and 100 Hz) stimulations were recorded before and after the 50 jumps. NMES was delivered at the maximal tolerated intensity. Despite average jump height being ∼16% lower in the NMES than in the CON session, a reduction over time in jump height was only found in the NMES condition (-6%). After the 50 jumps, MVC force was reduced to a greater extent in NMES than in CON (-25% ± 11% vs -11% ± 12%). Similarly, forces evoked by single stimulations, as well as by 10-Hz and 100-Hz paired stimulations, were reduced to a greater extent in NMES (-33% ± 12%, -42% ± 15%, and -25% ± 13%) than in CON (-21% ± 6%, -30% ± 9%, and -14% ± 11%). VAL was not significantly altered by either condition. Performing repeated squat jumps with concomitant NMES induced a greater fatigue than squat jumps performed alone and might potentially represent a stronger training stimulus.

  13. [Efficacy observation of dysphagia after acute stroke treated with acupuncture and functional electric stimulation].

    Science.gov (United States)

    Chang, Ling; He, Peng-Lan; Zhou, Zhen-Zhong; Li, Yan-Hua

    2014-08-01

    To observe the impacts on the recovery of swallowing function in patients of dysphagia after acute stroke treated with acupuncture and functional electric stimulation. Seventy-four patients were randomized into an acupuncture plus electric stimulation group (38 cases) and an electric stimulation group (36 cases). The functional electric stimulator was used in the two groups. The electric pads were placed on the hyoid bone, the upper part of thyroid cartilage, the masseter muscle and the mandibular joint. The treatment lasted for 30 mm each time. In the acupuncture plus electric stimulation group, acupuncture was supplemented at motor area of Jiao's scalp acupuncture, lower 2/5 of sensory area, Baihui (CV 20), Lianquan (CV 23), Jinjin (EX-HN 12) and Yuye (EX-HN 13), 30 mm each time. The treatment was given once a day, 6 treatments for one session and there was 1 day at interval between the sessions, 4 sessions were required totally in the two groups. The dysphagia scale was adopted for efficacy evaluation before treatment and after 4 sessions of treatment in the two groups. The removal rate of nasal feeding tube was observed after treatment. The dysphagia score was increased apparently after treatment compared with that before treatment in the two groups (both P electric stimulation group, the dysphagia score was increased much more apparently than that in the electric stimulation group (8.01 +/- 1.25 vs 6.73 +/- 1.36, P electric stimulation group, better than 58.3% (21/36) in the electric stimulation group (P electric stimulation group, which was higher than 50. 0% (18/36) in the electric stimulation group (P electric stimulation achieves the much better efficacy on dysphagia after acute stroke and promotes the early removal of nasal feeding tube. The efficacy is better than that of the simple electric stimulation therapy.

  14. Comparison of electrode sites in electrical stimulation of the cochlea.

    Science.gov (United States)

    Lusted, H S; Shelton, C; Simmons, F B

    1984-07-01

    There is considerable controversy about the "best" location for single channel cochlear implant electrodes. We measured the electrically induced auditory brain stem response (EABR) in a series of normal to totally denervated cat ears in response to promontory (P), round window (RW) and scala tympani (ST) stimulation. The status of the ganglion cell population was then assessed by light microscopy. In ears with light to medium ganglion cell loss the ST EABR yielded the most definitive input-output functions. RW responses were present at increased thresholds and smaller peak amplitudes. P responses were worse or even missing completely. In severely damaged ears, including some with no detectable ganglion cells, ST and RW EABRs were both markedly reduced with considerable overlap between the two sites. P responses, when present, were almost buried in the electrical noise near threshold. Extrapolating these results to humans suggests that when ganglion cell loss is very severe the RW or ST is an acceptable stimulation site. When ganglion cell loss is moderate or better, ST electrodes are superior.

  15. BCI-Triggered functional electrical stimulation therapy for upper limb

    Directory of Open Access Journals (Sweden)

    Cesar Marquez-Chin

    2016-08-01

    Full Text Available We present here the integration of brain-computer interfacing (BCI technology with functional electrical stimulation therapy to restore voluntary function. The system was tested with a single man with chronic (6 years severe left hemiplegia resulting from a stroke. The BCI, implemented as a simple “brain-switch” activated by power decreases in the 18 Hz – 28 Hz frequency range of the participant’s electroencephalograpic signals, triggered a neuroprosthesis designed to facilitate forward reaching, reaching to the mouth, and lateral reaching movements. After 40 90-minute sessions in which the participant attempted the reaching tasks repeatedly, with the movements assisted by the BCI-triggered neuroprosthesis, the participant’s arm function showed a clinically significant six point increase in the Fugl-Meyer Asessment Upper Extermity Sub-Score. These initial results suggest that the combined use of BCI and functional electrical stimulation therapy may restore voluntary reaching function in individuals with chronic severe hemiplegia for whom the rehabilitation alternatives are very limited.

  16. Sex and Electrode Configuration in Transcranial Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Michael J. Russell

    2017-08-01

    Full Text Available Transcranial electrical stimulation (tES can be an effective non-invasive neuromodulation procedure. Unfortunately, the considerable variation in reported treatment outcomes, both within and between studies, has made the procedure unreliable for many applications. To determine if individual differences in cranium morphology and tissue conductivity can account for some of this variation, the electrical density at two cortical locations (temporal and frontal directly under scalp electrodes was modeled using a validated MRI modeling procedure in 23 subjects (12 males and 11 females. Three different electrode configurations (non-cephalic, bi-cranial, and ring commonly used in tES were modeled at three current intensities (0.5, 1.0, and 2.0 mA. The aims were to assess the effects of configuration and current intensity on relative current received at a cortical brain target directly under the stimulating electrode and to characterize individual variation. The different electrode configurations resulted in up to a ninefold difference in mean current densities delivered to the brains. The ring configuration delivered the least current and the non-cephalic the most. Female subjects showed much less current to the brain than male subjects. Individual differences in the current received and differences in electrode configurations may account for significant variability in current delivered and, thus, potentially a significant portion of reported variation in clinical outcomes at two commonly targeted regions of the brain.

  17. BCI-Triggered Functional Electrical Stimulation Therapy for Upper Limb

    Science.gov (United States)

    Marquez-Chin, Cesar; Marquis, Aaron; Popovic, Milos R.

    2016-01-01

    We present here the integration of brain-computer interfacing (BCI) technology with functional electrical stimulation therapy to restore voluntary function. The system was tested with a single man with chronic (6 years) severe left hemiplegia resulting from a stroke. The BCI, implemented as a simple “brain-switch” activated by power decreases in the 18 Hz – 28 Hz frequency range of the participant’s electroencephalograpic signals, triggered a neuroprosthesis designed to facilitate forward reaching, reaching to the mouth, and lateral reaching movements. After 40 90-minute sessions in which the participant attempted the reaching tasks repeatedly, with the movements assisted by the BCI-triggered neuroprosthesis, the participant’s arm function showed a clinically significant six point increase in the Fugl-Meyer Asessment Upper Extermity Sub-Score. These initial results suggest that the combined use of BCI and functional electrical stimulation therapy may restore voluntary reaching function in individuals with chronic severe hemiplegia for whom the rehabilitation alternatives are very limited. PMID:27990247

  18. Spatiotemporal structure of intracranial electric fields induced by transcranial electric stimulation in humans and nonhuman primates

    DEFF Research Database (Denmark)

    Opitz, Alexander; Falchier, Arnaud; Yan, Chao-Gan

    2016-01-01

    Transcranial electric stimulation (TES) is an emerging technique, developed to non-invasively modulate brain function. However, the spatiotemporal distribution of the intracranial electric fields induced by TES remains poorly understood. In particular, it is unclear how much current actually...... reaches the brain, and how it distributes across the brain. Lack of this basic information precludes a firm mechanistic understanding of TES effects. In this study we directly measure the spatial and temporal characteristics of the electric field generated by TES using stereotactic EEG (s-EEG) electrode...... arrays implanted in cebus monkeys and surgical epilepsy patients. We found a small frequency dependent decrease (10%) in magnitudes of TES induced potentials and negligible phase shifts over space. Electric field strengths were strongest in superficial brain regions with maximum values of about 0.5 m...

  19. Anatomically based lower limb nerve model for electrical stimulation

    Directory of Open Access Journals (Sweden)

    Soboleva Tanya K

    2007-12-01

    Full Text Available Abstract Background Functional Electrical Stimulation (FES is a technique that aims to rehabilitate or restore functionality of skeletal muscles using external electrical stimulation. Despite the success achieved within the field of FES, there are still a number of questions that remain unanswered. One way of providing input to the answers is through the use of computational models. Methods This paper describes the development of an anatomically based computer model of the motor neurons in the lower limb of the human leg and shows how it can be used to simulate electrical signal propagation from the beginning of the sciatic nerve to a skeletal muscle. One-dimensional cubic Hermite finite elements were used to represent the major portions of the lower limb nerves. These elements were fit to data that had been digitised using images from the Visible Man project. Nerves smaller than approximately 1 mm could not be seen in the images, and thus a tree-branching algorithm was used to connect the ends of the fitted nerve model to the respective skeletal muscle. To simulate electrical propagation, a previously published mammalian nerve model was implemented and solved on the anatomically based nerve mesh using a finite difference method. The grid points for the finite difference method were derived from the fitted finite element mesh. By adjusting the tree-branching algorithm, it is possible to represent different levels of motor-unit recruitment. Results To illustrate the process of a propagating nerve stimulus to a muscle in detail, the above method was applied to the nerve tree that connects to the human semitendinosus muscle. A conduction velocity of 89.8 m/s was obtained for a 15 μm diameter nerve fibre. This signal was successfully propagated down the motor neurons to a selected group of motor units in the muscle. Conclusion An anatomically and physiologically based model of the posterior motor neurons in the human lower limb was developed. This

  20. Transcutaneous electrical nerve stimulation for spasticity: A systematic review.

    Science.gov (United States)

    Fernández-Tenorio, E; Serrano-Muñoz, D; Avendaño-Coy, J; Gómez-Soriano, J

    2016-07-26

    Although transcutaneous electrical nerve stimulation (TENS) has traditionally been used to treat pain, some studies have observed decreased spasticity after use of this technique. However, its use in clinical practice is still limited. Our purpose was twofold: to determine whether TENS is effective for treating spasticity or associated symptoms in patients with neurological involvement, and to determine which stimulation parameters exert the greatest effect on variables associated with spasticity. Two independent reviewers used PubMed, PEDro, and Cochrane databases to search for randomised clinical trials addressing TENS and spasticity published before 12 May 2015, and selected the articles that met the inclusion criteria. Of the initial 96 articles, 86 were excluded. The remaining 10 articles present results from 207 patients with a cerebrovascular accident, 84 with multiple sclerosis, and 39 with spinal cord lesions. In light of our results, we recommend TENS as a treatment for spasticity due to its low cost, ease of use, and absence of adverse reactions. However, the great variability in the types of stimulation used in the studies, and the differences in parameters and variables, make it difficult to assess and compare any results that might objectively determine the effectiveness of this technique and show how to optimise parameters. Copyright © 2016 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. High-frequency matrix converter with square wave input

    Science.gov (United States)

    Carr, Joseph Alexander; Balda, Juan Carlos

    2015-03-31

    A device for producing an alternating current output voltage from a high-frequency, square-wave input voltage comprising, high-frequency, square-wave input a matrix converter and a control system. The matrix converter comprises a plurality of electrical switches. The high-frequency input and the matrix converter are electrically connected to each other. The control system is connected to each switch of the matrix converter. The control system is electrically connected to the input of the matrix converter. The control system is configured to operate each electrical switch of the matrix converter converting a high-frequency, square-wave input voltage across the first input port of the matrix converter and the second input port of the matrix converter to an alternating current output voltage at the output of the matrix converter.

  2. High-frequency Trader Subjectivity

    DEFF Research Database (Denmark)

    Borch, Christian; Lange, Ann-Christina

    2017-01-01

    In this article, we examine the recent shift in financial markets toward high-frequency trading (HFT). This turn is being legitimized with reference to how algorithms are allegedly more rational and efficient than human traders, and less prone to emotionally motivated decisions. We argue......-techniques of the ideal high-frequency trader. We demonstrate that these traders face the challenge of avoiding emotional interference in their algorithms and that they deploy a set of disciplinary self-techniques to curb the importance of emotional attachment....

  3. Electrical nerve stimulation to promote micturition in spinal cord injury patients: A review of current attempts.

    Science.gov (United States)

    Ren, Jian; Chew, Daniel J; Biers, Suzanne; Thiruchelvam, Nikesh

    2016-03-01

    In this review, we focus on the current attempts of electrical nerve stimulation for micturition in spinal cord injury (SCI) patients. A literature search was performed through PubMed using "spinal cord injury," "electrical nerve stimulation AND bladder," "sacral anterior root stimulation/stimulator" and "Brindley stimulator" from January 1975 to January 2014. Twenty studies were selected for this review. Electrical nerve stimulation is a clinical option for promoting micturition in SCI patients. Well-designed, randomized and controlled studies are essential for further investigation. © 2015 Wiley Periodicals, Inc.

  4. Electrical stimulation: a novel tool for tissue engineering.

    Science.gov (United States)

    Balint, Richard; Cassidy, Nigel J; Cartmell, Sarah H

    2013-02-01

    New advances in tissue engineering are being made through the application of different types of electrical stimuli to influence cell proliferation and differentiation. Developments made in the last decade have allowed us to improve the structure and functionality of tissue-engineered products through the use of growth factors, hormones, drugs, physical stimuli, bioreactor use, and two-dimensional (2-D) and three-dimensional (3-D) artificial extracellular matrices (with various material properties and topography). Another potential type of stimulus is electricity, which is important in the physiology and development of the majority of all human tissues. Despite its great potential, its role in tissue regeneration and its ability to influence cell migration, orientation, proliferation, and differentiation has rarely been considered in tissue engineering. This review highlights the importance of endogenous electrical stimulation, gathering the current knowledge on its natural occurrence and role in vivo, discussing the novel methods of delivering this stimulus and examining its cellular and tissue level effects, while evaluating how the technique could benefit the tissue engineering discipline in the future.

  5. Comparison of electrical nerve stimulation, electrical muscle stimulation and magnetic nerve stimulation to assess the neuromuscular function of the plantar flexor muscles.

    Science.gov (United States)

    Neyroud, Daria; Temesi, John; Millet, Guillaume Y; Verges, Samuel; Maffiuletti, Nicola A; Kayser, Bengt; Place, Nicolas

    2015-07-01

    As it might lead to less discomfort, magnetic nerve stimulation (MNS) is increasingly used as an alternative to electrical stimulation methods. Yet, MNS and electrical nerve stimulation (ENS) and electrical muscle stimulation (EMS) have not been formally compared for the evaluation of plantar flexor neuromuscular function. We quantified plantar flexor neuromuscular function with ENS, EMS and MNS in 10 volunteers in fresh and fatigued muscles. Central alterations were assessed through changes in voluntary activation level (VAL) and peripheral function through changes in M-wave, twitch and doublet (PS100) amplitudes. Discomfort associated with 100-Hz paired stimuli delivered with each method was evaluated on a 10-cm visual analog scale. VAL, agonist and antagonist M-wave amplitudes and PS100 were similar between the different methods in both fresh and fatigued states. Potentiated peak twitch was lower in EMS compared to ENS, whereas no difference was found between ENS and MNS for any parameter. Discomfort associated with MNS (1.5 ± 1.4 cm) was significantly less compared to ENS (5.5 ± 1.9 cm) and EMS (4.2 ± 2.6 cm) (p evaluate neuromuscular properties, MNS, EMS and ENS can be used interchangeably for plantar flexor neuromuscular function assessment as they provide similar evaluation of central and peripheral factors in unfatigued and fatigued states. Importantly, electrical current spread to antagonist muscles was similar between the three methods while discomfort from MNS was much less compared to ENS and EMS. MNS may be potentially employed to assess neuromuscular function of plantar flexor muscles in fragile populations.

  6. Development of Functional Electrical Stimulation Rowing: The Rowstim Series.

    Science.gov (United States)

    Andrews, Brian; Gibbons, Robin; Wheeler, Garry

    2017-11-01

    Potentially, functional electrical stimulation (FES)-assisted exercise may have an important therapeutic role in reducing comorbidities associated with spinal cord injury (SCI). Here, we present an overview of these secondary life-threatening conditions, discuss the rationale behind the development of a hybrid exercise called FES rowing, and describe our experience in developing FES rowing technology. FES rowing and sculling are unique forms of adaptive rowing for those with SCI. The paralyzed leg musculature is activated by multiple channels of electrical pulses delivered via self-adhesive electrodes attached to the skin. The stimulated muscle contractions are synchronized with voluntary rowing movements of the upper limbs. A range of steady-state FES rowing exercise intensities have been demonstrated from 15.2 ± 1.8 mL/kg/min in tetraplegia to 22.9 ±7.1 mL/kg/min in paraplegia. We expect that such high levels may help some to achieve significant reductions in the risks to their health, particularly where a dose-response relationship exists as is the case for cardiovascular disease and Type II diabetes. Furthermore, preliminary results suggest that cyclical forces more than 1.5 times body weight are imposed on the leg long bones which may help to reduce the risk of fragility fractures. We have demonstrated the feasibility of FES rowing on land and water using adapted rowing technology that includes; a fixed stretcher indoor ergometer (adapted Concept 2, Model E), a floating stretcher indoor ergometer (adapted Concept 2 Dynamic), a turbine powered water rowing tank, a custom hydraulic sculling simulator and a single scull (adapted Alden 16). This has involved volunteers with paraplegia and tetraplegia with SCI ranging from C4 to T12 AIS A using at least 4-channels of surface electrical stimulation. FES rowers, with SCI, have competed alongside non-SCI rowers over the Olympic distance of 2000 m at the British Indoor Rowing Championships in 2004, 2005, and 2006

  7. Electric Field Model of Transcranial Electric Stimulation in Nonhuman Primates: Correspondence to Individual Motor Threshold.

    Science.gov (United States)

    Lee, Won Hee; Lisanby, Sarah H; Laine, Andrew F; Peterchev, Angel V

    2015-09-01

    To develop a pipeline for realistic head models of nonhuman primates (NHPs) for simulations of noninvasive brain stimulation, and use these models together with empirical threshold measurements to demonstrate that the models capture individual anatomical variability. Based on structural MRI data, we created models of the electric field (E-field) induced by right unilateral (RUL) electroconvulsive therapy (ECT) in four rhesus macaques. Individual motor threshold (MT) was measured with transcranial electric stimulation (TES) administered through the RUL electrodes in the same subjects. The interindividual anatomical differences resulted in 57% variation in median E-field strength in the brain at fixed stimulus current amplitude. Individualization of the stimulus current by MT reduced the E-field variation in the target motor area by 27%. There was significant correlation between the measured MT and the ratio of simulated electrode current and E-field strength (r(2) = 0.95, p = 0.026). Exploratory analysis revealed significant correlations of this ratio with anatomical parameters including of the superior electrode-to-cortex distance, vertex-to-cortex distance, and brain volume (r(2) > 0.96, p field models appropriately capture individual anatomical variability relevant to the dosing of TES/ECT. These findings are exploratory due to the small number of subjects. This study can contribute insight in NHP studies of ECT and other brain stimulation interventions, help link the results to clinical studies, and ultimately lead to more rational brain stimulation dosing paradigms.

  8. Iterative learning control for electrical stimulation and stroke rehabilitation

    CERN Document Server

    Freeman, Chris T; Burridge, Jane H; Hughes, Ann-Marie; Meadmore, Katie L

    2015-01-01

    Iterative learning control (ILC) has its origins in the control of processes that perform a task repetitively with a view to improving accuracy from trial to trial by using information from previous executions of the task. This brief shows how a classic application of this technique – trajectory following in robots – can be extended to neurological rehabilitation after stroke. Regaining upper limb movement is an important step in a return to independence after stroke, but the prognosis for such recovery has remained poor. Rehabilitation robotics provides the opportunity for repetitive task-oriented movement practice reflecting the importance of such intense practice demonstrated by conventional therapeutic research and motor learning theory. Until now this technique has not allowed feedback from one practice repetition to influence the next, also implicated as an important factor in therapy. The authors demonstrate how ILC can be used to adjust external functional electrical stimulation of patients’ mus...

  9. Pharyngeal Electrical Stimulation for Treatment of Dysphagia in Subacute Stroke

    DEFF Research Database (Denmark)

    Bath, Philip M W; Scutt, Polly; Love, Jo

    2016-01-01

    BACKGROUND AND PURPOSE: Dysphagia is common after stroke, associated with increased death and dependency, and treatment options are limited. Pharyngeal electric stimulation (PES) is a novel treatment for poststroke dysphagia that has shown promise in 3 pilot randomized controlled trials. METHODS......: We randomly assigned 162 patients with a recent ischemic or hemorrhagic stroke and dysphagia, defined as a penetration aspiration score (PAS) of ≥3 on video fluoroscopy, to PES or sham treatment given on 3 consecutive days. The primary outcome was swallowing safety, assessed using the PAS, at 2 weeks....... Secondary outcomes included dysphagia severity, function, quality of life, and serious adverse events at 6 and 12 weeks. RESULTS: In randomized patients, the mean age was 74 years, male 58%, ischemic stroke 89%, and PAS 4.8. The mean treatment current was 14.8 (7.9) mA and duration 9.9 (1.2) minutes per...

  10. Role of Functional Electrical Stimulation in Tetraplegia Hand Surgery.

    Science.gov (United States)

    Bersch, Ines; Fridén, Jan

    2016-06-01

    The use of functional electrical stimulation (FES) to improve upper limb function is an established method in the rehabilitation of persons with tetraplegia after spinal cord injury. Surgical reconstruction is another well-established yet underused technique to improve the performance of the upper extremities. Hand surgery plays an essential role in restoring hand function, mobility, and quality of life in the tetraplegic population. The knowledge about the effects of FES on a structural and functional level is fundamental for understanding how and when FES can be used best to support the effect of hand surgery, both pre- and postoperatively. In this article we discuss principles of FES and how FES improves functional outcome after surgical reconstruction. The reported results are based on preliminary clinical observations. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  11. Deqi Sensations of Transcutaneous Electrical Nerve Stimulation on Auricular Points

    Directory of Open Access Journals (Sweden)

    Xiaoling Wang

    2013-01-01

    Full Text Available Deqi sensation, a psychophysical response characterized by a spectrum of different needling sensations, is essential for Chinese acupuncture clinical efficacy. Previous research works have investigated the component of Deqi response upon acupuncture on acupoints on the trunk and limbs. However, the characteristics of Deqi sensations of transcutaneous electrical nerve stimulation (TENS on auricular points are seldom reported. In this study, we investigated the individual components of Deqi during TENS on auricular concha area and the superior scapha using quantitative measurements in the healthy subjects and depression patients. The most striking characteristics of Deqi sensations upon TENS on auricular points were tingling, numbness, and fullness. The frequencies of pressure, warmness, heaviness, and soreness were relatively lower. The dull pain and coolness are rare. The characteristics of Deqi were similar for the TENS on concha and on the superior scapha.

  12. Functional electrical stimulation improves brain perfusion in cranial trauma patients

    Directory of Open Access Journals (Sweden)

    Bárbara Juarez Amorim

    2011-08-01

    Full Text Available OBJECTIVE: Demonstrate brain perfusion changes due to neuronal activation after functional electrical stimulation (FES. METHOD: It was studied 14 patients with hemiplegia who were submitted to a program with FES during fourteen weeks. Brain perfusion SPECT was performed before and after FES therapy. These patients were further separated into 2 groups according to the hemiplegia cause: cranial trauma and major vascular insults. All SPECT images were analyzed using SPM. RESULTS: There was a significant statistical difference between the two groups related to patient's ages and extent of hypoperfusion in the SPECT. Patients with cranial trauma had a reduction in the hypoperfused area and patients with major vascular insult had an increase in the hypoperfused area after FES therapy. CONCLUSION: FES therapy can result in brain perfusion improvement in patients with brain lesions due to cranial trauma but probably not in patients with major vascular insults with large infarct area.

  13. Blockade of NMDA receptors prevents analgesic tolerance to repeated transcutaneous electrical nerve stimulation (TENS) in rats

    Science.gov (United States)

    Hingne, Priyanka M.; Sluka, Kathleen A.

    2008-01-01

    Repeated daily application transcutaneous electrical nerve stimulation (TENS) results in tolerance, at spinal opioid receptors, to the anti-hyperalgesia produced by TENS. Since N-Methyl-D-Aspartate (NMDA) receptor antagonists prevent analgesic tolerance to opioid agonists we hypothesized that blockade of NMDA receptors will prevent tolerance to TENS. In rats with knee joint inflammation, TENS was applied for 20 minute daily at high frequency (100 Hz), low frequency (4 Hz), or sham TENS. Rats were treated with the NMDA antagonist MK-801 (0.01 mg/kg-0.1 mg/kg) or vehicle daily before TENS. Paw withdrawal thresholds were tested before and after inflammation, and before and after TENS treatment for 4 days. On day 1 TENS reversed the decreased mechanical withdrawal threshold induced by joint inflammation. On day 4 TENS had no effect on the decreased withdrawal threshold in the group treated with vehicle demonstrating development of tolerance. However, in the group treated with 0.1 mg/kg MK-801, TENS significantly reversed the mechanical withdrawal thresholds on day 4 demonstrating that tolerance did not develop. Vehicle treated animals developed cross-tolerance at spinal opioid receptors. Treatment with MK-801 reversed this cross-tolerance at spinal opioid receptors. In summary, blockade of NMDA receptors prevents analgesic tolerance to daily TENS by preventing tolerance at spinal opioid receptors. Perspective Tolerance observed to the clinical treatment of TENS could be prevented by administration of pharmaceutical agents with NMDA receptors activity such as ketamine or dextromethorphan. PMID:18061543

  14. Tinnitus Treatment with Precise and Optimal Electric Stimulation: Opportunities and Challenges

    OpenAIRE

    Zeng, FG; Djalilian, H; Lin, H.

    2015-01-01

    © 2015 Wolters Kluwer Health, Inc. All rights reserved. PURPOSE OF REVIEW: Electric stimulation is a potent means of neuromodulation that has been used to restore hearing and minimize tremor, but its application on tinnitus symptoms has been limited. We examine recent evidence to identify the knowledge gaps in the use of electric stimulation for tinnitus treatment. RECENT FINDINGS: Recent studies using electric stimulation to suppress tinnitus in humans are categorized according to their poin...

  15. Biophysical Model of Cortical Network Activity and the Influence of Electrical Stimulation

    Science.gov (United States)

    2015-11-13

    SECURITY CLASSIFICATION OF: We examined the effects of subdural electrical stimulation on a high-density network consisting of several populations of...multicompartment cell types. The results can be summarized as follows: 1) Electrical stimulation mainly affects and activates axon initial and the most...of Electrical Stimulation . The views, opinions and/or findings contained in this report are those of the author(s) and should not contrued as an

  16. Subthalamic nucleus electrical stimulation modulates calcium activity of nigral astrocytes.

    Directory of Open Access Journals (Sweden)

    Elodie Barat

    Full Text Available BACKGROUND: The substantia nigra pars reticulata (SNr is a major output nucleus of the basal ganglia, delivering inhibitory efferents to the relay nuclei of the thalamus. Pathological hyperactivity of SNr neurons is known to be responsible for some motor disorders e.g. in Parkinson's disease. One way to restore this pathological activity is to electrically stimulate one of the SNr input, the excitatory subthalamic nucleus (STN, which has emerged as an effective treatment for parkinsonian patients. The neuronal network and signal processing of the basal ganglia are well known but, paradoxically, the role of astrocytes in the regulation of SNr activity has never been studied. PRINCIPAL FINDINGS: In this work, we developed a rat brain slice model to study the influence of spontaneous and induced excitability of afferent nuclei on SNr astrocytes calcium activity. Astrocytes represent the main cellular population in the SNr and display spontaneous calcium activities in basal conditions. Half of this activity is autonomous (i.e. independent of synaptic activity while the other half is dependent on spontaneous glutamate and GABA release, probably controlled by the pace-maker activity of the pallido-nigral and subthalamo-nigral loops. Modification of the activity of the loops by STN electrical stimulation disrupted this astrocytic calcium excitability through an increase of glutamate and GABA releases. Astrocytic AMPA, mGlu and GABA(A receptors were involved in this effect. SIGNIFICANCE: Astrocytes are now viewed as active components of neural networks but their role depends on the brain structure concerned. In the SNr, evoked activity prevails and autonomous calcium activity is lower than in the cortex or hippocampus. Our data therefore reflect a specific role of SNr astrocytes in sensing the STN-GPe-SNr loops activity and suggest that SNr astrocytes could potentially feedback on SNr neuronal activity. These findings have major implications given the

  17. Chronic stress decreases cerebrovascular responses during rat hindlimb electrical stimulation

    Directory of Open Access Journals (Sweden)

    Sohee eLee

    2015-12-01

    Full Text Available Repeated stress is one of the major risk factors for cerebrovascular disease, including stroke and vascular dementia. However, the functional alterations in the cerebral hemodynamic response induced by chronic stress have not been clarified. Here, we investigated the in vivo cerebral hemodynamic changes and accompanying cellular and molecular changes in chronically stressed rats. After three weeks of restraint stress, the elicitation of stress was verified by behavioral despair in the forced swimming test and by physical indicators of stress. The evoked changes in the cerebral blood volume and pial artery responses following hindpaw electrical stimulation were measured using optical intrinsic signal imaging. We observed that, compared to the control group, animals under chronic restraint stress exhibited a decreased hemodynamic response, with a smaller pial arterial dilation in the somatosensory cortex during hindpaw electrical stimulation. The effect of chronic restraint stress on vasomodulator enzymes, including neuronal nitric oxide synthase (nNOS and heme oxygenase-2 (HO-2, was assessed in the somatosensory cortex. Chronic restraint stress downregulated nNOS and HO-2 compared to the control group. In addition, we examined the subtypes of cells that can explain the environmental changes due to the decreased vasomodulators. The expression of parvalbumin in GABAergic interneurons and glutamate receptor-1 in neurons were decreased, whereas the microglial activation was increased. Our results suggest that the chronic stress-induced alterations in cerebral vascular function and the modulations of the cellular expression in the neuro-vasomodulatory system may be crucial contributing factors in the development of various vascular-induced conditions in the brain.

  18. Frequency-dependent reduction of voltage-gated sodium current modulates retinal ganglion cell response rate to electrical stimulation

    Science.gov (United States)

    Tsai, David; Morley, John W.; Suaning, Gregg J.; Lovell, Nigel H.

    2011-10-01

    The ability to elicit visual percepts through electrical stimulation of the retina has prompted numerous investigations examining the feasibility of restoring sight to the blind with retinal implants. The therapeutic efficacy of these devices will be strongly influenced by their ability to elicit neural responses that approximate those of normal vision. Retinal ganglion cells (RGCs) can fire spikes at frequencies greater than 200 Hz when driven by light. However, several studies using isolated retinas have found a decline in RGC spiking response rate when these cells were stimulated at greater than 50 Hz. It is possible that the mechanism responsible for this decline also contributes to the frequency-dependent 'fading' of electrically evoked percepts recently reported in human patients. Using whole-cell patch clamp recordings of rabbit RGCs, we investigated the causes for the spiking response depression during direct subretinal stimulation of these cells at 50-200 Hz. The response depression was not caused by inhibition arising from the retinal network but, instead, by a stimulus-frequency-dependent decline of RGC voltage-gated sodium current. Under identical experimental conditions, however, RGCs were able to spike at high frequency when driven by light stimuli and intracellular depolarization. Based on these observations, we demonstrated a technique to prevent the spiking response depression.

  19. Transcutaneous electrical spinal-cord stimulation in humans

    Science.gov (United States)

    Gerasimenko, Yury; Gorodnichev, Ruslan; Moshonkina, Tatiana; Sayenko, Dimitry; Gad, Parag; Edgerton, V. Reggie

    2016-01-01

    Locomotor behavior is controlled by specific neural circuits called central pattern generators primarily located at the lumbosacral spinal cord. These locomotor-related neuronal circuits have a high level of automaticity; that is, they can produce a “stepping” movement pattern also seen on electromyography (EMG) in the absence of supraspinal and/or peripheral afferent inputs. These circuits can be modulated by epidural spinal-cord stimulation and/or pharmacological intervention. Such interventions have been used to neuromodulate the neuronal circuits in patients with motor-complete spinal-cord injury (SCI) to facilitate postural and locomotor adjustments and to regain voluntary motor control. Here, we describe a novel non-invasive stimulation strategy of painless transcutaneous electrical enabling motor control (pcEmc) to neuromodulate the physiological state of the spinal cord. The technique can facilitate a stepping performance in non-injured subjects with legs placed in a gravity-neutral position. The stepping movements were induced more effectively with multi-site than single-site spinal-cord stimulation. From these results, a multielectrode surface array technology was developed. Our preliminary data indicate that use of the multielectrode surface array can fine-tune the control of the locomotor behavior. As well, the pcEmc strategy combined with exoskeleton technology is effective for improving motor function in paralyzed patients with SCI. The potential impact of using pcEmc to neuromodulate the spinal circuitry has significant implications for furthering our understanding of the mechanisms controlling locomotion and for rehabilitating sensorimotor function even after severe SCI. PMID:26205686

  20. Transcutaneous electrical spinal-cord stimulation in humans.

    Science.gov (United States)

    Gerasimenko, Yury; Gorodnichev, Ruslan; Moshonkina, Tatiana; Sayenko, Dimitry; Gad, Parag; Reggie Edgerton, V

    2015-09-01

    Locomotor behavior is controlled by specific neural circuits called central pattern generators primarily located at the lumbosacral spinal cord. These locomotor-related neuronal circuits have a high level of automaticity; that is, they can produce a "stepping" movement pattern also seen on electromyography (EMG) in the absence of supraspinal and/or peripheral afferent inputs. These circuits can be modulated by epidural spinal-cord stimulation and/or pharmacological intervention. Such interventions have been used to neuromodulate the neuronal circuits in patients with motor-complete spinal-cord injury (SCI) to facilitate postural and locomotor adjustments and to regain voluntary motor control. Here, we describe a novel non-invasive stimulation strategy of painless transcutaneous electrical enabling motor control (pcEmc) to neuromodulate the physiological state of the spinal cord. The technique can facilitate a stepping performance in non-injured subjects with legs placed in a gravity-neutral position. The stepping movements were induced more effectively with multi-site than single-site spinal-cord stimulation. From these results, a multielectrode surface array technology was developed. Our preliminary data indicate that use of the multielectrode surface array can fine-tune the control of the locomotor behavior. As well, the pcEmc strategy combined with exoskeleton technology is effective for improving motor function in paralyzed patients with SCI. The potential impact of using pcEmc to neuromodulate the spinal circuitry has significant implications for furthering our understanding of the mechanisms controlling locomotion and for rehabilitating sensorimotor function even after severe SCI. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  1. The value of electrical stimulation as an exercise training modality

    Science.gov (United States)

    Currier, Dean P.; Ray, J. Michael; Nyland, John; Noteboom, Tim

    1994-01-01

    Voluntary exercise is the traditional way of improving performance of the human body in both the healthy and unhealthy states. Physiological responses to voluntary exercise are well documented. It benefits the functions of bone, joints, connective tissue, and muscle. In recent years, research has shown that neuromuscular electrical stimulation (NMES) simulates voluntary exercise in many ways. Generically, NMES can perform three major functions: suppression of pain, improve healing of soft tissues, and produce muscle contractions. Low frequency NMES may gate or disrupt the sensory input to the central nervous system which results in masking or control of pain. At the same time NMES may contribute to the activation of endorphins, serotonin, vasoactive intestinal polypeptides, and ACTH which control pain and may even cause improved athletic performances. Soft tissue conditions such as wounds and inflammations have responded very favorably to NMES. NMES of various amplitudes can induce muscle contractions ranging from weak to intense levels. NMES seems to have made its greatest gains in rehabilitation where directed muscle contractions may improve joint ranges of motion correct joint contractures that result from shortening muscles; control abnormal movements through facilitating recruitment or excitation into the alpha motoneuron in orthopedically, neurologically, or healthy subjects with intense sensory, kinesthetic, and proprioceptive information; provide a conservative approach to management of spasticity in neurological patients; by stimulation of the antagonist muscle to a spastic muscle stimulation of the agonist muscle, and sensory habituation; serve as an orthotic substitute to conventional bracing used with stroke patients in lieu of dorsiflexor muscles in preventing step page gait and for shoulder muscles to maintain glenohumeral alignment to prevent subluxation; and of course NMES is used in maintaining or improving the performance or torque producing

  2. Decreased central fatigue in multiple sclerosis patients after 8 weeks of surface functional electrical stimulation

    National Research Council Canada - National Science Library

    Chang, Ya-Ju; Hsu, Miao-Ju; Chen, Shin-Man; Lin, Cheng-Hsiang; Wong, Alice M K

    2011-01-01

    .... Surface functional electrical stimulation (FES), which can challenge the peripheral neuromuscular system without overloading the central nervous system, is a relatively safe therapeutic strategy...

  3. Maximizing muscle force via low-cadence functional electrical stimulation cycling

    National Research Council Canada - National Science Library

    Fornusek, Ché; Davis, Glen M

    2004-01-01

    This study investigated the effect of pedal cadence upon torque production, power output and muscle fatigue rates during functional electrical stimulation evoked cycling in spinal cord injured individuals...

  4. Effect of transcutaneous electrical nerve stimulation induced parotid stimulation on salivary flow

    Directory of Open Access Journals (Sweden)

    Sreenivasulu Pattipati

    2013-01-01

    Full Text Available Aims and Objectives: The main objective of this study was to evaluate the duration of stimulation over the parotid salivary flow following the use of transcutaneous electric nerve stimulation (TENS in different age groups. Materials and Methods: The study was carried out in three different age groups. Under group A individuals from 21 to 35 years of age, group B 36-50 years and group C above 51 years were considered. In each group 30 subjects were taken of whom 15 were males and 15 were females. The placement of pads was approximated bilaterally over the parotid glands. The working parameters of TENS unit were fixed at 50 Hz and the unit was in normal mode. Results: Subjects belonging to group B were showing statistically significant increases in the duration of stimulated parotid salivary flow following the use of TENS. Conclusion: TENS can be considered as a non-pharmacological alternative to improve salivation for longer period in xerostomia patients.

  5. High-Frequency Seafloor Acoustics

    CERN Document Server

    Jackson, Darrell R

    2007-01-01

    High-Frequency Seafloor Acoustics is the first book in a new series sponsored by the Office of Naval Research on the latest research in underwater acoustics. This exciting new title provides ready access to experimental data, theory, and models relevant to high-frequency seafloor acoustics and will be of interest to sonar engineers and researchers working in underwater acoustics. The physical characteristics of the seafloor affecting acoustic propagation and scattering are covered, including physical and geoacoustic properties and surface roughness. Current theories for acoustic propagation in sediments are presented along with corresponding models for reflection, scattering, and seafloor penetration. The main text is backed up by an extensive bibliography and technical appendices.

  6. Control of Microstructures and the Practical Properties of API X80 Grade Heavy-Wall High-Frequency Electric Resistance-Welded Pipe with Excellent Low-Temperature Toughness

    Science.gov (United States)

    Goto, Sota; Nakata, Hiroshi; Toyoda, Shunsuke; Okabe, Takatoshi; Inoue, Tomohiro

    2017-10-01

    This paper describes development of heavy-walled API X80 grade high-frequency electric resistance-welded (HFW) line pipes and conductor-casing pipes with wall thicknesses up to 20.6 mm. A fine bainitic-ferrite microstructure, which is preferable for low-temperature toughness, was obtained by optimizing the carbon content and applying the thermomechanical controlled hot-rolling process. As a result, the Charpy ductile-brittle transition temperature (DBTT) was well below 227 K (-46 °C) in the base metal of the HFW line pipe. When the controlled hot-rolling ratio (CR) was increased from 23 to 48 pct, the area average grain size decreased from 15 to 8 μm. The dependence of CTOD properties on CR was caused by the largest grain which is represented by the area average grain size. No texture development due to the increase of CR from 23 to 48 pct was observed. In addition, because controlled in-line heat treatment of the longitudinal weld seam also produced the fine bainitic-ferrite microstructure at the weld seam, DBTT was lower than 227 K (-46 °C) at the weld portion. The developed pipes showed good girth weldability without preheat treatment, and fracture in the tensile test initiated from the base metal in all cases.

  7. General public and workers exposure to high-frequency electric fields in Spanish hospitals Exposición de trabajadores y usuarios a campos eléctricos de alta frecuencia en hospitales españoles

    Directory of Open Access Journals (Sweden)

    Alberto Caldés Casas

    2013-03-01

    Full Text Available Introduction: Electromagnetic fields (EMF are commonly used in hospitals to detect and treat certain diseases or ailments, exposing healthcare workers daily to such fields and casting doubts about workers and patients safety. Objectives: To quantify the actual exposure to high-frequency electric fields of workers and public hospitals users in the Balearic Islands (Spain and the compliance with the references levels established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP. Material and Methods: High-frequency radiation exposure levels were measured in different areas and compared with ICNIRP levels and Spanish regulation, using a broadband field strength meter and a spectrum analyzer. Results: 1,290 measurements were performed obtaining a median electric field of 0.31 V/m (1st quartile: 0.16 V/m; 3rd quartile: 0.67 V/m. Users and workers are exposed to electric fields from 0.19 V/m to 0.25 V/m in all areas, but Rehabilitation and Radiology. In the former, the patients (not under microwave therapy are exposed to EMF between 1.87 V/m and 25.71 V/m. Discussion and conclusions: Although effective electric field values are lower than the reference levels, measures should be taken to reduce exposure of especially sensitive people (infants, children, pregnant women,... and ensure regular monitoring of the exposure.Introducción: Los campos electromagnéticos (CEM se utilizan con frecuencia en los hospitales para detectar y tratar ciertas enfermedades o dolencias, exponiendo diariamente a los trabajadores sanitarios a esos campos y sembrando dudas sobre la seguridad de trabajadores y pacientes. Objetivos: Cuantificar la exposición real de trabajadores y usuarios de los hospitales públicos de las Islas Baleares (España a campos eléctricos de alta frecuencia y el cumplimiento de los niveles de referencia establecidos por la Comisión Internacional de Protección contra la Radiación No Ionizante (ICNIRP. Material y m

  8. Comparison of 10-kHz High-Frequency and Traditional Low-Frequency Spinal Cord Stimulation for the Treatment of Chronic Back and Leg Pain: 24-Month Results From a Multicenter, Randomized, Controlled Pivotal Trial.

    Science.gov (United States)

    Kapural, Leonardo; Yu, Cong; Doust, Matthew W; Gliner, Bradford E; Vallejo, Ricardo; Sitzman, B Todd; Amirdelfan, Kasra; Morgan, Donna M; Yearwood, Thomas L; Bundschu, Richard; Yang, Thomas; Benyamin, Ramsin; Burgher, Abram H

    2016-11-01

    Pain relief with spinal cord stimulation (SCS) has focused historically on paresthesias overlapping chronically painful areas. A higher level evidence supports the use of SCS in treating leg pain than supports back pain, as it is difficult to achieve adequate paresthesia coverage, and then pain relief, in the low back region. In comparison, 10-kHz high-frequency (HF10 therapy) SCS therapy does not rely on intraoperative paresthesia mapping and remains paresthesia-free during therapy. To compare long-term results of HF10 therapy and traditional low-frequency SCS. A pragmatic randomized, controlled, pivotal trial with 24-month follow-up was conducted across 11 comprehensive pain treatment centers. Subjects had Visual Analog Scale scores of ≥5.0/10.0 cm for both back and leg pain, and were assigned randomly (1:1) to receive HF10 therapy or low-frequency SCS. The primary end point was a responder rate, defined as ≥50% back pain reduction from baseline at 3 months with a secondary end point at 12 months (previously reported). In this article, 24-month secondary results are presented. Non-inferiority was first assessed, and if demonstrated the results were tested for superiority. In the study, 198 subjects were randomized (101 HF10 therapy, 97 traditional SCS). One hundred seventy-one subjects (90 HF10 therapy, 81 traditional SCS) successfully completed a short-term trial and were implanted. Subjects averaged 54.9 ± 12.9 years old, 13.6 ± 11.3 years since diagnosis, 86.6% had back surgery, 88.3% were taking opioid analgesics. At 3 months, 84.5% of implanted HF10 therapy subjects were responders for back pain and 83.1% for leg pain, and 43.8% of traditional SCS subjects were responders for back pain and 55.5% for leg pain (P back and leg pain comparisons, non-inferiority and superiority). At 24 months, more subjects were responders to HF10 therapy than traditional SCS (back pain: 76.5% vs 49.3%; 27.2% difference, 95% CI, 10.1%-41.8%; P pain: 72.9% vs 49.3%; 23

  9. Comparison of 10-kHz High-Frequency and Traditional Low-Frequency Spinal Cord Stimulation for the Treatment of Chronic Back and Leg Pain: 24-Month Results From a Multicenter, Randomized, Controlled Pivotal Trial

    Science.gov (United States)

    Yu, Cong; Doust, Matthew W.; Gliner, Bradford E.; Vallejo, Ricardo; Sitzman, B. Todd; Amirdelfan, Kasra; Morgan, Donna M.; Yearwood, Thomas L.; Bundschu, Richard; Yang, Thomas; Benyamin, Ramsin; Burgher, Abram H.

    2016-01-01

    BACKGROUND: Pain relief with spinal cord stimulation (SCS) has focused historically on paresthesias overlapping chronically painful areas. A higher level evidence supports the use of SCS in treating leg pain than supports back pain, as it is difficult to achieve adequate paresthesia coverage, and then pain relief, in the low back region. In comparison, 10-kHz high-frequency (HF10 therapy) SCS therapy does not rely on intraoperative paresthesia mapping and remains paresthesia-free during therapy. OBJECTIVE: To compare long-term results of HF10 therapy and traditional low-frequency SCS. METHODS: A pragmatic randomized, controlled, pivotal trial with 24-month follow-up was conducted across 11 comprehensive pain treatment centers. Subjects had Visual Analog Scale scores of ≥5.0/10.0 cm for both back and leg pain, and were assigned randomly (1:1) to receive HF10 therapy or low-frequency SCS. The primary end point was a responder rate, defined as ≥50% back pain reduction from baseline at 3 months with a secondary end point at 12 months (previously reported). In this article, 24-month secondary results are presented. Non-inferiority was first assessed, and if demonstrated the results were tested for superiority. RESULTS: In the study, 198 subjects were randomized (101 HF10 therapy, 97 traditional SCS). One hundred seventy-one subjects (90 HF10 therapy, 81 traditional SCS) successfully completed a short-term trial and were implanted. Subjects averaged 54.9 ± 12.9 years old, 13.6 ± 11.3 years since diagnosis, 86.6% had back surgery, 88.3% were taking opioid analgesics. At 3 months, 84.5% of implanted HF10 therapy subjects were responders for back pain and 83.1% for leg pain, and 43.8% of traditional SCS subjects were responders for back pain and 55.5% for leg pain (P back and leg pain comparisons, non-inferiority and superiority). At 24 months, more subjects were responders to HF10 therapy than traditional SCS (back pain: 76.5% vs 49.3%; 27.2% difference, 95% CI, 10

  10. [Transitory transesophageal atrial electric stimulation. Preliminary report on 19 cases and considerations on the method, indications and results (author's transl)].

    Science.gov (United States)

    Pistolese, M; Richichi, G; Catalano, V; Boccadamo, R

    1975-01-01

    Literature provides sufficient evidence that transitory electric stimulation via esophagus (SATE) - after the first positive experimental attempts on dogs - can be applied to man with a simple, rapid and harmless method. The study covers 19 patients subjected to high frequency transesophageal atrial stimulation by way of a bipolar electrode inserted through a nasogastric tube and connected to an external generator capable of producing tension impulses. Said impulses are variable up to 150 volts, lasting 2.5 microsec. with a frequency of up to 450/min. The 19 patients can be divided into 2 groups. The first including 15 patients on which SATE was effected for diagnostic purposes: in coronary deficiency (8 patients), in the disease of sinus node (3 patients), and lastly in the research for the A-V-block latent in 4 patients with acute post-infarctual A-V-block which regressed during the immediate clinical course of the illness. The other group includes 4 patients in which the atrial stimulation indication was the treatment of rapid, paroxysmic atrial rhythms, inaffected by drugs. By using impulses of 25-30 volts, the AA. have obtained a stable stimulation.

  11. Tenderness enhancement of beef from Bos indicus and Bos taurus cattle following electrical stimulation.

    Science.gov (United States)

    Gursansky, B; O'Halloran, J M; Egan, A; Devine, C E

    2010-11-01

    High voltage electrical stimulation (1130 V peak, 14.28 bidirectional half sinusoidal pulses/s) or low voltage stimulation (45 V peak, 36 alternating square wave pulses/s) was used on cattle: (1) low voltage stimulation applied for 10 or 40 s with fast and slow chilling or high voltage stimulation for 60 s with normal chilling, applied to 100% Bos taurus cattle, (2) low voltage stimulation (40 s) and high voltage stimulation (60 s) with normal chilling applied to mixed Bos indicus and B.taurus cattle, (3) high voltage stimulation (54 s) with normal chilling applied to B. taurus and B. indicus cattle of 0-100% B. indicus composition, and (4) high voltage stimulation (60 s) applied to 100% B. taurus and 100% B. indicus cattle. All stimulation parameters enhanced the tenderness of steaks from M. longissimus thoracis et lumborum (LTL) aged at 1°C up to 28 days compared with non stimulated LTL. Short low voltage stimulation of 10s was marginally more effective than no stimulation and longer durations of 40s were very effective and high voltage stimulation was most effective. The shear force values for non stimulated B. indicus LTL are much greater than for B. taurus, but following high voltage stimulation LTL of B. indicus were similar to B. taurus and all had lower shear force values than from non stimulated carcasses. Thus adequate electrical stimulation removes any toughness of LTL related to B. indicus genetic composition. Copyright © 2010. Published by Elsevier Ltd.

  12. High-frequency magnetic components

    CERN Document Server

    Kazimierczuk, Marian K

    2013-01-01

    A unique text on the theory and design fundaments of inductors and transformers, updated with more coverage on the optimization of magnetic devices and many new design examples The first edition is popular among a very broad audience of readers in different areas of engineering and science. This book covers the theory and design techniques of the major types of high-frequency power inductors and transformers for a variety of applications, including switching-mode power supplies (SMPS) and resonant dc-to-ac power inverters and dc-to-dc power converters. It describes eddy-current phenomena (su

  13. Electrical field stimulation promotes anastomotic healing in poorly perfused rat colon.

    LENUS (Irish Health Repository)

    Kennelly, Rory

    2011-03-01

    Hypoperfusion of the bowel is a risk factor for anastomotic failure. Electrical field stimulation has been shown to improve repair in ischemic tissue, but its influence in hypoperfused colon has not been investigated. The hypothesis of this experimental animal study was that electrical field stimulation improves anastomotic healing in ischemic bowel.

  14. Spasticity reduction using electrical stimulation in the lower limb of spinal cord injury patients

    NARCIS (Netherlands)

    van der Salm, Arjan

    2005-01-01

    The goal of this thesis was to investigate the influence of electrical stimulation on spasticity of leg muscles in spinal cord injury patients and its impact on gait. Both, the carry-over effect and the instant effect of electrical stimulation during gait were investigated.

  15. Electrical Stimulation Promotes Cardiac Differentiation of Human Induced Pluripotent Stem Cells

    Science.gov (United States)

    Hernández, Damián; Millard, Rodney; Sivakumaran, Priyadharshini; Wong, Raymond C. B.; Crombie, Duncan E.; Hewitt, Alex W.; Liang, Helena; Hung, Sandy S. C.; Pébay, Alice; Shepherd, Robert K.; Dusting, Gregory J.; Lim, Shiang Y.

    2016-01-01

    Background. Human induced pluripotent stem cells (iPSCs) are an attractive source of cardiomyocytes for cardiac repair and regeneration. In this study, we aim to determine whether acute electrical stimulation of human iPSCs can promote their differentiation to cardiomyocytes. Methods. Human iPSCs were differentiated to cardiac cells by forming embryoid bodies (EBs) for 5 days. EBs were then subjected to brief electrical stimulation and plated down for 14 days. Results. In iPS(Foreskin)-2 cell line, brief electrical stimulation at 65 mV/mm or 200 mV/mm for 5 min significantly increased the percentage of beating EBs present by day 14 after plating. Acute electrical stimulation also significantly increased the cardiac gene expression of ACTC1, TNNT2, MYH7, and MYL7. However, the cardiogenic effect of electrical stimulation was not reproducible in another iPS cell line, CERA007c6. Beating EBs from control and electrically stimulated groups expressed various cardiac-specific transcription factors and contractile muscle markers. Beating EBs were also shown to cycle calcium and were responsive to the chronotropic agents, isoproterenol and carbamylcholine, in a concentration-dependent manner. Conclusions. Our results demonstrate that brief electrical stimulation can promote cardiac differentiation of human iPS cells. The cardiogenic effect of brief electrical stimulation is dependent on the cell line used. PMID:26788064

  16. Electrical Stimulation Promotes Cardiac Differentiation of Human Induced Pluripotent Stem Cells

    Directory of Open Access Journals (Sweden)

    Damián Hernández

    2016-01-01

    Full Text Available Background. Human induced pluripotent stem cells (iPSCs are an attractive source of cardiomyocytes for cardiac repair and regeneration. In this study, we aim to determine whether acute electrical stimulation of human iPSCs can promote their differentiation to cardiomyocytes. Methods. Human iPSCs were differentiated to cardiac cells by forming embryoid bodies (EBs for 5 days. EBs were then subjected to brief electrical stimulation and plated down for 14 days. Results. In iPS(Foreskin-2 cell line, brief electrical stimulation at 65 mV/mm or 200 mV/mm for 5 min significantly increased the percentage of beating EBs present by day 14 after plating. Acute electrical stimulation also significantly increased the cardiac gene expression of ACTC1, TNNT2, MYH7, and MYL7. However, the cardiogenic effect of electrical stimulation was not reproducible in another iPS cell line, CERA007c6. Beating EBs from control and electrically stimulated groups expressed various cardiac-specific transcription factors and contractile muscle markers. Beating EBs were also shown to cycle calcium and were responsive to the chronotropic agents, isoproterenol and carbamylcholine, in a concentration-dependent manner. Conclusions. Our results demonstrate that brief electrical stimulation can promote cardiac differentiation of human iPS cells. The cardiogenic effect of brief electrical stimulation is dependent on the cell line used.

  17. 9 CFR 307.7 - Safety requirements for electrical stimulating (EST) equipment.

    Science.gov (United States)

    2010-01-01

    ... is surrounded by physical barriers, the enclosure shall be either electrically grounded or it shall... manual stimulation or before the carcass chain is started in an automatic system. (c) Operation— (1... personnel, the electricity supplied to the stimulating surfaces shall be locked-off when cleaning...

  18. Tinnitus treatment with precise and optimal electric stimulation: opportunities and challenges.

    Science.gov (United States)

    Zeng, Fan-Gang; Djalilian, Hamid; Lin, Harrison

    2015-10-01

    Electric stimulation is a potent means of neuromodulation that has been used to restore hearing and minimize tremor, but its application on tinnitus symptoms has been limited. We examine recent evidence to identify the knowledge gaps in the use of electric stimulation for tinnitus treatment. Recent studies using electric stimulation to suppress tinnitus in humans are categorized according to their points of attacks. First, noninvasive, direct current stimulation uses an active electrode in the ear canal, tympanic membrane, or temporal scalp. Second, inner ear stimulation uses charge-balanced biphasic stimulation by placing an active electrode on the promontory or round window, or a cochlear implant array in the cochlea. Third, intraneural implants can provide targeted stimulation of specific sites along the auditory pathway. Although these studies demonstrated some success in tinnitus suppression, none established a link between tinnitus suppression efficacy and tinnitus-generating mechanisms. Electric stimulation provides a unique opportunity to suppress tinnitus. Challenges include matching electric stimulation sites and patterns to tinnitus locus and type, meeting the oftentimes-contradictory demands between tinnitus suppression and other indications, such as speech understanding, and justifying the costs and risks of electric stimulation for tinnitus symptoms.

  19. Prolonged high frequency electrical stimulation is lethal to motor axons of mice heterozygously deficient for the myelin protein P0 gene

    DEFF Research Database (Denmark)

    Alvarez, Susana; Moldovan, Mihai; Krarup, Christian

    2013-01-01

    The relationship between dysmyelination and the progression of neuropathy in Charcot-Marie-Tooth (CMT) hereditary polyneuropathy is unclear. Mice heterozygously deficient for the myelin protein P₀ gene (P₀+/-) are indistinguishable from wild-type (WT) at birth and then develop a slowly progressing...... plantar muscles and the sciatic nerve, respectively. In 7-month old mice, there was recovery of CMAP and CNAP following RS. When mice were about one year old, electrophysiological recovery following RS was incomplete and in P₀+/- also associated with morphological signs of partial Wallerian degeneration...

  20. High-frequency complex pitch

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Dau, Torsten

    2012-01-01

    Harmonics in a complex tone are typically considered unresolved when they interact with neighboring harmonics in the cochlea and cannot be heard out separately. Recent studies have suggested that the low pitch evoked by unresolved high-frequency harmonics may be coded via temporal fine-structure ......Harmonics in a complex tone are typically considered unresolved when they interact with neighboring harmonics in the cochlea and cannot be heard out separately. Recent studies have suggested that the low pitch evoked by unresolved high-frequency harmonics may be coded via temporal fine......-structure cues. However, these conclusions rely on the assumptions that combination tones were properly masked and that the ability of listeners to hear out individual partials provides an adequate measure of resolvability. Those assumptions were tested by measuring the audibility of combination tones...... and their effects on pitch matches, the effects of relative component phases and of dichotic presentation, and listeners' ability to hear out individual partials. The results confirmed that combination tones affected pitch, but pitch remained salient when they were masked. The lack of dependence of pitch...

  1. Videoradiography at submental electrical stimulation during apnea in obstructive sleep apnea syndrome; A case report

    Energy Technology Data Exchange (ETDEWEB)

    Hillarp, B.; Rosen, I.; Wickstroem, O. (Malmoe Allmaenna Sjukhus (Sweden). Dept. of Diagnostic Radiology Malmoe Allmaenna Sjukhus (Sweden). Dept. of Clinical Neurophysiology)

    1991-05-01

    Percutaneous submental electrical stimulation during sleep may be a new therapeutic method for patients with obstructive sleep apnea syndrome (OSAS). Electrical stimulation to the submental region during obstructive apnea is reported to break the apnea without arousal and to diminish apneic index, time spent in apnea, and oxygen desaturation. The mode of breaking the apnea by electrical stimulation has not yet been shown. However, genioglossus is supposed to be the muscle responsible for breaking the apnea by forward movement of the tongue. To visualize the effect of submental electrical stimulation, one patient with severe OSAS has been examined with videoradiography. Submental electrical stimulation evoked an immediate complex muscle activity in the tongue, palate, and hyoid bone. This was followed by a forward movement of the tongue which consistently broke obstructive apnea without apparent arousal. Time spent in apnea was diminished but intervals between apnea were not affected. (orig.).

  2. Low voltage electrical stimulation of lamb carcasses: effects on meat quality.

    Science.gov (United States)

    Polidori, P; Lee, S; Kauffman, R G; Marsh, B B

    1999-11-01

    The effects of an early post mortem low voltage electrical stimulation (28 V, 60 Hz) on biochemical changes and on final tenderness in muscles Longissimus thoracis et lumborum and Semimembranosus from lamb carcasses were studied. It was shown that electrical stimulation accelerated the glycolytic process resulting in a significant fall in pH during the first 6 h post mortem in both muscles examined and in a significant reduction in adenosine triphosphate (ATP) content in muscle Longissimus thoracis et lumborum. The effect of electrical stimulation on tenderness was recorded by measuring shear force values 2 and 7 days post mortem. Tenderness was significantly improved by electrical stimulation for the Longissimus thoracis et lumborum both at 2 and at 7 days post mortem, while for Semimembranosus electrical stimulation significantly increased tenderness just at 7 days post mortem.

  3. Therapeutic Angiogenesis via Solar Cell-Facilitated Electrical Stimulation.

    Science.gov (United States)

    Jeong, Gun-Jae; Oh, Jin Young; Kim, Yeon-Ju; Bhang, Suk Ho; Jang, Hyeon-Ki; Han, Jin; Yoon, Jeong-Kee; Kwon, Sang-Mo; Lee, Tae Il; Kim, Byung-Soo

    2017-11-08

    Cell therapy has been suggested as a treatment modality for ischemic diseases, but the poor survival and engraftment of implanted cells limit its therapeutic efficacy. To overcome such limitation, we used electrical stimulation (ES) derived from a wearable solar cell for inducing angiogenesis in ischemic tissue. ES enhanced the secretion of angiogenic growth factors and the migration of mesenchymal stem cells (MSCs), myoblasts, endothelial progenitor cells, and endothelial cells in vitro. In a mouse ischemic hindlimb model, ES generated by a solar cell and applied to the ischemic region promoted migration of MSCs toward the ischemic site and upregulated expression of angiogenic paracrine factors (vascular endothelial, basic fibroblast, and hepatocyte growth factors; and stromal cell-derived factor-1α). Importantly, solar cell-generated ES promoted the formation of capillaries and arterioles at the ischemic region, attenuated muscle necrosis and fibrosis, and eventually prevented loss of the ischemic limb. Solar cell ES therapy showed higher angiogenic efficacy than conventional MSC therapy. This study shows the feasibility of using solar cell ES as a novel treatment for therapeutic angiogenesis.

  4. Functional electrical stimulation in spinal cord injury respiratory care.

    Science.gov (United States)

    Jarosz, Renata; Littlepage, Meagan M; Creasey, Graham; McKenna, Stephen L

    2012-01-01

    The management of chronic respiratory insufficiency and/or long-term inability to breathe independently has traditionally been via positive-pressure ventilation through a mechanical ventilator. Although life-sustaining, it is associated with limitations of function, lack of independence, decreased quality of life, sleep disturbance, and increased risk for infections. In addition, its mechanical and electronic complexity requires full understanding of the possible malfunctions by patients and caregivers. Ventilator-associated pneumonia, tracheal injury, and equipment malfunction account for common complications of prolonged ventilation, and respiratory infections are the most common cause of death in spinal cord-injured patients. The development of functional electric stimulation (FES) as an alternative to mechanical ventilation has been motivated by a goal to improve the quality of life of affected individuals. In this article, we will review the physiology, types, characteristics, risks and benefits, surgical techniques, and complications of the 2 commercially available FES strategies - phrenic nerve pacing (PNP) and diaphragm motor point pacing (DMPP).

  5. Models of brainstem responses to bilateral electrical stimulation.

    Science.gov (United States)

    Colburn, H Steven; Chung, Yoojin; Zhou, Yi; Brughera, Andrew

    2009-03-01

    A simple, biophysically specified cell model is used to predict responses of binaurally sensitive neurons to patterns of input spikes that represent stimulation by acoustic and electric waveforms. Specifically, the effects of changes in parameters of input spike trains on model responses to interaural time difference (ITD) were studied for low-frequency periodic stimuli, with or without amplitude modulation. Simulations were limited to purely excitatory, bilaterally driven cell models with basic ionic currents and multiple input fibers. Parameters explored include average firing rate, synchrony index, modulation frequency, and latency dispersion of the input trains as well as the excitatory conductance and time constant of individual synapses in the cell model. Results are compared to physiological recordings from the inferior colliculus (IC) and discussed in terms of ITD-discrimination abilities of listeners with cochlear implants. Several empirically observed aspects of ITD sensitivity were simulated without evoking complex neural processing. Specifically, our results show saturation effects in rate-ITD curves, the absence of sustained responses to high-rate unmodulated pulse trains, the renewal of sensitivity to ITD in high-rate trains when inputs are amplitude-modulated, and interactions between envelope and fine-structure delays for some modulation frequencies.

  6. Microcurrent electrical nerve stimulation facilitates regrowth of mouse soleus muscle.

    Science.gov (United States)

    Ohno, Yoshitaka; Fujiya, Hiroto; Goto, Ayumi; Nakamura, Ayane; Nishiura, Yuka; Sugiura, Takao; Ohira, Yoshinobu; Yoshioka, Toshitada; Goto, Katsumasa

    2013-01-01

    Microcurrent electrical nerve stimulation (MENS) has been used to facilitate recovery from skeletal muscle injury. However, the effects of MENS on unloading-associated atrophied skeletal muscle remain unclear. Effects of MENS on the regrowing process of unloading-associated atrophied skeletal muscle were investigated. Male C57BL/6J mice (10-week old) were randomly assigned to untreated normal recovery (C) and MENS-treated (M) groups. Mice of both groups are subjected to continuous hindlimb suspension (HS) for 2 weeks followed by 7 days of ambulation recovery. Mice in M group were treated with MENS for 60 min 1, 3, and 5 days following HS, respectively, under anesthesia. The intensity, the frequency, and the pulse width of MENS were set at 10 μA, 0.3 Hz, and 250 msec, respectively. Soleus muscles were dissected before and immediately after, 1, 3 and 7 days after HS. Soleus muscle wet weight and protein content were decreased by HS. The regrowth of atrophied soleus muscle in M group was faster than that in C group. Decrease in the reloading-induced necrosis of atrophied soleus was facilitated by MENS. Significant increases in phosphorylated levels of p70 S6 kinase and protein kinase B (Akt) in M group were observed, compared with C group. These observations are consistent with that MENS facilitated regrowth of atrophied soleus muscle. MENS may be a potential extracellular stimulus to activate the intracellular signals involved in protein synthesis.

  7. Transcutaneous electrical nerve stimulation therapy in reduction of orofacial pain

    Directory of Open Access Journals (Sweden)

    Đorđević Igor

    2014-01-01

    Full Text Available Introduction. Patients with craniomandibular disorders suffer from hypertonic, fatigued and painful masticatory muscles. This condition can lead to limitation of mandibular jaw movements. All of these symptoms and signs are included in myofascial pain dysfunction syndrome. Transcutaneous electrical nerve stimulation (TENS has been used for treatment of these patients. Objective. The aim of this study was to assess the effect of TENS therapy on chronic pain reduction in patients with the muscular dysfunction symptom. Methods. In order to evaluate the effect of TENS therapy before and after the treatment, Craniomandibular Index (Helkimo was used. Pain intensity was measured by VAS. Patients had TENS treatment over two-week period. BURST TENS modality was used. Current intensity was individually adjusted. Results. Two patients did not respond to TENS therapy. Complete pain reduction was recorded in 8 patients, while pain reduction was not significantly different after TENS therapy in 10 patients. Conclusion. TENS therapy was confirmed as therapeutic procedure in orofacial muscle relaxation and pain reduction.

  8. Enhancing vestibular function in the elderly with imperceptible electrical stimulation.

    Science.gov (United States)

    Serrador, Jorge M; Deegan, Brian M; Geraghty, Maria C; Wood, Scott J

    2018-01-10

    Age-related loss of vestibular function can result in decrements in gaze stabilization and increased fall risk in the elderly. This study was designed to see if low levels of electrical stochastic noise applied transcutaneously to the vestibular system can improve a gaze stabilization reflex in young and elderly subject groups. Ocular counter-rolling (OCR) using a video-based technique was obtained in 16 subjects during low frequency passive roll tilts. Consistent with previous studies, there was a significant reduction in OCR gains in the elderly compared to the young group. Imperceptible stochastic noise significantly increased OCR in the elderly (Mean 23%, CI: 17-35%). Increases in OCR gain were greatest for those with lowest baseline gain and were negligible in those with normal gain. Since stimulation was effective at low levels undetectable to subjects, stochastic noise may provide a new treatment alternative to enhance vestibular function, specifically otolith-ocular reflexes, in the elderly or patient populations with reduced otolith-ocular function.

  9. Efficacy of Carcass Electrical Stimulation in Meat Quality Enhancement: A Review

    OpenAIRE

    Kazeem Dauda Adeyemi; Awis Qurni Sazili

    2014-01-01

    The use of electrical stimulation (ES) as a management tool to improve meat quality and efficiency of meat processing is reviewed. The basis of the efficacy of ES is its ability to fast track postmortem glycolysis, which in turn stimulates myriad histological, physical, biochemical, biophysical and physiological changes in the postmortem muscle. Electrical stimulation hastens the onset and resolution of rigor mortis thereby reducing processing time and labor and plays a vital role in improvin...

  10. Electrical stimulation vs. pulsed and continuous-wave optical stimulation of the rat prostate cavernous nerves, in vivo

    Science.gov (United States)

    Perkins, William C.; Lagoda, Gwen A.; Burnett, Arthur; Fried, Nathaniel M.

    2015-07-01

    Identification and preservation of the cavernous nerves (CNs) during prostate cancer surgery is critical for post-operative sexual function. Electrical nerve stimulation (ENS) mapping has previously been tested as an intraoperative tool for CN identification, but was found to be unreliable. ENS is limited by the need for electrode-tissue contact, poor spatial precision from electrical current spreading, and stimulation artifacts interfering with detection. Alternatively, optical nerve stimulation (ONS) provides noncontact stimulation, improved spatial selectivity, and elimination of stimulation artifacts. This study compares ENS to pulsed/CW ONS to explore the ONS mechanism. A total of eighty stimulations were performed in 5 rats, in vivo. ENS (4 V, 5 ms, 10 Hz) was compared to ONS using a pulsed diode laser nerve stimulator (1873 nm, 5 ms, 10 Hz) or CW diode laser nerve stimulator (1455 nm). Intracavernous pressure (ICP) response and nerve compound action potentials (nCAPs) were measured. All three stimulation modes (ENS, ONS-CW, ONS-P) produced comparable ICP magnitudes. However, ENS demonstrated more rapid ICP response times and well defined nCAPs compared to unmeasurable nCAPs for ONS. Further experiments measuring single action potentials during ENS and ONS are warranted to further understand differences in the ENS and ONS mechanisms.

  11. Simulation of the Electrical Field in Equine Larynx to Optimize Functional Electrical Stimulation in Denervated Musculus Cricoarythenoideus Dorsalis

    OpenAIRE

    Martin Reichel; Johannes Martinek

    2014-01-01

    Distribution of the electrical field is very important to activate muscle and nerve cells properly. One therapeutic method to treat Recurrent Laryngeal Neuropathy (RLN) in horses can be performed by Functional Electrical Stimulation (FES). Current method to optimize the stimulation effect is to use implanted quadripolar electrodes to the musculus cricoarythenoideus dorsalis (CAD) and testing electrode configuration until best possible optimum is reached. For better understanding and finding o...

  12. Simulation of the electrical field in equine larynx to optimize functional electrical stimulation in denervated musculus cricoarythenoideus dorsalis

    OpenAIRE

    Martin Reichel; Johannes Martinek

    2014-01-01

    Distribution of the electrical field is very important to activate muscle and nerve cells properly. One therapeutic method to treat Recurrent Laryngeal Neuropathy (RLN) in horses can be performed by Functional Electrical Stimulation (FES). Current method to optimize the stimulation effect is to use implanted quadripolar electrodes to the musculus cricoarythenoideus dorsalis (CAD) and testing electrode configuration until best possible optimum is reached. For better understanding and finding o...

  13. A Novel In Vitro System for Comparative Analyses of Bone Cells and Bacteria under Electrical Stimulation

    Directory of Open Access Journals (Sweden)

    Thomas Josef Dauben

    2016-01-01

    Full Text Available Electrical stimulation is a promising approach to enhance bone regeneration while having potential to inhibit bacterial growth. To investigate effects of alternating electric field stimulation on both human osteoblasts and bacteria, a novel in vitro system was designed. Electric field distribution was simulated numerically and proved by experimental validation. Cells were stimulated on Ti6Al4V electrodes and in short distance to electrodes. Bacterial growth was enumerated in supernatant and on the electrode surface and biofilm formation was quantified. Electrical stimulation modulated gene expression of osteoblastic differentiation markers in a voltage-dependent manner, resulting in significantly enhanced osteocalcin mRNA synthesis rate on electrodes after stimulation with 1.4VRMS. While collagen type I synthesis increased when stimulated with 0.2VRMS, it decreased after stimulation with 1.4VRMS. Only slight and infrequent influence on bacterial growth was observed following stimulations with 0.2VRMS and 1.4VRMS after 48 and 72 h, respectively. In summary this novel test system is applicable for extended in vitro studies concerning definition of appropriate stimulation parameters for bone cell growth and differentiation, bacterial growth suppression, and investigation of general effects of electrical stimulation.

  14. A Novel In Vitro System for Comparative Analyses of Bone Cells and Bacteria under Electrical Stimulation

    Science.gov (United States)

    Zaatreh, Sarah; Kreikemeyer, Bernd

    2016-01-01

    Electrical stimulation is a promising approach to enhance bone regeneration while having potential to inhibit bacterial growth. To investigate effects of alternating electric field stimulation on both human osteoblasts and bacteria, a novel in vitro system was designed. Electric field distribution was simulated numerically and proved by experimental validation. Cells were stimulated on Ti6Al4V electrodes and in short distance to electrodes. Bacterial growth was enumerated in supernatant and on the electrode surface and biofilm formation was quantified. Electrical stimulation modulated gene expression of osteoblastic differentiation markers in a voltage-dependent manner, resulting in significantly enhanced osteocalcin mRNA synthesis rate on electrodes after stimulation with 1.4V RMS. While collagen type I synthesis increased when stimulated with 0.2V RMS, it decreased after stimulation with 1.4V RMS. Only slight and infrequent influence on bacterial growth was observed following stimulations with 0.2V RMS and 1.4V RMS after 48 and 72 h, respectively. In summary this novel test system is applicable for extended in vitro studies concerning definition of appropriate stimulation parameters for bone cell growth and differentiation, bacterial growth suppression, and investigation of general effects of electrical stimulation. PMID:28044132

  15. Fundamentals of Transcranial Electric and Magnetic Stimulation Dose: Definition, Selection, and Reporting Practices

    Science.gov (United States)

    Peterchev, Angel V.; Wagner, Timothy A.; Miranda, Pedro C.; Nitsche, Michael A.; Paulus, Walter; Lisanby, Sarah H.; Pascual-Leone, Alvaro; Bikson, Marom

    2011-01-01

    The growing use of transcranial electric and magnetic (EM) brain stimulation in basic research and in clinical applications necessitates a clear understanding of what constitutes the dose of EM stimulation and how it should be reported. The biological effects of EM stimulation are mediated through an electromagnetic field injected (via electric stimulation) or induced (via magnetic stimulation) in the body. Therefore, transcranial EM stimulation dose ought to be defined by all parameters of the stimulation device that affect the electromagnetic field generated in the body, including the stimulation electrode or coil configuration parameters: shape, size, position, and electrical properties, as well as the electrode or coil current (or voltage) waveform parameters: pulse shape, amplitude, width, polarity, and repetition frequency; duration of and interval between bursts or trains of pulses; total number of pulses; and interval between stimulation sessions and total number of sessions. Knowledge of the electromagnetic field generated in the body may not be sufficient but is necessary to understand the biological effects of EM stimulation. We believe that reporting of EM stimulation dose should be guided by the principle of reproducibility: sufficient information about the stimulation parameters should be provided so that the dose can be replicated. This paper provides fundamental definition and principles for reporting of dose that encompass any transcranial EM brain stimulation protocol. PMID:22305345

  16. Transcutaneous electrical nerve stimulation (TENS) for pain management in labour

    Science.gov (United States)

    Dowswell, Therese; Bedwell, Carol; Lavender, Tina; Neilson, James P

    2014-01-01

    Background Transcutaneous nerve stimulation (TENS) has been proposed as a means of reducing pain in labour. The TENS unit emits low-voltage electrical impulses which vary in frequency and intensity. During labour, TENS electrodes are generally placed on the lower back, although TENS may be used to stimulate acupuncture points or other parts of the body. The physiological mechanisms whereby TENS relieves pain are uncertain. TENS machines are frequently operated by women, which may increase a sense of control in labour. Objectives To assess the effects of TENS on pain in labour. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (30 April 2011) and reference lists of retrieved papers. Selection criteria Randomised controlled trials comparing women receiving TENS for pain management in labour versus routine care, alternative non-pharmacological methods of pain relief, or placebo devices. We included all types of TENS machines. Data collection and analysis Two review authors assessed for inclusion all trials identified by the search strategy, carried out data extraction and assessed risk of bias. We have recorded reasons for excluding studies. Main results Seventeen trials with 1466 women contribute data to the review. Thirteen examined TENS applied to the back, two to acupuncture points, and two to the cranium. Overall, there was little difference in pain ratings between TENS and control groups, although women receiving TENS to acupuncture points were less likely to report severe pain (average risk ratio 0.41, 95% confidence interval 0.31 to 0.54; measured in two studies). The majority of women using TENS said they would be willing to use it again in a future labour. Where TENS was used as an adjunct to epidural analgesia there was no evidence that it reduced pain. There was no consistent evidence that TENS had any impact on interventions and outcomes in labour. There was little information on outcomes for mothers and babies. No

  17. Gastric electrical stimulation for treatment of clinically severe gastroparesis

    Directory of Open Access Journals (Sweden)

    Naga Venkatesh G Jayanthi

    2013-01-01

    Full Text Available Background: Severe, drug-resistant gastroparesis is a debilitating condition. Several, but not all, patients can get significant relief from nausea and vomiting by gastric electrical stimulation (GES. A trial of temporary, endoscopically delivered GES may be of predictive value to select patients for laparoscopic-implantation of a permanent GES device. Materials and Methods: We conducted a clinical audit of consecutive gastroparesis patients, who had been selected for GES, from May 2008 to January 2012. Delayed gastric emptying was diagnosed by scintigraphy of ≥50% global improvement in symptom-severity and well-being was a good response. Results: There were 71 patients (51 women, 72% with a median age of 42 years (range: 14-69. The aetiology of gastroparesis was idiopathic (43 patients, 61%, diabetes (15, 21%, or post-surgical (anti-reflux surgery, 6 patients; Roux-en-Y gastric bypass, 3; subtotal gastrectomy, 1; cardiomyotomy, 1; other gastric surgery, 2 (18%. At presentation, oral nutrition was supplemented by naso-jejunal tube feeding in 7 patients, surgical jejunostomy in 8, or parenterally in 1 (total 16 patients; 22%. Previous intervention included endoscopic injection of botulinum toxin (botox into the pylorus in 16 patients (22%, pyloroplasty in 2, distal gastrectomy in 1, and gastrojejunostomy in 1. It was decided to directly proceed with permanent GES in 4 patients. Of the remaining, 51 patients have currently completed a trial of temporary stimulation and 39 (77% had a good response and were selected for permanent GES, which has been completed in 35 patients. Outcome data are currently available for 31 patients (idiopathic, 21 patients; diabetes, 3; post-surgical, 7 with a median follow-up period of 10 months (1-28; 22 patients (71% had a good response to permanent GES, these included 14 (68% with idiopathic, 5 (71% with post-surgical, and remaining 3 with diabetic gastroparesis. Conclusions: Overall, 71% of well-selected patients

  18. Skin collagen reproduction increased by ascorbic acid derivative iontophoresis by frequent-reversal bipolar electric stimulation.

    Science.gov (United States)

    Hori, Yusuke; Akimoto, Ryuji; Hori, Akiko; Kato, Katsuhiko; Chino, Daisuke; Matsumoto, Shohei; Kamiya, Shohei; Watanabe, Yasuo

    2009-01-01

    The effect of the iontophoresis of ascorbic acid (Vitamin C; VC) derivative with frequent-reversal bipolar electric stimulation on the production of collagen in rat skin was evaluated in terms of hydroxyproline content through high-performance liquid chromatography. First, a control group was not given electrical stimulation and four groups were stimulated with a unipolar pulse for 0.5-10 min every day for one week. The hydroxyproline level in the skin was increased depending on the length of the stimulation. Second, a control group was not given any electrical stimulation, and three groups were treated with (a) VC solution without any stimulation, (b) a bipolar pulse for 10 min with saline, or (c) a bipolar pulse for 5 min with the VC solution. Significant increases were found in all the stimulation groups, although these treated with the VC solution without any stimulation did not have any effects compared to the control. Thus, in order to increase the hydroxyproline levels in skin, a VC must be delivered with bipolar stimulation as a method of iontophoresis. These results suggest that our newly developed electric stimulation is effective at increasing skin collagen content, and that bipolar stimulation is more effective on the iontophoresis of not only VC but also some medicines such as low- and high-molecular drugs directed to the target organ (7).

  19. Ocular torsion responses to sinusoidal electrical vestibular stimulation.

    Science.gov (United States)

    Mackenzie, Stuart W; Reynolds, Raymond F

    2017-11-21

    Eye movements evoked by electrical vestibular stimulation (EVS) offer potential for diagnosing vestibular dysfunction. However, ocular recording techniques are often too invasive or impractical for routine clinical use. Furthermore, the kinematic nature of the EVS signal is not fully understood in terms of movement sensations. We apply sinusoidal EVS stimuli varying from 0.05 to 20Hz, and record the eye in darkness using an infrared camera. Eye movement was measured offline using commercially available software to track iris striations. Response gain and phase were calculated separately for eye position, velocity and acceleration across all frequencies, to determine how the brain interprets the EVS signal. Ocular torsion responses were observed at the same frequency as the stimulus, for all frequencies, while lateral/vertical responses were minimal or absent. Response gain and phase resembled previously reported responses to natural rotation, but only when analysing eye velocity, not position or acceleration. Our method offers a simple, affordable, reliable and non-invasive method for tracking the ocular response to EVS. It is more convenient than scleral coil recordings, or marking the sclera to aid video tracking. It also allows us to assess the torsional VOR at frequencies not possible with natural stimuli. Ocular torsion responses to EVS can be readily assessed using sinusoidal stimuli combined with an infrared camera. Gain and phase analysis suggests that the central nervous system interprets the stimulus as head roll velocity. Future work will assess the diagnostic potential for patients with vestibular disorders. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  20. Assessing kinematics and kinetics of functional electrical stimulation rowing.

    Science.gov (United States)

    Draghici, Adina E; Picard, Glen; Taylor, J Andrew; Shefelbine, Sandra J

    2017-02-28

    Hybrid functional electrical stimulation (FES) rowing has positive effects on cardiovascular fitness, producing significantly greater aerobic power than either upper body or FES exercise alone. However, there is minimal information on the kinematics, kinetics, and mechanical efficiency of FES-rowing in the spinal cord injured (SCI) population. This study examined the biomechanics of FES-rowing to determine how motions, forces, and aerobic demand change with increasing intensity. Six individuals with SCI and six able-bodied subjects performed a progressive aerobic capacity rowing test. Differences in kinematics (motion profiles), kinetics (forces produced by the feet and arms), external mechanical work, and mechanical efficiency (work produced/volume of oxygen consumed) were compared in able-bodied rowing vs. SCI FES-rowing at three comparable subpeak workloads. With increasing exercise intensity (measured as wattage), able-bodied rowing increased stroke rate by decreasing recovery time, while FES-rowing maintained a constant stroke rate, with no change in drive or recovery times. While able-bodied rowers increased leg and arm forces with increasing intensity, FES-rowers used only their arms to achieve a higher intensity with a constant and relatively low contribution of the legs. Oxygen consumption increased in both groups, but more so in able-bodied rowers, resulting in able-bodied rowers having twice the mechanical efficiency of FES-rowers. Our results suggest that despite its ability to allow for whole body exercise, the total force output achievable with FES-rowing results in only modest loading of the legs that affects overall rowing performance and that may limit forces applied to bone. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Higher success rate with transcranial electrical stimulation of motor-evoked potentials using constant-voltage stimulation compared with constant-current stimulation in patients undergoing spinal surgery.

    Science.gov (United States)

    Shigematsu, Hideki; Kawaguchi, Masahiko; Hayashi, Hironobu; Takatani, Tsunenori; Iwata, Eiichiro; Tanaka, Masato; Okuda, Akinori; Morimoto, Yasuhiko; Masuda, Keisuke; Tanaka, Yuu; Tanaka, Yasuhito

    2017-10-01

    During spine surgery, the spinal cord is electrophysiologically monitored via transcranial electrical stimulation of motor-evoked potentials (TES-MEPs) to prevent injury. Transcranial electrical stimulation of motor-evoked potential involves the use of either constant-current or constant-voltage stimulation; however, there are few comparative data available regarding their ability to adequately elicit compound motor action potentials. We hypothesized that the success rates of TES-MEP recordings would be similar between constant-current and constant-voltage stimulations in patients undergoing spine surgery. The objective of this study was to compare the success rates of TES-MEP recordings between constant-current and constant-voltage stimulation. This is a prospective, within-subject study. Data from 100 patients undergoing spinal surgery at the cervical, thoracic, or lumbar level were analyzed. The success rates of the TES-MEP recordings from each muscle were examined. Transcranial electrical stimulation with constant-current and constant-voltage stimulations at the C3 and C4 electrode positions (international "10-20" system) was applied to each patient. Compound muscle action potentials were bilaterally recorded from the abductor pollicis brevis (APB), deltoid (Del), abductor hallucis (AH), tibialis anterior (TA), gastrocnemius (GC), and quadriceps (Quad) muscles. The success rates of the TES-MEP recordings from the right Del, right APB, bilateral Quad, right TA, right GC, and bilateral AH muscles were significantly higher using constant-voltage stimulation than those using constant-current stimulation. The overall success rates with constant-voltage and constant-current stimulations were 86.3% and 68.8%, respectively (risk ratio 1.25 [95% confidence interval: 1.20-1.31]). The success rates of TES-MEP recordings were higher using constant-voltage stimulation compared with constant-current stimulation in patients undergoing spinal surgery. Copyright © 2017

  2. Electrical pulse stimulation of cultured human skeletal muscle cells as an in vitro model of exercise.

    Directory of Open Access Journals (Sweden)

    Nataša Nikolić

    Full Text Available Physical exercise leads to substantial adaptive responses in skeletal muscles and plays a central role in a healthy life style. Since exercise induces major systemic responses, underlying cellular mechanisms are difficult to study in vivo. It was therefore desirable to develop an in vitro model that would resemble training in cultured human myotubes.Electrical pulse stimulation (EPS was applied to adherent human myotubes. Cellular contents of ATP, phosphocreatine (PCr and lactate were determined. Glucose and oleic acid metabolism were studied using radio-labeled substrates, and gene expression was analyzed using real-time RT-PCR. Mitochondrial content and function were measured by live imaging and determination of citrate synthase activity, respectively. Protein expression was assessed by electrophoresis and immunoblotting.High-frequency, acute EPS increased deoxyglucose uptake and lactate production, while cell contents of both ATP and PCr decreased. Chronic, low-frequency EPS increased oxidative capacity of cultured myotubes by increasing glucose metabolism (uptake and oxidation and complete fatty acid oxidation. mRNA expression level of pyruvate dehydrogenase complex 4 (PDK4 was significantly increased in EPS-treated cells, while mRNA expressions of interleukin 6 (IL-6, cytochrome C and carnitin palmitoyl transferase b (CPT1b also tended to increase. Intensity of MitoTracker®Red FM was doubled after 48 h of chronic, low-frequency EPS. Protein expression of a slow fiber type marker (MHCI was increased in EPS-treated cells.Our results imply that in vitro EPS (acute, high-frequent as well as chronic, low-frequent of human myotubes may be used to study effects of exercise.

  3. Transcutaneous electrical nerve stimulation (TENS) for neuropathic pain in adults.

    Science.gov (United States)

    Gibson, William; Wand, Benedict M; O'Connell, Neil E

    2017-09-14

    Neuropathic pain, which is due to nerve disease or damage, represents a significant burden on people and society. It can be particularly unpleasant and achieving adequate symptom control can be difficult. Non-pharmacological methods of treatment are often employed by people with neuropathic pain and may include transcutaneous electrical nerve stimulation (TENS). This review supersedes one Cochrane Review 'Transcutaneous electrical nerve stimulation (TENS) for chronic pain' (Nnoaham 2014) and one withdrawn protocol 'Transcutaneous electrical nerve stimulation (TENS) for neuropathic pain in adults' (Claydon 2014). This review replaces the original protocol for neuropathic pain that was withdrawn. To determine the analgesic effectiveness of TENS versus placebo (sham) TENS, TENS versus usual care, TENS versus no treatment and TENS in addition to usual care versus usual care alone in the management of neuropathic pain in adults. We searched CENTRAL, MEDLINE, Embase, PsycINFO, AMED, CINAHL, Web of Science, PEDro, LILACS (up to September 2016) and various clinical trials registries. We also searched bibliographies of included studies for further relevant studies. We included randomised controlled trials where TENS was evaluated in the treatment of central or peripheral neuropathic pain. We included studies if they investigated the following: TENS versus placebo (sham) TENS, TENS versus usual care, TENS versus no treatment and TENS in addition to usual care versus usual care alone in the management of neuropathic pain in adults. Two review authors independently screened all database search results and identified papers requiring full-text assessment. Subsequently, two review authors independently applied inclusion/exclusion criteria to these studies. The same review authors then independently extracted data, assessed for risk of bias using the Cochrane standard tool and rated the quality of evidence using GRADE. We included 15 studies with 724 participants. We found a

  4. Model study of combined electrical and near-infrared neural stimulation on the bullfrog sciatic nerve.

    Science.gov (United States)

    You, Mengxian; Mou, Zongxia

    2017-07-01

    This paper implemented a model study of combined electrical and near-infrared (808 nm) neural stimulation (NINS) on the bullfrog sciatic nerve. The model includes a COMSOL model to calculate the electric-field distribution of the surrounding area of the nerve, a Monte Carlo model to simulate light transport and absorption in the bullfrog sciatic nerve during NINS, and a NEURON model to simulate the neural electrophysiology changes under electrical stimulus and laser irradiation. The optical thermal effect is considered the main mechanism during NINS. Therefore, thermal change during laser irradiation was calculated by the Monte Carlo method, and the temperature distribution was then transferred to the NEURON model to stimulate the sciatic nerve. The effects on thermal response by adjusting the laser spot size, energy of the beam, and the absorption coefficient of the nerve are analyzed. The effect of the ambient temperature on the electrical stimulation or laser stimulation and the interaction between laser irradiation and electrical stimulation are also studied. The results indicate that the needed stimulus threshold for neural activation or inhibition is reduced by laser irradiation. Additionally, the needed laser energy for blocking the action potential is reduced by electrical stimulus. Both electrical and laser stimulation are affected by the ambient temperature. These results provide references for subsequent animal experiments and could be of great help to future basic and applied studies of infrared neural stimulation (INS).

  5. Transcutaneus electrical nerve stimulation for overactive bladder increases rectal motor activity in children: a randomized controlled study

    DEFF Research Database (Denmark)

    Jønsson, Iben; Hagstrøm, Søren; Siggaard, Charlotte

    Transcutaneus electrical nerve stimulation for overactive bladder increases rectal motor activity in children: a randomized controlled study......Transcutaneus electrical nerve stimulation for overactive bladder increases rectal motor activity in children: a randomized controlled study...

  6. Electrical stimulation enhances cell migration and integrative repair in the meniscus

    Science.gov (United States)

    Yuan, Xiaoning; Arkonac, Derya E.; Chao, Pen-Hsiu Grace; Vunjak-Novakovic, Gordana

    2014-01-01

    Electrical signals have been applied towards the repair of articular tissues in the laboratory and clinical settings for over seventy years. We focus on healing of the meniscus, a tissue essential to knee function with limited innate repair potential, which has been largely unexplored in the context of electrical stimulation. Here we demonstrate for the first time that electrical stimulation enhances meniscus cell migration and integrative tissue repair. We optimize pulsatile direct current electrical stimulation parameters on cells at the micro-scale, and apply these to healing of full-thickness defects in explants at the macro-scale. We report increased expression of the adenosine A2b receptor in meniscus cells after stimulation at the micro- and macro-scale, and propose a role for A2bR in meniscus electrotransduction. Taken together, these findings advance our understanding of the effects of electrical signals and their mechanisms of action, and contribute to developing electrotherapeutic strategies for meniscus repair.

  7. Delay-Dependent Response in Weakly Electric Fish under Closed-Loop Pulse Stimulation.

    Science.gov (United States)

    Forlim, Caroline Garcia; Pinto, Reynaldo Daniel; Varona, Pablo; Rodríguez, Francisco B

    2015-01-01

    In this paper, we apply a real time activity-dependent protocol to study how freely swimming weakly electric fish produce and process the timing of their own electric signals. Specifically, we address this study in the elephant fish, Gnathonemus petersii, an animal that uses weak discharges to locate obstacles or food while navigating, as well as for electro-communication with conspecifics. To investigate how the inter pulse intervals vary in response to external stimuli, we compare the response to a simple closed-loop stimulation protocol and the signals generated without electrical stimulation. The activity-dependent stimulation protocol explores different stimulus delivery delays relative to the fish's own electric discharges. We show that there is a critical time delay in this closed-loop interaction, as the largest changes in inter pulse intervals occur when the stimulation delay is below 100 ms. We also discuss the implications of these findings in the context of information processing in weakly electric fish.

  8. Stimulated angiogenesis for fracture healing augmented by low-magnitude, high-frequency vibration in a rat model-evaluation of pulsed-wave doppler, 3-D power Doppler ultrasonography and micro-CT microangiography.

    Science.gov (United States)

    Cheung, Wing-Hoi; Sun, Ming-Hui; Zheng, Yong-Ping; Chu, Winnie Chiu-Wing; Leung, Andraay Hon-Chi; Qin, Ling; Wei, Fang-Yuan; Leung, Kwok-Sui

    2012-12-01

    This study aimed to investigate the mechanism of low-magnitude high-frequency vibration (LMHFV) treatment on angiogenesis and blood flow for enhancement of fracture healing. Nine-month-old ovariectomized (OVX) and sham-operated (Sham) rats received closed fractures creation at the femora and were randomized into LMHFV treatment (Sham-V, OVX-V) or control (Sham-C, OVX-C) groups. Pulsed-wave Doppler indicated an increase in blood flow velocity of the femoral artery at weeks 2 (OVX pair: p = 0.030) and 4 (OVX pair: p = 0.012; Sham pair: p = 0.020) post-treatment. Significantly enhanced vascular volume (VV) at the fracture site in the vibration groups was demonstrated by 3-D high-frequency power Doppler at week 2 (Sham pair: p = 0.021) and micro-computed tomography (microCT) microangiography at weeks 2 (OVX pair: p = 0.009) and 4 (OVX pair: p = 0.034), which echoed the osteogenesis findings by radiographic and microCT analysis. VV in the OVX groups was inferior to the Sham groups. However, OVX-V showed higher percentages of angiogenic enhancement than Sham-V. Despite impaired neo-angiogenesis in osteoporotic fractures, LMHFV could increase blood flow and angiogenesis in both normal and osteoporotic fractures, thus enhancing fracture healing. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  9. Transcutaneous electrical nerve stimulation (TENS) for fibromyalgia in adults.

    Science.gov (United States)

    Johnson, Mark I; Claydon, Leica S; Herbison, G Peter; Jones, Gareth; Paley, Carole A

    2017-10-09

    Fibromyalgia is characterised by persistent, widespread pain; sleep problems; and fatigue. Transcutaneous electrical nerve stimulation (TENS) is the delivery of pulsed electrical currents across the intact surface of the skin to stimulate peripheral nerves and is used extensively to manage painful conditions. TENS is inexpensive, safe, and can be self-administered. TENS reduces pain during movement in some people so it may be a useful adjunct to assist participation in exercise and activities of daily living. To date, there has been only one systematic review in 2012 which included TENS, amongst other treatments, for fibromyalgia, and the authors concluded that TENS was not effective. To assess the analgesic efficacy and adverse events of TENS alone or added to usual care (including exercise) compared with placebo (sham) TENS; no treatment; exercise alone; or other treatment including medication, electroacupuncture, warmth therapy, or hydrotherapy for fibromyalgia in adults. We searched the following electronic databases up to 18 January 2017: CENTRAL (CRSO); MEDLINE (Ovid); Embase (Ovid); CINAHL (EBSCO); PsycINFO (Ovid); LILACS; PEDRO; Web of Science (ISI); AMED (Ovid); and SPORTDiscus (EBSCO). We also searched three trial registries. There were no language restrictions. We included randomised controlled trials (RCTs) or quasi-randomised trials of TENS treatment for pain associated with fibromyalgia in adults. We included cross-over and parallel-group trial designs. We included studies that evaluated TENS administered using non-invasive techniques at intensities that produced perceptible TENS sensations during stimulation at either the site of pain or over nerve bundles proximal (or near) to the site of pain. We included TENS administered as a sole treatment or TENS in combination with other treatments, and TENS given as a single treatment or as a course of treatments. Two review authors independently determined study eligibility by assessing each record and

  10. Relation between stimulation characteristics and clinical outcome in studies using electrical stimulation to improve motor control of the upper extremity in stroke

    NARCIS (Netherlands)

    de Kroon, Joke R.; IJzerman, Maarten Joost; Chae, John; Lankhorst, Gustaaf J.; Zilvold, G.; Zilvold, Gerrit

    Objective: Electrical stimulation can be applied in a variety of ways to the hemiparetic upper extremity following stroke. The aim of this review is to explore the relationship between characteristics of stimulation and the effect of electrical stimulation on the recovery of upper limb motor control

  11. Relation between stimulation characteristics and clinical outcome in studies using electrical stimulation to improve motor control of the upper extremity in stroke

    NARCIS (Netherlands)

    de Kroon, J.R.; IJzerman, M.J.; Chae, J.; Lankhorst, G.J.; Zilvold, G.

    2005-01-01

    Objective: Electrical stimulation can be applied in a variety of ways to the hemiparetic upper extremity following stroke. The aim of this review is to explore the relationship between characteristics of stimulation and the effect of electrical stimulation on the recovery of upper limb motor control

  12. Econometrics of financial high-frequency data

    CERN Document Server

    Hautsch, Nikolaus

    2011-01-01

    This book covers major approaches in high-frequency econometrics. It discusses implementation details, provides insights into properties of high-frequency data as well as institutional settings and presents applications.

  13. High-frequency fatigue after alpine slalom skiing.

    Science.gov (United States)

    Tomazin, Katja; Dolenec, Ales; Strojnik, Vojko

    2008-05-01

    The aim of the study was to examine the presence of high-frequency fatigue (HFF) after simulated alpine slalom skiing race. Eight male alpine skiers (18.4+/-1.2 y.a., 182.3+/-3.5 cm, 80.5+/-3.4 kg) completed the study. Their average FIS points in slalom were 30.1+/-5.4. After the special skiing warm up, the following initial tests were performed: blood lactate concentration, twitch response of the relaxed VL muscle, knee torque during low- (20 Hz) and high-frequency (100 Hz) electrical stimulation of vastus lateralis muscle, and maximum, voluntary isometric knee extension torque. Then, subjects performed slalom with 45 gates, whose duration was approximately 45 s. The same test sequence, except blood lactate test was used after slalom and the measurements started exactly 60 and 180 s after slalom. Blood lactate concentration measurement started exactly 3 and 5 min after slalom. A 1x3 repeated measures; time-series design was used with one within factor of time (before 60 s, and 180 s after skiing). The average blood lactate level increased from 1.6 (0.6) pre-slalom to 7.1(1.6) mmol(-l) 15 min post-slalom (F2,14=70.1; P<0.001). Sixty seconds after slalom, twitch contraction time shortened from 78.2 (5.7) pre-slalom to 66.0 (7.2) ms post-slalom (F1.19,8.3=9.9; P<0.05). Peak twitch torque was potentiated from 21.6 (3.8) to 26.4 (5.3) Nm (F2,14=16.7; P<0.05). Slalom reduced high-frequency torque from 64.4 (35) to 58.2 (34.2) Nm 60 s post-slalom (F2,14=3.8; P<0.05), while low-frequency torque stayed virtually the same. Slalom induced HFF, which is typical of SSC exercises of maximum intensity and short duration.

  14. Semiconditional electrical stimulation of pudendal nerve afferents stimulation to manage neurogenic detrusor overactivity in patients with spinal cord injury.

    Science.gov (United States)

    Lee, Young-Hee; Kim, Jung Moon; Im, Hyung Tae; Lee, Kye-Wook; Kim, Sung Hoon; Hur, Dong Min

    2011-10-01

    To evaluate the effect of semiconditional electrical stimulation of the pudendal nerve afferents for the neurogenic detrusor overactivity in patients with spinal cord injury. Forty patients (36 males, 4 males) with spinal cord injury who had urinary incontinence and frequency, as well as felt bladder contraction with bladder filling sense or autonomic dysreflexic symptom participated in this study. Patients with neurogenic detrusor overactivity were subdivided into complete injury and incomplete injury groups by ASIA classification and subdivided into tetraplegia and paraplegia groups by neurologic level of injury. Bladder function, such as bladder volumes infused to the bladder until the first occurrence of neurogenic detrusor overactivity (V(ini)) and the last contraction suppressed by electrical stimulation (V(max)) was measured by water cystometry (CMG) and compared with the results of each subgroup. Among the 40 subjects, 35 patients showed neurogenic detrusor overactivity in the CMG study. Among these 35 patients, detrusor overactivity was suppressed effectively by pudendal nerve afferent electrical stimulation in 32 patients. The infusion volume until the occurrence of the first reflex contraction (V(ini)) was 99.4±80.3 ml. The volume of saline infused to the bladder until the last contraction suppressed by semiconditional pudendal nerve stimulation (V(max)) was 274.3±93.2 ml, which was significantly greater than V(ini). In patients with good response to the pudendal nerve afferent stimulation, the bladder volume significantly increased by stimulation in all the patients. In this study, semiconditional electrical stimulation on the dorsal penile afferent nerve could effectively inhibit neurogenic detrusor overactivity and increase bladder volume in patients with spinal cord injury.

  15. Tissue heterogeneity as a mechanism for localized neural stimulation by applied electric fields

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, P C [Institute of Biophysics and Biomedical Engineering, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon (Portugal); Correia, L [Institute of Biophysics and Biomedical Engineering, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon (Portugal); Salvador, R [Institute of Biophysics and Biomedical Engineering, Faculty of Sciences, University of Lisbon, 1749-016 Lisbon (Portugal); Basser, P J [Section on Tissue Biophysics and Biomimetics, NICHD, National Institutes of Health, Bethesda, MD 20892-1428 (United States)

    2007-09-21

    We investigate the heterogeneity of electrical conductivity as a new mechanism to stimulate excitable tissues via applied electric fields. In particular, we show that stimulation of axons crossing internal boundaries can occur at boundaries where the electric conductivity of the volume conductor changes abruptly. The effectiveness of this and other stimulation mechanisms was compared by means of models and computer simulations in the context of transcranial magnetic stimulation. While, for a given stimulation intensity, the largest membrane depolarization occurred where an axon terminates or bends sharply in a high electric field region, a slightly smaller membrane depolarization, still sufficient to generate action potentials, also occurred at an internal boundary where the conductivity jumped from 0.143 S m{sup -1} to 0.333 S m{sup -1}, simulating a white-matter-grey-matter interface. Tissue heterogeneity can also give rise to local electric field gradients that are considerably stronger and more focal than those impressed by the stimulation coil and that can affect the membrane potential, albeit to a lesser extent than the two mechanisms mentioned above. Tissue heterogeneity may play an important role in electric and magnetic 'far-field' stimulation.

  16. Olfactory hallucinations elicited by electrical stimulation via subdural electrodes: effects of direct stimulation of olfactory bulb and tract.

    Science.gov (United States)

    Kumar, Gogi; Juhász, Csaba; Sood, Sandeep; Asano, Eishi

    2012-06-01

    In 1954, Penfield and Jasper briefly described that percepts of unpleasant odor were elicited by intraoperative electrical stimulation of the olfactory bulb in patients with epilepsy. Since then, few peer-reviewed studies have reported such phenomena elicited by stimulation mapping via subdural electrodes implanted on the ventral surface of the frontal lobe. Here, we determined what types of olfactory hallucinations could be reproduced by such stimulation in children with focal epilepsy. This study included 16 children (age range: 5 to 17 years) who underwent implantation of subdural electrodes to localize the presumed epileptogenic zone and eloquent areas. Pairs of electrodes were electrically stimulated, and clinical responses were observed. In case a patient reported a perception, she/he was asked to describe its nature. We also described the stimulus parameters to elicit a given symptom. Eleven patients reported a perception of smell in response to electrical stimulation while the remaining five did not. Nine patients perceived an unpleasant smell (like bitterness, smoke, or garbage) while two perceived a pleasant smell (like strawberry or good food). Such olfactory hallucinations were induced by stimulation proximal to the olfactory bulb or tract on either hemisphere but not by that of orbitofrontal gyri lateral to the medial orbital sulci. The range of stimulus parameters employed to elicit olfactory hallucinations was comparable to those for other sensorimotor symptoms. Our systematic study of children with epilepsy replicated stimulation-induced olfactory hallucinations. We failed to provide evidence that a positive olfactory perception could be elicited by conventional stimulation of secondary olfactory cortex alone. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Stimulating Music: The Pleasures and Dangers of “Electric Music,” 1750–1900

    Science.gov (United States)

    Kennaway, James

    2014-01-01

    Far from being a purely modern idea, the notion of “electric music” was already common in the eighteenth and nineteenth centuries. The shift in thinking about music from cosmic harmony to nervous stimulation made metaphors and speculative theories relating music and electricity irresistible. This essay considers the development of the idea of electric music, looking at its associations with a sexual “body electric.” It will then examine how this conception of music went from being the subject of sympathy to becoming part of a medical critique of music as a dangerous stimulant, with echoes in music criticism and beyond. PMID:24587689

  18. Electrical stimulation of sacral dermatomes in multiple sclerosis patients with neurogenic detrusor overactivity.

    Science.gov (United States)

    Fjorback, M V; Van Rey, F S; Rijkhoff, N J M; Nøhr, M; Petersen, T; Heesakkers, J P

    2007-01-01

    Transcutaneous electrical stimulation of the dorsal penile/clitoral nerve (DPN) has been shown to suppress detrusor contractions in patients with neurogenic detrusor overactivity (NDO). However, the long-term use of surface electrodes in the genital region may not be well tolerated and may introduce hygienic challenges. The aim of this study was to assess whether electrical stimulation of the sacral dermatomes could suppress detrusor contractions in multiple sclerosis (MS) patients with NDO, hereby providing an alternative to DPN stimulation. A total of 14 MS patients (8 M, 6 F) with low bladder capacity (stimulation was applied. In the second and third filling electrical stimulation of either the DPN or sacral dermatomes was applied automatically whenever the detrusor pressure exceeded 10 cmH2O. The control filling showed detrusor overactivity in 12 of the 14 patients. In 10 of the 12 patients one or more detrusor contractions could be suppressed with DPN stimulation. Electrical stimulation of the sacral dermatomes failed to suppress detrusor contractions in all patients. Although therapeutic effects may be present from stimulation of the sacral dermatomes, we were unable to demonstrate any acute effects during urodynamics. For this reason stimulation of the sacral dermatomes is not an option in a system that relies on the acute suppression of a detrusor contraction. Copyright (c) 2007 Wiley-Liss, Inc.

  19. Stimulation parameter optimization for functional electrical stimulation assisted gait in human spinal cord injury using response surface methodology.

    Science.gov (United States)

    Kim, Yongchul; Schmit, Brian D; Youm, Youngil

    2006-06-01

    The aims of this study were to identify the reflex moment induced by flexion withdrawal reflex and to optimize stimulation parameters for restoring swing motion with respect to initial kinematic conditions in human with spinal cord injury. The influence of hip position and passive movement in the reflex moment were tested in six subjects with chronic spinal cord injury. The two-dimensional dynamic models consisted of thigh, shank and foot segments were developed to compute the swing-phase response and the response surface method was also used to optimize stimulation parameters for restoration of gait by functional electrical stimulation. At three different hip positions, significant linear relationship was found between the reflex moment and hip angle (P spinal cord injured patients. From dynamic simulation, we concluded that optimal solutions of pulse amplitude, frequency and duration time of burst for electrical stimulation assisted gait were influenced by initial kinematic conditions at toe-off. The reflex model and the results of this study can be applied to the design and control strategies of neuroprosthetic devices using functional electrical stimulation for spinal cord injured patients.

  20. Direct and crossed effects of somatosensory electrical stimulation on motor learning and neuronal plasticity in humans

    NARCIS (Netherlands)

    Veldman, M. P.; Zijdewind, I.; Solnik, S.; Maffiuletti, N. A.; Berghuis, K. M. M.; Javet, M.; Negyesi, J.; Hortobagyi, T.

    2015-01-01

    Purpose Sensory input can modify voluntary motor function. We examined whether somatosensory electrical stimulation (SES) added to motor practice (MP) could augment motor learning, interlimb transfer, and whether physiological changes in neuronal excitability underlie these changes. Methods

  1. Movement Along the Spine Induced by Transcranial Electrical Stimulation Related Electrode Positioning

    NARCIS (Netherlands)

    Hoebink, Eric A.; Journee, Henricus L.; de Kleuver, Marinus; Berends, Hanneke; Racz, Ilona; van Hal, Chantal

    2016-01-01

    Study Design. A prospective, nonrandomized cohort study. Objective. To describe a technique quantifying movement induced by transcranial electrical stimulation (TES) induced movement in relation to the positioning of electrodes during spinal deformity surgery. Summary of Background Data. TES induced

  2. Neuromuscular electrical stimulation for preventing skeletal-muscle weakness and wasting in critically ill patients

    DEFF Research Database (Denmark)

    Maffiuletti, Nicola A.; Roig, Marc; Karatzanos, Eleftherios

    2013-01-01

    Background: Neuromuscular electrical stimulation (NMES) therapy may be useful in early musculoskeletal rehabilitation during acute critical illness. The objective of this systematic review was to evaluate the effectiveness of NMES for preventing skeletal-muscle weakness and wasting in critically...

  3. Magnetic and electric stimulation to elicit the masseteric exteroceptive suppression period

    DEFF Research Database (Denmark)

    Komiyama, Osamu; Wang, Kelun; Svensson, Peter

    2010-01-01

    OBJECTIVES: The present study compared the perception of electric and magnetic stimuli for reflex appearance threshold (RT) and reflex saturation threshold (RS) of the exteroceptive suppression reflex (ES) in the masseter muscle. METHODS: Twelve healthy males and 12 females (age: 24.2+/-3.2 years...... and RS for the early and late ES (ES1 and ES2, respectively). RESULTS: ES2 had a lower RT and RS compared to ES1 in electric and magnetic stimulation. Significantly lower NRS values at RT and RS were found with painless magnetic stimulation compared to electric stimulation (p...: In contrast to electrical stimulation, both ES1 and ES2 appeared and saturated with painless magnetic stimuli. SIGNIFICANCE: The present results indicate that both ES1 and ES2 have a non-nociceptive origin. Painless magnetic stimuli will be an advantage in ES reflex examinations for various orofacial pain...

  4. Passive reach and grasp with functional electrical stimulation and robotic arm support

    NARCIS (Netherlands)

    Westerveld, Ard J.; Schouten, Alfred C.; Veltink, Peter H.; van der Kooij, Herman

    2014-01-01

    Rehabilitation of arm and hand function is crucial to increase functional independence of stroke subjects. Here, we investigate the technical feasibility of an integrated training system combining robotics and functional electrical stimulation (FES) to support reach and grasp during functional

  5. Referred pain and cutaneous responses from deep tissue electrical pain stimulation in the groin

    DEFF Research Database (Denmark)

    Aasvang, E K; Werner, M U; Kehlet, H

    2015-01-01

    , supporting individual differences in anatomy and sensory processing. Future studies investigating the responses to deep tissue electrical stimulation in persistent postherniotomy pain patients may advance our understanding of underlying pathophysiological mechanisms and strategies for treatment...

  6. Effects of Smoke Exposure and Other Lifestyle Factors on Pain Response to Electrical Stimulation in Women

    Directory of Open Access Journals (Sweden)

    Joy Yenn May Wee

    2008-01-01

    Full Text Available BACKGROUND: A relationship between smoking and development of pain syndromes has been suggested in the literature. The present study examined associations between smoke exposure and other related variables, and pain response to suprathreshold electrical stimulation.

  7. Electrical nerve stimulation as an aid to the placement of a brachial plexus block : clinical communication

    Directory of Open Access Journals (Sweden)

    K.E. Joubert

    2002-07-01

    Full Text Available Most local anaesthetic blocks are placed blindly, based on a sound knowledge of anatomy. Very often the relationship between the site of deposition of local anaesthetic and the nerve to be blocked is unknown. Large motor neurons may be stimulated with the aid of an electrical current. By observing for muscle twitches, through electrical stimulation of the nerve, a needle can be positioned extremely close to the nerve. The accuracy of local anaesthetic blocks can be improved by this technique. By using the lowest possible current a needle could be positioned within 2-5mm of a nerve. The correct duration of stimulation ensures that stimulation of sensory nerves does not occur. The use of electrical nerve stimulation in veterinary medicine is a novel technique that requires further evaluation.

  8. Biophysical Stimuli: A Review of Electrical and Mechanical Stimulation in Hyaline Cartilage.

    Science.gov (United States)

    Vaca-González, Juan J; Guevara, Johana M; Moncayo, Miguel A; Castro-Abril, Hector; Hata, Yoshie; Garzón-Alvarado, Diego A

    2017-09-01

    Objective Hyaline cartilage degenerative pathologies induce morphologic and biomechanical changes resulting in cartilage tissue damage. In pursuit of therapeutic options, electrical and mechanical stimulation have been proposed for improving tissue engineering approaches for cartilage repair. The purpose of this review was to highlight the effect of electrical stimulation and mechanical stimuli in chondrocyte behavior. Design Different information sources and the MEDLINE database were systematically revised to summarize the different contributions for the past 40 years. Results It has been shown that electric stimulation may increase cell proliferation and stimulate the synthesis of molecules associated with the extracellular matrix of the articular cartilage, such as collagen type II, aggrecan and glycosaminoglycans, while mechanical loads trigger anabolic and catabolic responses in chondrocytes. Conclusion The biophysical stimuli can increase cell proliferation and stimulate molecules associated with hyaline cartilage extracellular matrix maintenance.

  9. Transcutaneous electrical stimulation (TES) for treatment of constipation in children.

    Science.gov (United States)

    Ng, Ruey Terng; Lee, Way Seah; Ang, Hak Lee; Teo, Kai Ming; Yik, Yee Ian; Lai, Nai Ming

    2016-11-11

    Childhood constipation is a common problem with substantial health, economic and emotional burdens. Existing therapeutic options, mainly pharmacological, are not consistently effective, and some are associated with adverse effects after prolonged use. Transcutaneous electrical stimulation (TES), a non-pharmacological approach, is postulated to facilitate bowel movement by modulating the nerves of the large bowel via the application of electrical current transmitted through the abdominal wall. Our main objective was to evaluate the effectiveness and safety of TES when employed to improve bowel function and constipation-related symptoms in children with constipation. We searched MEDLINE (PubMed) (1950 to July 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 7, 2015), EMBASE (1980 to July 2015), the Cochrane IBD Group Specialized Register, trial registries and conference proceedings to identify applicable studies . Randomized controlled trials that assessed any type of TES, administered at home or in a clinical setting, compared to no treatment, a sham TES, other forms of nerve stimulation or any other pharmaceutical or non-pharmaceutical measures used to treat constipation in children were considered for inclusion. Two authors independently assessed studies for inclusion, extracted data and assessed risk of bias of the included studies. We calculated the risk ratio (RR) and corresponding 95% confidence interval (CI) for categorical outcomes data and the mean difference (MD) and corresponding 95% CI for continuous outcomes. We evaluated the overall quality of the evidence supporting the outcomes assessed in this review using the GRADE criteria. One study from Australia including 46 children aged 8 to 18 years was eligible for inclusion. There were multiple reports identified, including one unpublished report, that focused on different outcomes of the same study. The study had unclear risk of selection bias, high risks of

  10. Hypoalgesia in response to transcutaneous electrical nerve stimulation (TENS) depends on stimulation intensity.

    Science.gov (United States)

    Moran, Fidelma; Leonard, Tracey; Hawthorne, Stephanie; Hughes, Ciara M; McCrum-Gardner, Evie; Johnson, Mark I; Rakel, Barbara A; Sluka, Kathleen A; Walsh, Deirdre M

    2011-08-01

    Transcutaneous electrical nerve stimulation (TENS) is an electrophysical modality used for pain management. This study investigated the dose response of different TENS intensities on experimentally induced pressure pain. One hundred and thirty TENS naïve healthy individuals (18-64 years old; 65 males, 65 females) were randomly allocated to 5 groups (n = 26 per group): Strong Non Painful TENS; Sensory Threshold TENS; Below Sensory Threshold TENS; No Current Placebo TENS; and Transient Placebo TENS. Active TENS (80 Hz) was applied to the forearm for 30 minutes. Transient Placebo TENS was applied for 42 seconds after which the current amplitude automatically reset to 0 mA. Pressure pain thresholds (PPT) were recorded from 2 points on the hand and forearm before and after TENS to measure hypoalgesia. There were significant differences between groups at both the hand and forearm (ANOVA; P = .005 and .002). At 30 minutes, there was a significant hypoalgesic effect in the Strong Non Painful TENS group compared to: Below Sensory Threshold TENS, No Current Placebo TENS and Transient Placebo TENS groups (P TENS and No Current Placebo TENS groups at the hand (P = .001). There was no significant difference between Strong Non Painful TENS and Sensory Threshold TENS groups. The area under the curve for the changes in PPT significantly correlated with the current amplitude (r(2) = .33, P = .003). These data therefore show that there is a dose-response effect of TENS with the largest effect occurring with the highest current amplitudes. This study shows a dose response for the intensity of TENS for pain relief with the strongest intensities showing the greatest effect; thus, we suggest that TENS intensity should be titrated to achieve the strongest possible intensity to achieve maximum pain relief. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

  11. Muscle fiber type specific induction of slow myosin heavy chain 2 gene expression by electrical stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Crew, Jennifer R.; Falzari, Kanakeshwari [Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064 (United States); DiMario, Joseph X., E-mail: joseph.dimario@rosalindfranklin.edu [Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science, 3333 Green Bay Road, North Chicago, IL 60064 (United States)

    2010-04-01

    Vertebrate skeletal muscle fiber types are defined by a broad array of differentially expressed contractile and metabolic protein genes. The mechanisms that establish and maintain these different fiber types vary throughout development and with changing functional demand. Chicken skeletal muscle fibers can be generally categorized as fast and fast/slow based on expression of the slow myosin heavy chain 2 (MyHC2) gene in fast/slow muscle fibers. To investigate the cellular and molecular mechanisms that control fiber type formation in secondary or fetal muscle fibers, myoblasts from the fast pectoralis major (PM) and fast/slow medial adductor (MA) muscles were isolated, allowed to differentiate in vitro, and electrically stimulated. MA muscle fibers were induced to express the slow MyHC2 gene by electrical stimulation, whereas PM muscle fibers did not express the slow MyHC2 gene under identical stimulation conditions. However, PM muscle fibers did express the slow MyHC2 gene when electrical stimulation was combined with inhibition of inositol triphosphate receptor (IP3R) activity. Electrical stimulation was sufficient to increase nuclear localization of expressed nuclear-factor-of-activated-T-cells (NFAT), NFAT-mediated transcription, and slow MyHC2 promoter activity in MA muscle fibers. In contrast, both electrical stimulation and inhibitors of IP3R activity were required for these effects in PM muscle fibers. Electrical stimulation also increased levels of peroxisome-proliferator-activated receptor-{gamma} co-activator-1 (PGC-1{alpha}) protein in PM and MA muscle fibers. These results indicate that MA muscle fibers can be induced by electrical stimulation to express the slow MyHC2 gene and that fast PM muscle fibers are refractory to stimulation-induced slow MyHC2 gene expression due to fast PM muscle fiber specific cellular mechanisms involving IP3R activity.

  12. A functional electrical stimulation system for human walking inspired by reflexive control principles

    OpenAIRE

    Meng, Lin; Porr, Bernd; Macleod, Catherine A.; Gollee, Henrik

    2017-01-01

    This study presents an innovative multichannel functional electrical stimulation gait-assist system which employs a well-established purely reflexive control algorithm, previously tested in a series of bipedal walking robots. In these robots, ground contact information was used to activate motors in the legs, generating a gait cycle similar to that of humans. Rather than developing a sophisticated closed-loop functional electrical stimulation control strategy for stepping, we have instead uti...

  13. The Spatial Extent of Epiretinal Electrical Stimulation in the Healthy Mouse Retina

    Directory of Open Access Journals (Sweden)

    Zohreh Hosseinazdeh

    2017-07-01

    Full Text Available Background/Aims: Retinal prostheses use electrical stimulation to restore functional vision to patients blinded by retinitis pigmentosa. A key detail is the spatial pattern of ganglion cells activated by stimulation. Therefore, we characterized the spatial extent of network-mediated electrical activation of retinal ganglion cells (RGCs in the epiretinal monopolar electrode configuration. Methods: Healthy mouse RGC activities were recorded with a micro-electrode array (MEA. The stimuli consisted of monophasic rectangular cathodic voltage pulses and cycling full-field light flashes. Results: Voltage tuning curves exhibited significant hysteresis, reflecting adaptation to electrical stimulation on the time scale of seconds. Responses decreased from 0 to 300 µm, and were also dependent on the strength of stimulation. Applying the Rayleigh criterion to the half-width at half-maximum of the electrical point spread function suggests a visual acuity limit of no better than 20/946. Threshold voltage showed only a modest increase across these distances. Conclusion: The existence of significant hysteresis requires that future investigations of electrical retinal stimulation control for such long-memory adaptation. The spread of electrical activation beyond 200 µm suggests that neighbouring electrodes in epiretinal implants based on indirect stimulation of RGCs may be indiscriminable at interelectrode spacings as large as 400 µm.

  14. Functional electrical stimulation assisted cycling of patients with subacute stroke: kinetic and kinematic analysis.

    Science.gov (United States)

    Szecsi, J; Krewer, C; Müller, F; Straube, A

    2008-10-01

    Cycling is a safe and functionally effective exercise for patients with early post-stroke and poor balance. Such exercise is considered even more effective when functional electrical stimulation is added. Our principal aim was to determine the biomechanically quantifiable parameters of cycling that can be improved in patients with subacute hemiparesis by incorporating functional electrical stimulation. These parameters were defined as objective goals that can be achieved in clinical applications. A secondary aim was to determine whether they could be used to identify subjects who would benefit from such therapy. Using a tricycle testbed, we tested 39 subacute (mean 10.9 weeks post-stroke (SD 5.9)), hemiplegic subjects. During isometric measurements we recorded volitional and electrically evoked crank torques, the latter at maximal tolerable intensity. During ergometric measurements, volitional pedaling was alternated with combined pedaling (volitional supported by stimulation), performed at 30-s intervals. Power, smoothness, and symmetry of cycling were evaluated. Twenty-six percent of the subjects significantly improved the smoothness of their cycling with functional electrical stimulation. Only 8% and 10% significantly increased their power and symmetry, respectively. The improvement in smoothness significantly correlated with the capability of the individual to generate electrical torque (Spearman's rank correlation coefficient=0.66 at P=0.001). The smoothness of cycling was the most sensitive parameter improved by functional electrical stimulation. This improvement depended on the amount of torque evoked, and the torque achieved, in turn, correlated with the tolerated intensity of stimulation.

  15. Motor Skill Acquisition and Retention after Somatosensory Electrical Stimulation in Healthy Humans

    NARCIS (Netherlands)

    Veldman, Menno P; Zijdewind, Inge; Maffiuletti, Nicola A; Hortobágyi, Tibor

    2016-01-01

    Somatosensory electrical stimulation (SES) can increase motor performance, presumably through a modulation of neuronal excitability. Because the effects of SES can outlast the period of stimulation, we examined the possibility that SES can also enhance the retention of motor performance, motor

  16. Modeling binaural responses in the auditory brainstem to electric stimulation of the auditory nerve.

    Science.gov (United States)

    Chung, Yoojin; Delgutte, Bertrand; Colburn, H Steven

    2015-02-01

    Bilateral cochlear implants (CIs) provide improvements in sound localization and speech perception in noise over unilateral CIs. However, the benefits arise mainly from the perception of interaural level differences, while bilateral CI listeners' sensitivity to interaural time difference (ITD) is poorer than normal. To help understand this limitation, a set of ITD-sensitive neural models was developed to study binaural responses to electric stimulation. Our working hypothesis was that central auditory processing is normal with bilateral CIs so that the abnormality in the response to electric stimulation at the level of the auditory nerve fibers (ANFs) is the source of the limited ITD sensitivity. A descriptive model of ANF response to both acoustic and electric stimulation was implemented and used to drive a simplified biophysical model of neurons in the medial superior olive (MSO). The model's ITD sensitivity was found to depend strongly on the specific configurations of membrane and synaptic parameters for different stimulation rates. Specifically, stronger excitatory synaptic inputs and faster membrane responses were required for the model neurons to be ITD-sensitive at high stimulation rates, whereas weaker excitatory synaptic input and slower membrane responses were necessary at low stimulation rates, for both electric and acoustic stimulation. This finding raises the possibility of frequency-dependent differences in neural mechanisms of binaural processing; limitations in ITD sensitivity with bilateral CIs may be due to a mismatch between stimulation rate and cell parameters in ITD-sensitive neurons.

  17. 42 CFR 414.232 - Special payment rules for transcutaneous electrical nerve stimulators (TENS).

    Science.gov (United States)

    2010-10-01

    ... nerve stimulators (TENS). 414.232 Section 414.232 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... Special payment rules for transcutaneous electrical nerve stimulators (TENS). (a) General payment rule. Except as provided in paragraph (b) of this section, payment for TENS is made on a purchase basis with...

  18. Cycle-to-cycle control of swing phase of paraplegic gait induced by surface electrical stimulation

    NARCIS (Netherlands)

    Franken, H.M.; Franken, H.M.; Veltink, Petrus H.; Baardman, G.; Redmeijer, R.A.; Boom, H.B.K.

    1995-01-01

    Parameterised swing phase of gait in paraplegics was obtained using surface electrical stimulation of the hip flexors, hamstrings and quadriceps; the hip flexors were stimulated to obtain a desired hip angle range, the hamstrings to provide foot clearance in the forward swing, and the quadriceps to

  19. Acupuncture with manual and electrical stimulation for labour pain : a longitudinal randomised controlled trial

    OpenAIRE

    Vixner, Linda; Schytt, Erica; Stener-Victorin, Elisabet; Waldenström, Ulla; Pettersson, Hans; Mårtensson, Lena B.

    2014-01-01

    Background: Acupuncture is commonly used to reduce pain during labour despite contradictory results. The aim of this study is to evaluate the effectiveness of acupuncture with manual stimulation and acupuncture with combined manual and electrical stimulation (electro-acupuncture) compared with standard care in reducing labour pain. Our hypothesis was that both acupuncture stimulation techniques were more effective than standard care, and that electro-acupuncture was most effective.  Methods: ...

  20. Muscular Strength Gains and Sensory Perception Changes: A Comparison of Electrical and Combined Electrical/Magnetic Stimulation.

    Science.gov (United States)

    1992-04-10

    Electrotherapy 2d ed. Norwalk, CT: Appleton & Lange; 1991:385-399. 18. Cadwell J. Principles of magnetoelectric stimulation. In: Chokroverty S, ed. Magnetic...press). 23. Cummings J. Electrical stimulation of healthy muscle and tissue repair. In: Nelson RM, Currier DP, eds. Clinical Electrotherapy , 2d ed...flow, and and influencing changes. In: Nelson RM, Currier DP, eds. Clinical Electrotherapy , 2d ed. Norwalk, CT: Appleton & Lange;1991:171-199 27

  1. The efficacy of electrical stimulation in lower extremity cutaneous wound healing: A systematic review.

    Science.gov (United States)

    Ashrafi, Mohammed; Alonso-Rasgado, Teresa; Baguneid, Mohamed; Bayat, Ardeshir

    2017-02-01

    Current gold standard lower extremity cutaneous wound management is not always effective. Cutaneous wounds generate a "current of injury" which is directly involved in wound healing processes. Application of exogenous electrical stimulation has been hypothesised to imitate the natural electric current that occurs in cutaneous wounds. The aim of this extensive review was to provide a detailed update on the variety of electrical stimulation modalities used in the management of lower extremity wounds. Several different waveforms and delivery methods of electrical stimulation have been used. Pulsed current appears superior to other electrical modalities available. The majority of studies support the beneficial effects of pulsed current over conservative management of lower extremity cutaneous wounds. Although it appears to have no benefit over causal surgical intervention, it is a treatment option which could be utilised in those patients unsuitable for surgery. Other waveforms and modalities appear promising; however, they still lack large trial data to recommend a firm conclusion with regards to their use. Current studies also vary in quantity, quality and protocol across the different modalities. The ideal electrical stimulation device needs to be non-invasive, portable and cost-effective and provides minimal interference with patients' daily life. Further studies are necessary to establish the ideal electrical stimulation modality, parameters, method of delivery and duration of treatment. The development and implementation of newer devices in the management of acute and chronic wounds provides an exciting direction in the field of electrotherapy. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Transcutaneous electric nerve stimulation (TENS) for cancer pain in adults.

    Science.gov (United States)

    Hurlow, Adam; Bennett, Michael I; Robb, Karen A; Johnson, Mark I; Simpson, Karen H; Oxberry, Stephen G

    2012-03-14

    Cancer-related pain is complex and multi-dimensional but the mainstay of cancer pain management has predominantly used a biomedical approach. There is a need for non-pharmacological and innovative approaches. Transcutaneous Electric Nerve Stimulation (TENS) may have a role in pain management but the effectiveness of TENS is currently unknown. This is an update of the original review published in Issue 3, 2008. The aim of this systematic review was to determine the effectiveness of TENS for cancer-related pain in adults. The initial review searched The Cochrane Library, MEDLINE, EMBASE, CINAHL, PsychINFO, AMED and PEDRO databases in April 2008. We performed an updated search of CENTRAL, MEDLINE, EMBASE, CINAHL and PEDRO databases in November 2011. We included only randomised controlled trials (RCTS) investigating the use of TENS for the management of cancer-related pain in adults. The search strategy identified a further two studies for possible inclusion. One of the review authors screened each abstract using a study eligibility tool. Where eligibility could not be determined, a second author assessed the full paper. One author used a standardised data extraction sheet to collect information on the studies and independently assess the quality of the studies using the validated five-point Oxford Quality Scale. The small sample sizes and differences in patient study populations of the three included studies (two from the original review and a third included in this update) prevented meta-analysis. For the original review the search strategy identified 37 possible published studies; we divided these between two pairs of review authors who decided on study selection; all four review authors discussed and agreed final scores. Only one additional RCT met the eligibility criteria (24 participants) for this updated review. Although this was a feasibility study, not designed to investigate intervention effect, it suggested that TENS may improve bone pain on movement in a

  3. Interaction of transcranial magnetic stimulation and electrical transmastoid stimulation in human subjects

    DEFF Research Database (Denmark)

    Taylor, Janet L; Petersen, Nicolas Caesar; Butler, Jane E

    2002-01-01

    Transcranial magnetic stimulation activates corticospinal neurones directly and transsynaptically and hence, activates motoneurones and results in a response in the muscle. Transmastoid stimulation results in a similar muscle response through activation of axons in the spinal cord. This study......-wave, facilitation still occurred at ISIs of -6 and -5 ms and depression of the paired response at ISIs of 0, 1, 4 and 5 ms. The interaction of the response to transmastoid stimulation with the multiple descending volleys elicited by magnetic stimulation of the cortex is complex. However, depression of the response...

  4. The reinforcing effect of electrical stimulation of the tongue in thirsty rats : brief communication

    NARCIS (Netherlands)

    Slangen, J.L.; Weijmen, J.A.W.M.

    Thirsty rats repeatedly closed the electric circuit of a drinkometer with their tongue in the absence of water. The hypothesis that electrical stimulation of the tongue has reinforcing properties was tested. The results indicate that persistent licking by a thirsty rat is dependent on a current as

  5. Alternating stimulation of synergistic muscles during functional electrical stimulation cycling improves endurance in persons with spinal cord injury.

    Science.gov (United States)

    Decker, M J; Griffin, L; Abraham, L D; Brandt, L

    2010-12-01

    Therapeutic effects of functional electrical stimulation (FES) cycling for persons with spinal cord injury (SCI) are limited by high rates of muscular fatigue. FES-cycling performance limits and surface mechanomyography (MMG) of 12 persons with SCI were compared under two different stimulation protocols of the quadriceps muscles. One strategy used the standard "co-activation" protocol from the manufacturer of the FES cycle which involved intermittent simultaneous activation of the entire quadriceps muscle group for 400 ms. The other strategy was an "alternation" stimulation protocol which involved alternately stimulating the rectus femoris (RF) muscle for 100 ms and the vastus medialis (VM) and vastus lateralis (VL) muscles for 100 ms, with two sets with a 400 ms burst. Thus, during the alternation protocol, each of the muscle groups rested for two 100 ms "off" periods in each 400 ms burst. There was no difference in average cycling cadence (28 RPM) between the two protocols. The alternation stimulation protocol produced longer ride times and longer virtual distances traveled and used lower stimulation intensity levels with no differences in average MMG amplitudes compared to the co-activation protocol. These results demonstrate that FES-cycling performance can be enhanced by a synergistic muscle alternation stimulation strategy. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Intrusive thoughts elicited by direct electrical stimulation during stereo-electroencephalography

    Directory of Open Access Journals (Sweden)

    Irina Popa

    2016-07-01

    Full Text Available Cortical direct electrical stimulation (DES is a method of brain mapping used during invasive presurgical evaluation of patients with intractable epilepsy. Intellectual auras like intrusive thoughts, also known as forced thinking (FT, have been reported during frontal seizures. However there are few reports on FT obtained during DES in frontal cortex. We report three cases in which we obtained intrusive thoughts while stimulating the dorsolateral prefrontal cortex and the white matter in the prefrontal region. In order to highlight the effective connectivity that might explain this clinical response, we have analyzed cortico-cortical potentials evoked by single pulse electrical stimulation.

  7. Cortical somatosensory evoked potentials from lumbosacral dermatomes: airpuff versus electrical stimulation.

    Science.gov (United States)

    Schimsheimer, R J; Boejharat, K R; van der Sluijs, J C; Stijnen, T; Gryz, E

    1995-01-01

    Cortical potentials were elicited by airpuff stimulation of the L5 and S1 dermatome in a group of 24 healthy volunteers. The results were compared with the SEPs obtained by conventional electrical stimulation. Both stimulus modalities produce stable and good reproducible cortical responses of similar waveform. The most stable second negative peak, labeled N2, was used in this study. Mean latencies (in msec) were: N2 L5 air = 67.1 +/- 3.3, N2 L5 electr. = 55.7 +/- 3.7 N2 S1 air = 67.2 +/- 3.9, and N2 S1 electr. = 55.1 +/- 2.9 The maximum R/L difference (mean + 3 SD) was 5.7 msec, 5.9 msec, 7.2 msec and 7.2 msec for respectively N2 L5 air, N2 L5 electrical, N2 S1 air and N2 S1 electrical. Single regression analysis showed a significant influence of height, but not age upon all latencies. Multiple regression analysis with height and age as independent variables showed a significant influence of height and age together upon the latencies of the electrical SEP (both L5 and S1). For the airpuff SEP only height was significant. Gender had no effect on the cortical components. The amplitude of peak N2 after electrical stimulation of the S1 dermatome was significant higher than after airpuff stimulation, 2.9 and 1.7 microvolt respectively. For the L5 dermatome both types of stimuli produced responses of nearly equal amplitude, 2.5 and 2.1 microvolt for electrical and airpuff stimulation respectively. Airpuff SEPs may provide a good alternative for electrical stimulation.

  8. Influence of transcutaneous electrical stimulation on heterotopic ossification: an experimental study in Wistar rats

    Directory of Open Access Journals (Sweden)

    T.G.G. Zotz

    2015-01-01

    Full Text Available Heterotopic ossification (HO is a metaplastic biological process in which there is newly formed bone in soft tissues, resulting in joint mobility deficit and pain. Different treatment modalities have been tried to prevent HO development, but there is no consensus on a therapeutic approach. Since electrical stimulation is a widely used resource in physiotherapy practice to stimulate joint mobility, with analgesic and anti-inflammatory effects, its usefulness for HO treatment was investigated. We aimed to identify the influence of electrical stimulation on induced HO in Wistar rats. Thirty-six male rats (350-390 g were used, and all animals were anesthetized for blood sampling before HO induction, to quantify the serum alkaline phosphatase. HO induction was performed by bone marrow implantation in both quadriceps of the animals, which were then divided into 3 groups: control (CG, transcutaneous electrical nerve stimulation (TENS group (TG, and functional electrical stimulation (FES group (FG with 12 rats each. All animals were anesthetized and electrically stimulated twice per week, for 35 days from induction day. After this period, another blood sample was collected and quadriceps muscles were bilaterally removed for histological and calcium analysis and the rats were killed. Calcium levels in muscles showed significantly lower results when comparing TG and FG (P

  9. Electrical stimulation to reduce chronic toe-flexor hypertonicity. A case report.

    Science.gov (United States)

    Fulbright, J S

    1984-04-01

    Electrical stimulation reduces hypertonicity, but the mechanism for the effectiveness is not well understood. In this particular case, electrical stimulation to the toe extensors resulted in inhibition of the toe-flexor hypertonicity. This phenomenon may be explained by Sherrington's theory of reciprocal inhibition. Liberson found that electrical stimulation of an agonist is associated with a concomitant inhibition of the antagonist in the healthy individual. I applied Liberson's findings in my treatment of the patient. By facilitating the toe extensors, and thus inhibiting the toe flexors, toe posturing improved considerably and allowed the patient volitionally to control his toes, which, in turn, improved his foot and toe comfort. Stimulation also allowed the patient to assume a plantigrade and forefoot weight-bearing position to improve his gait. This patient benefitted dramatically from the use of electrical stimulation in inhibiting hypertonicity, and I believe this modality may be helpful in other cases dealing with increased muscle tone. The patient will continue to be observed on a regular basis for reassessment of the long-term effects of electrical stimulation on hypertonicity and on the skin at the electrode sites.

  10. Renewal-process approximation of a stochastic threshold model for electrical neural stimulation.

    Science.gov (United States)

    Bruce, I C; Irlicht, L S; White, M W; O'Leary, S J; Clark, G M

    2000-01-01

    In a recent set of modeling studies we have developed a stochastic threshold model of auditory nerve response to single biphasic electrical pulses (Bruce et al., 1999c) and moderate rate (less than 800 pulses per second) pulse trains (Bruce et al., 1999a). In this article we derive an analytical approximation for the single-pulse model, which is then extended to describe the pulse-train model in the case of evenly timed, uniform pulses. This renewal-process description provides an accurate and computationally efficient model of electrical stimulation of single auditory nerve fibers by a cochlear implant that may be extended to other forms of electrical neural stimulation.

  11. A wearable multi-pad electrode prototype for selective functional electrical stimulation of upper extremities.

    Science.gov (United States)

    Hai-Peng Wang; Ai-Wen Guo; Zheng-Yang Bi; Fei Li; Xiao-Ying Lu; Zhi-Gong Wang

    2017-07-01

    In this paper, a surface multi-pad stimulation electrode with selective characteristics was designed, it was safe to use and easy to mount. Then a wearable and distributed multi-pad functional electrical stimulation (FES) prototype combined with sensing, communication and smart technology was designed, which can achieve a fast, intelligent optimization to determine stimulation electrode sites and comfortable stimulation. In addition, in order to improve the application and convenience of FES in the rehabilitation at clinical and home-setting, an Android application (APP) based on smart phone was designed for running an algorithm of searching optimal stimulation site. The prototype has been validated by performing selective stimulation on one healthy subject, and showed that the FES system can automatically determine the stimulation site.

  12. Chronic effects of low-frequency low-intensity electrical stimulation of stretched human muscle

    Science.gov (United States)

    Shenkman, Boris S.; Lyubaeva, Ekaterina V.; Popov, Daniil V.; Netreba, Aleksey I.; Bravy, Yan R.; Tarakin, Pavel P.; Lemesheva, Yulia S.; Vinogradova, Olga L.

    2007-02-01

    Effects of low-frequency electrical stimulation, which is currently considered to be a possible countermeasure for long-duration spaceflights, with and without stretch were evaluated. Twelve young male volunteers were randomly distributed into two groups. In one group anterior thigh muscles—knee extensors of both legs were stimulated with frequency of 15 Hz for 4.5 wks, six times a week; each session was 6-h long. In the other group, electrical stimulation with the same parameters was applied to stretched knee extensors. Following stimulation the subjects exhibited an increase in fatigue resistance, and in the succinate dehydrogenase activity and a 10% gain in the percentage of muscle fibers with slow myosin heavy chain isoforms. In a stimulated group the peak voluntary strength went down significantly, the CSA of fast muscle fibers in m. quadriceps femoris became slightly less in size (10%). Electrical stimulation of the stretched muscles induced an insignificant decline in their strength and an increase of cross-sectional area of muscle fibers of both types. Thus chronic low-frequency electrical stimulation may be proposed as a candidate countermeasure against muscle strength and mass loss if it is combined with stretch.

  13. Treatment of neurogenic detrusor overactivity in spinal cord injured patients by conditional electrical stimulation.

    Science.gov (United States)

    Hansen, J; Media, S; Nøhr, M; Biering-Sørensen, F; Sinkjaer, T; Rijkhoff, N J M

    2005-06-01

    The feasibility of automatic event driven electrical stimulation of the dorsal penile/clitoral nerve in the treatment of neurogenic detrusor overactivity (NDO) was evaluated in individuals with spinal cord injury. The study included 2 women and 14 men older than 18 years with NDO, bladder capacity below 500 ml and complete or incomplete suprasacral spinal cord injury. Detrusor pressure (Pdet) was recorded during ordinary, natural bladder filling. In a similar subsequent recording Pdet was used to trigger electrical stimulation when pressure exceeded 10 cm H2O. Of the 16 patients enrolled in this study 13 had increased bladder capacity together with a storage pressure decrease as a result of automatic, event driven electrical stimulation. In 2 patients stimulation could not inhibit the first undesired contraction, leakage occurred and finally 1 could not tolerate stimulation. During stimulated filling Pdet never exceeded 55 cm H2O. Thus, storage pressure was sufficiently low to prevent kidney damage. An average bladder capacity increase of 53% was achieved. This study demonstrates the feasibility of automatic, event driven electrical stimulation in the treatment of NDO. Although the setup in this experiment is not suitable in a clinical setting, the treatment modality is promising and it warrants further investigation.

  14. Spinal cord stimulation for electrical storm refractory to conventional medical treatment: an emerging indication?

    Science.gov (United States)

    Walega, David; Rosenow, Joshua M

    2015-04-01

    To observe the effect of thoracic spinal cord stimulation with dual octipolar epidural electrodes on episodes of ventricular tachycardia and ventricular fibrillation in a patient with nonischemic familial cardiomyopathy and severe electrical storm refractory to conventional medical treatment. Following implantation of temporary bilateral octipolar thoracic epidural electrodes and constant low-grade stimulation, episodes of ventricular tachycardia and ventricular fibrillation were eradicated, and a permanent system was surgically implanted uneventfully. Electrical storm ceased thereafter, though ventricular function from progressive cardiomyopathy worsened, requiring heart transplantation several months later. Spinal cord stimulation may play an important therapeutic role in the treatment of refractory electrical storm when conventional medical treatments have failed. The mechanism by which stimulation of the spinal cord confers a therapeutic effect is not completely understood, although direct modulation of sympathetic and parasympathetic tone in the cardiac conduction system is most likely, based on animal models of ischemia-induced ventricular tachycardia. © 2014 International Neuromodulation Society.

  15. Effects of sustained electrical stimulation on spasticity assessed by the pendulum test

    Directory of Open Access Journals (Sweden)

    Vargas Luna José L.

    2016-09-01

    Full Text Available Neuromodulation using electrical stimulation is able to enhance motor control of individuals suffering an upper motor neuron disorder. This work examined the effect of sustained electrical stimulation to modify spasticity in the leg muscles. We applied transcutaneous spinal cord stimulation with a pulse rate of 50 Hz for 30 min. The subjects were assessed before and after the intervention using in a pendulum test setup. The motion of the free swinging leg was acquired through video tracking and goniometer measurements. The quantification was done through the R2n index which shows consistency identifying the spasticity levels. In all incomplete SCI subjects having severe spasticity, the results show that electrical stimulation is effective to modify the increased muscle tone.

  16. Electrical Stimulation of the Upper Limb in Stroke: Stimulation of the Extensors of the Hand vs. Alternate Stimulation of Flexors and Extensors

    NARCIS (Netherlands)

    de Kroon, J.R.; IJzerman, Maarten Joost; Lankhorst, G.J.; Zilvold, G.

    2004-01-01

    Objective: To investigate whether there is a difference in functional improvement in the affected arm of chronic stroke patients when comparing two methods of electrical stimulation. Design: Explanatory trial in which 30 chronic stroke patients with impaired arm function were randomly allocated to

  17. Platelet activation using electric pulse stimulation: growth factor profile and clinical implications.

    Science.gov (United States)

    Torres, Andrew S; Caiafa, Antonio; Garner, Allen L; Klopman, Steve; LaPlante, Nicole; Morton, Christine; Conway, Kenneth; Michelson, Alan D; Frelinger, Andrew L; Neculaes, V Bogdan

    2014-09-01

    Autologous platelet gel therapy using platelet-rich plasma has emerged as a promising alternative for chronic wound healing, hemostasis, and wound infection control. A critical step for this therapeutic approach is platelet activation, typically performed using bovine thrombin (BT) and calcium chloride. However, exposure of humans to BT can stimulate antibody formation, potentially resulting in severe hemorrhagic or thrombotic complications. Electric pulse stimulation using nanosecond PEFs (pulse electric fields) is an alternative, nonbiochemical platelet activation method, thereby avoiding exposure to xenogeneic thrombin and associated risks. In this study, we identified specific requirements for a clinically relevant activator instrument by dynamically measuring current, voltage, and electric impedance for platelet-rich plasma samples. From these samples, we investigated the profile of growth factors released from human platelets with electric pulse stimulation versus BT, specifically platelet-derived growth factor, transforming growth factor β, and epidermal growth factor, using commercial enzyme-linked immunosorbent assay kits. Electric pulse stimulation triggers growth factor release from platelet α-granules at the same or higher level compared with BT. Electric pulse stimulation is a fast, inexpensive, easy-to-use platelet activation method for autologous platelet gel therapy.

  18. Electrical stimulation of nerve cells using conductive nanofibrous scaffolds for nerve tissue engineering.

    Science.gov (United States)

    Ghasemi-Mobarakeh, Laleh; Prabhakaran, Molamma P; Morshed, Mohammad; Nasr-Esfahani, Mohammad Hossein; Ramakrishna, Seeram

    2009-11-01

    Fabrication of scaffolds with suitable chemical, mechanical, and electrical properties is critical for the success of nerve tissue engineering. Electrical stimulation was directly applied to electrospun conductive nanofibrous scaffolds to enhance the nerve regeneration process. In the present study, electrospun conductive nanofibers were prepared by mixing 10 and 15 wt% doped polyaniline (PANI) with poly (epsilon-caprolactone)/gelatin (PG) (70:30) solution (PANI/PG) by electrospinning. The fiber diameter, pore size, hydrophilicity, tensile properties, conductivity, Fourier transform infrared (FTIR), and X-ray photoelectron spectroscopy spectra of nanofibers were determined, and the in vitro biodegradability of the different nanofibrous scaffolds was also evaluated. Nanofibrous scaffolds containing 15% PANI was found to exhibit the most balanced properties to meet all the required specifications for electrical stimulation for its enhanced conductivity and is used for in vitro culture and electrical stimulation of nerve stem cells. 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and scanning electron microscopy results showed that conductive nanofibrous scaffolds are suitable substrates for the attachment and proliferation of nerve stem cells. Electrical stimulation through conductive nanofibrous PANI/PG scaffolds showed enhanced cell proliferation and neurite outgrowth compared to the PANI/PG scaffolds that were not subjected to electrical stimulation.

  19. TRANSCUTANEOUS ELECTRICAL NERVE-STIMULATION (TENS) IN RAYNAUDS-PHENOMENON

    NARCIS (Netherlands)

    MULDER, P; DOMPELING, EC; VANSLOCHTERENVANDERBOOR, JC; KUIPERS, WD; SMIT, AJ

    Transcutaneous nerve stimulation (TENS) has been described as resulting in vasodilatation. The effect of 2 Hz TENS of the right hand during forty-five minutes on skin temperature and plethysmography of the third digit of both hands and feet and on transcutaneous oxygen tension (TcpO2) of the right

  20. Experimental electrical stimulation of the bladder using a new device

    DEFF Research Database (Denmark)

    Petersen, T; Christiansen, P; Nielsen, B

    1986-01-01

    electrodes at each ureterovesical junction evoked bladder pressure increase similar to those produced in previous investigations in dogs. Sacral nerve stimulation of S2 evoked bladder contraction at a minimal current. Microscopic examination revealed no cellular reactions to the carbon fibers...

  1. Effects of acute selective pudendal nerve electrical stimulation after simulated childbirth injury

    Science.gov (United States)

    Gill, Bradley C.; Dissaranan, Charuspong; Zutshi, Massarat; Balog, Brian M.; Lin, Danli; Damaser, Margot S.

    2013-01-01

    During childbirth, a combinatorial injury occurs and can result in stress urinary incontinence (SUI). Simulated childbirth injury, consisting of vaginal distension (VD) and pudendal nerve crush (PNC), results in slowed recovery of continence, as well as decreased expression of brain-derived neurotrophic factor (BDNF), a regenerative cytokine. Electrical stimulation has been shown to upregulate BDNF in motor neurons and facilitate axon regrowth through the increase of βII-tubulin expression after injury. In this study, female rats underwent selective pudendal nerve motor branch (PNMB) stimulation after simulated childbirth injury or sham injury to determine whether such stimulation affects bladder and anal function after injury and whether the stimulation increases BDNF expression in Onuf's nucleus after injury. Rats received 4 h of VD followed by bilateral PNC and 1 h of subthreshold electrical stimulation of the left PNMB and sham stimulation of the right PNMB. Rats underwent filling cystometry and anal pressure recording before, during, and after the stimulation. Bladder and anal contractile function were partially disrupted after injury. PNMB stimulation temporarily inhibited bladder contraction after injury. Two days and 1 wk after injury, BDNF expression in Onuf's nucleus of the stimulated side was significantly increased compared with the sham-stimulated side, whereas βII-tubulin expression in Onuf's nucleus of the stimulated side was significantly increased only 1 wk after injury. Acute electrical stimulation of the pudendal nerve proximal to the crush site upregulates BDNF and βII-tubulin in Onuf's nucleus after simulated childbirth injury, which could be a potential preventive option for SUI after childbirth injury. PMID:23152293

  2. Electrical stimulation in white oyster mushroom (Pleurotus florida) production

    Science.gov (United States)

    Roshita, I.; Nurfazira, K. M. P.; Fern, C. Shi; Ain, M. S. Nur

    2017-09-01

    White oyster mushroom (Pleurotus florida) is an edible mushroom that gained popularity due to its nutritional values, low production cost and ease of cultivation. There are several research reported on the mushroom fruiting bodies which were actively developed when applying electrical shock treatment. This study was aimed to investigate the effects of different electrical voltages on the growth and yield of white oyster mushroom (Pleurotus florida). Five different electrical voltages had been applied during spawning period which were 6V, 9V, 12V, 15V and mushroom bags without any treatment served as control. Treatment at 6V showed the highest rate for mycelium growth while 15V took the shortest time for fruiting body formation. However, no significant different (P>0.05) among all the treatments was observed for the time taken for the mycelium to fill-up the bag and pinhead emergence. The total fresh weight and percentage of biological efficiency for treatment at 9V showed higher values compared to control. Treatment at 9V also showed the largest pileus diameter and the most firm in the pileus texture. Meanwhile, treatment at 6V showed the highest a* value (redness). In addition, different electrical voltage treatments applied did not show any significant effect on substrate utilization efficiency, colour L* and b* values. In conclusion, among all the electrical treatments applied, 9V could be considered as the best treatment to enhance the yield of white oyster mushroom.

  3. Dynamic impedance model of the skin-electrode interface for transcutaneous electrical stimulation.

    Directory of Open Access Journals (Sweden)

    José Luis Vargas Luna

    Full Text Available Transcutaneous electrical stimulation can depolarize nerve or muscle cells applying impulses through electrodes attached on the skin. For these applications, the electrode-skin impedance is an important factor which influences effectiveness. Various models describe the interface using constant or current-depending resistive-capacitive equivalent circuit. Here, we develop a dynamic impedance model valid for a wide range stimulation intensities. The model considers electroporation and charge-dependent effects to describe the impedance variation, which allows to describe high-charge pulses. The parameters were adjusted based on rectangular, biphasic stimulation pulses generated by a stimulator, providing optionally current or voltage-controlled impulses, and applied through electrodes of different sizes. Both control methods deliver a different electrical field to the tissue, which is constant throughout the impulse duration for current-controlled mode or have a very current peak for voltage-controlled. The results show a predominant dependence in the current intensity in the case of both stimulation techniques that allows to keep a simple model. A verification simulation using the proposed dynamic model shows coefficient of determination of around 0.99 in both stimulation types. The presented method for fitting electrode-skin impedance can be simple extended to other stimulation waveforms and electrode configuration. Therefore, it can be embedded in optimization algorithms for designing electrical stimulation applications even for pulses with high charges and high current spikes.

  4. A Unique Electrical Thermal Stimulation System Comparable to Moxibustion of Subcutaneous Tissue

    Directory of Open Access Journals (Sweden)

    Hyoun-Seok Myoung

    2014-01-01

    Full Text Available Moxibustion strengthens immunity and it is an effective treatment modality, but, depending on the material quantity, shape, and composition, the thermal strength and intensity can be difficult to control, which may cause pain or epidermal burns. To overcome these limitations, a heat stimulating system which is able to control the thermal intensity was developed. The temperature distributions on epidermis, at 5 mm and 10 mm of depth, in rabbit femoral tissue were compared between moxibustion and the electric thermal stimulation system. The stimulation system consists of a high radio frequency dielectric heating equipment (2 MHz frequency, maximum power 200 W, isolation probe, isolation plate, negative pressure generator, and a temperature assessment system. The temperature was modulated by controlling the stimulation pulse duty ratio, repetition number, and output. There were 95% and 91% temperature distribution correlations between moxibustion and the thermal stimulus at 5 mm and 10 mm of depth in tissue, respectively. Moreover, the epidermal temperature in thermal stimulation was lower than that in moxibustion. These results showed that heat loss by the electric thermal stimulation system is less than that by the traditional moxibustion method. Furthermore, the proposed electric thermal stimulation did not cause adverse effects, such as suppuration or blisters, and also provided subcutaneous stimulation comparable to moxibustion.

  5. Modification of electrical pain threshold by voluntary breathing-controlled electrical stimulation (BreEStim in healthy subjects.

    Directory of Open Access Journals (Sweden)

    Shengai Li

    Full Text Available BACKGROUND: Pain has a distinct sensory and affective (i.e., unpleasantness component. BreEStim, during which electrical stimulation is delivered during voluntary breathing, has been shown to selectively reduce the affective component of post-amputation phantom pain. The objective was to examine whether BreEStim increases pain threshold such that subjects could have improved tolerance of sensation of painful stimuli. METHODS: Eleven pain-free healthy subjects (7 males, 4 females participated in the study. All subjects received BreEStim (100 stimuli and conventional electrical stimulation (EStim, 100 stimuli to two acupuncture points (Neiguan and Weiguan of the dominant hand in a random order. The two different treatments were provided at least three days apart. Painful, but tolerable electrical stimuli were delivered randomly during EStim, but were triggered by effortful inhalation during BreEStim. Measurements of tactile sensation threshold, electrical sensation and electrical pain thresholds, thermal (cold sensation, warm sensation, cold pain and heat pain thresholds were recorded from the thenar eminence of both hands. These measurements were taken pre-intervention and 10-min post-intervention. RESULTS: There was no difference in the pre-intervention baseline measurement of all thresholds between BreEStim and EStim. The electrical pain threshold significantly increased after BreEStim (27.5±6.7% for the dominant hand and 28.5±10.8% for the non-dominant hand, respectively. The electrical pain threshold significantly decreased after EStim (9.1±2.8% for the dominant hand and 10.2±4.6% for the non-dominant hand, respectively (F[1, 10] = 30.992, p = .00024. There was no statistically significant change in other thresholds after BreEStim and EStim. The intensity of electrical stimuli was progressively increased, but no difference was found between BreEStim and EStim. CONCLUSION: Voluntary breathing controlled electrical stimulation

  6. MAGNETIC VERSUS ELECTRICAL STIMULATION IN THE INTERPOLATION TWITCH TECHNIQUE OF ELBOW FLEXORS

    Directory of Open Access Journals (Sweden)

    Sofia I. Lampropoulou

    2012-12-01

    Full Text Available The study compared peripheral magnetic with electrical stimulation of the biceps brachii m. (BB in the single pulse Interpolation Twitch Technique (ITT. 14 healthy participants (31±7 years participated in a within-subjects repeated-measures design study. Single, constant-current electrical and magnetic stimuli were delivered over the motor point of BB with supramaximal intensity (20% above maximum at rest and at various levels of voluntary contraction. Force measurements from right elbow isometric flexion and muscle electromyograms (EMG from the BB, the triceps brachii m. (TB and the abductor pollicis brevis m. (APB were obtained. The twitch forces at rest and maximal contractions, the twitch force-voluntary force relationship, the M-waves and the voluntary activation (VA of BB between magnetic and electrical stimulation were compared. The mean amplitude of the twitches evoked at MVC was not significantly different between electrical (0.62 ± 0.49 N and magnetic (0.81 ± 0.49 N stimulation (p > 0.05, and the maximum VA of BB was comparable between electrical (95% and magnetic (93% stimulation (p > 0. 05. No differences (p >0.05 were revealed in the BB M-waves between electrical (13.47 ± 0.49 mV.ms and magnetic (12.61 ± 0.58 mV.ms stimulation. The TB M-waves were also similar (p > 0.05 but electrically evoked APB M-waves were significantly larger than those evoked by magnetic stimulation (p < 0.05. The twitch-voluntary force relationship over the range of MVCs was best described by non-linear functions for both electrical and magnetic stimulation. The electrically evoked resting twitches were consistently larger in amplitude than the magnetically evoked ones (mean difference 3.1 ± 3.34 N, p < 0.05. Reduction of the inter-electrodes distance reduced the twitch amplitude by 6.5 ± 6.2 N (p < 0.05. The fundamental similarities in voluntary activation assessment of BB with peripheral electrical and magnetic stimulation point towards a promising

  7. Synchronization of neuron population subject to steady DC electric field induced by magnetic stimulation.

    Science.gov (United States)

    Yu, Kai; Wang, Jiang; Deng, Bin; Wei, Xile

    2013-06-01

    Electric fields, which are ubiquitous in the context of neurons, are induced either by external electromagnetic fields or by endogenous electric activities. Clinical evidences point out that magnetic stimulation can induce an electric field that modulates rhythmic activity of special brain tissue, which are associated with most brain functions, including normal and pathological physiological mechanisms. Recently, the studies about the relationship between clinical treatment for psychiatric disorders and magnetic stimulation have been investigated extensively. However, further development of these techniques is limited due to the lack of understanding of the underlying mechanisms supporting the interaction between the electric field induced by magnetic stimulus and brain tissue. In this paper, the effects of steady DC electric field induced by magnetic stimulation on the coherence of an interneuronal network are investigated. Different behaviors have been observed in the network with different topologies (i.e., random and small-world network, modular network). It is found that the coherence displays a peak or a plateau when the induced electric field varies between the parameter range we defined. The coherence of the neuronal systems depends extensively on the network structure and parameters. All these parameters play a key role in determining the range for the induced electric field to synchronize network activities. The presented results could have important implications for the scientific theoretical studies regarding the effects of magnetic stimulation on human brain.

  8. Role of Cortical Cell Type and Morphology in Sub- and Suprathreshold Uniform Electric Field Stimulation

    Science.gov (United States)

    Radman, Thomas; Ramos, Raddy L; Brumberg, Joshua C; Bikson, Marom

    2009-01-01

    Background The neocortex is the most common target of sub-dural electrotherapy and non-invasive brain stimulation modalities including transcranial magnetic stimulation (TMS) and transcranial current simulation (TCS). Specific neuronal elements targeted by cortical stimulation are considered to underlie therapeutic effects, but the exact cell-type(s) affected by these methods remains poorly understood. Objective We determined if neuronal morphology or cell type predicted responses to sub- and suprathreshold uniform electric fields. Methods We characterized the effects of sub- and supra-threshold electrical stimulation on identified cortical neurons in vitro. Uniform electric fields were applied to rat motor cortex brain slices, while recording from interneurons and pyramidal cells across cortical layers, using whole cell patch clamp. Neuron morphology was reconstructed following intracellular dialysis of biocytin. Based solely on volume-weighted morphology, we developed a parsimonious model of neuronal soma polarization by sub-threshold electric fields. Results We found that neuronal morphology correlated with somatic sub-threshold polarization. Based on neuronal morphology, we predict layer V pyramidal neuronal soma to be the most sensitive to polarization by optimally oriented sub-threshold fields. Supra-threshold electric field action potential threshold was shown to reflect both direct cell polarization and synaptic (network) activation. Layer V/VI neuron absolute electric field action potential thresholds were lower than Layer II/III pyramidal neurons and interneurons. Compared to somatic current injection, electric fields promoted burst firing and modulated action potential firing times. PMID:20161507

  9. Tissue engineering bioreactor systems for applying physical and electrical stimulations to cells.

    Science.gov (United States)

    Jin, GyuHyun; Yang, Gi-Hoon; Kim, GeunHyung

    2015-05-01

    Bioreactor systems in tissue engineering applications provide various types of stimulation to mimic the tissues in vitro and in vivo. Various bioreactors have been designed to induce high cellular activities, including initial cell attachment, cell growth, and differentiation. Although cell-stimulation processes exert mostly positive effects on cellular responses, in some cases such stimulation can also have a negative effect on cultured cells. In this review, we discuss various types of bioreactor and the positive and negative effects of stimulation (physical, chemical, and electrical) on various cultured cell types. © 2014 Wiley Periodicals, Inc.

  10. Robust neurite extension following exogenous electrical stimulation within single walled carbon nanotube-composite hydrogels.

    Science.gov (United States)

    Koppes, A N; Keating, K W; McGregor, A L; Koppes, R A; Kearns, K R; Ziemba, A M; McKay, C A; Zuidema, J M; Rivet, C J; Gilbert, R J; Thompson, D M

    2016-07-15

    The use of exogenous electrical stimulation to promote nerve regeneration has achieved only limited success. Conditions impeding optimized outgrowth may arise from inadequate stimulus presentation due to differences in injury geometry or signal attenuation. Implantation of an electrically-conductive biomaterial may mitigate this attenuation and provide a more reproducible signal. In this study, a conductive nanofiller (single-walled carbon nanotubes [SWCNT]) was selected as one possible material to manipulate the bulk electrical properties of a collagen type I-10% Matrigel™ composite hydrogel. Neurite outgrowth within hydrogels (SWCNT or nanofiller-free controls) was characterized to determine if: (1) nanofillers influence neurite extension and (2) electrical stimulation of the nanofiller composite hydrogel enhances neurite outgrowth. Increased SWCNT loading (10-100-μg/mL) resulted in greater bulk conductivity (up to 1.7-fold) with no significant changes to elastic modulus. Neurite outgrowth increased 3.3-fold in 20-μg/mL SWCNT loaded biomaterials relative to the nanofiller-free control. Electrical stimulation promoted greater outgrowth (2.9-fold) within SWCNT-free control. The concurrent presentation of electrical stimulation and SWCNT-loaded biomaterials resulted in a 7.0-fold increase in outgrowth relative to the unstimulated, nanofiller-free controls. Local glia residing within the DRG likely contribute, in part, to the observed increases in outgrowth; but it is unknown which specific nanofiller properties influence neurite extension. Characterization of neuronal behavior in model systems, such as those described here, will aid the rational development of biomaterials as well as the appropriate delivery of electrical stimuli to support nerve repair. Novel biomedical devices delivering electrical stimulation are being developed to mitigate symptoms of Parkinson's, treat drug-resistant depression, control movement or enhance verve regeneration. Carbon

  11. Motor behaviors in the sheep evoked by electrical stimulation of the subthalamic nucleus.

    Science.gov (United States)

    Lentz, Linnea; Zhao, Yan; Kelly, Matthew T; Schindeldecker, William; Goetz, Steven; Nelson, Dwight E; Raike, Robert S

    2015-11-01

    Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is used to treat movement disorders, including advanced Parkinson's disease (PD). The pathogenesis of PD and the therapeutic mechanisms of DBS are not well understood. Large animal models are essential for investigating the mechanisms of PD and DBS. The purpose of this study was to develop a novel sheep model of STN DBS and quantify the stimulation-evoked motor behaviors. To do so, a large sample of animals was chronically-implanted with commercial DBS systems. Neuroimaging and histology revealed that the DBS leads were implanted accurately relative to the neurosurgical plan and also precisely relative to the STN. It was also possible to repeatedly conduct controlled evaluations of stimulation-evoked motor behavior in the awake-state. The evoked motor responses depended on the neuroanatomical location of the electrode contact selected for stimulation, as contacts proximal to the STN evoked movements at significantly lower voltages. Tissue stimulation modeling demonstrated that selecting any of the contacts stimulated the STN, whereas selecting the relatively distal contacts often also stimulated thalamus but only the distal-most contact stimulated internal capsule. The types of evoked motor behaviors were specific to the stimulation frequency, as low but not high frequencies consistently evoked movements resembling human tremor or dyskinesia. Electromyography confirmed that the muscle activity underlying the tremor-like movements in the sheep was consistent with human tremor. Overall, this work establishes that the sheep is a viable a large-animal platform for controlled testing of STN DBS with objective motor outcomes. Moreover, the results support the hypothesis that exaggerated low-frequency activity within individual nodes of the motor network can drive symptoms of human movement disorders, including tremor and dyskinesia. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. An electric stimulation system for electrokinetic particle manipulation in microfluidic devices.

    Science.gov (United States)

    Lopez-de la Fuente, M S; Moncada-Hernandez, H; Perez-Gonzalez, V H; Lapizco-Encinas, B H; Martinez-Chapa, S O

    2013-03-01

    Microfluidic devices have grown significantly in the number of applications. Microfabrication techniques have evolved considerably; however, electric stimulation systems for microdevices have not advanced at the same pace. Electric stimulation of micro-fluidic devices is an important element in particle manipulation research. A flexible stimulation instrument is desired to perform configurable, repeatable, automated, and reliable experiments by allowing users to select the stimulation parameters. The instrument presented here is a configurable and programmable stimulation system for electrokinetic-driven microfluidic devices; it consists of a processor, a memory system, and a user interface to deliver several types of waveforms and stimulation patterns. It has been designed to be a flexible, highly configurable, low power instrument capable of delivering sine, triangle, and sawtooth waveforms with one single frequency or two superimposed frequencies ranging from 0.01 Hz to 40 kHz, and an output voltage of up to 30 Vpp. A specific stimulation pattern can be delivered over a single time period or as a sequence of different signals for different time periods. This stimulation system can be applied as a research tool where manipulation of particles suspended in liquid media is involved, such as biology, medicine, environment, embryology, and genetics. This system has the potential to lead to new schemes for laboratory procedures by allowing application specific and user defined electric stimulation. The development of this device is a step towards portable and programmable instrumentation for electric stimulation on electrokinetic-based microfluidic devices, which are meant to be integrated with lab-on-a-chip devices.

  13. Distributed low-frequency functional electrical stimulation delays muscle fatigue compared to conventional stimulation.

    Science.gov (United States)

    Malesević, Nebojsa M; Popović, Lana Z; Schwirtlich, Laszlo; Popović, Dejan B

    2010-10-01

    We present a low-frequency stimulation method via multi-pad electrodes for delaying muscle fatigue. We compared two protocols for muscle activation of the quadriceps in paraplegics. One protocol involved a large cathode at 30 HZ (HPR, high pulse-rate), and the other involved four smaller cathodes at 16 HZ (LPR, low pulse-rate). The treatment included 30-min daily sessions for 20 days. One leg was treated with the HPR protocol and the other with the LPR protocol. Knee-joint torque was measured before and after therapy to assess the time interval before the knee-joint torque decreased to 70% of the initial value. The HPR therapy provided greater increases in muscle endurance and force in prolonged training. Yet the LPR stimulation produced less muscle fatigue compared to the HPR stimulation. The results suggest that HPR is the favored protocol for training, and LPR is better suited for prolonged stimulation.

  14. The effect of an aerobic training program on the electrical remodeling of the heart: high-frequency components of the signal-averaged electrocardiogram are predictors of the maximal aerobic power

    Directory of Open Access Journals (Sweden)

    M. Marocolo

    2007-02-01

    Full Text Available Increased heart rate variability (HRV and high-frequency content of the terminal region of the ventricular activation of signal-averaged ECG (SAECG have been reported in athletes. The present study investigates HRV and SAECG parameters as predictors of maximal aerobic power (VO2max in athletes. HRV, SAECG and VO2max were determined in 18 high-performance long-distance (25 ± 6 years; 17 males runners 24 h after a training session. Clinical visits, ECG and VO2max determination were scheduled for all athletes during thew training period. A group of 18 untrained healthy volunteers matched for age, gender, and body surface area was included as controls. SAECG was acquired in the resting supine position for 15 min and processed to extract average RR interval (Mean-RR and root mean squared standard deviation (RMSSD of the difference of two consecutive normal RR intervals. SAECG variables analyzed in the vector magnitude with 40-250 Hz band-pass bi-directional filtering were: total and 40-µV terminal (LAS40 duration of ventricular activation, RMS voltage of total (RMST and of the 40-ms terminal region of ventricular activation. Linear and multivariate stepwise logistic regressions oriented by inter-group comparisons were adjusted in significant variables in order to predict VO2max, with a P < 0.05 considered to be significant. VO2max correlated significantly (P < 0.05 with RMST (r = 0.77, Mean-RR (r = 0.62, RMSSD (r = 0.47, and LAS40 (r = -0.39. RMST was the independent predictor of VO2max. In athletes, HRV and high-frequency components of the SAECG correlate with VO2max and the high-frequency content of SAECG is an independent predictor of VO2max.

  15. Semiconditional Electrical Stimulation of Pudendal Nerve Afferents Stimulation to Manage Neurogenic Detrusor Overactivity in Patients with Spinal Cord Injury

    OpenAIRE

    Lee, Young-Hee; Kim, Jung Moon; Im, Hyung Tae; Lee, Kye-Wook; Kim, Sung Hoon; Hur, Dong Min

    2011-01-01

    Objective To evaluate the effect of semiconditional electrical stimulation of the pudendal nerve afferents for the neurogenic detrusor overactivity in patients with spinal cord injury. Forty patients (36 males, 4 males) with spinal cord injury who had urinary incontinence and frequency, as well as felt bladder contraction with bladder filling sense or autonomic dysreflexic symptom participated in this study. Method Patients with neurogenic detrusor overactivity were subdivided into complete i...

  16. Chronic Spinal Cord Electrical Stimulation Protects Against 6-hydroxydopamine Lesions

    Science.gov (United States)

    Yadav, Amol P.; Fuentes, Romulo; Zhang, Hao; Vinholo, Thais; Wang, Chi-Han; Freire, Marco Aurelio M.; Nicolelis, Miguel A. L.

    2014-01-01

    Although L-dopa continues to be the gold standard for treating motor symptoms of Parkinson's disease (PD), it presents long-term complications. Deep brain stimulation is effective, but only a small percentage of idiopathic PD patients are eligible. Based on results in animal models and a handful of patients, dorsal column stimulation (DCS) has been proposed as a potential therapy for PD. To date, the long-term effects of DCS in animal models have not been quantified. Here, we report that DCS applied twice a week in rats treated with bilateral 6-OHDA striatal infusions led to a significant improvement in symptoms. DCS-treated rats exhibited a higher density of dopaminergic innervation in the striatum and higher neuronal cell count in the substantia nigra pars compacta compared to a control group. These results suggest that DCS has a chronic therapeutical and neuroprotective effect, increasing its potential as a new clinical option for treating PD patients.

  17. Effects of repetition and temperature on Contingent Electrical Stimulation

    DEFF Research Database (Denmark)

    Castrillon, Eduardo E.; Zhou, Xinwen; Svensson, Peter

    ) activity associated with bruxism. Repetition of the electrical stimulus and skin surface temperature (ST) may affect the perception of CES and possibly also the inhibitory EMG effects.Objectives: To determine the effects of stimulus repetition and skin ST on the perception of CES.  Methods: Healthy...

  18. Chronic Electrical Stimulation with a Suprachoroidal Retinal Prosthesis: A Preclinical Safety and Efficacy Study

    Science.gov (United States)

    Nayagam, David A. X.; Williams, Richard A.; Allen, Penelope J.; Shivdasani, Mohit N.; Luu, Chi D.; Salinas-LaRosa, Cesar M.; Finch, Sue; Ayton, Lauren N.; Saunders, Alexia L.; McPhedran, Michelle; McGowan, Ceara; Villalobos, Joel; Fallon, James B.; Wise, Andrew K.; Yeoh, Jonathan; Xu, Jin; Feng, Helen; Millard, Rodney; McWade, Melanie; Thien, Patrick C.; Williams, Chris E.; Shepherd, Robert K.

    2014-01-01

    Purpose To assess the safety and efficacy of chronic electrical stimulation of the retina with a suprachoroidal visual prosthesis. Methods Seven normally-sighted feline subjects were implanted for 96–143 days with a suprachoroidal electrode array and six were chronically stimulated for 70–105 days at levels that activated the visual cortex. Charge balanced, biphasic, current pulses were delivered to platinum electrodes in a monopolar stimulation mode. Retinal integrity/function and the mechanical stability of the implant were assessed monthly using electroretinography (ERG), optical coherence tomography (OCT) and fundus photography. Electrode impedances were measured weekly and electrically-evoked visual cortex potentials (eEVCPs) were measured monthly to verify that chronic stimuli were suprathreshold. At the end of the chronic stimulation period, thresholds were confirmed with multi-unit recordings from the visual cortex. Randomized, blinded histological assessments were performed by two pathologists to compare the stimulated and non-stimulated retina and adjacent tissue. Results All subjects tolerated the surgical and stimulation procedure with no evidence of discomfort or unexpected adverse outcomes. After an initial post-operative settling period, electrode arrays were mechanically stable. Mean electrode impedances were stable between 11–15 kΩ during the implantation period. Visually-evoked ERGs & OCT were normal, and mean eEVCP thresholds did not substantially differ over time. In 81 of 84 electrode-adjacent tissue samples examined, there were no discernible histopathological differences between stimulated and unstimulated tissue. In the remaining three tissue samples there were minor focal fibroblastic and acute inflammatory responses. Conclusions Chronic suprathreshold electrical stimulation of the retina using a suprachoroidal electrode array evoked a minimal tissue response and no adverse clinical or histological findings. Moreover, thresholds and

  19. Epilepsia partialis continua responsive to neocortical electrical stimulation.

    Science.gov (United States)

    Valentin, Antonio; Ughratdar, Ismail; Cheserem, Beverly; Morris, Robert; Selway, Richard; Alarcon, Gonzalo

    2015-08-01

    Epilepsia partialis continua (EPC), defined as a syndrome of continuous focal jerking, is a rare form of focal status epilepticus that usually affects a distal limb, and when prolonged, can produce long-lasting deficits in limb function. Substantial electrophysiologic evidence links the origin of EPC to the motor cortex; thus surgical resection carries the risk of significant handicap. We present two patients with focal, drug-resistant EPC, who were admitted for intracranial video-electroencephalography monitoring to elucidate the location of the epileptogenic focus and identification of eloquent motor cortex with functional mapping. In both cases, the focus resided at or near eloquent motor cortex and therefore precluded resective surgery. Chronic cortical stimulation delivered through subdural strips at the seizure focus (continuous stimulation at 60-130 Hz, 2-3 mA) resulted in >90% reduction in seizures and abolition of the EPC after a follow-up of 22 months in both patients. Following permanent implantation of cortical stimulators, no adverse effects were noted. EPC restarted when intensity was reduced or batteries depleted. Battery replacement restored previous improvement. This two-case report opens up avenues for the treatment of this debilitating condition. Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

  20. Spatial Mapping in the Rat Olfactory Bulb by Odor and Direct Electrical Stimulation.

    Science.gov (United States)

    Coelho, Daniel H; Costanzo, Richard M

    2016-09-01

    To directly measure the spatial mapping in the olfactory bulb by odor presentation and by direct electrical stimulation. Experimental (animal). University research laboratory. Odor (n = 8) and electrical stimulation (n = 4) of the olfactory bulb in rats were used to demonstrate the spatial mapping of neural responses in the olfactory bulb. Both multiunit responses to odor stimulation and evoked potential responses to localized electrical stimulation were measured in different regions of the olfactory bulb. Responses that were recorded simultaneously from an array of 32 electrodes positioned at different locations within the olfactory bulb were mapped. Results show different spatial patterns of neural activity for different odors (odor maps). Direct stimulation of the olfactory bulb with electrical current pulses from electrodes positioned at different locations was also effective in generating spatial patterns of neural activity. These data suggest that by programming an array of stimulating electrodes, it should be possible to selectively activate different regions of the olfactory bulb, generating unique patterns of neural activity as seen in normal smell. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

  1. Electrically stimulated osteogenesis on Ti-PPy/PLGA constructs prepared by laser-assisted processes.

    Science.gov (United States)

    Paun, Irina Alexandra; Stokker-Cheregi, Flavian; Luculescu, Catalin Romeo; Acasandrei, Adriana Maria; Ion, Valentin; Zamfirescu, Marian; Mustaciosu, Cosmin Catalin; Mihailescu, Mona; Dinescu, Maria

    2015-10-01

    This work describes a versatile laser-based protocol for fabricating micro-patterned, electrically conductive titanium-polypyrrole/poly(lactic-co-glycolic)acid (Ti-PPy/PLGA) constructs for electrically stimulated (ES) osteogenesis. Ti supports were patterned using fs laser ablation in order to create high spatial resolution microstructures meant to provide mechanical resistance and physical cues for cell growth. Matrix Assisted Pulsed Laser Evaporation (MAPLE) was used to coat the patterned Ti supports with PPy/PLGA layers acting as biocompatible surfaces having chemical and electrical properties suitable for cell differentiation and mineralization. In vitro biological assays on osteoblast-like MG63 cells showed that the constructs maintained cell viability without cytotoxicity. At 24 h after cell seeding, electrical stimulation with currents of 200 μA was applied for 4 h. This treatment was shown to promote earlier onset of osteogenesis. More specifically, the alkaline phosphatase activity of the stimulated cultures reached the maximum before that of the non-stimulated ones, i.e. controls, indicating faster cell differentiation. Moreover, mineralization was found to occur at an earlier stage in the stimulated cultures, as compared to the controls, starting with Day 6 of cell culture. At later stages, calcium levels in the stimulated cultures were higher than those in control samples by about 70%, with Ca/P ratios similar to those of natural bone. In all, the laser-based protocol emerges as an efficient alternative to existing fabrication technologies. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Stimulation of shank muscles during functional electrical stimulation cycling increases ankle excursion in individuals with spinal cord injury.

    Science.gov (United States)

    Fornusek, Ché; Davis, Glen M; Baek, Ilhun

    2012-11-01

    To investigate the effect of shank muscle stimulation on ankle joint excursion during passive and functional electrical stimulation (FES) leg cycling. Within-subject comparisons. Laboratory setting. Well-trained FES cyclists (N=7) with chronic spinal cord injuries. Two experimental sessions were performed on an isokinetic FES cycle ergometer with a pedal boot that allowed the ankle to plantarflex and dorsiflex during cycling. During the first session, the optimal stimulation timings to induce plantarflexion and dorsiflexion were investigated by systematically altering the stimulation angles of the shank muscles (tibialis anterior [TA] and triceps surae [TS]). During the second session, TA and TS stimulation was included with standard FES cycling (quadriceps, hamstrings, and gluteals) for 6 subjects. Ankle, knee, and hip movements were analyzed using 2-dimensional video. The ankle excursions during passive cycling were 19°±6°. TA and TS stimulation increased ankle joint excursion up to 33°±10° and 27°±7°, respectively. Compared with passive cycling, ankle joint excursion was not significantly increased during standard FES cycling (24°±7°). TA and TS stimulation significantly increased the ankle excursion when applied during standard FES cycling (41°±4°). Freeing the ankle joint to rotate during FES cycling was found to be safe. The combination of shank muscle stimulation and repetitive ankle joint movement may be beneficial for improving ankle flexibility and leg conditioning. Further research is required to test and design ankle supports that might maximize the benefits of shank muscle activation. Copyright © 2012 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  3. Pressure changes under the ischial tuberosities during gluteal neuromuscular stimulation in spinal cord injury: a comparison of sacral nerve root stimulation with surface functional electrical stimulation.

    Science.gov (United States)

    Liu, Liang Qin; Ferguson-Pell, Martin

    2015-04-01

    To compare the magnitude of interface pressure changes during gluteal maximus contraction by stimulating sacral nerve roots with surface electrical stimulations in patients with spinal cord injuries (SCIs). Pilot interventional study. Spinal injury research laboratory. Adults (N=18) with suprasacral complete SCI. Sacral nerve root stimulation (SNRS) via a functional magnetic stimulator (FMS) or a sacral anterior root stimulator (SARS) implant; and surface functional electrical stimulation (FES). Interface pressure under the ischial tuberosity (IT) defined as peak pressure, gradient at peak pressure, and average pressure. With optimal FMS, a 29% average reduction of IT peak pressure was achieved during FMS (mean ± SD: 160.1±24.3mmHg at rest vs 114.7±18.0mmHg during FMS, t5=6.3, P=.002). A 30% average reduction of peak pressure during stimulation via an SARS implant (143.2±31.7mmHg at rest vs 98.5±21.5mmHg during SARS, t5=4.4, P=.007) and a 22% average decrease of IT peak pressure during FES stimulation (153.7±34.8mmHg at rest vs 120.5±26.1mmHg during FES, t5=5.3, P=.003) were obtained. In 4 participants who completed both the FMS and FES studies, the percentage of peak pressure reduction with FMS was slightly greater than with FES (mean difference, 7.8%; 95% confidence interval, 1.6%-14.0; P=.04). SNRS or surface FES can induce sufficient gluteus maximus contraction and significantly reduce ischial pressure. SNRS via an SARS implant may be more convenient and efficient for frequently activating the gluteus maximus. Copyright © 2015 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  4. Maximizing muscle force via low-cadence functional electrical stimulation cycling.

    Science.gov (United States)

    Fornusek, Ché; Davis, Glen M

    2004-09-01

    This study investigated the effect of pedal cadence upon torque production, power output and muscle fatigue rates during functional electrical stimulation evoked cycling in spinal cord injured individuals. All subjects had complete thoracic spinal cord injuries T4-T9 (ASIA A) and had been functional electrical stimulation training regularly for at least 6 months. One trial (n = 8) examined a low vs high pedal rate (20 and 50 rev x min(-1)) upon isolated muscle fatigue over 5 minutes. A second trial (n = 9) investigated the effect of cadence (15 vs 50 rev x min(-1)) upon performance during 35-minutes of functional electrical stimulation evoked cycling. Peak torque produced by left quadriceps decayed significantly faster at the higher pedal cadence, indicating a higher rate of muscle fatigue. Functional electrical stimulation cycling over 35 minutes also revealed that peak and average torques were significantly greater at the lower cadence. From 15 minutes onwards, power output was significantly higher at 50 rev x min(-1) FES-cycling, compared with 15 rev x min(-1). The higher muscle forces observed during low cadence functional electrical stimulation cycling should offer improvements over traditional pedalling velocities for training leg strength in individuals with spinal cord injury.

  5. Electric stimulation and decimeter wave therapy improve the recovery of injured sciatic nerves.

    Science.gov (United States)

    Zhao, Feng; He, Wei; Zhang, Yingze; Tian, Dehu; Zhao, Hongfang; Yu, Kunlun; Bai, Jiangbo

    2013-07-25

    Drug treatment, electric stimulation and decimeter wave therapy have been shown to promote the repair and regeneration of the peripheral nerves at the injured site. This study prepared a Mackinnon's model of rat sciatic nerve compression. Electric stimulation was given immediately after neurolysis, and decimeter wave radiation was performed at 1 and 12 weeks post-operation. Histological observation revealed that intraoperative electric stimulation and decimeter wave therapy could improve the local blood circulation of repaired sites, alleviate hypoxia of compressed nerves, and lessen adhesion of compressed nerves, thereby decreasing the formation of new entrapments and enhancing compressed nerve regeneration through an improved microenvironment for regeneration. Immunohistochemical staining results revealed that intraoperative electric stimulation and decimeter wave could promote the expression of S-100 protein. Motor nerve conduction velocity and amplitude, the number and diameter of myelinated nerve fibers, and sciatic functional index were significantly increased in the treated rats. These results verified that intraoperative electric stimulation and decimeter wave therapy contributed to the regeneration and the recovery of the functions in the compressed nerves.

  6. Role of electrical stimulation for rehabilitation and regeneration after spinal cord injury: an overview.

    Science.gov (United States)

    Hamid, Samar; Hayek, Ray

    2008-09-01

    Structural discontinuity in the spinal cord after injury results in a disruption in the impulse conduction resulting in loss of various bodily functions depending upon the level of injury. This article presents a summary of the scientific research employing electrical stimulation as a means for anatomical or functional recovery for patients suffering from spinal cord injury. Electrical stimulation in the form of functional electrical stimulation (FES) can help facilitate and improve upper/lower limb mobility along with other body functions lost due to injury e.g. respiratory, sexual, bladder or bowel functions by applying a controlled electrical stimulus to generate contractions and functional movement in the paralysed muscles. The available rehabilitative techniques based on FES technology and various Food and Drug Administration, USA approved neuroprosthetic devices that are in use are discussed. The second part of the article summarises the experimental work done in the past 2 decades to study the effects of weakly applied direct current fields in promoting regeneration of neurites towards the cathode and the new emerging technique of oscillating field stimulation which has shown to promote bidirectional regeneration in the injured nerve fibres. The present article is not intended to be an exhaustive review but rather a summary aiming to highlight these two applications of electrical stimulation and the degree of anatomical/functional recovery associated with these in the field of spinal cord injury research.

  7. The effect of intra-operative transcutaneous electrical nerve stimulation on posterior neck pain following thyroidectomy.

    Science.gov (United States)

    Park, C; Choi, J B; Lee, Y-S; Chang, H-S; Shin, C S; Kim, S; Han, D W

    2015-04-01

    Posterior neck pain following thyroidectomy is common because full neck extension is required during the procedure. We evaluated the effect of intra-operative transcutaneous electrical nerve stimulation on postoperative neck pain in patients undergoing total thyroidectomy under general anaesthesia. One hundred patients were randomly assigned to one of two groups; 50 patients received transcutaneous electrical nerve stimulation applied to the trapezius muscle and 50 patients acted as controls. Postoperative posterior neck pain and anterior wound pain were evaluated using an 11-point numerical rating scale at 30 min, 6 h, 24 h and 48 h following surgery. The numerical rating scale for posterior neck pain was significantly lower in the transcutaneous electrical nerve stimulation group compared with the control group at all time points (p < 0.05). There were no significant differences in the numerical rating scale for anterior wound pain at any time point. No adverse effects related to transcutaneous electrical nerve stimulation were observed. We conclude that intra-operative transcutaneous electrical nerve stimulation applied to the trapezius muscle reduced posterior neck pain following thyroidectomy. © 2014 The Association of Anaesthetists of Great Britain and Ireland.

  8. Cardiomyocyte behavior on biodegradable polyurethane/gold nanocomposite scaffolds under electrical stimulation

    Energy Technology Data Exchange (ETDEWEB)

    Ganji, Yasaman [Faculty of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave, Tehran (Iran, Islamic Republic of); Institute for Materials Science, Dept. Biocompatible Nanomaterials, University of Kiel, Kaiserstr. 2, D-24143 Kiel (Germany); Li, Qian [Institute for Materials Science, Dept. Biocompatible Nanomaterials, University of Kiel, Kaiserstr. 2, D-24143 Kiel (Germany); Quabius, Elgar Susanne [Dept. of Otorhinolaryngology, Head and Neck Surgery, University of Kiel, Arnold-Heller-Str. 3, Building 27, D-24105 Kiel (Germany); Institute of Immunology, University of Kiel, Arnold-Heller-Str. 3, Building 17, D-24105 Kiel (Germany); Böttner, Martina [Department of Anatomy, University of Kiel, Otto-Hahn-Platz 8, 24118 Kiel (Germany); Selhuber-Unkel, Christine, E-mail: cse@tf.uni-kiel.de [Institute for Materials Science, Dept. Biocompatible Nanomaterials, University of Kiel, Kaiserstr. 2, D-24143 Kiel (Germany); Kasra, Mehran [Faculty of Biomedical Engineering, Amirkabir University of Technology, 424 Hafez Ave, Tehran (Iran, Islamic Republic of)

    2016-02-01

    Following a myocardial infarction (MI), cardiomyocytes are replaced by scar tissue, which decreases ventricular contractile function. Tissue engineering is a promising approach to regenerate such damaged cardiomyocyte tissue. Engineered cardiac patches can be fabricated by seeding a high density of cardiac cells onto a synthetic or natural porous polymer. In this study, nanocomposite scaffolds made of gold nanotubes/nanowires incorporated into biodegradable castor oil-based polyurethane were employed to make micro-porous scaffolds. H9C2 cardiomyocyte cells were cultured on the scaffolds for one day, and electrical stimulation was applied to improve cell communication and interaction in neighboring pores. Cells on scaffolds were examined by fluorescence microscopy and scanning electron microscopy, revealing that the combination of scaffold design and electrical stimulation significantly increased cell confluency of H9C2 cells on the scaffolds. Furthermore, we showed that the gene expression levels of Nkx2.5, atrial natriuretic peptide (ANF) and natriuretic peptide precursor B (NPPB), which are functional genes of the myocardium, were up-regulated by the incorporation of gold nanotubes/nanowires into the polyurethane scaffolds, in particular after electrical stimulation. - Highlights: • Biodegradable polyurethane/gold nanocomposites for cardiomyocyte adhesion are proposed. • The nanocomposite scaffolds are porous and electrical stimulation enhances cell adhesion. • Expression levels of functional myocardium genes were upregulated after electrical stimulation.

  9. Electrical stimulation as an adjunct to spinal fusion: a meta-analysis of controlled clinical trials.

    Science.gov (United States)

    Akai, Masami; Kawashima, Noritaka; Kimura, Toshitaka; Hayashi, Kunihiko

    2002-10-01

    This study was a meta-analysis to examine whether electrical stimulation has a specific effect on spinal fusion. Little evidence exists on the efficacy of electrical stimulation for improving fusion rate of spinal fusion surgery. Using MEDLINE (1966-2000) and EMBASE (1985-1999), a search for articles was carried out using the Medical Subject Headings: (1) electric stimulation or electromagnetic fields, (2) spinal fusion, (3) controlled or clinical trial, and (4) human. Data were extracted from all the hit articles and additionally collected from appropriate journal lists. A total of five randomized controlled trials (RCT) on bones assessing healing of spinal fusion were identified and scored on methodological quality. All the identified studies reported positive findings, but the quality score of each trial showed wide flaws. Because of relatively homogenous subjects who had spine fusion and radiographic assessment from these studies, pooling of the data was able to be performed. Excluding one trial with the lowest score, the combined results of four trials, whose major endpoints were the success rate of the fusion, revealed a statistically significant effect of electrical stimulation with various techniques, but the selected trials still showed wide variation in view of stimulation modalities and treatment protocol. The pooled result of the studies in this review revealed the efficacy of electrical stimulation based on proved methodological quality. As problems on therapeutic modality and protocol remain, there is a further need for improvement in design to constitute acceptable proof and to establish treatment programs that better demonstrate electrical stimulation effects on spinal fusion. Copyright 2002 Wiley-Liss, Inc.

  10. A Study on Duration of Effect of Transcutaneous Electrical Nerve Stimulation Therapy on Whole Saliva Flow.

    Science.gov (United States)

    Bhasin, Neha; Reddy, Sreedevi; Nagarajappa, Anil Kumar; Kakkad, Ankur

    2015-06-01

    Saliva is a complex fluid, whose important role is to maintain the well being of oral cavity. Salivary gland hypofunction or hyposalivation is the condition of having reduced saliva production which leads to the subjective complaint of oral dryness termed xerostomia.(7) Management of xerostomia includes palliative therapy using topical agents or systemic therapy. Electrostimulation to produce saliva was studied in the past and showed moderate promise but never became part of mainstream therapy. Hence, this study was undertaken to evaluate the effect of transcutaneous electrical nerve stimulation (TENS) on whole salivary flow rate in healthy adults and to evaluate how long this effect of TENS lasts on salivary flow. One hundred healthy adult subjects were divided into five age groups with each group containing 20 subjects equally divided into males and females in each group. Unstimulated saliva was collected using a graduated test tube fitted with funnel and quantity was measured. Transcutaneous electrical nerve stimulation unit was activated and stimulated saliva was collected. Saliva was again collected 30 minutes and 24 hours post stimulation. The mean unstimulated whole saliva flow rate for all subjects (n = 100) was 2.60 ml/5 min. During stimulation, it increased to 3.60 ± 0.39 ml/5 min. There was 38.46% increase in salivary flow. Ninety six out of 100 responded positively to TENS therapy. Salivary flow remained increased 30 minutes and 24 hours post stimulation with the values being 3.23 ± 0.41 ml/5 min and 2.69 ± 0.39 ml/5 min respectively. Repeated measures One way analysis of variance (ANOVA) test showed that the difference between these values were statistically significant. Transcutaneous electrical nerve stimulation therapy was effective for stimulation of whole saliva in normal, healthy subjects and its effect retained till 30 minutes and a little up to 24 hours. Transcutaneous electrical nerve stimulation may work best synergistically with other

  11. Application of conductive polymers, scaffolds and electrical stimulation for nerve tissue engineering.

    Science.gov (United States)

    Ghasemi-Mobarakeh, Laleh; Prabhakaran, Molamma P; Morshed, Mohammad; Nasr-Esfahani, Mohammad Hossein; Baharvand, Hossein; Kiani, Sahar; Al-Deyab, Salem S; Ramakrishna, Seeram

    2011-04-01

    Among the numerous attempts to integrate tissue engineering concepts into strategies to repair nearly all parts of the body, neuronal repair stands out. This is partially due to the complexity of the nervous anatomical system, its functioning and the inefficiency of conventional repair approaches, which are based on single components of either biomaterials or cells alone. Electrical stimulation has been shown to enhance the nerve regeneration process and this consequently makes the use of electrically conductive polymers very attractive for the construction of scaffolds for nerve tissue engineering. In this review, by taking into consideration the electrical properties of nerve cells and the effect of electrical stimulation on nerve cells, we discuss the most commonly utilized conductive polymers, polypyrrole (PPy) and polyaniline (PANI), along with their design and modifications, thus making them suitable scaffolds for nerve tissue engineering. Other electrospun, composite, conductive scaffolds, such as PANI/gelatin and PPy/poly(ε-caprolactone), with or without electrical stimulation, are also discussed. Different procedures of electrical stimulation which have been used in tissue engineering, with examples on their specific applications in tissue engineering, are also discussed. Copyright © 2011 John Wiley & Sons, Ltd.

  12. Stimulation of neurite outgrowth using an electrically conducting polymer

    OpenAIRE

    Christine E Schmidt; Shastri, Venkatram R.; Vacanti, Joseph P.; Langer, Robert

    1997-01-01

    Damage to peripheral nerves often cannot be repaired by the juxtaposition of the severed nerve ends. Surgeons have typically used autologous nerve grafts, which have several drawbacks including the need for multiple surgical procedures and loss of function at the donor site. As an alternative, the use of nerve guidance channels to bridge the gap between severed nerve ends is being explored. In this paper, the electrically conductive polymer—oxidized polypyrrole (PP)—has been evaluated for use...

  13. Novel 10-kHz High-frequency Therapy (HF10 Therapy) Is Superior to Traditional Low-frequency Spinal Cord Stimulation for the Treatment of Chronic Back and Leg Pain: The SENZA-RCT Randomized Controlled Trial.

    Science.gov (United States)

    Kapural, Leonardo; Yu, Cong; Doust, Matthew W; Gliner, Bradford E; Vallejo, Ricardo; Sitzman, B Todd; Amirdelfan, Kasra; Morgan, Donna M; Brown, Lora L; Yearwood, Thomas L; Bundschu, Richard; Burton, Allen W; Yang, Thomas; Benyamin, Ramsin; Burgher, Abram H

    2015-10-01

    Current treatments for chronic pain have limited effectiveness and commonly known side effects. Given the prevalence and burden of intractable pain, additional therapeutic approaches are desired. Spinal cord stimulation (SCS) delivered at 10 kHz (as in HF10 therapy) may provide pain relief without the paresthesias typical of traditional low-frequency SCS. The objective of this randomized, parallel-arm, noninferiority study was to compare long-term safety and efficacy of SCS therapies in patients with back and leg pain. A total of 198 subjects with both back and leg pain were randomized in a 1:1 ratio to a treatment group across 10 comprehensive pain treatment centers. Of these, 171 passed a temporary trial and were implanted with an SCS system. Responders (the primary outcome) were defined as having 50% or greater back pain reduction with no stimulation-related neurological deficit. At 3 months, 84.5% of implanted HF10 therapy subjects were responders for back pain and 83.1% for leg pain, and 43.8% of traditional SCS subjects were responders for back pain and 55.5% for leg pain (P back and leg pain comparisons). The relative ratio for responders was 1.9 (95% CI, 1.4 to 2.5) for back pain and 1.5 (95% CI, 1.2 to 1.9) for leg pain. The superiority of HF10 therapy over traditional SCS for leg and back pain was sustained through 12 months (P back and leg pain with broad applicability to patients, physicians, and payers.

  14. Differential effects of subcutaneous electrical stimulation (SQS) and transcutaneous electrical nerve stimulation (TENS) in rodent models of chronic neuropathic or inflammatory pain.

    Science.gov (United States)

    Vera-Portocarrero, Louis P; Cordero, Toni; Billstrom, Tina; Swearingen, Kim; Wacnik, Paul W; Johanek, Lisa M

    2013-01-01

    Electrical stimulation has been used for many years for the treatment of pain. Present-day research demonstrates that stimulation targets and parameters impact the induction of specific pain-modulating mechanisms. New targets are increasingly being investigated clinically, but the scientific rationale for a particular target is often not well established. This present study compares the behavioral effects of targeting peripheral axons by electrode placement in the subcutaneous space vs. electrode placement on the surface of the skin in a rodent model. Rodent models of inflammatory and neuropathic pain were used to investigate subcutaneous electrical stimulation (SQS) vs. transcutaneous electrical nerve stimulation (TENS). Electrical parameters and relative location of the leads were held constant under each condition. SQS had cumulative antihypersensitivity effects in both inflammatory and neuropathic pain rodent models, with significant inhibition of mechanical hypersensitivity observed on days 3-4 of treatment. In contrast, reduction of thermal hyperalgesia in the inflammatory model was observed during the first four days of treatment with SQS, and reduction of cold allodynia in the neuropathic pain model was seen only on the first day with SQS. TENS was effective in the inflammation model, and in agreement with previous studies, tolerance developed to the antihypersensitivity effects of TENS. With the exception of a reversal of cold hypersensitivity on day 1 of testing, TENS did not reveal significant analgesic effects in the neuropathic pain rodent model. The results presented show that TENS and SQS have different effects that could point to unique biologic mechanisms underlying the analgesic effect of each therapy. Furthermore, this study is the first to demonstrate in an animal model that SQS attenuates neuropathic and inflammatory-induced pain behaviors. © 2013 Medtronic, Inc.

  15. Motor cortex electric stimulation for the treatment of neuropathic pain

    Directory of Open Access Journals (Sweden)

    Walter J. Fagundes-Pereyra

    2010-12-01

    Full Text Available OBJECTIVE: Motor cortex stimulation (MCS is considered to be an effective treatment for chronic neuropathic pain. The aim of the present study was to assess the efficacy of MCS for treating neuropathic pain. METHOD: 27 patients with chronic neuropathic pain were operated. Electrodes were implanted with the use of an stereotactic frame. Electrophysiological evaluations (motor stimulation and somatosensory evoked potentials were performed, with guidance by means of three-dimensional reconstruction of magnetic resonance images of the brain. 10 patients (37% presented central neuropathic pain (post-stroke pain and 17 others (63% presented peripheral neuropathic pain (brachial plexus avulsion, phantom limb pain or trigeminal pain. RESULTS: In 15 patients (57.7% the pain relief was 50% or more; while in ten patients (38.5%, more than 60% of the original pain was relieved. No differences were found in relation to central and peripheral neuropathic pain (p=0.90, pain location (p=0.81, presence of motor deficit (p=0.28 and pain duration (p=0.72. No major complications were observed. CONCLUSION: MCS was efficient for treating patients presenting chronic central or peripheral neuropathic pain.

  16. Electrical stimulation of the primate lateral habenula suppresses saccadic eye movement through a learning mechanism.

    Directory of Open Access Journals (Sweden)

    Masayuki Matsumoto

    Full Text Available The lateral habenula (LHb is a brain structure which represents negative motivational value. Neurons in the LHb are excited by unpleasant events such as reward omission and aversive stimuli, and transmit these signals to midbrain dopamine neurons which are involved in learning and motivation. However, it remains unclear whether these phasic changes in LHb neuronal activity actually influence animal behavior. To answer this question, we artificially activated the LHb by electrical stimulation while monkeys were performing a visually guided saccade task. In one block of trials, saccades to one fixed direction (e.g., right direction were followed by electrical stimulation of the LHb while saccades to the other direction (e.g., left direction were not. The direction-stimulation contingency was reversed in the next block. We found that the post-saccadic stimulation of the LHb increased the latencies of saccades in subsequent trials. Notably, the increase of the latency occurred gradually as the saccade was repeatedly followed by the stimulation, suggesting that the effect of the post-saccadic stimulation was accumulated across trials. LHb stimulation starting before saccades, on the other hand, had no effect on saccade latency. Together with previous studies showing LHb activation by reward omission and aversive stimuli, the present stimulation experiment suggests that LHb activity contributes to learning to suppress actions which lead to unpleasant events.

  17. Non-Invasive Electrical Brain Stimulation Montages for Modulation of Human Motor Function.

    Science.gov (United States)

    Curado, Marco; Fritsch, Brita; Reis, Janine

    2016-02-04

    Non-invasive electrical brain stimulation (NEBS) is used to modulate brain function and behavior, both for research and clinical purposes. In particular, NEBS can be applied transcranially either as direct current stimulation (tDCS) or alternating current stimulation (tACS). These stimulation types exert time-, dose- and in the case of tDCS polarity-specific effects on motor function and skill learning in healthy subjects. Lately, tDCS has been used to augment the therapy of motor disabilities in patients with stroke or movement disorders. This article provides a step-by-step protocol for targeting the primary motor cortex with tDCS and transcranial random noise stimulation (tRNS), a specific form of tACS using an electrical current applied randomly within a pre-defined frequency range. The setup of two different stimulation montages is explained. In both montages the emitting electrode (the anode for tDCS) is placed on the primary motor cortex of interest. For unilateral motor cortex stimulation the receiving electrode is placed on the contralateral forehead while for bilateral motor cortex stimulation the receiving electrode is placed on the opposite primary motor cortex. The advantages and disadvantages of each montage for the modulation of cortical excitability and motor function including learning are discussed, as well as safety, tolerability and blinding aspects.

  18. Effects of exercise and electrical stimulation on lumbar stabilization in asymptomatic subjects: a comparative study.

    Science.gov (United States)

    Bilgin, Sevil; Temucin, Cagrı Mesut; Nurlu, Gulay; Kaya, Derya Ozer; Kose, Nezire; Gunduz, Arzu Guclu

    2013-01-01

    Segmental stabilization training and electrical stimulation are used as a treatment for patients with low back pain. There is limited information on the efficacy of two interventions in the literature. In this study, the efficacy of the two interventions on the multifidus muscle activation and fatigue, segmental stabilization training and electrical stimulation, were examined and compared. Our sample consists of 30 asymptomatic individuals, randomly assigned to one of three groups: the group that was given segmental stabilization training, the group that was given electrical stimulation and the control group that received no treatment. The muscle activity and fatigability of the multifidus were recorded by the surface electromyography before and after the intervention. No difference is detected for any of the multifidus muscle activation and fatigue characteristics either within or between groups. Both techniques did not improve multifidus activation capacity. An effort at submaximal and maximal level affects and increases the activity of multifidus.

  19. Effect of transcutaneous electrical muscle stimulation on muscle volume in patients with septic shock

    DEFF Research Database (Denmark)

    Poulsen, Jesper Brøndum; Møller, Kirsten; Jensen, Claus V

    2011-01-01

    Objective: Intensive care unit admission is associated with muscle wasting and impaired physical function. We investigated the effect of early transcutaneous electrical muscle stimulation on quadriceps muscle volume in patients with septic shock. Design: Randomized interventional study using...... randomization of the quadriceps muscles, transcutaneous electrical muscle stimulation was applied on the intervention side for 7 consecutive days and for 60 mins per day. All patients underwent computed tomographic scans of both thighs immediately before and after the 7-day treatment period. The quadriceps...... sequential organ failure assessment score. Conclusions: We observed a marked decrease in quadriceps volume within the first week of intensive care for septic shock. This loss of muscle mass was unaffected by transcutaneous electrical muscle stimulation applied for 60 mins per day for 7 days....

  20. Direct Electrical Stimulation of the Human Entorhinal Region and Hippocampus Impairs Memory.

    Science.gov (United States)

    Jacobs, Joshua; Miller, Jonathan; Lee, Sang Ah; Coffey, Tom; Watrous, Andrew J; Sperling, Michael R; Sharan, Ashwini; Worrell, Gregory; Berry, Brent; Lega, Bradley; Jobst, Barbara C; Davis, Kathryn; Gross, Robert E; Sheth, Sameer A; Ezzyat, Youssef; Das, Sandhitsu R; Stein, Joel; Gorniak, Richard; Kahana, Michael J; Rizzuto, Daniel S

    2016-12-07

    Deep brain stimulation (DBS) has shown promise for treating a range of brain disorders and neurological conditions. One recent study showed that DBS in the entorhinal region improved the accuracy of human spatial memory. Based on this line of work, we performed a series of experiments to more fully characterize the effects of DBS in the medial temporal lobe on human memory. Neurosurgical patients with implanted electrodes performed spatial and verbal-episodic memory tasks. During the encoding periods of both tasks, subjects received electrical stimulation at 50 Hz. In contrast to earlier work, electrical stimulation impaired memory performance significantly in both spatial and verbal tasks. Stimulation in both the entorhinal region and hippocampus caused decreased memory performance. These findings indicate that the entorhinal region and hippocampus are causally involved in human memory and suggest that refined methods are needed to use DBS in these regions to improve memory. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Effects of electrical stimulation pattern on quadriceps force production and fatigue.

    Science.gov (United States)

    Deley, Gaelle; Laroche, Davy; Babault, Nicolas

    2014-05-01

    Mixed stimulation programs (MIX) that switch from constant frequency trains (CFT) to variable frequency trains have been proposed to offset the rapid fatigue induced by CFT during electrical stimulation. However, this has never been confirmed with long stimulation patterns, such as those used to evoke functional contractions. The purpose of this study was to test the hypothesis that MIX programs were less fatiguing than CFTs in strength training-like conditions (6-s contractions, 30-min). Thirteen healthy subjects underwent 2 sessions corresponding to MIX and CFT programs. Measurements included maximal voluntary isometric torque and torque evoked by each contraction. There were greater decreases of voluntary and evoked torque (P train types might be a useful strategy to offset rapid fatigue during electrical stimulation sessions with long-duration contractions. Copyright © 2014 Wiley Periodicals, Inc.

  2. A Closed Loop Brain-machine Interface for Epilepsy Control Using Dorsal Column Electrical Stimulation.

    Science.gov (United States)

    Pais-Vieira, Miguel; Yadav, Amol P; Moreira, Derek; Guggenmos, David; Santos, Amílcar; Lebedev, Mikhail; Nicolelis, Miguel A L

    2016-09-08

    Although electrical neurostimulation has been proposed as an alternative treatment for drug-resistant cases of epilepsy, current procedures such as deep brain stimulation, vagus, and trigeminal nerve stimulation are effective only in a fraction of the patients. Here we demonstrate a closed loop brain-machine interface that delivers electrical stimulation to the dorsal column (DCS) of the spinal cord to suppress epileptic seizures. Rats were implanted with cortical recording microelectrodes and spinal cord stimulating electrodes, and then injected with pentylenetetrazole to induce seizures. Seizures were detected in real time from cortical local field potentials, after which DCS was applied. This method decreased seizure episode frequency by 44% and seizure duration by 38%. We argue that the therapeutic effect of DCS is related to modulation of cortical theta waves, and propose that this closed-loop interface has the potential to become an effective and semi-invasive treatment for refractory epilepsy and other neurological disorders.

  3. Semiparametric Identification of Human Arm Dynamics for Flexible Control of a Functional Electrical Stimulation Neuroprosthesis.

    Science.gov (United States)

    Schearer, Eric M; Liao, Yu-Wei; Perreault, Eric J; Tresch, Matthew C; Memberg, William D; Kirsch, Robert F; Lynch, Kevin M

    2016-12-01

    We present a method to identify the dynamics of a human arm controlled by an implanted functional electrical stimulation neuroprosthesis. The method uses Gaussian process regression to predict shoulder and elbow torques given the shoulder and elbow joint positions and velocities and the electrical stimulation inputs to muscles. We compare the accuracy of torque predictions of nonparametric, semiparametric, and parametric model types. The most accurate of the three model types is a semiparametric Gaussian process model that combines the flexibility of a black box function approximator with the generalization power of a parameterized model. The semiparametric model predicted torques during stimulation of multiple muscles with errors less than 20% of the total muscle torque and passive torque needed to drive the arm. The identified model allows us to define an arbitrary reaching trajectory and approximately determine the muscle stimulations required to drive the arm along that trajectory.

  4. [Blink restoration by the functional electrical stimulation in unilateral facial nerve palsy rabbits].

    Science.gov (United States)

    Xue, Yubin; Feng, Guodong; Ding, Xiuyong; Zhao, Yang; Cui, Tingting; Gao, Zhiqiang

    2014-07-01

    Tocompare the effects of different waveforms and parameters of electrical stimulation to elicit a blink, and construct a functional electrical stimulation (FES) system to restore synchronous blink in unilateral facial nerve palsy (FNP). Firstly, twenty-four rabbits were surgically induced unilateral FNP and were divided into three groups, who received square, sine and triangle pulse wareforms, respectirely. Both the healthy and the paralysis eyelids of the rabbits received pulse train stimulation to produce a blink in both eyes. For each rabbit, twenty-seven combinations of frequencies (25 Hz, 50 Hz and 100 Hz) and nine pulse widths (1-9 ms) were stimulated. The threshold amplitude and electric charge to elicit a blink was compared between different waveforms and different parameters. Secondly, a FES system was constructed to treat six surgically induced unilateral FNP rabbit chosen in the twenty-four rabbits, it consisted by an electromyogram (EMG) amplifier module which record the EMG of the healthy muscle, and a stimulator which received the EMG input and output a pulse train stimulation when triggered by the EMG. When the carrier frequency of the pulse train was 25 Hz, it was not able to induce a smooth blink. However, when the carrier frequencies were 50 Hz and 100 Hz, a smooth blink could be induced. The voltage required by 100 Hz was lower than 50 Hz, but it cost more electric charge. The amplitude that square waveforms required was far lower than sine and triangle, but the electric charge between the three waveforms was similar. Synchronous blink could be restored in the six unilateral FNP rabbits with the FES system. To elicit a blink, square pulse train delivered in 50 Hz is a preferable option. The motion of the healthy eyelids as a source of information for stimulation of the paralyzed sides can restore the synchronous blink in unilateral FNP rabbits.

  5. Transcutaneous parasacral electrical neural stimulation in children with primary monosymptomatic enuresis: a prospective randomized clinical trial.

    Science.gov (United States)

    de Oliveira, Liliana Fajardo; de Oliveira, Dayana Maria; da Silva de Paula, Lidyanne Ilídia; de Figueiredo, André Avarese; de Bessa, José; de Sá, Cacilda Andrade; Bastos Netto, José Murillo

    2013-10-01

    Parasacral transcutaneous electrical neural stimulation is widely used to treat hyperactive bladder in children and adults. Its use in nonmonosymptomatic enuresis has demonstrated improvement in number of dry nights. We assessed the effectiveness of parasacral transcutaneous electrical neural stimulation in the treatment of monosymptomatic primary enuresis. This prospective randomized clinical trial included 29 girls and 16 boys older than 6 years with primary monosymptomatic enuresis. Children were randomly divided into 2 groups consisting of controls, who were treated with behavioral therapy, and an experimental group, who were treated with behavioral therapy plus 10 sessions of parasacral transcutaneous electrical neural stimulation. Neural stimulation was performed with the electrodes placed in the sacral region (S2/S3). Sessions always followed the same pattern, with duration of 20 minutes, frequency of 10 Hz, a generated pulse of 700 μs and intensity determined by the sensitivity threshold of the child. Sessions were done 3 times weekly on alternate days. Patients in both groups were followed at 2-week intervals for the first month and then monthly for 6 consecutive months. Rate of wet nights was 77% in controls and 78.3% in the experimental group at onset of treatment (p = 0.82), and 49.5% and 31.2%, respectively, at the end of treatment (p = 0.02). Analyzing the average rate of improvement, there was a significantly greater increase in dry nights in the group undergoing neural stimulation (61.8%) compared to controls (37.3%, p = 0.0038). At the end of treatment percent improvement in children undergoing electrical stimulation had no relation to gender (p = 0.391) or age (p = 0.911). Treatment of primary monosymptomatic enuresis with 10 sessions of parasacral transcutaneous electrical neural stimulation plus behavioral therapy proved to be effective. However, no patient had complete resolution of symptoms. Copyright © 2013 American Urological Association

  6. Effect of Transcutaneous Electric Nerve Stimulation on Pain after Total Knee Arthroplasty: A Blind Randomized Controlled Trial.

    Science.gov (United States)

    Beckwée, David; Bautmans, Ivan; Lefeber, Nina; Lievens, Pierre; Scheerlinck, Thierry; Vaes, Peter

    2017-05-01

    Transcutaneous electric nerve stimulation (TENS) has proven to be effective for postsurgical pain relief. However, there is a lack of well-constructed clinical trials investigating the effect of TENS after total knee arthroplasty (TKA). In addition, previous investigations reported that low- and high-frequency TENSs produced analgesic tolerance after 4 or 5 days of treatment. The aim of this study is to explore the effect of burst TENS on pain during hospitalization after TKA and to investigate whether burst TENS produces analgesic tolerance after 4 or 5 days of treatment. This stratified, triple blind, randomized controlled trial was approved by the University Hospital Brussels. Sixty-eight subjects were screened for eligibility before surgery; 54 were found eligible and 53 were included in the analyses. Patients were allocated to either a burst TENS or sham burst TENS group. TENS was applied daily during continuous passive mobilization. Knee pain intensity, knee range of motion, and analgesic consumption were assessed daily. Patients received burst TENS (N = 25) or sham burst TENS (N = 28). No significant differences in knee pain intensity were found between the groups (p > 0.05). Within the TENS and the sham TENS groups, the difference in knee pain before and after treatment did not evolve over time (p > 0.05). This study found no effects of burst TENS compared with sham burst TENS on pain during hospitalization after TKA. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  7. Establishment of a novel in vitro test setup for electric and magnetic stimulation of human osteoblasts.

    Science.gov (United States)

    Grunert, P C; Jonitz-Heincke, A; Su, Y; Souffrant, R; Hansmann, D; Ewald, H; Krüger, A; Mittelmeier, W; Bader, R

    2014-11-01

    When large defects occur, bone regeneration can be supported by bone grafting and biophysical stimuli like electric and magnetic stimulation (EMS). Clinically established EMS modes are external coils and surgical implants like an electroinductive screw system, which combines a magnetic and electric field, e.g., for the treatment of avascular bone necrosis or pseudarthrosis. For optimization of this implant system, an in vitro test setup was designed to investigate effects of EMS on human osteoblasts on different 3D scaffolds (based on calcium phosphate and collagen). Prior to the cell experiments, numerical simulations of the setup, as well as experimental validation, via measurements of the electric parameters induced by EMS were conducted. Human osteoblasts (3 × 10(5) cells) were seeded onto the scaffolds and cultivated. After 24 h, screw implants (Stryker ASNIS III s-series) were centered in the scaffolds, and EMS was applied (3 × 45 min per day at 20 Hz) for 3 days. Cell viability and collagen type 1 (Col1) synthesis were determined subsequently. Numerical simulation and validation showed an adequate distribution of the electric field within the scaffolds. Experimental measurements of the electric potential revealed only minimal deviation from the simulation. Cell response to stimulation varied with scaffold material and mode of stimulation. EMS-stimulated cells exhibited a significant decrease of metabolic activity in particular on collagen scaffolds. In contrast, the Col1/metabolic activity ratio was significantly increased on collagen and non-sintered calcium phosphate scaffolds after 3 days. Exclusive magnetic stimulation showed similar but nonsignificant tendencies in metabolic activity and Col1 synthesis. The cell tests demonstrate that the new test setup is a valuable tool for in vitro testing and parameter optimization of the clinically used electroinductive screw system. It combines magnetic and electric stimulation, allowing in vitro investigations

  8. The electrical stimulation of carbon nanotubes to provide a cardiomimetic cue to MSCs.

    Science.gov (United States)

    Mooney, Emma; Mackle, Joseph N; Blond, David J-P; O'Cearbhaill, Eoin; Shaw, Georgina; Blau, Werner J; Barry, Frank P; Barron, Valerie; Murphy, J Mary

    2012-09-01

    Once damaged, cardiac muscle has little intrinsic repair capability due to the poor regeneration potential of remaining cardiomyocytes. One method of overcoming this issue is to deliver functional cells to the injured myocardium to promote repair. To address this limitation we sought to test the hypothesis that electroactive carbon nanotubes (CNT) could be employed to direct mesenchymal stem cell (MSC) differentiation towards a cardiomyocyte lineage. Using a two-pronged approach, MSCs exposed to medium containing CNT and MSCs seeded on CNT based polylactic acid scaffolds were electrically stimulated in an electrophysiological bioreactor. After electrical stimulation the cells reoriented perpendicular to the direction of the current and adopted an elongated morphology. Using qPCR, an upregulation in a range of cardiac markers was detected, the greatest of which was observed for cardiac myosin heavy chain (CMHC), where a 40-fold increase was observed for the electrically stimulated cells after 14 days, and a 12-fold increase was observed for the electrically stimulated cells seeded on the PLA scaffolds after 10 days. Differentiation towards a cardioprogenitor cell was more evident from the western blot analysis, where upregulation of Nkx2.5, GATA-4, cardiac troponin t (CTT) and connexin43 (C43) was seen to occur. This was echoed in immunofluorescent staining, where increased levels of CTT, CMHC and C43 protein expression were observed after electrical stimulation for both cells and cell-seeded scaffolds. More interestingly, there was evidence of increased cross talk between the cells as shown by the pattern of C43 staining after electrical stimulation. These results establish a paradigm for nanoscale biomimetic cues that can be readily translated to other electroactive tissue repair applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Effect of oscillating electrical field stimulation on motor function recovery and myelin regeneration after spinal cord injury in rats.

    Science.gov (United States)

    Tian, Da-Sheng; Jing, Jue-Hua; Qian, Jun; Chen, Lei; Zhu, Bin

    2016-05-01

    [Purpose] The aim of this study was to evaluate the effect of oscillating electrical field stimulation on motor function recovery and myelin regeneration in rats with spinal cord injury. [Subjects and Methods] A rat model of spinal cord injury was constructed by using the Allen weight-drop method. These rats were randomly divided into normal, spinal cord injury, and spinal cord injury + oscillating electrical field stimulation groups. The experimental group received the intervention with oscillating electrical field stimulation, and the control group received the intervention with an electrical field stimulator without oscillating electrical field stimulation. Each group was then randomly divided into seven subgroups according to observation time (1, 2, 4, 6, 8, 10, and 12 weeks). Basso-Beattie-Bresnahan score and inclined plate test score evaluation, motor evoked potential detection, and histological observation were performed. [Results] In the first 2 weeks of oscillating electrical field stimulation, the oscillating electrical field stimulation and inclined plate test scores of spinal cord injury group and spinal cord injury + oscillating electrical field stimulation group were not significantly different. In the fourth week, the scores of the spinal cord injury group were significantly lower than those of the spinal cord injury + oscillating electrical field stimulation group. The motor evoked potential incubation period in the spinal cord injury + oscillating electrical field stimulation group at the various time points was shorter than that in the spinal cord injury group. In the sixth week, the relative area of myelin in the spinal cord injury + oscillating electrical field stimulation group was evidently larger than that in the spinal cord injury group. [Conclusion] Oscillating electrical field stimulation could effectively improve spinal cord conduction function and promote motor function recovery in rats with spinal cord injury, as well as promote myelin

  10. Effects of paired transcutaneous electrical stimulation delivered at single and dual sites over lumbosacral spinal cord.

    Science.gov (United States)

    Sayenko, Dimitry G; Atkinson, Darryn A; Floyd, Terrance C; Gorodnichev, Ruslan M; Moshonkina, Tatiana R; Harkema, Susan J; Edgerton, V Reggie; Gerasimenko, Yury P

    2015-11-16

    It was demonstrated previously that transcutaneous electrical stimulation of multiple sites over the spinal cord is more effective in inducing robust locomotor behavior as compared to the stimulation of single sites alone in both animal and human models. To explore the effects and mechanisms of interactions during multi-site spinal cord stimulation we delivered transcutaneous electrical stimulation to the single or dual locations over the spinal cord corresponding to approximately L2 and S1 segments. Spinally evoked motor potentials in the leg muscles were investigated using single and paired pulses of 1ms duration with conditioning-test intervals (CTIs) of 5 and 50ms. We observed considerable post-stimulation modulatory effects which depended on CTIs, as well as on whether the paired stimuli were delivered at a single or dual locations, the rostro-caudal relation between the conditioning and test stimuli, and on the muscle studied. At CTI-5, the paired stimulation delivered at single locations (L2 or S1) provided strong inhibitory effects, evidenced by the attenuation of the compound responses as compared with responses from either single site. In contrast, during L2-S1 paradigm, the compound responses were potentiated. At CTI-50, the magnitude of inhibition did not differ among paired stimulation paradigms. Our results suggest that electrical stimuli delivered to dual sites over the lumbosacral enlargement in rostral-to-caudal order, may recruit different populations of motor neurons initially through projecting sensory and intraspinal connections and then directly, resulting in potentiation of the compound spinally evoked motor potentials. The interactive and synergistic effects indicate multi-segmental convergence of descending and ascending influences on the neuronal circuitries during electrical spinal cord stimulation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  11. Effect of early treatment with transcutaneous electrical diaphragmatic stimulation (TEDS) on pulmonary inflammation induced by bleomycin

    OpenAIRE

    Santos,Laisa A.; Silva, Carlos A.; Polacow, Maria L. O.

    2013-01-01

    BACKGROUND : Bleomycin (B) is an antineoplastic drug that has pulmonary fibrosis as a side effect. There are few experimental studies about the effects of physical therapy treatment in this case. OBJECTIVE: The objective was to study rat lungs treated with B and precocious intervention by transcutaneous electrical diaphragmatic stimulation (TEDS). METHOD : Wistar rats were divided into 4 groups (n=5): a control group (C); a stimulated group (TEDS); a group treated with a single dose of...

  12. Effects of sympathetic stimulation on the rhythmical jaw movements produced by electrical stimulation of the cortical masticatory areas of rabbits.

    Science.gov (United States)

    Roatta, S; Windhorst, U; Djupsjöbacka, M; Lytvynenko, S; Passatore, M

    2005-03-01

    The somatomotor and sympathetic nervous systems are intimately linked. One example is the influence of peripheral sympathetic fibers on the discharge characteristics of muscle spindles. Since muscle spindles play important roles in various motor behaviors, including rhythmic movements, the working hypothesis of this research was that changes in sympathetic outflow to muscle spindles can change rhythmic movement patterns. We tested this hypothesis in the masticatory system of rabbits. Rhythmic jaw movements and EMG activity induced by long-lasting electrical cortical stimulation were powerfully modulated by electrical stimulation of the peripheral stump of the cervical sympathetic nerve (CSN). This modulation manifested itself as a consistent and marked reduction in the excursion of the mandibular movements (often preceded by a transient modest enhancement), which could be attributed mainly to corresponding changes in masseter muscle activity. These changes outlasted the duration of CSN stimulation. In some of the cortically evoked rhythmic jaw movements (CRJMs) changes in masticatory frequency were also observed. When the jaw-closing muscles were subjected to repetitive ramp-and-hold force pulses, the CRMJs changed characteristics. Masseter EMG activity was strongly enhanced and digastric EMG slightly decreased. This change was considerably depressed during CSN stimulation. These effects of CSN stimulation are similar in sign and time course to the depression exerted by sympathetic activity on the jaw-closing muscle spindle discharge. It is suggested that the change in proprioceptive information induced by an increase in sympathetic outflow (a) has important implications even under normal conditions for the control of motor function in states of high sympathetic activity, and (b) is one of the mechanisms responsible for motor impairment under certain pathological conditions such as chronic musculoskeletal head-neck disorders, associated with stress conditions.

  13. Auditory Responses to Electric and Infrared Neural Stimulation of the Rat Cochlear Nucleus

    Science.gov (United States)

    Verma, Rohit; Guex, Amelie A.; Hancock, Kenneth E.; Durakovic, Nedim; McKay, Colette M.; Slama, Michaël C. C.; Brown, M. Christian; Lee, Daniel J.

    2014-01-01

    In an effort to improve the auditory brainstem implant, a prosthesis in which user outcomes are modest, we applied electric and infrared neural stimulation (INS) to the cochlear nucleus in a rat animal model. Electric stimulation evoked regions of neural activation in the inferior colliculus and short-latency, multipeaked auditory brainstem responses (ABRs). Pulsed INS, delivered to the surface of the cochlear nucleus via an optical fiber, evoked broad neural activation in the inferior colliculus. Strongest responses were recorded when the fiber was placed at lateral positions on the cochlear nucleus, close to the temporal bone. INS-evoked ABRs were multipeaked but longer in latency than those for electric stimulation; they resembled the responses to acoustic stimulation. After deafening, responses to electric stimulation persisted, whereas those to INS disappeared, consistent with a reported “optophonic” effect, a laser-induced acoustic artifact. Thus, for deaf individuals who use the auditory brainstem implant, INS alone did not appear promising as a new approach. PMID:24508368

  14. Auditory responses to electric and infrared neural stimulation of the rat cochlear nucleus.

    Science.gov (United States)

    Verma, Rohit U; Guex, Amélie A; Hancock, Kenneth E; Durakovic, Nedim; McKay, Colette M; Slama, Michaël C C; Brown, M Christian; Lee, Daniel J

    2014-04-01

    In an effort to improve the auditory brainstem implant, a prosthesis in which user outcomes are modest, we applied electric and infrared neural stimulation (INS) to the cochlear nucleus in a rat animal model. Electric stimulation evoked regions of neural activation in the inferior colliculus and short-latency, multipeaked auditory brainstem responses (ABRs). Pulsed INS, delivered to the surface of the cochlear nucleus via an optical fiber, evoked broad neural activation in the inferior colliculus. Strongest responses were recorded when the fiber was placed at lateral positions on the cochlear nucleus, close to the temporal bone. INS-evoked ABRs were multipeaked but longer in latency than those for electric stimulation; they resembled the responses to acoustic stimulation. After deafening, responses to electric stimulation persisted, whereas those to INS disappeared, consistent with a reported "optophonic" effect, a laser-induced acoustic artifact. Thus, for deaf individuals who use the auditory brainstem implant, INS alone did not appear promising as a new approach. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Perception of electrical and mechanical stimulation of the skin: implications for electrotactile feedback

    Science.gov (United States)

    Marcus, Patrick L.; Fuglevand, Andrew J.

    2009-12-01

    Spinal cord injury is often accompanied by impaired tactile and proprioceptive sensations. Normally, somatosensensory information derived from such sensations is important in the formation of voluntary motor commands. Therefore, as a preliminary step toward the development of an electrotactile feedback system to restore somatosensation, psychophysical methods were used to characterize perceptual attributes associated with electrical stimulation of the skin on the back of the neck in human subjects. These data were compared to mechanical stimulation of the skin on the back of neck and on the distal pad of the index finger. Spatial acuity of the neck, evaluated using two-point thresholds, was not significantly different for electrical (37 ± 14 mm) or mechanical stimulation (39 ± 10 mm). The exponent (β) of the best fitting power function relating perceived intensity to applied stimulus strength was used to characterize perceptual sensitivity to mechanical and electrical stimuli. For electrical stimuli, both current amplitude-modulated and frequency-modulated trains of pulses were tested. Perceptual sensitivity was significantly greater for current amplitude modulation (β = 1.14 ± 0.37) compared to frequency modulation (β = 0.57 ± 0.24) and mechanical stimulation (0.51 ± 0.12). Finally, based on the data gathered here, we derive a transfer function that could be used in the future to convert mechanical stimuli detected with artificial sensors placed on the fingers into electrotactile signals that evoke perceptions similar to those arising from normal mechanical stimulation of the skin.

  16. TENS (transcutaneous electrical nerve stimulation) for labour pain.

    Science.gov (United States)

    Francis, Richard

    2012-05-01

    Because TENS is applied inconsistently and not always in line with optimal TENS application theory, this may explain why TENS for labour pain appears to be effective in some individuals and not in others. This article reviews TENS theory, advises upon optimal TENS application for labour pain and discusses some of the limitations of TENS research on labour pain. TENS application for labour pain may include TENS applied to either side of the lower spine, set to 200 mus pulse duration and 100 pulses per second. As pain increases, TENS intensity should be increased and as pain decreases, TENS intensity should be reduced to maintain a strong but pain free intensity of stimulation. This application may particularly reduce back pain during labour.

  17. Emerging subspecialties in neurology: deep brain stimulation and electrical neuro-network modulation.

    Science.gov (United States)

    Hassan, Anhar; Okun, Michael S

    2013-01-29

    Deep brain stimulation (DBS) is a surgical therapy that involves the delivery of an electrical current to one or more brain targets. This technology has been rapidly expanding to address movement, neuropsychiatric, and other disorders. The evolution of DBS has created a niche for neurologists, both in the operating room and in the clinic. Since DBS is not always deep, not always brain, and not always simply stimulation, a more accurate term for this field may be electrical neuro-network modulation (ENM). Fellowships will likely in future years evolve their scope to include other technologies, and other nervous system regions beyond typical DBS therapy.

  18. Wireless electrical stimulation: an innovative powerful tool for the treatment of a complicated chronic ulcer.

    Science.gov (United States)

    Castana, Ourania; Dimitrouli, Aekaterini; Argyrakos, Theodoros; Theodorakopoulou, Emilia; Stampolidis, Nektarios; Papadopoulos, Emmanouil; Pallantzas, Athanasios; Stasinopoulos, Ioannis; Poulas, Konstantinos

    2013-03-01

    High-voltage electrical stimulation has been long proposed as a method of accelerating the wound healing process. Its beneficial effect has been successfully evaluated in the treatment of a number of chronic ulcers and burns. We present here the implementation of a new wireless electrical stimulation technique for the treatment of a complicated chronic ulcer of the lower limb. The device is transferring charges to the wound, without any contact with it, creating a microcurrent that is able to generate the current of injury. The results suggest that this easy-to-use method is an effective therapeutic option for chronic ulcers.

  19. Invasive and transcranial photoacoustic imaging of the vascular response to brain electrical stimulation

    Science.gov (United States)

    Tsytsarev, Vassiliy; Yao, Junjie; Hu, Song; Li, Li; Favazza, Christopher P.; Maslov, Konstantin I.; Wang, Lihong V.

    2010-02-01

    Advances in the brain functional imaging greatly facilitated the understanding of neurovascular coupling. For monitoring of the microvascular response to the brain electrical stimulation in vivo we used optical-resolution photoacoustic microscopy (OR-PAM) through the cranial openings as well as transcranially. Both types of the vascular response, vasoconstriction and vasodilatation, were clearly observed with good spatial and temporal resolution. Obtained results confirm one of the primary points of the neurovascular coupling theory that blood vessels could present vasoconstriction or vasodilatation in response to electrical stimulation, depending on the balance between inhibition and excitation of the different parts of the elements of the neurovascular coupling system.

  20. Electrical Stimulation of the Ventral Tegmental Area Induces Reanimation from General Anesthesia

    Science.gov (United States)

    Solt, Ken; Van Dort, Christa J.; Chemali, Jessica J.; Taylor, Norman E.; Kenny, Jonathan D.; Brown, Emery N.

    2014-01-01

    BACKGROUND Methylphenidate or a D1 dopamine receptor agonist induce reanimation (active emergence) from general anesthesia. We tested whether electrical stimulation of dopaminergic nuclei also induces reanimation from general anesthesia. METHODS In adult rats, a bipolar insulated stainless steel electrode was placed in the ventral tegmental area (VTA, n = 5) or substantia nigra (SN, n = 5). After a minimum 7-day recovery period, the isoflurane dose sufficient to maintain loss of righting was established. Electrical stimulation was initiated and increased in intensity every 3 min to a maximum of 120μA. If stimulation restored the righting reflex, an additional experiment was performed at least 3 days later during continuous propofol anesthesia. Histological analysis was conducted to identify the location of the electrode tip. In separate experiments, stimulation was performed in the prone position during general anesthesia with isoflurane or propofol, and the electroencephalogram was recorded. RESULTS To maintain loss of righting, the dose of isoflurane was 0.9% ± 0.1 vol%, and the target plasma dose of propofol was 4.4 μg/ml ± 1.1 μg/ml (mean ± SD). In all rats with VTA electrodes, electrical stimulation induced a graded arousal response including righting that increased with current intensity. VTA stimulation induced a shift in electroencephalogram peak power from δ (anesthesia with isoflurane or propofol. These results are consistent with the hypothesis that dopamine release by VTA, but not SN, neurons induces reanimation from general anesthesia. PMID:24398816

  1. Spectral distribution of local field potential responses to electrical stimulation of the retina.

    Science.gov (United States)

    Wong, Yan T; Halupka, Kerry; Kameneva, Tatiana; Cloherty, Shaun L; Grayden, David B; Burkitt, Anthony N; Meffin, Hamish; Shivdasani, Mohit N

    2016-06-01

    Different frequency bands of the local field potential (LFP) have been shown to reflect neuronal activity occurring at varying cortical scales. As such, recordings of the LFP may offer a novel way to test the efficacy of neural prostheses and allow improvement of stimulation strategies via neural feedback. Here we use LFP measurements from visual cortex to characterize neural responses to electrical stimulation of the retina. We aim to show that the LFP is a viable signal that contains sufficient information to optimize the performance of sensory neural prostheses. Clinically relevant electrode arrays were implanted in the suprachoroidal space of one eye in four felines. LFPs were simultaneously recorded in response to stimulation of individual electrodes using penetrating microelectrode arrays from the visual cortex. The frequency response of each electrode was extracted using multi-taper spectral analysis and the uniqueness of the responses was determined via a linear decoder. We found that cortical LFPs are reliably modulated by electrical stimulation of the retina and that the responses are spatially localized. We further characterized the spectral distribution of responses, with maximum information being contained in the low and high gamma bands. Finally, we found that LFP responses are unique to a large range of stimulus parameters (∼40) with a maximum conveyable information rate of 6.1 bits. These results show that the LFP can be used to validate responses to electrical stimulation of the retina and we provide the first steps towards using these responses to provide more efficacious stimulation strategies.

  2. Can preoperative electrical nociceptive stimulation predict acute pain after groin herniotomy?

    DEFF Research Database (Denmark)

    Aasvang, Eske Kvanner; Hansen, J.B.; Kehlet, H.

    2008-01-01

    recently been shown to correlate to acute postoperative pain after cesarean section, but the findings have not been confirmed in larger studies or other procedures. Preoperative electrical pain detection threshold and pain tolerance were assessed in patients undergoing a primary unilateral groin hernia...... repair. The correlation between the pain data for electrical stimulation was compared with the postoperative pain during the first week in 165 patients, whereof 3 were excluded. Preoperative electrical pain detection threshold and electrical pain tolerance threshold did not correlate to postoperative......Preoperative identification of patients at risk for high-intensity postoperative pain may be used to predict patients at risk for development of a persistent pain state and allocate patients to more intensive specific pain therapy. Preoperative pain threshold to electrocutaneus stimulation has...

  3. Can preoperative electrical nociceptive stimulation predict acute pain after groin herniotomy?

    DEFF Research Database (Denmark)

    Aasvang, Eske Kvanner; Hansen, Jeanette Birch; Kehlet, Henrik

    2008-01-01

    UNLABELLED: Preoperative identification of patients at risk for high-intensity postoperative pain may be used to predict patients at risk for development of a persistent pain state and allocate patients to more intensive specific pain therapy. Preoperative pain threshold to electrocutaneus...... stimulation has recently been shown to correlate to acute postoperative pain after cesarean section, but the findings have not been confirmed in larger studies or other procedures. Preoperative electrical pain detection threshold and pain tolerance were assessed in patients undergoing a primary unilateral...... groin hernia repair. The correlation between the pain data for electrical stimulation was compared with the postoperative pain during the first week in 165 patients, whereof 3 were excluded. Preoperative electrical pain detection threshold and electrical pain tolerance threshold did not correlate...

  4. An investigation into the induced electric fields from transcranial magnetic stimulation

    Science.gov (United States)

    Hadimani, Ravi; Lee, Erik; Duffy, Walter; Waris, Mohammed; Siddiqui, Waquar; Islam, Faisal; Rajamani, Mahesh; Nathan, Ryan; Jiles, David; David C Jiles Team; Walter Duffy Collaboration

    Transcranial magnetic stimulation (TMS) is a promising tool for noninvasive brain stimulation that has been approved by the FDA for the treatment of major depressive disorder. To stimulate the brain, TMS uses large, transient pulses of magnetic field to induce an electric field in the head. This transient magnetic field is large enough to cause the depolarization of cortical neurons and initiate a synaptic signal transmission. For this study, 50 unique head models were created from MRI images. Previous simulation studies have primarily used a single head model, and thus give a limited image of the induced electric field from TMS. This study uses finite element analysis simulations on 50 unique, heterogeneous head models to better investigate the relationship between TMS and the electric field induced in brain tissues. Results showed a significant variation in the strength of the induced electric field in the brain, which can be reasonably predicted by the distance from the TMS coil to the stimulated brain. Further, it was seen that some models had high electric field intensities in over five times as much brain volume as other models.

  5. Myoelectric Signals from Paretic Wrist Extensor Controlling Electrical Stimulation of the Same Muscle

    DEFF Research Database (Denmark)

    Rune, Thorsen; Fin, Biering-Sørensen; Hansen, Steffen Duus

    1996-01-01

    A device for enhancement of the grip in C5/6 spinal cord lesioned tetraplegics is under development. It uses the myoelectric signal from the paretic wrist extensor for control of electrical stimulation of the same muscle. The tetraplegics shall with the device be able to obtain a passive grip bet...... between the thumb an the index finger by extension of the wrist. Surface electrodes are used for myoelectric recording and stimulation. Main problems are filtering of the recorded signal and stimulation. Solutions to these problems are addressed and discussed....

  6. Short time effect of Delta oscillation under microcurrent transcutaneous electrical nerve stimulation at ST36.

    Science.gov (United States)

    Li, Shunan; Li, Donghui; Li, Huiyan; Wang, Jiang

    2014-01-01

    This paper was to study the short time effect of Delta brain oscillation under microcurrent transcutaneous electrical nerve stimulation (MTENS) at ST36 (Zusanli). The 64-channal electroencephalograph (EEG) signals from 12 healthy volunteers were recorded including baseline stage, during stimulation and after stimulation. Autoregressive (AR) Burg method was used to estimate the power spectrum. Then power variation rate (PVR) was calculated to quantify the effects compared with the baseline in Delta band. The results showed that MTENS at ST36 on right side led to increased Delta band power in left frontal.

  7. Mandarin speech perception in combined electric and acoustic stimulation.

    Directory of Open Access Journals (Sweden)

    Yongxin Li

    Full Text Available For deaf individuals with residual low-frequency acoustic hearing, combined use of a cochlear implant (CI and hearing aid (HA typically provides better speech understanding than with either device alone. Because of coarse spectral resolution, CIs do not provide fundamental frequency (F0 information that contributes to understanding of tonal languages such as Mandarin Chinese. The HA can provide good representation of F0 and, depending on the range of aided acoustic hearing, first and second formant (F1 and F2 information. In this study, Mandarin tone, vowel, and consonant recognition in quiet and noise was measured in 12 adult Mandarin-speaking bimodal listeners with the CI-only and with the CI+HA. Tone recognition was significantly better with the CI+HA in noise, but not in quiet. Vowel recognition was significantly better with the CI+HA in quiet, but not in noise. There was no significant difference in consonant recognition between the CI-only and the CI+HA in quiet or in noise. There was a wide range in bimodal benefit, with improvements often greater than 20 percentage points in some tests and conditions. The bimodal benefit was compared to CI subjects' HA-aided pure-tone average (PTA thresholds between 250 and 2000 Hz; subjects were divided into two groups: "better" PTA (50 dB HL. The bimodal benefit differed significantly between groups only for consonant recognition. The bimodal benefit for tone recognition in quiet was significantly correlated with CI experience, suggesting that bimodal CI users learn to better combine low-frequency spectro-temporal information from acoustic hearing with temporal envelope information from electric hearing. Given the small number of subjects in this study (n = 12, further research with Chinese bimodal listeners may provide more information regarding the contribution of acoustic and electric hearing to tonal language perception.

  8. Adaptive fuzzy logic restriction rules for error correction and safe stimulation patterns during functional electrical stimulation.

    Science.gov (United States)

    Hansen, M; Haugland, M K

    2001-01-01

    Adaptive restriction rules based on fuzzy logic have been developed to eliminate errors and to increase stimulation safety in the foot-drop correction application, specifically when using adaptive logic networks to provide a stimulation control signal based on neural activity recorded from peripheral sensory nerve branches. The fuzzy rules were designed to increase flexibility and offer easier customization, compared to earlier versions of restriction rules. The rules developed quantified the duration of swing and stance phases into states of accepting or rejecting new transitions, based on the cyclic nature of gait and statistics on the current gait patterns. The rules were easy to custom design for a specific application, using linguistic terms to model the actions of the rules. The rules were tested using pre-recorded gait data processed through a gait event detector and proved to reduce detection delay and the number of errors, compared to conventional rules.

  9. Implantable power generation system utilizing muscle contractions excited by electrical stimulation.

    Science.gov (United States)

    Sahara, Genta; Hijikata, Wataru; Tomioka, Kota; Shinshi, Tadahiko

    2016-06-01

    An implantable power generation system driven by muscle contractions for supplying power to active implantable medical devices, such as pacemakers and neurostimulators, is proposed. In this system, a muscle is intentionally contracted by an electrical stimulation in accordance with the demands of the active implantable medical device for electrical power. The proposed system, which comprises a small electromagnetic induction generator, electrodes with an electrical circuit for stimulation and a transmission device to convert the linear motion of the muscle contractions into rotational motion for the magneto rotor, generates electrical energy. In an ex vivo demonstration using the gastrocnemius muscle of a toad, which was 28 mm in length and weighed 1.3 g, the electrical energy generated by the prototype exceeded the energy consumed for electrical stimulation, with the net power being 111 µW. It was demonstrated that the proposed implantable power generation system has the potential to replace implantable batteries for active implantable medical devices. © IMechE 2016.

  10. DC electric stimulation upregulates angiogenic factors in endothelial cells through activation of VEGF receptors.

    Science.gov (United States)

    Bai, Huai; Forrester, John V; Zhao, Min

    2011-07-01

    Small direct current (DC) electric fields direct some important angiogenic responses of vascular endothelial cells. Those responses indicate promising use of electric fields to modulate angiogenesis. We sought to determine the regulation of electric fields on transcription and expression of a serial of import angiogenic factors by endothelial cells themselves. Using semi-quantitative PCR and ELISA we found that electric stimulation upregulates the levels of mRNAs and proteins of a number of angiogenic proteins, most importantly VEGF165, VEGF121 and IL-8 in human endothelial cells. The up-regulation of mRNA levels might be specific, as the mRNA encoding bFGF, TGF-beta and eNOS are not affected by DC electric stimulation at 24h time-point. Inhibition of VEGF receptor (VEGFR1 or VEGFR2) signaling significantly decreased VEGF production and completely abolished IL-8 production. DC electric stimulation selectively regulates production of some growth factors and cytokines important for angiogenesis through a feed-back loop mediated by VEGF receptors. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. Cortical potentials after electrical intraneural stimulation of the optic nerve during orbital enucleation.

    Science.gov (United States)

    Benedičič, Mitja; Beltram, Matej; Olup, Brigita Drnovšek; Bošnjak, Roman

    2012-12-01

    The aim of this study was to present cortical potentials after electrical intraneural stimulation of the optic nerve during orbital enucleation due to malignant melanoma of the choroid or the ciliary body. These cortical potentials were related to cortical potentials after electrical epidural stimulation of the optic nerve, recorded during non-manipulative phases of neurosurgery for central skull base tumors. Cortical potentials were recorded with surface occipital electrode (Oz) in six patients undergoing orbital enucleation under total intravenous anesthesia. Two thin needle stimulating electrodes were inserted inside the intraorbital part of the optic nerve. The electrical stimulus consisted of a rectangular current pulse of varying intensity (0.2-10.0 mA) and duration (0.1-0.3 ms); the stimulation rate was 2 Hz; the bandpass filter was 1-1,000 Hz; the analysis time was 50-300 ms. Cortical potentials could not be obtained or were inconsistently elicitable in three patients with longstanding history (>3 months) of severe visual deterioration, while they consisted of several positive and negative deflections in a patient with a short history of mild visual impairment. In two other patients, cortical potentials consisted of N20, P30 and N40 waves. Cortical potentials after electrical intraneural stimulation of the optic nerve could be recorded in patients with a short history of visual deterioration and without optic nerve atrophy and appear more heterogeneous than cortical potentials after electrical epidural stimulation of the optic nerve, recorded during non-manipulative phases of neurosurgery for central skull base tumors.

  12. Metabolic and structural changes in lower-limb skeletal muscle following neuromuscular electrical stimulation: a systematic review.

    Directory of Open Access Journals (Sweden)

    Maurice J H Sillen

    Full Text Available BACKGROUND: Transcutaneous neuromuscular electrical stimulation (NMES can be applied as a complementary intervention to regular exercise training programs. A distinction can be made between high-frequency (HF NMES and low-frequency (LF NMES. In order to increase understanding of the mechanisms of functional improvements following NMES, the purpose of this study was to systematically review changes in enzyme activity, muscle fiber type composition and muscle fiber size in human lower-limb skeletal muscles following only NMES. METHODS: Trials were collected up to march 2012 and were identified by searching the Medline/PubMed, EMBASE, Cochrane Central Register of Controlled Trials, CINAHL and The Physical Therapy Evidence Database (PEDro databases and reference lists. 18 trials were reviewed in detail: 8 trials studied changes in enzyme activities, 7 trials studied changes in muscle fiber type composition and 14 trials studied changes in muscle fiber size following NMES. RESULTS: The methodological quality generally was poor, and the heterogeneity in study design, study population, NMES features and outcome parameters prohibited the use of meta-analysis. Most of the LF-NMES studies reported significant increases in oxidative enzyme activity, while the results concerning changes in muscle fiber composition and muscle size were conflicting. HF-NMES significantly increased muscle size in 50% of the studies. CONCLUSION: NMES seems to be a training modality resulting in changes in oxidative enzyme activity, skeletal muscle fiber type and skeletal muscle fiber size. However, considering the small sample sizes, the variance in study populations, the non-randomized controlled study designs, the variance in primary outcomes, and the large heterogeneity in NMES protocols, it is difficult to draw definitive conclusions about the effects of stimulation frequencies on muscular changes.

  13. Effect of electrical vs. chemical deep brain stimulation at midbrain sites on micturition in anaesthetized rats.

    Science.gov (United States)

    Stone, E; Coote, J H; Lovick, T A

    2015-05-01

    To understand how deep brain stimulation of the midbrain influences control of the urinary bladder. In urethane-anaesthetized male rats, saline was infused continuously into the bladder to evoke cycles of filling and voiding. The effect of electrical (0.1-2.0 ms pulses, 5-180 Hz, 0.5-2.5 V) compared to chemical stimulation (microinjection of D,L-homocysteic acid, 50 nL 0.1 M solution) at the same midbrain sites was tested. Electrical stimulation of the periaqueductal grey matter and surrounding midbrain disrupted normal coordinated voiding activity in detrusor and sphincters muscles and suppressed urine output. The effect occurred within seconds was reversible and not secondary to cardiorespiratory changes. Bladder compliance remained unchanged. Chemical stimulation over the same area using microinjection of D,L-homocysteic acid (DLH) to preferentially activate somatodendritic receptors decreased the frequency of micturition but did not disrupt the coordinated pattern of voiding. In contrast, chemical stimulation within the caudal ventrolateral periaqueductal grey, in the area where critical synapses in the micturition reflex pathway are located, increased the frequency of micturition. Electrical deep brain stimulation within the midbrain can inhibit reflex micturition. We suggest that the applied stimulus entrained activity in the neural circuitry locally, thereby imposing an unphysiological pattern of activity. In a way similar to the use of electrical signals to 'jam' radio transmission, this may prevent a synchronized pattern of efferent activity being transmitted to the spinal outflows to orchestrate a coordinated voiding response. Further experiments to record neuronal firing in the midbrain during the deep brain stimulation will be necessary to test this hypothesis. © 2015 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

  14. Overview of the Advanced High Frequency Branch

    Science.gov (United States)

    Miranda, Felix A.

    2015-01-01

    This presentation provides an overview of the competencies, selected areas of research and technology development activities, and current external collaborative efforts of the NASA Glenn Research Center's Advanced High Frequency Branch.

  15. Enhanced Working Memory Binding by Direct Electrical Stimulation of the Parietal Cortex

    Directory of Open Access Journals (Sweden)

    Agustina Birba

    2017-06-01

    Full Text Available Recent works evince the critical role of visual short-term memory (STM binding deficits as a clinical and preclinical marker of Alzheimer’s disease (AD. These studies suggest a potential role of posterior brain regions in both the neurocognitive deficits of Alzheimer’s patients and STM binding in general. Thereupon, we surmised that stimulation of the posterior parietal cortex (PPC might be a successful approach to tackle working memory deficits in this condition, especially at early stages. To date, no causal evidence exists of the role of the parietal cortex in STM binding. A unique approach to assess this issue is afforded by single-subject direct intracranial electrical stimulation of specific brain regions during a relevant cognitive task. Electrical stimulation has been used both for clinical purposes and to causally probe brain mechanisms. Previous evidence of electrical currents spreading through white matter along well defined functional circuits indicates that visual working memory mechanisms are subserved by a specific widely distributed network. Here, we stimulated the parietal cortex of a subject with intracranial electrodes as he performed the visual STM task. We compared the ensuing results to those from a non-stimulated condition and to the performance of a matched control group. In brief, direct stimulation of the parietal cortex induced a selective improvement in STM. These results, together with previous studies, provide very preliminary but promising ground to examine behavioral changes upon parietal stimulation in AD. We discuss our results regarding: (a the usefulness of the task to target prodromal stages of AD; (b the role of a posterior network in STM binding and in AD; and (c the potential opportunity to improve STM binding through brain stimulation.

  16. Dose postural control improve following application of transcutaneous electrical nerve stimulation in diabetic peripheral neuropathic patients? A randomized placebo control trial.

    Science.gov (United States)

    Saadat, Z; Rojhani-Shirazi, Z; Abbasi, L

    2017-06-09

    peripheral neuropathy is the most common problem of diabetes. Neuropathy leads to lower extremity somatosensory deficits and postural instability in these patients. However, there are not sufficient evidences for improving postural control in these patients. To investigate the effects of transcutaneous electrical nerve stimulation (TENS) on postural control in patients with diabetic neuropathy. Twenty eighth patients with diabetic neuropathy (40-55 Y/O) participated in this RCT study. Fourteen patients in case group received TENS and sham TENS was used for control group. Force plate platform was used to extract sway velocity and COP displacement parameters for postural control evaluation. The mean sway velocity and center of pressure displacement along the mediolateral and anteroposterior axes were not significantly different between two groups after TENS application (p>0.05). Application of 5min high frequency TENS on the knee joint could not improve postural control in patients with diabetic neuropathy. Copyright © 2017. Published by Elsevier Ltd.

  17. Efficacy of brain-computer interface-driven neuromuscular electrical stimulation for chronic paresis after stroke.

    Science.gov (United States)

    Mukaino, Masahiko; Ono, Takashi; Shindo, Keiichiro; Fujiwara, Toshiyuki; Ota, Tetsuo; Kimura, Akio; Liu, Meigen; Ushiba, Junichi

    2014-04-01

    Brain computer interface technology is of great interest to researchers as a potential therapeutic measure for people with severe neurological disorders. The aim of this study was to examine the efficacy of brain computer interface, by comparing conventional neuromuscular electrical stimulation and brain computer interface-driven neuromuscular electrical stimulation, using an A-B-A-B withdrawal single-subject design. A 38-year-old male with severe hemiplegia due to a putaminal haemorrhage participated in this study. The design involved 2 epochs. In epoch A, the patient attempted to open his fingers during the application of neuromuscular electrical stimulation, irrespective of his actual brain activity. In epoch B, neuromuscular electrical stimulation was applied only when a significant motor-related cortical potential was observed in the electroencephalogram. The subject initially showed diffuse functional magnetic resonance imaging activation and small electro-encephalogram responses while attempting finger movement. Epoch A was associated with few neurological or clinical signs of improvement. Epoch B, with a brain computer interface, was associated with marked lateralization of electroencephalogram (EEG) and blood oxygenation level dependent responses. Voluntary electromyogram (EMG) activity, with significant EEG-EMG coherence, was also prompted. Clinical improvement in upper-extremity function and muscle tone was observed. These results indicate that self-directed training with a brain computer interface may induce activity- dependent cortical plasticity and promote functional recovery. This preliminary clinical investigation encourages further research using a controlled design.

  18. Clinical efficacy of electrical stimulation exercise training : Effects on health, fitness, and function

    NARCIS (Netherlands)

    Janssen, T. W J; Glaser, R. M.; Shuster, D. B.

    1998-01-01

    The purpose of this article is to summarize research findings pertaining to the effects of functional electrical stimulation (FES) lower limb exercise training on health, fitness, and function in individuals with spinal cord injury. This lays the foundation for defining the potential clinical

  19. Effects of haloperidol on behavioral responses induced by electrical stimulation of medial prefrontal cortex.

    Science.gov (United States)

    Nakamura-Palacios, E M

    1996-10-01

    The effects of haloperidol on circling and spying behaviors induced by electrical stimulation of the medial prefrontal cortex (PFC) were evaluated. Male Wistar rats with an electrode implanted into the left medial PFC (B: 2.5 mm A, 0.6 mm L and 2.7 mm V) were electrically stimulated in a sequence of ten 30-sec trains separated by 30-sec intervals (60 Hz) in each session, and simultaneously observed in the open field. The animals with circling (CI) and spying (SP) behaviors were treated with intraperitoneal haloperidol (HAL ip, 5 mg/kg, N = 6) and saline (SAL ip, N = 7) or intracortical HAL (ic, 5 micrograms, N = 6) and SAL (ic, N = 9), 20 min before the session of electrical stimulation. HAL ic significantly decreased (P < 0.05) CI (mean frequency +/- SEM: 0.5 +/- 0.16) and nonsignificantly decreased SP behavior (0.6 +/- 0.17) compared to SAL ic (CI: 0.9 0.02, SP: 1 +/- 0). HAL ip full abolished these behaviors (P < 0.05) (CI: 0.02 +/- 0, SP: 1 +/- 0) compared to SAL ip (CI: 0.86 +/- 0.06, SP: 0:93 +/- 0.06). These results show that haloperidol, a dopaminergic antagonist and antipsychotic agent, interfered significantly with the expression of behaviors induced by electrical stimulation of the left medial PFC, suggesting that the induction of these behaviors may involve the dopaminergic neurotransmission.

  20. Electrical stimulation of sacral dermatomes in multiple sclerosis patients with neurogenic detrusor overactivity.

    NARCIS (Netherlands)

    Fjorback, M.V.; Rey, F. van; Rijkhoff, N.J.M.; Nohr, M.; Petersen, T.; Heesakkers, J.P.

    2007-01-01

    AIMS: Transcutaneous electrical stimulation of the dorsal penile/clitoral nerve (DPN) has been shown to suppress detrusor contractions in patients with neurogenic detrusor overactivity (NDO). However, the long-term use of surface electrodes in the genital region may not be well tolerated and may

  1. Controlling your impulses: Electrical stimulation of the human supplementary motor complex prevents impulsive errors

    NARCIS (Netherlands)

    Spieser, L.; van den Wildenberg, W.; Hasbroucq, T.; Ridderinkhof, K.R.; Burle, B.

    2015-01-01

    To err is human. However, an inappropriate urge does not always result in error. Impulsive errors thus entail both a motor system capture by an urge to act and a failed inhibition of that impulse. Here we show that neuromodulatory electrical stimulation of the supplementary motor complex in healthy

  2. Effects of electric stimulation-assisted cycling training in people with chronic stroke

    NARCIS (Netherlands)

    Janssen, T.W.J.; Beltman, J.M.; Elich, P.; Koppe, P.A.; Konijnenbelt, H.; de Haan, A.; Gerrits, K.H.L.

    2008-01-01

    Janssen TW, Beltman JM, Elich P, Koppe PA, Konijnenbelt H, de Haan A, Gerrits KH. Effects of electric stimulation-assisted cycling training in people with chronic stroke. Objective: To evaluate whether leg cycling training in subjects with chronic stroke can improve cycling performance, aerobic

  3. Evidence of skeletal muscle damage following electrically stimulated isometric muscle contractions in humans

    DEFF Research Database (Denmark)

    Mackey, Abigail; Bojsen-Moller, Jens; Qvortrup, Klaus

    2008-01-01

    It is unknown whether muscle damage at the level of the sarcomere can be induced without lengthening contractions. To investigate this, we designed a study where seven young, healthy men underwent 30 min of repeated electrical stimulated contraction of m. gastrocnemius medialis, with the ankle an...

  4. Electrical stimulation therapy for slow transit constipation in children: a systematic review.

    Science.gov (United States)

    Lu, Ming-Liang; He, Jin; Lu, Shifeier

    2015-05-01

    Slow transit constipation is a common disorder in children, which often does not respond well to ordinary treatments. We have conducted a systematic review of reported studies in order to better define the current state of knowledge about electrical stimulation treatment of slow transit constipation in children. We searched PubMed, Embase, Cochrane Library, BioMed Central, and ISI Web of Knowledge with relevant terms; six studies, all from one center, met the criteria for inclusion. Two trials were randomized clinical trials, and four were prospective studies. The number of subjects included in the studies was 8 to 39, with ages 3 to 18 years. Treatment sessions varied from 20 to 30 min 3 times per week to 1 h daily, and duration of therapy varied from 3 weeks to 6 months. Statistically significant improvements after electrical stimulation therapy were recorded in one to four outcome measures in each of the studies: frequency of defecation, soiling, Bristol Stool Scale, radionuclear transit studies, and quality of life; however, the improvements were of modest degree and of uncertain clinical significance. Quality assessment of the studies found various levels of bias, with attrition bias and reporting bias in all six. This systemic review found moderate support for the effectiveness of electrical stimulation therapy in slow transit constipation in children. However, better-designed studies, with larger and more diverse patient populations followed for longer time periods, will be needed in order to reliably determine the efficacy of electrical stimulation therapy in the treatment of this disorder.

  5. Comparison of electrical stimulation methods for reduction of triceps sureae spasticiy in SCI-patients

    NARCIS (Netherlands)

    van der Salm, Arjan; Veltink, Petrus H.; IJzerman, Maarten Joost; Groothuis-Oudshoorn, Catharina Gerarda Maria; Nene, A.V.; Hermens, Hermanus J.

    Objectives To compare the effect of 3 methods of electric stimulation to reduce spasticity of the triceps surae in patients with complete spinal cord injury (SCI) and to investigate the carryover effect. Design Placebo-controlled study with repeated measurements after the interventions. Setting

  6. [Long-term evaluation of spinal cord electric stimulation in peripheral vascular disease].

    Science.gov (United States)

    Duato Jané, A; Lorente Navarro, C; Azcona Elizalde, J M; Revilla Martín, J M; Marsal Machín, T; Buisán Bardají, J M

    1993-01-01

    We reported an study about the Electric Medullar Stimulation on Peripheral Vascular Pathology, in cases of critical Ischaemia of lower limbs. Short-time and longtime results are exposed. Arteriopathies included into the study were: arteriosclerosis, "mixed arteriopathy and TAO". Examination was made by Doppler-Ultrasonography.

  7. Effects of transcutaneous electrical nerve stimulation (TENS) on cognition and behaviour in aging

    NARCIS (Netherlands)

    Scherder, E.J A; van Someren, E.W J; Bouma, J.M.; van der Berg, M

    2000-01-01

    In previous studies, transcutaneous electrical nerve stimulation (TENS) improved cognition and behaviour in patients with Alzheimer's disease (AD). The rationale underlying these studies was that TENS could activate, e.g. the septo-hippocampal region and the hypothalamus through direct and indirect

  8. Effects of transcutaneous electrical nerve stimulation (TENS) on memory in elderly with mild cognitive impairment

    NARCIS (Netherlands)

    Luijpen, MW; Swaab, DF; Sergeant, JA; van Dijk, KRA; Scherder, EJA

    2005-01-01

    In previous studies, transcutaneous electrical nerve stimulation (TENS) was shown to have a positive effect on memory in Alzheimer's disease (AD) patients. Moreover, the reported effects appeared to be more beneficial in early stages of Alzheimer's disease compared to later stage intervention. Based

  9. Effects of transcutaneous electrical nerve stimulation (TENS) on memory in elderly with mild cognitive impairment.

    NARCIS (Netherlands)

    Luijpen, M.W.; Swaab, D.F.; Sergeant, J.A.; Dijk, K.R.A.; Scherder, E.J.

    2005-01-01

    In previous studies, transcutaneous electrical nerve stimulation (TENS) was shown to have a positive effect on memory in Alzheimer's disease (AD) patients. Moreover, the reported effects appeared to be more beneficial in early stages of Alzheimer's disease compared to later stage intervention. Based

  10. Functional electrical stimulation-assisted walking for persons with incomplete spinal injuries

    DEFF Research Database (Denmark)

    Ladouceur, M.; Barbeau, H.

    2000-01-01

    This study investigated the changes in maximal overground walking speed (MOWS) that occurred during; walking training with a functional electrical stimulation (FES) orthosis by chronic spinal cord injured persons with incomplete motor function loss. The average walking: speed over a distance of 10...

  11. Electrospun conducting polymer nanofibers and electrical stimulation of nerve stem cells.

    Science.gov (United States)

    Prabhakaran, Molamma P; Ghasemi-Mobarakeh, Laleh; Jin, Guorui; Ramakrishna, Seeram

    2011-11-01

    Tissue engineering of nerve grafts requires synergistic combination of scaffolds and techniques to promote and direct neurite outgrowth across the lesion for effective nerve regeneration. In this study, we fabricated a composite polymeric scaffold which is conductive in nature by electrospinning and further performed electrical stimulation of nerve stem cells seeded on the electrospun nanofibers. Poly-L-lactide (PLLA) was blended with polyaniline (PANi) at a ratio of 85:15 and electrospun to obtain PLLA/PANi nanofibers with fiber diameters of 195 ± 30 nm. The morphology, chemical and mechanical properties of the electrospun PLLA and PLLA/PANi scaffolds were carried out by scanning electron microscopy (SEM), X-ray photo electron spectroscopy (XPS) and tensile instrument. The electrospun PLLA/PANi fibers showed a conductance of 3 × 10⁻⁹ S by two-point probe measurement. In vitro electrical stimulation of the nerve stem cells cultured on PLLA/PANi scaffolds applied with an electric field of 100 mV/mm for a period of 60 min resulted in extended neurite outgrowth compared to the cells grown on non-stimulated scaffolds. Our studies further strengthen the implication of electrical stimulation of nerve stem cells on conducting polymeric scaffolds towards neurite elongation that could be effective for nerve tissue regeneration. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  12. Control of thumb force using surface functional electrical stimulation and muscle load sharing

    NARCIS (Netherlands)

    Westerveld, A.J.; Schouten, A.C.; Veltink, P.H.; Van der Kooij, H.

    2013-01-01

    Background Stroke survivors often have difficulties in manipulating objects with their affected hand. Thumb control plays an important role in object manipulation. Surface functional electrical stimulation (FES) can assist movement. We aim to control the 2D thumb force by predicting the sum of

  13. Control of thumb force using surface functional electrical stimulation and muscle load sharing

    NARCIS (Netherlands)

    Westerveld, Ard; Westerveld, Ard J.; Schouten, Alfred Christiaan; Veltink, Petrus H.; van der Kooij, Herman

    2013-01-01

    Background: Stroke survivors often have difficulties in manipulating objects with their affected hand. Thumb control plays an important role in object manipulation. Surface functional electrical stimulation (FES) can assist movement. We aim to control the 2D thumb force by predicting the sum of

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