Measurement of Leaked High-Frequency Burst Electric Field and EMI Evaluation for Cardiac Pacemaker in Fusion Facility

2012 ◽  
Vol 132 (5) ◽  
pp. 356-361
Author(s):  
Yukio Yamanaka ◽  
Jianqing Wang ◽  
Osamu Fujiwara ◽  
Tatsuhiko Uda
Keyword(s):  
Electric Field ◽  
High Frequency ◽  
Cardiac Pacemaker ◽  
Frequency Burst

Formation of Regular Domain Structures in Quenched Ferroelectrics Under the Influence of an External High-frequency Electric Field

2019 ◽  
Vol 9 (3) ◽  
pp. 344-352 ◽  
Author(s):  
L.I. Stefanovich ◽  
O.Y. Mazur ◽  
V.V. Sobolev
Keyword(s):  
Lithium Niobate ◽  
Electric Field ◽  
Domain Structure ◽  
High Frequency ◽  
Evolution Equations ◽  
Regular Domain ◽  
Field Frequency ◽  
Domain Structures ◽  
Alternating Electric Field ◽  
Lithium Niobate Crystals

Introduction: Within the framework of the phenomenological theory of phase transitions of the second kind of Ginzburg-Landau, the kinetics of ordering of a rapidly quenched highly nonequilibrium domain structure is considered using the lithium tantalate and lithium niobate crystals as an example. Experimental: Using the statistical approach, evolution equations describing the formation of the domain structure under the influence of a high-frequency alternating electric field in the form of a standing wave were obtained. Numerical analysis has shown the possibility of forming thermodynamically stable mono- and polydomain structures. It turned out that the process of relaxation of the system to the state of thermodynamic equilibrium can proceed directly or with the formation of intermediate quasi-stationary polydomain asymmetric phases. Results: It is shown that the formation of Regular Domain Structures (RDS) is of a threshold character and occurs under the influence of an alternating electric field with an amplitude less than the critical value, whose value depends on the field frequency. The conditions for the formation of RDSs with a micrometer spatial scale were determined. Conclusion: As shown by numerical studies, the RDSs obtained retain their stability, i.e. do not disappear even after turning off the external electric field. Qualitative analysis using lithium niobate crystals as an example has shown the possibility of RDSs formation in high-frequency fields with small amplitude under resonance conditions

scholarly journals High-fidelity transmission of high-frequency burst stimuli from peripheral nerve to thalamic nuclei in children with dystonia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Estefanía Hernandez-Martin ◽  
Enrique Arguelles ◽  
Yifei Zheng ◽  
Ruta Deshpande ◽  
Terence D. Sanger
Keyword(s):  
Deep Brain Stimulation ◽  
Peripheral Nerve ◽  
Brain Stimulation ◽  
High Frequency ◽  
Sensory Information ◽  
Brain Structures ◽  
High Fidelity ◽  
Thalamic Nuclei ◽  
Frequency Burst ◽  
Deep Brain

AbstractHigh-frequency peripheral nerve stimulation has emerged as a noninvasive alternative to thalamic deep brain stimulation for some patients with essential tremor. It is not known whether such techniques might be effective for movement disorders in children, nor is the mechanism and transmission of the peripheral stimuli to central brain structures understood. This study was designed to investigate the fidelity of transmission from peripheral nerves to thalamic nuclei in children with dystonia undergoing deep brain stimulation surgery. The ventralis intermediate (VIM) thalamus nuclei showed a robust evoked response to peripheral high-frequency burst stimulation, with a greatest response magnitude to intra-burst frequencies between 50 and 100 Hz, and reliable but smaller responses up to 170 Hz. The earliest response occurred at 12–15 ms following stimulation onset, suggesting rapid high-fidelity transmission between peripheral nerve and thalamic nuclei. A high-bandwidth, low-latency transmission path from peripheral nerve to VIM thalamus is consistent with the importance of rapid and accurate sensory information for the control of coordination and movement via the cerebello-thalamo-cortical pathway. Our results suggest the possibility of non-invasive modulation of thalamic activity in children with dystonia, and therefore the possibility that a subset of children could have beneficial clinical response without the need for invasive deep brain stimulation.

scholarly journals High-frequency burst spiking in layer 5 thick-tufted pyramids of rat primary somatosensory cortex encodes exploratory touch

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Christiaan P. J. de Kock ◽  
Jean Pie ◽  
Anton W. Pieneman ◽  
Rebecca A. Mease ◽  
Arco Bast ◽  
...  
Keyword(s):  
Somatosensory Cortex ◽  
Information Content ◽  
High Frequency ◽  
Temporal Structure ◽  
Cell Types ◽  
Primary Somatosensory Cortex ◽  
Excitatory Cell ◽  
Cortical Microcircuit ◽  
Subcortical Regions ◽  
Frequency Burst

AbstractDiversity of cell-types that collectively shape the cortical microcircuit ensures the necessary computational richness to orchestrate a wide variety of behaviors. The information content embedded in spiking activity of identified cell-types remain unclear to a large extent. Here, we recorded spike responses upon whisker touch of anatomically identified excitatory cell-types in primary somatosensory cortex in naive, untrained rats. We find major differences across layers and cell-types. The temporal structure of spontaneous spiking contains high-frequency bursts (≥100 Hz) in all morphological cell-types but a significant increase upon whisker touch is restricted to layer L5 thick-tufted pyramids (L5tts) and thus provides a distinct neurophysiological signature. We find that whisker touch can also be decoded from L5tt bursting, but not from other cell-types. We observed high-frequency bursts in L5tts projecting to different subcortical regions, including thalamus, midbrain and brainstem. We conclude that bursts in L5tts allow accurate coding and decoding of exploratory whisker touch.

Encoding properties of the wing hinge stretch receptor in the hawkmothManduca sexta

2001 ◽  
Vol 204 (21) ◽  
pp. 3693-3702 ◽  
Author(s):  
Mark A. Frye
Keyword(s):  
Manduca Sexta ◽  
Instantaneous Frequency ◽  
High Frequency ◽  
Dynamic Deformation ◽  
Stretch Receptor ◽  
Tonic Firing ◽  
Frequency Burst ◽  
Natural Dynamic ◽  
Oscillation Rate

SUMMARYTo characterize the in vivo responses of the wing hinge stretch receptor of Manduca sexta, I recorded its activity and simultaneously tracked the up-and-down motion of the wing while the hawkmoth flew tethered in a wind tunnel. The stretch receptor fires a high-frequency burst of spikes near each dorsal stroke reversal. The onset of the burst is tightly tuned to a set-point in wing elevation, and the number of spikes contained within the burst encodes the maximal degree of wing elevation during the stroke. In an effort to characterize its mechanical encoding properties, I constructed an actuator that delivered deformations to the wing hinge and simultaneously recorded the resultant stretch and tension and the activity of the stretch receptor. Stimuli included stepwise changes in length as well as more natural dynamic deformation that was measured in vivo. Step changes in length reveal that the stretch receptor encodes the static amplitude of stretch with both phasic and tonic firing dynamics. In vivo sinusoidal deformation revealed (i) that the timing of stretch receptor activity is tightly phase-locked within the oscillation cycle, (ii) that the number of spikes per burst is inversely related to oscillation frequency and (iii) that the instantaneous frequency of the burst increases with oscillation rate. At all oscillation rates tested, the instantaneous frequency of the burst increases with amplitude.

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