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Julia P Slopsema, John M Boss, Lane A Heyboer, Carson M Tobias, Brooke P Draggoo, Kathleen E Finn, Payton J Hoff, Katharine H Polasek
Background: Electrical stimulation is increasingly relevant in a variety of medical treatments. In this study, surface electrical stimulation was evaluated as a method to non-invasively target a neural function, specifically natural sensation in the distal limbs. Method: Electrodes were placed over the median and ulnar nerves at the elbow and the common peroneal and lateral sural cutaneous nerves at the knee. Strength-duration curves for sensation were compared between nerves...
2018: Open Biomedical Engineering Journal
Wenjiao Zhao, Guihua Lu, Li Liu, Zhishan Sun, Mingxin Wu, Wenyan Yi, Haiyan Chen, Yanhui Li, Lilong Tang, Jianping Zeng
BACKGROUND The aim of this study was to compare the use of the standard 12-lead electrocardiogram (ECG) with the SAN-Atrial-AVN-His (SAAH) ECG (Model PHS-A10), a new automated and integrated signals recognition system that detects micro-waveforms within the P, QRS, and T-wave, in a pig model of acute myocardial infarction (MI). MATERIAL AND METHODS Six medium-sized domestic Chinese pigs underwent general anesthesia, and an angioplasty balloon was placed and dilated for 120 minutes in the first diagonal coronary artery arising from the left anterior descending (LAD) coronary artery...
March 4, 2018: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
Lari M Koponen, Jaakko O Nieminen, Tuomas P Mutanen, Risto J Ilmoniemi
State-of-the-art noninvasive electromagnetic recording techniques allow observing neuronal dynamics down to the millisecond scale. Direct measurement of faster events has been limited to in vitro or invasive recordings. To overcome this limitation, we introduce a new paradigm for transcranial magnetic stimulation. We adjusted the stimulation waveform on the microsecond scale, by varying the duration between the positive and negative phase of the induced electric field, and studied corresponding changes in the elicited motor responses...
March 2, 2018: Human Brain Mapping
Carles Subirà, Candelaria de Haro, Rudys Magrans, Rafael Fernández, Lluís Blanch
Patient-ventilator asynchrony exists when the phases of breath delivered by the ventilator do not match those of the patient. Asynchronies occur throughout mechanical ventilation and negatively affect patient comfort, duration of mechanical ventilation, length of ICU stays, and mortality. Identifying asynchronies requires careful attention to patients and their ventilator waveforms. This review discusses the different types of asynchronies, how they are generated, and their impact on patient comfort and outcome...
February 27, 2018: Respiratory Care
Thomas Tarnaud, Wout Joseph, Luc Martens, Emmeric Tanghe
Neuronal excitability is determined in a complex way by several interacting factors, such as membrane dynamics, fibre geometry, electrode configuration, myelin impedance, neuronal terminations[Formula: see text] This study aims to increase understanding in excitability, by investigating the impact of these factors on different models of myelinated and unmyelinated fibres (five well-known membrane models are combined with three electrostimulation models, that take into account the spatial structure of the neuron)...
February 24, 2018: Medical & Biological Engineering & Computing
Maciej Skotak, Eren Alay, Namas Chandra
Measurement issues leading to the acquisition of artifact-free shock wave pressure-time profiles are discussed. We address the importance of in-house sensor calibration and data acquisition sampling rate. Sensor calibration takes into account possible differences between calibration methodology in a manufacturing facility, and those used in the specific laboratory. We found in-house calibration factors of brand new sensors differ by less than 10% from their manufacturer supplied data. Larger differences were noticeable for sensors that have been used for hundreds of experiments and were as high as 30% for sensors close to the end of their useful lifetime...
2018: Frontiers in Neurology
Daniel Cury Ribeiro, Ashleigh Day, Clark R Dickerson
Objectives: To assess: (1) the presence of any carry-over effect between interventions; (2) the immediate effects of inferior shoulder mobilization on shoulder and scapular muscle activity; and (3) to compare muscle activity response between the control and mobilization conditions. Repeated measures, cross-over, pre-post intervention study with sample of convenience. Methods: Twenty-two asymptomatic individuals performed 10 repetitions of shoulder abduction before and after the control and mobilization, with a dosage of three sets of 30-s duration, with grade-IV...
December 2017: Journal of Manual & Manipulative Therapy
Young-Min Byoun, Young-Tai Noh, Young-Geun Kim, Seung-Hwan Ma, Gwan-Hoon Kim
Effect of pulse reverse current (PRC) method on brass coatings electroplated from gold solution was investigated by various plating parameters such as plating duration, the anodic duty cycle, the anodic current density and the cathodic current density. The reversed current results in a significant change in the morphology of electrodeposits, improvement of the overall current efficiency and reduction of deposit porosity. With longer pulses, hemispherical surface features are generated, while larger grains result from shorter pulse widths...
March 1, 2018: Journal of Nanoscience and Nanotechnology
Jae Lee, Charles Spence
To date, crossmodal spatial cuing research has primarily investigated spatial attention modulated by the positioning of auditory cues, without addressing the question of the role played by sound parameters such as intensity change, waveform structure, or duration. Therefore in the present study, we investigated exogenous spatial cuing following the presentation of auditory cues having different intensity profiles (looming or receding), waveforms (triangular structured waveform or white noise), and durations (250 ms or 500 ms)...
February 10, 2018: Acta Psychologica
Kaouther Kerboua, Oualid Hamdaoui
The mechanical disturbance created by an ultrasonic wave travelling through a liquid medium induces the formation of cavitation that oscillates due to rarefaction and compression of the wave. The duration and the magnitude of the pressure applied by the ultrasonic wave at each instant would generate a specific impact on the variation of the bubble radius, the temperature, the pressure and the mass inside it. In this paper, a numerical study is conducted to simulate four waveforms (sinusoidal, square, triangular and sawtooth) travelling an aqueous media saturated with oxygen with an amplitude of 1...
April 2018: Ultrasonics Sonochemistry
Daniel C Bridges, Kenneth R Tovar, Bian Wu, Paul K Hansma, Kenneth S Kosik
Action potentials can be recorded extracellularly from hundreds of neurons simultaneously with multi-electrode arrays. These can typically have as many as 120 or more electrodes. The brief duration of action potentials requires a high sampling frequency to reliably capture each waveform. The resulting raw data files are therefore large and difficult to visualize with traditional plotting tools. Common approaches to deal with the difficulties of data display, such as extracting spike times and performing spike train analysis, are useful in many contexts but they also significantly reduce data dimensionality...
2018: PloS One
Bosun Hwang, Jiwoo You, Thomas Vaessen, Inez Myin-Germeys, Cheolsoo Park, Byoung-Tak Zhang
BACKGROUND: Stress recognition using electrocardiogram (ECG) signals requires the intractable long-term heart rate variability (HRV) parameter extraction process. This study proposes a novel deep learning framework to recognize the stressful states, the Deep ECGNet, using ultra short-term raw ECG signals without any feature engineering methods. METHODS: The Deep ECGNet was developed through various experiments and analysis of ECG waveforms. We proposed the optimal recurrent and convolutional neural networks architecture, and also the optimal convolution filter length (related to the P, Q, R, S, and T wave durations of ECG) and pooling length (related to the heart beat period) based on the optimization experiments and analysis on the waveform characteristics of ECG signals...
February 8, 2018: Telemedicine Journal and E-health: the Official Journal of the American Telemedicine Association
Paul Brunet, Rocío Rincón, Zineb Matouk, Mohamed Chaker, Françoise Massines
Nanocomposite thin films formed of TiO2 in a polymer-like matrix are grown in a filamentary Argon (Ar) Dielectric Barrier Discharge (DBD) from a suspension of TiO2 nanoparticles in isopropanol (IPA). The sinusoidal voltage producing the plasma is designed to independently control the matrix growth rate and the transport of nanoparticles (NPs) aggregates to the surface. The useful FSK (Frequency Shift Keying) modulation mode is chosen to successively generate two sinusoidal voltages: a high frequency signal at 15 kHz and a low frequency signal at frequencies ranging from 0...
January 17, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
P Freislederer, C Heinz, H von Zimmermann, S Gerum, F Roeder, M Reiner, M Söhn, C Belka, K Parodi
Respiratory motion remains a source of major uncertainties in radiotherapy. Respiratory correlated computed tomography (referred to as 4DCT) serves as one way of reducing breathing artifacts in 3D-CTs and allows the investigation of tumor motion over time. The quality of the 4DCT images depends on the data acquisition scheme, which in turn is dependent on the vendor. Specifically, the only way Toshiba Aquilion LB CT scanners can reconstruct 4DCTs is a cycle-based reconstruction using triggers provided by an external surrogate signal...
January 12, 2018: Zeitschrift Für Medizinische Physik
Eric K Johnson, Steven J Springer, Wei Wang, Edward J Dranoff, Yan Zhang, Evelyn M Kanter, Kathryn A Yamada, Jeanne M Nerbonne
BACKGROUND: Myocardial, transient, outward currents, Ito, have been shown to play pivotal roles in action potential (AP) repolarization and remodeling in animal models. The properties and contribution of Ito to left ventricular (LV) repolarization in the human heart, however, are poorly defined. METHODS AND RESULTS: Whole-cell, voltage-clamp recordings, acquired at physiological (35°C to 37°C) temperatures, from myocytes isolated from the LV of nonfailing human hearts identified 2 distinct transient currents, Ito,fast (Ito,f) and Ito,slow (Ito,s), with significantly (P<0...
January 2018: Circulation. Arrhythmia and Electrophysiology
Narendra Bhadra, Emily Foldes, Tina Vrabec, Kevin Kilgore, Niloy Bhadra
OBJECTIVE: Application of kilohertz frequency alternating current (KHFAC) waveforms can result in nerve conduction block that is induced in less than a second. Conduction recovers within seconds when KHFAC is applied for about 5-10 min. This study investigated the effect of repeated and prolonged application of KHFAC on rat sciatic nerve with bipolar platinum electrodes. APPROACH: Varying durations of KHFAC at signal amplitudes for conduction block with intervals of no stimulus were studied...
January 8, 2018: Journal of Neural Engineering
M Shakerian, F Marica, A Afrough, F G Goora, M Li, S Vashaee, B J Balcom
A metallic core holder, fabricated from non-magnetic Hastelloy-C276, has been designed for Magnetic Resonance (MR) and Magnetic Resonance Imaging (MRI) of core plug samples at high pressures and temperatures. Core plug samples, 1.5″ in diameter and 2″ in length, can be tested in the core holder at elevated pressures and temperatures, up to 5000 psi and 80 °C. These are conditions commonly found in petroleum reservoirs. A radio frequency probe, which excites and detects magnetic resonance signals, was placed inside the metal vessel...
December 2017: Review of Scientific Instruments
A Cominelli, G Acconcia, P Peronio, M Ghioni, I Rech
In this paper, we describe a novel solution to increase the speed of Time-Correlated Single Photon Counting (TCSPC) measurements by almost an order of magnitude while providing, in principle, zero distortion regardless of the experimental conditions. Typically, the relatively long dead time associated with the conversion electronics requires a proper tune of the excitation power in order to avoid distortions of the reconstructed waveform due to pileup and counting loss. As a result, the maximum operating rate of a TCSPC channel is now limited between 1% and 5% of the excitation frequency, thus leading to relatively long acquisition times...
December 2017: Review of Scientific Instruments
John P Kelly, James O Phillips, Avery H Weiss
PURPOSE: To use eye movement recordings of young children to determine whether eye velocity from infantile nystagmus (IN) deprives the developing visual system of normal visual acuity. METHOS: The video-oculography recordings and visual acuity measurements (including Teller cards) of 15 children ≤6.0 years of age with IN without visual sensory disease (idiopathic IN) were reviewed retrospectively. Eye velocity that would limit visual acuity development was predicted from both empirical adult data adjusted for age and a temporal limitation model using published photoreceptor density data with age...
December 27, 2017: Journal of AAPOS: the Official Publication of the American Association for Pediatric Ophthalmology and Strabismus
T Lucini, A R Panizzi
In this article, we review and discuss the potential use of EPG (electropenetrography) as a powerful tool to unveil the feeding process of phytophagous stink bugs (pentatomids). These bugs are relatively big and vigorous, which presents a problem during wiring (i.e., attachment of the gold wire on the bug's pronotum) for use in EPG. Once this challenge was overcome, using the sand paper-and-wire technique, several species have been studied using EPG, yielding waveforms that, coupled with histological studies, revealed the ingestion sites on different host plants...
December 27, 2017: Neotropical Entomology
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