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Introduction: Symmetric biphasic pulses have been shown to increase the therapeutic window compared to standard cathodic pulses in ET Vim-DBS patients. Furthermore, three hours of stimulation with biphasic pulses caused less stimulation-induced ataxia compared to cathodic pulses. Therefore, an investigation of the longer-term safety of biphasic pulses is warranted. Methods: Seven ET patients were included in a randomized double-blind, cross-over design of one week home-use of symmetric biphasic stimulation (anodic phase first) versus cathodic stimulation. Amplitude was set in a doubleblinded way, at the tremor arrest threshold. The primary outcome was safety assessed by documenting the adverse events. Secondary outcome parameters were stimulation amplitude, tremor (Fahn-Tolosa-Marin Tremor Rating Scale) and ataxia (International Cooperative Ataxia Rating Scale) severity, quality of life (Quality of Life in Essential Tremor Questionnaire) and cognition (Montreal Cognitive Assessment). Three patients continued in the open-label extension phase for 3 months, during which biphasic stimulation-only was further assessed by the same outcome parameters. Results: During the 1 week testing, no adverse effects were reported. To obtain equivalent tremor control, the amplitude of the biphasic pulse was significantly higher compared to that of the cathodic pulse (p = 0.003). The other outcome parameters were not significantly different. During the open-label study, one patient used the remote control to increase the amplitude, leading to two falls caused by stimulation-induced ataxia. No other adverse effects occurred. Discussion and conclusion: In a small cohort, when tested for one week, symmetric biphasic pulses suggest to be safe, but require higher stimulation amplitudes. Further follow-up studies are needed to investigate long-term effects and safety. [ABSTRACT FROM AUTHOR]

IntroductionSymmetric biphasic pulses have been shown to increase the therapeutic window compared to standard cathodic pulses in ET Vim-DBS patients. Furthermore, three hours of stimulation with biphasic pulses caused less stimulation-induced ataxia compared to cathodic pulses. Therefore, an investigation of the longer-term safety of biphasic pulses is warranted.MethodsSeven ET patients were included in a randomized double-blind, cross-over design of one week home-use of symmetric biphasic stimulation (anodic phase first) versus cathodic stimulation. Amplitude was set in a double-blinded way, at the tremor arrest threshold. The primary outcome was safety assessed by documenting the adverse events. Secondary outcome parameters were stimulation amplitude, tremor (Fahn-Tolosa-Marin Tremor Rating Scale) and ataxia (International Cooperative Ataxia Rating Scale) severity, quality of life (Quality of Life in Essential Tremor Questionnaire) and cognition (Montreal Cognitive Assessment). Three patients continued in the open-label extension phase for 3 months, during which biphasic stimulation-only was further assessed by the same outcome parameters.ResultsDuring the 1 week testing, no adverse effects were reported. To obtain equivalent tremor control, the amplitude of the biphasic pulse was significantly higher compared to that of the cathodic pulse (p = 0.003). The other outcome parameters were not significantly different. During the open-label study, one patient used the remote control to increase the amplitude, leading to two falls caused by stimulation-induced ataxia. No other adverse effects occurred.Discussion and conclusionIn a small cohort, when tested for one week, symmetric biphasic pulses suggest to be safe, but require higher stimulation amplitudes. Further follow-up studies are needed to investigate long-term effects and safety.

Background: Since the inception of DBS, cathodic pulses have been used. Objective: To investigate the effect of anodic and symmetric biphasic pulses on the therapeutic window (TW) in essential tremor (ET) patients. Methods: A randomized, doubled-blinded, cross-over design was used to test the effect of cathodic, anodic and symmetric biphasic pulses (cathode-first and anode-first) on the TW in an acute clinical setting. TW was defined as the difference between the minimal stimulation amplitude provoking side effects and minimal stimulation amplitude inducing tremor arrest. Results: 9 ET patients (10 hemispheres) were included. Anodic stimulation induced a significantly larger TW compared to cathodic stimulation (p = 0.008). Symmetric biphasic stimulation also widened the TW compared to cathodic stimulation for both cathode- (p = 0.047) and anode-first (p = 0.008) biphasic pulses. For both anodic and biphasic pulses, the effect on TW was mainly driven by the change in side effect threshold. The order of the phases in the biphasic pulse had a significant effect on the side effect threshold (p = 0.039), with biphasic-anode first having the highest value. All pulse shapes were safe in the acute setting. Conclusion: Anodic and symmetric biphasic pulses increase TW in ET patients.

Since the inception of DBS, cathodic pulses have been used. To investigate the effect of anodic and symmetric biphasic pulses on the therapeutic window (TW) in essential tremor (ET) patients. A randomized, doubled-blinded, cross-over design was used to test the effect of cathodic, anodic and symmetric biphasic pulses (cathode-first and anode-first) on the TW in an acute clinical setting. TW was defined as the difference between the minimal stimulation amplitude provoking side effects and minimal stimulation amplitude inducing tremor arrest. 9 ET patients (10 hemispheres) were included. Anodic stimulation induced a significantly larger TW compared to cathodic stimulation (p = 0.008). Symmetric biphasic stimulation also widened the TW compared to cathodic stimulation for both cathode- (p = 0.047) and anode-first (p = 0.008) biphasic pulses. For both anodic and biphasic pulses, the effect on TW was mainly driven by the change in side effect threshold. The order of the phases in the biphasic pulse had a significant effect on the side effect threshold (p = 0.039), with biphasic-anode first having the highest value. All pulse shapes were safe in the acute setting. Anodic and symmetric biphasic pulses increase TW in ET patients. [Display omitted] • In the acute setting, both anodic and symmetric biphasic pulses are safe in ET patients. • Therapeutic windows are larger with anodic and symmetric biphasic compared to cathodic pulses. • The effects are mostly driven by increasing side effect thresholds. [ABSTRACT FROM AUTHOR]

Introduction: Symmetric biphasic pulses enlarge the therapeutic window in thalamic deep brain stimulation in patients with essential tremor. Adding an interphase gap to these symmetric biphasic pulses may further affect the therapeutic window., Materials and Methods: Nine patients (16 hemispheres) were included in this study. Biphasic pulses (anodic phase first) with interphase gaps of 0, 10, 20, 50, and 100 μs were tested, in random order. The outcome parameters were the therapeutic threshold (TT) and side-effect threshold (SET), and thus also the therapeutic window (TW)., Results: Increasing interphase gaps lowered both SET and TT (linear mixed-effects model; p < 0.001 and p < 0.001). Because SET decreased predominantly, increasing interphase gaps resulted in smaller TWs (linear mixed-effects model; p < 0.001)., Discussion and Conclusions: Introducing an interphase gap in a symmetric biphasic pulse may lead to less selectivity in fiber or neuronal activation. Our findings show that, in the context of anode-first biphasic pulses, the use of zero-interphase gaps results in the largest TW., Clinical Trial Registration: The Clinicaltrials.gov registration number for the study is NCT05177900., (Copyright © 2022 International Neuromodulation Society. Published by Elsevier Inc. All rights reserved.)

Symmetric biphasic pulses have been shown to acutely increase the therapeutic window of ventralis intermedius deep brain stimulation (Vim-DBS) for essential tremor (ET) compared to cathodic pulses. Acute supratherapeutic stimulation can induce ataxic side effects in Vim-DBS. To investigate the effect on tremor, ataxia and dysarthria of 3 h of biphasic stimulation in patients with DBS for ET. A randomized, doubled-blind, cross-over design was used to compare standard cathodic pulses with symmetric biphasic pulses (anode-first) during a 3-h period per pulse shape. During each 3-h period, all stimulation parameters were identical, except for the pulse shape. Tremor (Fahn-Tolosa-Marin Tremor Rating Scale), ataxia (International Cooperative Ataxia Rating Scale) and speech (acoustic and perceptual measures) were assessed hourly during the 3-h periods. Twelve ET patients were included. During the 3-h stimulation period, tremor control was equivalent between the two pulse shapes. Biphasic pulses elicited significantly less ataxia than cathodic pulses (p = 0.006). Diadochokinesis rate of speech was better for the biphasic pulse (p = 0.048), but other measures for dysarthria were not significantly different between the pulses. Symmetric biphasic pulses induce less ataxia than conventional pulses after 3 h of stimulation DBS in ET patients. • When compared for 3 h, at supratherapeutic thresholds: • Biphasic pulses induce less stimulation-induced ataxia compared to cathodic pulses. • Biphasic pulses induce equivalent tremor control compared to cathodic pulses. • Diadochokinesis rate of speech was better for biphasic than cathodic pulses. [ABSTRACT FROM AUTHOR]

Clustering techniques are of main interest for separation of partial discharge (PD) sources. The separation is achieved if it is possible to extract from the PD pulses specific information related to the source. In this sense, this paper explores the capability of fundamental quantities derived from PD current pulses such as the peak amplitude Ipeak, the apparent charge Q, and the energy E as parameters intended for source separation. For this purpose, an unconventional PD measuring circuit is used to acquire PD pulses from several laboratory test objects. Once the pulses are digitized and stored, the values of Ipeak, Q, and E are computed according to the proposed methods in time and frequency domain. A theoretical analysis is presented to illustrate how values of Ipeak, Q and E can be related to the pulse shape so that they can be used as source separation parameters. Then, the IpeakQE clusters are computed for laboratory measurements. The results showed that these parameters are suitable for separation of sources provided that the pulse shapes are different. This cluster technique was also proved to be independent of the change of the acquisition parameters that are relevant for unconventional measuring systems. In addition, the easiness of the quantities computation makes the clustering technique introduced in this paper feasible for practical applications. [ABSTRACT FROM AUTHOR]

Abstract: Cs2LiYCl6:Ce (CLYC) has been demonstrated to be sensitive to thermal neutrons via the 6Li(n, )t reaction, and recently to fast neutrons via the 35Cl(n,p) reaction. The scintillation properties of CLYC have been investigated in more detail to further understand its capabilities. Pulses from thermal neutron, fast neutron, and -ray induced excitations were captured, digitized over a time range, and analyzed to identify the scintillation mechanisms responsible for the observed shapes. Additionally, the timing resolutions of CLYC crystals of different sizes were measured in coincidence with a fast CeBr3 scintillator. The effect of high count rates on fast neutron energy resolution and pulse-shape discrimination was investigated up to 45kHz. [Copyright &y& Elsevier]

Abstract: When atoms are excited by laser radiation the conventional wisdom dictates that the spectral excitation profile – the excited-state population vs the detuning – broadens as the radiation intensity increases. This common expectation has been shown to be incorrect in the fluorescence signal following two-photon excitation of xenon atoms by a Gaussian laser pulse, which showed almost no power broadening [T. Halfmann, T. Rickes, N.V. Vitanov, K. Bergmann, Optics Communications, 220 (2003) 353] Here we go a step further and show that for a class of pulse shapes, the falling edges of which vanish as inverse powers of time, (with ), the spectral excitation profile must exhibit power narrowing, i.e. the spectral linewidth scales as , where is the Rabi frequency of the transition. We provide a simple physical explanation based upon the notions of adiabatic evolution and coherent population return and discuss important experimental applications. [Copyright &y& Elsevier]

Abstract: We investigate the effects of delayed infrared laser (IRL) pulse shape on the non-adiabatic rotational excitation and alignment of a polar molecule. We suggest a control scheme for choosing populations of molecular rotational states by wave packet interference. The rotational wave packets of polar molecule (here HBr) excited non-adiabatically by orienting pulse is controlled actually using the second delayed IRL pulse. By adjusting the time delay between the two laser pulses and the shape of delayed IRL pulse, constructive or destructive interference among these wave packets enables the population to be enhanced or repressed for the specific rotational state. We have used fourth order Runge–Kutta method to study the non-adiabatic rotational excitation (NAREX) dynamics. [Copyright &y& Elsevier]

This paper presents a pulse shape that is generated from error functions. For typical values of the parameters associated with the error functions, the proposed pulse resembles a Gaussian pulse. The mathematical analysis of the proposed pulse and its application in generating a trapezoidal pulse with smooth transitions for leading and trailing edges and variable width are presented. [ABSTRACT FROM AUTHOR]

We propose and demonstrate experimentally, for the first time, a prototype for all-optical ultra-wideband (UWB) transceiver at 500 Mb/s. We report 1) UWB pulse optimization that takes into account the transmitter RF front end and the U.S. federal communications commission (FCC) spectral mask, 2) a new approximate match filter receiver using optical signal processing, and 3) modulation at 500 Mb/s. Our previous optimization of UWB pulse shapes was based only on the FCC spectral mask, without taking into account the frequency response of the RF components (amplifier and antenna) in the UWB transmitter. Here, we modify our pulse optimization technique to ensure that the equivalent isotropic radiated power (EIRP) from the transmitter meets FCC specifications. For the RF hardware used, we achieve 63.6% efficiency over the FCC mask, which yields an 11.6- and a 5.9-dB improvement over Gaussian monocycle and doublet pulses, respectively. We also introduce simple optical signal processing at the receiver that allows the incoming RF signal to be matched against a square pulse whose duration is adapted to the channel. The exact matched filter would require a new optimized pulse that would include not only hardware frequency response but channel effects that vary with antenna placement as well. The proposed approximation allows a simple variation of the pulse duration: an increase to account for pulse expansion in the channel but an upper limit to combat multipath effects. Finally, we demonstrate the optimized pulse and approximate match filter receiver at 500 M/s. We attain a 10-6bit error rate at a 65-cm separation line of sight (LOS) link with simple on-off keying and no forward error correction. [ABSTRACT FROM PUBLISHER]

Pulse shapes previously proposed for ultrawideband communication systems are studied and compared to determine which provide the best performance. The performance measures considered are the bit error rate in multiple access interference environments and compliance with required spectral emission constraints. The Gaussian monocycles of higher orders and the prolate spheroidal function-based pulses are found to meet the spectral emission masks without frequency shifting. Frequency shifting and bandpass filtering must be used for the modified Hermite polynomial-based pulses to meet the spectral masks. The multiaccess performance average error rates of time-hopping ultrawideband systems using different pulse shapes are examined and compared using a newly published exact performance analysis method. The Gaussian monocycles are shown to achieve performance as good as the prolate spheroidal function-based pulses with the same effective bandwidths in numerical examples. The Gaussian monocycles outperform the modified Hermite polynomial-based pulses for the system models considered. Some tradeoffs of these pulses are also addressed in terms of the complexity of their implementations and the average bit error probabilities. [ABSTRACT FROM PUBLISHER]

We discuss coherent up-conversion of near-infrared femtosecond laser light into the extreme ultraviolet and soft-X-ray regions of the spectrum using the process of high-harmonic generation. We show that by using concepts from visible wavelength photonics, it is now possible to extend nonlinear optics well into the X-ray region of the spectrum. By manipulating the dynamics of the high harmonic process using optimized waveguide structures and pulse shapes, and on attosecond timescales, we can control the energy of the emitted photons, as well as increase the efficiency of the up-conversion process. Use of these optimized waveguide structures and pulse shapes can also improve the spatial and temporal coherence of the light. This work demonstrates that sophisticated concepts from nonlinear-optical photonics and coherent control can be applied to "extreme" nonlinear optics. [ABSTRACT FROM PUBLISHER]

We show that a conventional optical nonreturn-to-zero modulator based on a Mach-Zehnder interferometer always produces optical amplitude modulation at the clock frequency of the modulating signal, which in turn can generate a large clock-frequency component (CFC) in the received electrical signal when the optical signal has experienced excessive group velocity dispersion (GVD). We calculate the amplitude of these CFCs as a function of GVD for various optical bit sequences and pulse shapes. [ABSTRACT FROM PUBLISHER]