Wide Pulse Research Articles

Abstract WP125: Association of 24-Hour Systolic Blood Pressure Parameters Post-Intravenous Alteplase With Functional Outcomes at Discharge

Introduction: Elevation of post-stroke systolic blood pressure (SBP) can be a part of a compensatory mechanism to restore cerebral perfusion to the ischemic brain tissue, but comes at a risk of reperfusion injury. The ideal SBP in the 24-hour range post-IV-rtPA has been understudied. We investigated the association of different SBP parameters post-intravenous-alteplase (IV-rtPA) with the functional outcome at discharge at a tertiary care center. Methods: We performed a retrospective chart review of patients with an acute ischemic stroke treated with IV-rtPA at a comprehensive stroke center from July 2014 to March 2018. We excluded patients who underwent mechanical thrombectomy. At the comprehensive stroke center, the BP values are documented according to standard post-IV-rtPA care guidelines. We recorded the SBP values over a period of 24-hours post-IV-rtPA. A binary logistic regression analysis was performed, controlling for age, sex, pre-treatment NIHSS, atrial fibrillation, onset to treatment time, with the SBP parameters as the predictors. The primary outcome was the functional outcome at discharge. Good outcome was defined as a modified rankin scale (mRS) of ≤2 and a poor outcome as mRS of ≥3, upon discharge. Results: 84 patients met our inclusion criteria. 45 (53.57%) patients were male. The mean age was 63.50±15 years. 25 (29.76%) patients had a good outcome (mRS≤2) at discharge. In our cohort, the parameters of higher mean SBP (144.9±14 vs.135.5±18; OR, 1.06; 95% CI, 1.02-1.11; P 0.004), higher maximum SBP (176.56±17 vs.166.7±18; OR, 1.06; 95% CI, 1.02-1.1; P 0.005) and wider pulse pressure (65.5±12 vs.57.8±13; OR,1.08; 95% CI, 1.03-1.14; P 0.007) were significantly associated with a poor outcome at discharge. Parameters of SBP variability like standard deviation SBP (13.5±5 vs.11.5±4; OR, 1.17; 95% CI, 1-1.36; P 0.058), coefficient variation SBP (9.36±4 vs.8.49±3; OR, 1.11; 95% CI, 0.94-1.32; P 0.242), and SBP range (62.22±20 vs.54.68±15; OR, 1.04; 95% CI, 1-1.07; P 0.08) were not significantly associated with a poor outcome at discharge. Conclusions: Our study demonstrates an association between higher mean SBP, higher maximum SBP, and wider pulse pressure over a period of 24-hours post-IV-rtPA, and poor functional outcome upon discharge.

Mini Review on Anomalous Diffusion by MRI: Potential Advantages, Pitfalls, Limitations, Nomenclature, and Correct Interpretation of Literature

In this mini-review, we addressed the transient-anomalous diffusion by MRI, starting from the assumption that transient-anomalous diffusion is ubiquitously observed in biological tissues, as demonstrated by different single-particle-tracking optical experiments. The purpose of this review is to identify the main pitfalls that can be encountered when venturing into the field of anomalous diffusion quantified by diffusion-MRI methods. Therefore, the theory of anomalous diffusion deriving from its mathematical definition was reported and connected with the consolidated description and the established procedures of conventional diffusion-MRI of tissues. We highlighted the two different modalities for quantifying subdiffusion and superdiffusion parameters of anomalous diffusion. Then we showed that most of the papers concerning anomalous diffusion, actually deal with pseudo-superdiffusion due to the use of a superdiffusion signal representation. Pseudo-superdiffusion depends on water diffusion multi-compartmentalization and local magnetic in-homogeneities that mimic the superdiffusion of spins. In addition to the relatively large production of pseudosuperdiffusion images, anomalous diffusion research is still in its early stages due to the limited flexibility of conventional clinical MRI scanners that currently prevent the acquisition of diffusion-weighted images by varying the diffusion time (the necessary acquisition modality to quantify transient-subdiffusion in human tissues). Moreover, the wide diffusion gradient pulses complicates the definition of a reliable function representative of anomalous diffusion signal behavior to fit data. Nevertheless, it is important and possible to address these limitations, as one of the potentialities of anomalous diffusion imaging is to increase the resolution, sensitivity, and specificity of MRI.

A three-state dual-inductance bi-directional converter and its control for pulse-loaded three-port converter

The current-pulse load is generally characterized by wide frequency band and pulse variation, when it is directly connected to the power supply bus. The load power is presented as the instantaneous power. In order to balance the instantaneous power difference between the pulse load and the DC bus, a bi-directional DC/DC converter is usually connected in parallel to compensate for the current fluctuation caused by the characteristics of the pulse load. However, there is a large current spike in the bus current in the pre-stage when the pulse load is changed between light and heavy load. In this paper, a three-state dual-inductance bi-directional converter is proposed. In addition, the load current waveform is directly used to control the inductive branch switches, and an adaptive current feedback control strategy based on the valley voltage loop is proposed to control the power switches. The control method is applicable to the arbitrary change of the frequency and power of the pulse load. Finally, the experimental results show that the three-state dual-inductance bi-directional converter not only eliminates excessive bus current spikes, but also improves the transient response of the three-port power supply system.

High-output cardiac failure due to multiple femoral arteriovenous fistulae.

A 39-year-old woman presented with symptoms of dyspnea, orthopnea, paroxysmal nocturnal dyspnea, weight loss, night sweats and fatigue that were present for 3-months. She had been diagnosed with human immunodeficiency virus (HIV) infection in 2016 but had defaulted her antiretroviral therapy. She had a low CD4 count of 17 cells/μl and her HIV viral load was log 6.16 copies/ml. She had evidence of high-output cardiac failure on clinical examination that included a wide pulse pressure with a blood pressure of 138/59 mmHg, radial pulse had a collapsing character and the pulse rate was 125 beats per minute, jugular venous distention was observed, the apical impulse was displaced with no audible murmurs and bibasilar crackles were present. She had a thrill palpable over the right femoral artery and a continuous bruit was audible. Significant laboratory results included a hemoglobin concentration of 6.7 g/dL and an erythrocyte sedimentation rate of more than 140 mm/hour. Importantly, rapid plasma reagin, anti-nuclear antibodies and anti-neutrophil cytoplasmic antibodies were negative. Computed tomography angiogram (CT angiogram) revealed fusiform aneurysmal dilatation of the distal abdominal aorta and right common iliac artery with multiple right lower limb arteriovenous fistulae and venous aneurysms. There were no other clinical or radiological findings to suggest a large-vessel vasculitis such as Takayasu´s arteritis. Mycobacterium tuberculosis was cultured from multiple sources including a gastric aspirate, blood and sputum samples. A diagnosis of tuberculous arteritis was made. Anti-tuberculous and heart failure treatment were commenced and her antiretroviral therapy was reinitiated. She reported significant improvement of her symptoms. However, 1-week following hospital discharge, the patient demised.

Optimal Pulse-Shaping in Actively Q-Switched Ytterbium-Doped Fiber Lasers

In an actively Q-switched fiber laser (AQS-FL) a type of acousto-optic modulator (AOM) or (potentially) electro-optic modulator (EOM) controls the generation of output nanosecond wide pulses. An integrated Gaussian pulse shape is desirable in many applications such as material processing, microfabrication, ultrasound generation, gold photothermal therapy, etc. However, because of the system dynamics, generation of perfect Gaussian pulse shapes is not guaranteed in an AQS-FL, additionally designing the AQS-FL for a desired pulse peak and duration is an inverse problem which needs cumbersome trial-error efforts. We have developed a framework consisting of a rigorous FDM method plus a dedicated and innovative multi-objective genetic algorithm (GA) which assists the designer in achieving the desired Gaussian pulses within a reasonable time frame. The developed GA evolves the timing parameters of modulator plus the pump power and fiber length until the suitable goal is reached. To demonstrate the flexibility and design feasibility of our GA, three different single pulse and pulse train generation scenarios on a 7.5 m long Ytterbium-doped double clad fiber (YD-DCF) are examined to achieve the Gaussian,150 Wand 200 W peak power, 250 ns and 300 ns width pulses. To the best of our knowledge, it is the first implementation of an intelligent algorithm for optimizing the output pulse of an AQS-FL. It is worth noting that depending on the fiber host material and modulator specifications, much higher peak powers and different pulse durations are feasible, furthermore in case of utilizing the AOM, the pertaining limitations and feasibility are considered.

Use in systems with sunny batteries of four-stage liftly wide pulse converters

Use in systems with sunny batteries of four-stage liftly wide pulse converters

Case Report: Post Lumbar Discectomy Acute Iliac Arteriovenous Fistula; Endovascular Management and Literature Review

Posterior approach lumbar disc surgeries (LDS) can be associated with serious iatrogenic vascular complications which could be a serious life threatening condition. We report a rare case of right sided acute iliac vessels iatrogenic arteriovenous fistula (IAVF) which was diagnosed and managed in 24 hours duration in a 45 years old healthy female who underwent surgical posterior approach L4-5 discectomy. Intraoperative, she developed sudden hypotension, tachycardia, wide pulse pressure and acute drop of hemoglobin level without obvious operative site bleeding which raise the index of suspicion of vascular injury and urge the team for doing emergency CT angiography (CTA), vascular and endovascular team consultation for digital subtraction angiography (DSA) and endovascular management. Endovascular stenting is nowadays the modality of choice of intervention. We provide case report with literature review.

Landolfi's Sign: A Riddle for Primary Care Physicians.

Landolfi’s sign, alternating systolic constriction and diastolic dilatation of pupils, is a clinical hallmark of aortic regurgitation. It is thought to stem from exacerbation of physiological circulatory hippus in the vessels of iris due to a wide pulse pressure in a backdrop of severe aortic valvular incompetence. Degenerative and rheumatic heart diseases are exquisitely common in rural India and often these patients turn up late with complications to the primary care physicians. Herein, the authors report a 34-year-old pregnant female who presented with acute heart failure, and on examination, Landolfi’s sign was found. It was immediately followed by Doppler echocardiography to stamp it as a case of severe aortic regurgitation. The patient was stabilized with anti-failure medications and feto-maternal health was closely monitored. The authors want to conclude claiming that bedside clinical training in cardiology will forever remain important, more so, while dealing patients at non-sophisticated primary health-care facilities. Besides, they also argue that basic tool supports like an echocardiography should be made available at those centers.

Multispectral time-of-flight imaging using light-emitting diodes.

Multispectral and 3-D imaging are useful for a wide variety of applications, adding valuable spectral and depth information for image analysis. Single-photon avalanche diode (SPAD) based imaging systems provide photon time-of-arrival information, and can be used for imaging with time-correlated single photon counting techniques. Here we demonstrate an LED based synchronised illumination system, where temporally structured light can be used to relate time-of-arrival to specific wavelengths, thus recovering reflectance information. Cross-correlation of the received multi-peak histogram with a reference measurement yields a time delay, allowing depth information to be determined with cm-scale resolution despite the long sequence of relatively wide (∼10 ns) pulses. Using commercial LEDs and a SPAD imaging array, multispectral 3-D imaging is demonstrated across 9 visible wavelength bands.

Characterize the switching performance of a superconducting nanowire cryotron for reading superconducting nanowire single photon detectors

Scalable superconducting nanowire single photon detector (SNSPDs) arrays require cryogenic digital circuits for multiplexing the output detection pulses. Among existing superconducting digital devices, superconducting nanowire cryotron (nTron) is a three-terminal device with an ultra-compact size, which is promising for large scale monolithic integration. In this report, in order to evaluate the potential and possibility of using nTrons for reading and digitizing SNSPD signals, we characterized the grey zone, speed, timing jitter and power dissipation of a proper designed nTron. With a DC bias on the gate, the nTron can be triggered by a few μA high and nanoseconds wide input signal, showing the nTron was capable of reading an SNSPD pulse at the same signal level. The timing jitter depended on the input signal level. For a 20 μA high and 5 ns wide input pulse, the timing jitter was 33.3 ps, while a typical SNSPD’s jitter was around 50 ps. With removing the serial inductors and operating it in an AC bias mode. The nTron was demonstrated to be operated at a clock frequency of 615.4 MHz, which was faster than the maximum counting rate of a typical SNSPD. In additional, with a 50 Ω bias resistor and biased at 17.6 μA, the nTron had a total power dissipation of 19.7 nW. Although RSFQ circuits are faster than nTrons, for reading SNSPD or other detector arrays that demands less operation speed, our results suggest a digital circuit made from nTrons could be another promising alternative.

Pitch Matching in Cochlear Implant Users With Single-Sided Deafness: Effects of Electrode Position and Acoustic Stimulus Type.

Previous studies in patients with single-sided deafness (SSD) have reported results of pitch comparisons between electric stimulation of their cochlear implant (CI) and acoustic stimulation presented to their near-normal hearing contralateral ear. These comparisons typically used sinusoids, although the percept elicited by electric stimulation may be closer to a wideband stimulus. Furthermore, it has been shown that pitch comparisons between sounds with different timbres is a difficult task and subjected to various types of range biases. The present study aims to introduce a method to minimize non-sensory biases, and to investigate the effect of different acoustic stimulus types on the frequency and variability of the electric-acoustic pitch matches. Pitch matches were collected from 13 CI users with SSD using the binary search procedure. Electric stimulation was presented at either an apical or a middle electrode position, at a rate of 800 pps. Acoustic stimulus types were sinusoids (SINE), 1/3-octave wide narrow bands of Gaussian noises (NBN), or 1/3-octave wide pulse spreading harmonic complexes (PSHC). On the one hand, NBN and PSHC are presumed to better mimic the spread of excitation produced by a single-electrode stimulation than SINE. On the other hand, SINE and PSHC contain less inherent fluctuations than NBN and may therefore provide a temporal pattern closer to that produced by a constant-amplitude electric pulse train. Analysis of mean pitch match variance showed no differences between stimulus types. However, mean pitch matches showed effects of electrode position and stimulus type, with the middle electrode always matched to a higher frequency than the apical one (p < 0.001), and significantly higher across-subject pitch matches for PSHC compared with SINE (p = 0.017). Mean pitch matches for all stimulus types were better predicted by place-dependent characteristic frequencies (CFs) based on an organ of Corti map compared with a spiral ganglion map. CF predictions were closest to pitch matches with SINE for the apical electrode position, and conversely with NBN or PSHC for the middle electrode position. These results provide evidence that the choice of acoustic stimulus type can have a significant effect on electric-acoustic pitch matching.

Nonlinear optical lattices with a void impurity.

We examine a one-dimensional nonlinear (Kerr) waveguide array which contains a single "void" waveguide where the nonlinearity is identically zero. We uncover a family of nonlinear localized modes centered at or near the void, and their stability properties. Unlike a usual impurity problem, here the void acts like a repulsive impurity causing the center of the simplest mode to lie to the side of the void's position. We also compute the stability of extended nonlinear modes showing significant differences from the usual homogeneous nonlinear array. The transmission of a nonlinear pulse across the void shows three main regimes-transmission, reflection, and trapping at the void's position-and we identify a critical momentum for the pulse below (above) where the pulse gets reflected (transmitted), or trapped indefinitely at the void's position. For relatively wide pulses, we observe a steep increase from a regime of no transmission to a regime of high transmission, as the amplitude of the soliton increases beyond a critical wave-vector value. Finally, we consider the transmission of an extended nonlinear wave across the void impurity numerically, finding a rather complex structure of the transmission as a function of wave vector, with the creation of more and more transmission gaps as nonlinearity increases. The overall transmittance decreases and disappears eventually, where the boundaries separating passing from nonpassing regions are complex and fractal-like.

Transcatheter occlusion of giant congenital coronary cameral fistulae: a case series

BackgroundA coronary cameral fistula is a rare connection between a coronary artery and a cardiac chamber or vein bypassing the cardiac capillary bed system. Most of these fistulae are congenital and solitary, although they can be acquired and multiple.Cases presentationCase 1: A 10-year-old black South African boy presented with a long-standing history of fatigue; he had a heart murmur, and a bounding pulse and wide pulse pressure. An echocardiogram demonstrated a large coronary cameral fistula involving his left coronary artery and his left ventricle. This was also confirmed on ascending aortogram. Surgical ligation was done and his symptoms improved afterward, but a small residual fistula remained. Case 2: A 7-year-old black South African boy had decreased effort tolerance and a heart murmur on the mid-sternal border. He had cardiomegaly on chest roentgenogram and a dilated left coronary artery origin on echocardiogram. An ascending aortogram confirmed a large left coronary cameral fistula draining to the left ventricle. Case 3: A 28-year-old black South African woman with decreased effort tolerance and chest pain on exertion had a continuous murmur over the lower sternal border. Echocardiography demonstrated a dilated right coronary artery with a fistulous connection to her right ventricle. An ascending aortogram demonstrated a tortuous coronary cameral fistula arising from her right coronary artery to her right ventricle. All three patients were successfully treated percutaneously using the Amplatzer vascular plug type II device.ConclusionThe availability of numerous vascular closure devices has made transcatheter occlusion the treatment of choice for the majority of coronary cameral fistulae, rather than the traditional surgical ligation.

Genotoxic permanent hair dye precursors p-aminophenol and p-toluenediamine electrochemical oxidation mechanisms and evaluation in biological fluids

The p-toluenediamine (PTD) and p-aminophenol (PAP), genotoxic precursor agents widely used in permanent hair dyeing formulations, electrochemical mechanisms and evaluation in biological fluids, at a glassy carbon electrode, in a wide pH range, by cyclic, differential pulse, and square wave voltammetry, were investigated. The oxidation of both PTD and PAP is reversible. The PTD two electrons and two protons transfer diffusion-controlled reaction occurs at the molecule nitrogen atoms in the amine groups. Also PAP oxidation is a two electrons and two protons transfer diffusion-controlled reactions, and occur at the nitrogen and oxygen atoms of the molecule amine and hydroxyl groups. An electrochemical oxidation mechanism for PTD and PAP is proposed. The PTD and PAP diffusion coefficients, DPTD = 1.57 × 10−5 cm2 s−1 for PTD, and DPAP = 1.03 × 10−5 cm2 s−1 for PAP, were determined. The electrochemical quantification in 0.10–1.00 μM concentration range showed a detection limit of 0.12 μM for PTD and 0.17 μM PAP. A new electroanalytical method for the determination of PTD and PAP in fetal bovine serum biological fluid, and in artificial urine samples, using differential pulse voltammetry, was also developed.

Torque gains and neural adaptations following low-intensity motor nerve electrical stimulation training.

The purpose of the study was to assess neural adaptations of the plantar-flexors induced by an electrical stimulation training applied over the motor nerve at low intensity using two different stimulation frequencies. Thirty subjects were randomly assigned into 3 groups: 20 Hz, 100 Hz, and control group. The training consisted of 15 sessions of 25 stimulation trains applied over the tibial nerve and delivered at an intensity evoking 10% maximal voluntary isometric contraction (MVIC). Before and after training, MVIC was assessed and neural adaptations were evaluated by the voluntary activation level (VAL) and the V-wave (normalized by the superimposed muscle compound action potential, V/MSUP). H-reflex and motor-evoked potential (MEP) recorded during MVIC were studied to assess spinal and corticospinal excitabilities [i.e., maximal H-reflex during maximal voluntary isometric contraction (HSUP)/MSUP and maximal motor-evoked potential during maximal voluntary isometric contraction (MEPSUP)/MSUP]. MVIC significantly increased after training only for the two training groups (P = 0.017). This increase was accompanied by a significant increase of VAL only for these groups (P = 0.014), whereas statistical analysis revealed a time effect for V/MSUP (P = 0.022). HSUP/MSUP and MEPSUP/MSUP were significantly increased at post conditions only for the 100 Hz group (P = 0.021 and P = 0.029). Results show that low-intensity electrical stimulation training applied over the motor nerve can induce torque gains, accompanied by neural adaptations. Stimulation frequency differentially affected spinal and corticospinal excitabilities, indicating that neural adaptations could have a supraspinal origin for the 20-Hz protocol, whereas spinal and supraspinal mechanisms were implicated in the torque increases after the 100-Hz training.NEW & NOTEWORTHY This study brings new insights into the neurophysiological mechanisms responsible for torque gains after electrical stimulation training using wide pulse duration and low stimulation intensity applied over the motor nerve. Stimulation frequency had a distinct impact on spinal and/or supraspinal origins of the observed neural adaptations. The use of the aforementioned stimulation parameters in rehabilitation settings can be proved beneficial in terms of strength gains while avoiding any serious discomfort because of stimulation.

Unveiling the Hidden, Dark, and Short Life of a Vibronic State in a Boron Difluoride Formazanate Dye.

Boron difluoride (BF2 ) formazanate dyes are contenders for molecular species that exhibit a large Stokes shift and bright red emission. Excitation of 3-cyanoformazanate complexes with 10 μs wide pulses of specific wavelengths resulted in strong luminescence at 663 nm at both room temperature in solution and at 77 K in a frozen solution. Analysis of the short-lived excitation spectrum from this luminescence shows that it arises from a vibronic manifold of a higher-lying excited state. This dark state relaxes to the emitting state over 10 μs. TD-DFT calculations of the two lowest-energy excited states show that the relaxed geometries are planar for S1 but highly distorted in S2 . The specific time- and wavelength-dependence of the excitation profile provides a unique optical encryption capability through the comparison of emission intensities between adjacent vibronic bands only accessible in the 0-12 μs time domain.

Unveiling the Hidden, Dark, and Short Life of a Vibronic State in a Boron Difluoride Formazanate Dye

AbstractBoron difluoride (BF2) formazanate dyes are contenders for molecular species that exhibit a large Stokes shift and bright red emission. Excitation of 3‐cyanoformazanate complexes with 10 μs wide pulses of specific wavelengths resulted in strong luminescence at 663 nm at both room temperature in solution and at 77 K in a frozen solution. Analysis of the short‐lived excitation spectrum from this luminescence shows that it arises from a vibronic manifold of a higher‐lying excited state. This dark state relaxes to the emitting state over 10 μs. TD‐DFT calculations of the two lowest‐energy excited states show that the relaxed geometries are planar for S1 but highly distorted in S2. The specific time‐ and wavelength‐dependence of the excitation profile provides a unique optical encryption capability through the comparison of emission intensities between adjacent vibronic bands only accessible in the 0–12 μs time domain.

1.2: Invited Paper: Dynamic threshold voltage compensation IGZO‐GOA circuit for AMOLED display

A dual‐gate amorphous indium‐gallium‐zinc‐oxide (a‐IGZO) thin‐film transistor (TFT) has been proposed and designed in this work. Based on this specific structure, a technologically advanced external Vth compensation system, where Vth can be controllable by an external DC signal source, has been developed for gate driver on array (GOA). Subsequently, the working mode of this circuit was introduced. Moreover, detailed simulation has been performed to study the appropriate process window. Finally, the proposed GOA circuit exhibited stable high‐voltage output pulse, meanwhile, the lifetime showed an significant improvement with the utilization of the external Vth compensation system. It should be also mentioned that a wide pulse of 3.6ms has been obtained to sense Vth of driving TFTs in pixel circuits.

Detection of HV Winding Radial Deformation and PD in Power Transformer Using Stepped-Frequency Hyperboloid Method

Detection of winding deformation and partial discharge (PD) is essential for monitoring and failure risk assessment of power transformers. Recently, an online method based on electromagnetic waves has been proposed for detecting radial deformation (RD) in high-voltage (HV) transformer winding using ultra wide band pulses, called the hyperboloid method. In this method, a short pulse is transmitted toward HV winding and its reflection captured using a set of antennas. By comparing and analyzing signals in sound and deformed conditions, the RD can be detected. On the other hand, signals radiated from PD defect in transformers are generally appeared in the range of UHF band (0.3–3-GHz frequencies). In this paper, the hyperboloid method is proposed for implementation in UHF band, and the PD effect on the result of the hyperboloid method is investigated. Thus, a set of UHF sensors can be used for the detection of PD and detection and localization of RD defect. Results show that PD signals can affect the signal of the hyperboloid method and lead to wrong localization of RD. In order to solve this problem, the UHF stepped-frequency method is proposed, utilized, and tested on the HV winding of a 1.6-mega volt ampere (MVA) distribution transformer. Experimental results show the capability of the proposed method for detecting both defects using only one set of UHF antennas.

Improvement of processing quality based on VHF resonant micro-EDM pulse generator

As an important non-traditional machining technology, micro-electrical discharge machining (micro-EDM) has become one of the ideal methods for conducting material parts in the mesoscopic scale. However, the current micro-EDM pulse generator has low discharge frequency and wide pulse width, and its nano-scale high-efficiency erosion ability is still difficult to meet the increasing practical requirement. For this purpose, a micro-energy pulse source with narrow pulse width and high-voltage amplitude, which is different from the current typical micro-energy pulse generator, is designed for a pulse generator with more fine-etching ability. Using the principle of circuit resonance, the very high-frequency (VHF) resonant discharge pulse generator can produce an open-circuit voltage waveform with a discharge frequency of 90 MHz and a peak value of 70 V. The single-pulse discharge energy can be continuously processed as low as 6nJ. Based on the VHF pulse generator and the transistor-type pulse generator, the discharge erosion experiments are carried out, and the surface roughness and recast layer are analyzed and compared. The experimental results show that the former processing quality is obviously better than the latter. The surface roughness after processing at a discharge frequency of 90 MHz can reach Ra 42 nm, the average diameter of craters is 0.38 μm, and the hole edge processed at a discharge frequency of 55 MHz has almost no recast layer which achieves similar cold processing effects.