High Voltage Pulsed Current Research Articles

Increasing the fatigue resistance of aircraft parts magnetically impulse hardening

The results of fatigue tests of samples made of D16T aluminum alloy, treated by magnetic-pulse hardening (MPH) and the passage of a high-voltage pulsed electric current, are presented. It is shown that MPT increases the cyclic durability of samples by 2...2.5 times, regardless of the considered modes and hardening schemes during fatigue tests with loading by symmetric cantilever bending. However, there is a slight increase in fatigue life dissipation after this treatment. Passing a high-voltage pulse current through the sample increases the cyclic life by 1.9-2.4 times at a stress amplitude of fatigue tests of 320 MPa.

Efficacy of Bimodal High-Voltage Monopulsed Current in the Treatment of Pressure Ulcer: A Systematic Review

We aimed to systematically evaluate the efficacy of high-voltage pulsed current (HVPC) in the treatment of pressure ulcer. We searched the databases of PubMed, Cochrane Library, Elsevier and EMBASE to identify randomized controlled studies on the application of HVPC in pressure ulcer treatment, up to January 2019. Two authors independently screened the literature according to the inclusion and exclusion criteria, extracted the data and evaluated the quality. RevMan 5.3 software was used for statistical analysis. Four randomized controlled trials involving a total of 176 patients were included in the study. Meta-analysis showed that the percentage of wound area reduction in the HVPC treatment group was higher than that in the control group (95%CI 24.59, 47.76, P<0.001). Descriptive analysis showed that there was no significant difference in wound healing between the HVPC treatment group and the control group. One study reported that there was contact dermatitis, and the rest of the studies reported no adverse events. Compared with the conventional therapy, the combination with HVPC therapy can reduce the area of pressure ulcers more effectively. However, due to the small number of the studies included in this evaluation, the conclusions need to be verified by more high-quality studies.

Russian current versus high voltage current with isokinetic training on the quadriceps muscle strength and endurance.

Electrotherapy modalities are one of the increasing ways of muscle strength and endurance. However, it is not clear which electrotherapy modalities are more effective. The purpose of this study is to compare the effect of Russian current (RC) and high voltage pulsed current (HVPC) on the strength and endurance of the quadriceps muscle. The study was performed on 10 volleyball athletes. The participants’ extremities were divided into two groups as RC and HVPC. Muscle strength and endurance levels were assessed by an isokinetic device. Isokinetic training and 20-min electrotherapy were given in each treatment session. This training program consisted of a total of 12 sessions, scheduled twice a week for 6 weeks. After training, knee extensor peak torque values and endurance ratios have increased in both groups, but it was determined that this increase was only significant in terms of the endurance ratio (P<0.05). There was no significant difference between the muscle strength and the endurance ratio of the RC and HVPC groups (P>0.05). RC or HVPC have no advantages over each other, and therefore it has been determined that both currents can be used in order to strengthen muscles and increase muscular endurance. Additional studies whose longer-term effects will investigate are needed.

Effect of High Voltage Pulsed Current on the integration of total skin grafts in rats submitted to nicotine action

ObjectiveThe aim of this study was to evaluate the impact of High Voltage Pulsed Current (HVPC) on the integration of total skin grafts in rats submitted to nicotine action. Materials and methodsFor this purpose, 60 adult Wistar rats randomly distributed in 6 groups of 10 animals were analyzed. The electrical stimulation (anodic and cathodic stimulation, motor level, 30 min at 10 Hz; minimum voltage 20 μs and 100 μs pulse interval) was applied for seven days, starting on the third day after surgery and after the dressing was removed from the graft. ResultsAnodic HVPC promoted greater graft integration, demonstrating a lower percentage of tissue contraction, a lower number of inflammatory infiltrates and a greater amount of vascular endothelial growth factor (VEGF), as well as a higher number of newly formed blood vessels. ConclusionsHVPC can positively influence the integration of skin grafts in nicotine-treated rats. anodic HVPC is shown to promote greater integration in relation to a lower percentage of tissue contraction, a lower number of inflammatory infiltrates and a greater amount of vascular endothelial growth factor and newformed blood vessels. Whereas, the cathodic polarity has presented smaller amount of tissue gap.

THE METROLOGY SUPPORT IN UKRAINE OF TESTS OF OBJECTS OF ENERGY, AVIATION AND SPACE-ROCKET ENGINEERING ON RESISTIBILITY TO ACTION OF PULSES OF CURRENT (VOLTAGE) OF ARTIFICIAL LIGHTNING AND COMMUTATION PULSES OF VOLTAGE

Purpose. Presentation and analysis of the modern state of the metrology support in Ukraine of model tests of equipment of objects of energy on resistibility to the action of pulsed current (voltage) of artificial lightning and commutation pulses of voltage, and also objects of aviation and space-rocket engineering on resistibility to lightning. Methodology. Electrophysics bases of engineering of high-voltage and large pulsed currents, theoretical bases of the electrical engineering, technique of the strong electric and magnetic fields, and also measuring technique. Scientific methods of analysis of scientific and technical information. Results. Information is resulted, touching the modern consisting of Ukraine of providing high-voltage measuring facilities conducted on requirements of the normative documents of the USA of SAE ARP 5412:2013, SAE ARP 5416:2013, International Standard of IEC 62305-1:2010 and Standard GOST 1516.2-97 model tests of equipment of objects of energy on resistibility to lightning and commutation resistibility, and also objects of aviation and space-rocket engineering on resistibility to lightning. It is marked that similar measuring facilities are not made by domestic industry. It is indicated that R&amp;DPCI “Molniya” of the NTU “KhPI” disposes the proper measuring facilities of the own making, passing a state metrology check (calibration). Basic technical descriptions are described developed and created at this Institute: high-voltage high-current shunts of type of SC-300M1 and SC-300M2, intended for measuring of micro- and millisecond pulses of current amplitude to ±220 кА with the integral of their action to 15·106 J/Ohm; capacitive (type of CDV-100 and CDV-1,2) and ohmic (type of ODV-1,2 and ODV-2,5) dividers of pulsed voltage of micro- and millisecond duration, capable not only to measure but also form on the tested electric loading standard (non-standard) storm and commutation pulses of voltage amplitude to ±2 MV. Originality. First in the generalized kind possibilities are developed and created by the domestic scientific and technical workers of high-voltage high-current measuring facilities, intended for the aims of the metrology providing of model tests in obedience to the requirements of domestic and foreign normative documents of equipment of objects of energy on resistibility to lightning and commutation resistibility, and also objects of aviation and space-rocket engineering on resistibility to lightning. Practical value. Application in practice of model tests on powerful high-voltage pulsed current (voltage) of artificial lightning and commutation pulses of voltage of electrical equipment and component elements of objects of energy, aviation and space-rocket engineering on resistibility to lightning and commutation resistibility of the described special high-voltage measuring facilities will be instrumental in the decision of global in the world problem of protection from lightning of ground and air-based technical objects and to the increase of their strength security.

Hierarchical evaluation of electrical stimulation protocols for chronic wound healing: An effect size meta‐analysis

Electrical stimulation (ES) has been tested for decades to improve chronic wound healing. However, uncertainty remains on the magnitude of the efficacy and on the best applicable protocol. We conducted an effect size meta-analysis to assess the overall efficacy of ES on wound healing, to compare the efficacy of the different modalities of electrical stimulation, and to determine whether efficacy differs depending on the wound etiology, size, and age of the chronic wound. Twenty-nine randomized clinical trials with 1,510 patients and 1,753 ulcers were selected. Overall efficacy of ES on would healing was a 0.72 SMD (95% CI: 0.48, 1) corresponding to a moderate to large effect size. We found that unidirectional high voltage pulsed current (HVPC) with the active electrode over the wound was the best evidence-based protocol to improve wound healing with a 0.8 SMD (95% CI: 0.38, 1.21), while evaluation of the efficacy of direct current was limited by the small number of studies. ES was more effective on pressure ulcers compared to venous and diabetic ulcers, and efficacy trended to be inversely associated with the wound size and duration. This study confirms the overall efficacy of ES to enhance healing of chronic wounds and highlights the superiority of HVPC over other type of currents, which is more effective on pressure ulcers, and inversely associated with the wound size and duration. This will enable to standardize future ES practices.

Electrical Stimulation and Cutaneous Wound Healing: A Review of Clinical Evidence.

Electrical stimulation (ES) has been shown to have beneficial effects in wound healing. It is important to assess the effects of ES on cutaneous wound healing in order to ensure optimization for clinical practice. Several different applications as well as modalities of ES have been described, including direct current (DC), alternating current (AC), high-voltage pulsed current (HVPC), low-intensity direct current (LIDC) and electrobiofeedback ES. However, no one method has been advocated as the most optimal for the treatment of cutaneous wound healing. Therefore, this review aims to examine the level of evidence (LOE) for the application of different types of ES to enhance cutaneous wound healing in the skin. An extensive search was conducted to identify relevant clinical studies utilising ES for cutaneous wound healing since 1980 using PubMed, Medline and EMBASE. A total of 48 studies were evaluated and assigned LOE. All types of ES demonstrated positive effects on cutaneous wound healing in the majority of studies. However, the reported studies demonstrate contrasting differences in the parameters and types of ES application, leading to an inability to generate sufficient evidence to support any one standard therapeutic approach. Despite variations in the type of current, duration, and dosing of ES, the majority of studies showed a significant improvement in wound area reduction or accelerated wound healing compared to the standard of care or sham therapy as well as improved local perfusion. The limited number of LOE-1 trials for investigating the effects of ES in wound healing make critical evaluation and assessment somewhat difficult. Further, better-designed clinical trials are needed to improve our understanding of the optimal dosing, timing and type of ES to be used.

An in vitro pressure ulcer approach using High Voltage Pulsed Current (HVPC) stimulation

Purpose Immobilization will lead to pressure ulcers. The breadth and depth of impacts related to having a pressure ulcer on quality of life is significant in a physical, psychological, emotional, spiritual, social, and financial sense. In Indonesia, one study reported pressure ulcers in 72 of 253 patients (28%). High Voltage Pulsed Current (HVPC), an electrical stimulation current type, has been used to promote wound healing. One of its mechanisms is thought to be antimicrobial. Our study observed the effect of HVPC on extended spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBLKp), commonly found in pressure ulcer cultures in Hasan Sadikin Hospital, Bandung, Indonesia Methods A suspension of ESBLKp was poured over an agarose-based solid medium. Immediately after inoculation HVPC (250V, 100Hz, 70μs pulse interval (current controlled) was applied for 30, 60 and 120min respectively. The experiment was done in fourfold. After 24 hrs and 48 hrs incubation the growth-inhibitory zone was measured at each pole. Results & Discussion Both poles showed growth inhibition after both 24 and 48 hrs incubation. Maximum inhibitory zone (27mm) was reached after 48 hrs around the cathode with 120min HVPC application. Different patterns of inhibition were found at the cathode and anode, with the anode zone being smaller but with more clearing. HVPC stimulation is a promising intervention for pressure ulcers infested with K. pneumoniae. Future studies should define parameter and schedule for HPVC stimulation in vivo.

Estimulação elétrica de alta voltagem em nervo ciático de ratos: estudo pelo IFC

ObjectiveTo analyze the efficiency of high voltage pulsed current (HVPC) with early application in three different sites, in the regeneration of the sciatic nerve in rats submitted to crush injury, the sciatic functional index (SFI) was used to assess the functional recovery.MethodsAfter crushing of the nerve, 57 animals were submitted to cathodal HVPC at frequency of 50Hz and voltage of 100V, 20 minutes per day, 5 days per week. The rats were divided into five groups: control group; ganglion group; ganglion + muscle group; muscle group; and sham group. The SFI was determined weekly for seven weeks, from the preoperative period to the 6th postoperative week.ResultsCompared with the control group, the results showed a significantly better performance of group 2 for the first 3 weeks; group 3 showed significantly better performance in the third week; and group 4 showed a significantly negative performance during the 4th and 6th weeks.ConclusionEarly application of HVPC had a positive effect in the treatment of the spinal cord region and the sciatic nerve root ganglion with a dispersive electrode on the contralateral lumbar region or on the gastrocnemius. However, HVPC had a negative effect in the treatment with an active electrode on the gastrocnemius and a dispersive electrode on the contralateral thigh. Level of evidence II, Prospective comparative study.

Effect of High-Voltage Pulsed Current on Recovery After Grades I and II Lateral Ankle Sprains

High-voltage pulsed current (HVPC), a form of electrical stimulation, is known to curb edema formation in laboratory animals and is commonly applied for ankle sprains, but the clinical effects remain undocumented. To determine whether, as an adjunct to routine acute and subacute care, subsensory HVPC applied nearly continuously for the first 72 h after lateral ankle sprains affected time lost to injury. Multicenter, randomized, double-blind, placebo-controlled trial. Data were collected at 9 colleges and universities and 1 professional training site. 50 intercollegiate and professional athletes. Near-continuous live or placebo HVPC for 72 h postinjury in addition to routine acute and subacute care. Time lost to injury measured from time of injury until declared fit to play. Overall, time lost to injury was not different between treated and control groups (P = .55). However, grade of injury was a significant factor. Time lost to injury after grade I lateral ankle sprains was greater for athletes receiving live HVPC than for those receiving placebo HVPC (P = .049), but no differences were found between groups for grade II sprains (P = .079). Application of subsensory HVPC had no clinically meaningful effect on return to play after lateral ankle sprain.

Effect of high-voltage pulsed current plus conventional treatment on acute ankle sprain

The effectiveness of high-voltage pulsed current (HVPC) treatments in humans as a means of controlling edema and post-traumatic pain has not yet been established. To analyze the effects of HVPC plus conventional treatment on lateral ankle sprains. This was a randomized, controlled, double-blind clinical trial with three intervention groups: CG (control group with conventional treatment); HVPC(-) group (conventional treatment plus negative polarity HVPC); HVPC+ group (conventional treatment plus positive polarity HVPC). Twenty-eight participants with lateral ankle sprain (2 to 96 h post-trauma) were evaluated. Conventional treatment consisted of cryotherapy (20 min) plus therapeutic exercises. Additionally, the HVPC(-) and HVPC+ groups received 30 min of electrical stimulation (submotor level; 120 pps). Pain, edema, range of motion (ROM) and gait were assessed before the first treatment session and after the last treatment session. At the final evaluation, there were no significant differences between groups. Nevertheless, the HVPC(-) group had greater values in all assessed parameters. The data analysis showed that the HVPC(-) group had greater reductions in volume and girth, and greater recovery of ROM and gait velocity. This group also reached the end of the treatment (1.7 weeks; range 1.2-2.2) faster than the HVPC+ group and the CG (2.2 weeks; range 1.8-2.6). There were no differences between the study groups, but the results suggest that HVPC(-) can accelerate the initial phase of recovery from ankle sprain. Article registered in the Clinical Trials.gov under the number NCT 00732017.

Effect of the Simultaneous Application of NMES and HVPC on Knee Extension Torque

Electrical stimulation using simultaneous application of two current types for multiple effects is a current treatment option, but the effect of this treatment is not currently known. To compare isometric knee extension torque when using neuromuscular electrical stimulation (NMES) in combination with High Voltage Pulsed Current (HVPC) versus NMES alone during three contraction conditions of quadriceps. Counterbalanced, within-subjects design to test independent variables, stimulation protocol, and contraction condition; ANOVA to analyze dependent variable, peak torque. Athletic Training Research Laboratory. 14 healthy subjects (7 male and 7 female, age = 21.9 +/- 2.0 yr, height = 173.4 +/- 10.1 cm, weight = 76.1 +/- 16.7 kg). Participants performed three contraction conditions during two stimulation protocols. Peak isometric knee extension torque. The main effect for Stimulation Protocol was not significant: F1,26 = .01, P = .94. Simultaneous application of HVPC with NMES does not facilitate the neuromuscular response but may provide an efficient treatment when managing atrophy, strength loss, pain, and edema associated with reconstructive surgery.

112 Effects of High Voltage Pulsed Current on Bacterial Viability: An in Vitro Study

Background and Purpose: High voltage pulsed current (HVPC) has been shown to have positive effects on wound healing due in part to proposed bacteriocidal effects in wound beds. The purpose of this study was to examine the effects of electrical stimulation (HVPC) using in vitro Streptococcus A and clinically-accepted wound care guidelines. Methods: Commercially available Streptococcus A was grown overnight in Trypticase Soy Broth. Standard 100 millimeter (mm) Petri dishes of Trypticase Soy Agar with 5% sheep blood were then streaked using sterile cotton swabs. 52 plates were subjected to 45-minutes of HVPC with the following parameters: 120 pps, 200 V, 10-second on/off cycle, and 2-second ramp time. Negative polarity was used as the active electrode. 48 control plates were prepared identically without the application of the HVPC. Zones of inhibition were measured the following day at the positive and negative electrode sites to the nearest millimeter after a 24-hour incubation period using the Kirby-Bauer method. Results: Differences were calculated using a two-way ANOVA with SPSS 11.5. Mean inhibition at the positive and negative electrodes was 0.00 mm ± 0.00 and 10.13 ± 4.13 mm, respectively. Significant between group effects were found for the control and experimental groups (F1,199 = 289.4, p < 0.001), negative and positive electrodes (F1,199 = 289.4, p < 0.001), and interaction of groups by electrodes (F1,199 = 289, p < 0.001). Conclusion: In vitro, negative polarity HVPC using clinically accepted and feasible parameters can inhibit Streptococcus A growth around the negative (active) electrode. No growth inhibition was noted around the positive (dispersive) electrode. This could provide an alternate means of infection control in assistance with wound healing.

A comparison of four electrical stimulation types on Staphylococcus aureus growth in vitro

We evaluated the efficacy of common electrical stimulation (ES) types on bacterial growth in vitro using clinically relevant conditions. Four types of ES--continuous microamperage direct current (microADC), high-voltage pulsed current (HVPC), low-voltage monophasic milliamperage pulsed current (LVMmAPC), and low-voltage biphasic milliamperage pulsed current (LVBmAPC)--were each applied to a separate set of culture plates containing Staphylococcus aureus for 1 h at 37 degrees C on 3 consecutive days. After ES treatment, the zone of inhibition surrounding each electrode was measured. Zone of inhibition measurements showed a significant inhibitory effect for continuous microADC and HVPC (p < 0.05), but not for LVMmAPC and LVBmAPC. Differences in bacterial growth inhibition were not found for polarity and time. These data suggest that for infected wounds, HVPC and continuous microADC treatments may have an initial bacterial inhibitory effect, which does not significantly change with subsequent treatments.

Electrotherapy reverses inframalleolar ischemia: a retrospective, observational study.

To determine if high-voltage pulsed current (HVPC) augments ischemic wound healing and increases periwound perfusion. A 5-year, retrospective, observational study was conducted on successive patients with ischemic wounds who were poor candidates for revascularization. HVPC was applied directly to wounds at greater than 100 volts, 100 pulses per second, 1 hour per day. In addition to HVPC, patients received standard care for ischemic wounds at the study facility. Ischemic wounds for which HVPC was not clinically indicated or not available received standard care alone. Wound area measured by planimetry, wound appearance observed by digital imaging techniques, and microcirculation monitored by transcutaneous oxygen (TcPo(2)) levels. The group that received HVPC plus standard care showed smaller wound areas from weeks 20 though 52 after the start of treatment compared with the group that received standard care alone (P <.05; Mann-Whitney test). One year after the start of treatment, 90% of HVPC-treated wounds were healed, compared with 29% of the wounds that received only standard care (P <.05; Fisher exact test). For the HVPC group, maximum periwound TcPo(2) improved during electrotherapy (6 +/- 8 mm Hg [standard deviation; SD] at baseline improved to 26 +/- 20 SD, during HVPC, P <.05; Wilcoxon signed rank test). The results of this retrospective trial demonstrate that HVPC plus standard care improved the healing rate of high-risk ischemic wounds. A direct relationship was shown between improved healing rates and increased periwound perfusion. A prospective randomized controlled trial is needed to further support these observational, preliminary findings.

Effect of Electrical Stimulation on Chronic Leg Ulcer Size and Appearance

Electrical current has been recommended for use on chronic pressure ulcers; however, the ability of this modality to improve healing of other types of chronic ulcers is less well established. The purpose of this study was to examine the effect of high-voltage pulsed current (HVPC) on healing of chronic leg ulcers. Twenty-seven people with 42 chronic leg ulcers participated in the study. The subjects were separated into subgroups according to primary etiology of the wound (diabetes, arterial insufficiency, venous insufficiency) and then randomly assigned to receive either HVPC (100 microseconds, 150 V, 100 Hz) or a sham treatment for 45 minutes, 3 times weekly, for 4 weeks. Wound surface area and wound appearance were assessed during an initial examination, following a 1- to 2-week period during which subjects received only conventional wound therapy, after 4 weeks of sham or HVPC treatment, and at 1 month following treatments. The results indicated that HVPC applied to chronic leg ulcers reduced the wound surface area over the 4-week treatment period to approximately one half the initial wound size (mean decrease=44.3%, SD=8.8%, range=2.8%-100%), which was over 2 times greater than that observed in wounds treated with sham units (mean decrease=16.0%, SD=8.9%, range=-30.3%-83.7%). The results of the study indicate that HVPC administered 3 times a week should be considered to accelerate wound closure of chronic leg ulcers.

Update on High-Voltage Pulsed Current Research and Application

Electrotherapy is an effective modality for wound management. Studies show electric stimulation increases circulation and inhibits bacterial growth. The skin has electrical properties that require wound hydration for proper functioning. High-voltage pulsed current also may be used for edema reductio

Treatment of Hand and Wrist Pain

To determine the effectiveness of high voltage pulsed current (HVPC) in reducing chronic hand edema, 120 individuals were randomly assigned to one of two treatment groups. Group I clients were given an appropriate sized wrist splint, incorporating an energized, high voltage pulsed unit. Group II clients were given an identical splint with a non-energized unit. Each client received daily treatments at the worksite consisting of 30 minute sessions totaling 20 treatments during a 35 day period. Pre-treatment and post-treatment evaluations included measurements of pain, grip strength, and edema volume; repetitive task testing; and Semmes-Weinstein Monofilament sensory testing. In the energized group, post-treatment evaluation showed statistically significant decreases in the amount of stimulation required to stimulate the median nerve and the amount of hand edema and pain. The energized group also had improved repetitive task times. None of these improvements occurred in the non-energized group. Based on these results, HVPC appears to be an effective method for minimizing the severity of repetitive stress injuries of the wrist.

High-voltage pulsed current: Its influence on diameters of histamine-dilated arterioles in hamster cheek pouches

Results from five independent studies from our laboratory indicate that cathodal high-voltage pulsed current (HVPC) significantly curbs posttraumatic edema formation in several animal models. Conversely, anodal HVPC did not curb edema formation. The mechanism by which HVPC reduces edema formation is unknown. We hypothesize that HVPC causes a decrease in local blood flow by active vasoconstriction of arterioles. Because we had previously observed positive effects with cathodal HVPC but not anodal HVPC, we further hypothesized that cathodal but not anodal HVPC would reduce diameters of histamine-dilated arterioles. Changes in diameters of resistance arterioles (5 to 30 μm internal diameter) were measured directly in cheek pouches of anesthetized hamsters, using in vivo video microscopy. Three minutes after superfusion with the inflammatory mediator (histamine) was begun, sensory-level HVPC at 120pps was applied concurrently for 30 minutes. Five animals received cathodal HVPC and five received anodal HVPC. Four other animals received 30-minute treatments of both cathodal and anodal HVPC in random order. Three control animals received histamine without HVPC for 30 minutes. Diameter changes of one arteriole from each cheek pouch was measured every 20 seconds throughout the treatment period. One-way analysis of variance (ANOVA) with repeated measures showed that diameters of histamine-dilated controls varied little over 30 minutes, and that adding cathodal HVPC did not significantly alter diameters of arterioles superfused with histamine. However, applying anodal HVPC to histamine-dilated arterioles significantly reduced arteriolar diameters. These results do not support the hypothesis that cathodal HVPC curbs edema formation by increasing arteriolar tone in the injured area.

Effect of narrow, pulsed high voltages on bacterial viability.

High-voltage pulsed current (HVPC) has been used to promote the healing of decubitus ulcers and surgical wounds. The benefits of HVPC are thought to include an antimicrobial action. This study was undertaken to explore the development of an in vitro system for the systematic evaluation of the effects of HVPC. Using agarose-based media, the system allows for examination of the direct effect of HVPC on microorganisms as well as exploration of the possible in situ generation of bacteriostatic or bactericidal factors by the action of HVPC on constituents of the media. The solid media also allow characterization of the spatial extent of the current's effects such as changes in temperature or pH. The system was used to examine the effects of HVPC on four different species of bacteria: Escherichia coli, Klebsiella, Pseudomonas aeruginosa, and Staphylococcus aureus. Both direct and indirect bactericidal effects were observed at either the positive or negative electrode, or both, for each of the organisms, although zones of inhibition varied. Temperature and pH were examined as possible mechanisms for the indirect effect. Temperature changes observed during the application of HVPC were minimal and did not contribute to the antimicrobial effect. Extreme pH changes did not appear to be the major cause of the indirect effect because the zones of inhibition observed were generally larger than the zones of extremely acid or basic pHs. High-voltage pulsed current produced antimicrobial effects in this in vitro study. Additional studies are needed to elucidate the mechanisms and to determine whether the mechanisms occur in vivo.