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The study examined the effect of ZD7288, a blocker of hyperpolarization-activated 'funny' current I, on electrical activity in working atrial and ventricular myocardium in rats. In concentrations range from 3×10 to 3×10 M, the agent significantly increased the duration of action potentials at 50 and 90% repolarization levels in both atrial and ventricular myocardium at the fixed stimulation rate of 5 Hz. The blocker affected neither resting potential nor the upstroke velocity of action potential. In patch-clamp experiments, ZD7288 selectively inhibited I current, but produced no effect on delayed rectifier potassium currents that determine the rate of repolarization. The described effects of ZD7288 are not related to its non-specific effects on the ionic currents except I. [ABSTRACT FROM AUTHOR]

This paper establishes the analytical expression of the electric field induced by a uniformly charged plate (parallelepiped), which is useful for describing more complex configurations by addition of uniformly charged parallelepiped. Examples of applications involve capacitors (electrical engineering) and electrochemotherapy (medicine). The asymptotic behavior, at the origin and far away from the plates, is firstly discussed, followed by a comparison with an existing software, and finally the electric field (vector field and magnitude) is shown for two 3D orthogonal plates with equal or opposite charge density. [ABSTRACT FROM AUTHOR]

A number of methods have been developed recently that stimulate the human brain non-invasively through the intact scalp. The most common are transcranial magnetic stimulation (TMS), transcranial electric stimulation (TES) and transcranial direct current stimulation (TDCS). They are widely used to probe function and connectivity of brain areas as well as therapeutically in a variety of conditions such as depression or stroke. They are much less focal than conventional invasive methods which use small electrodes placed on or in the brain and are often thought to activate all classes of neurones in the stimulated area. However, this is not true. A large body of evidence from experiments on the motor cortex shows that non-invasive methods of brain stimulation can be surprisingly selective and that adjusting the intensity and direction of stimulation can activate different classes of inhibitory and excitatory inputs to the corticospinal output cells. Here we review data that have elucidated the action of TMS and TES, concentrating mainly on the most direct evidence available from spinal epidural recordings of the descending corticospinal volleys. The results show that it is potentially possible to test and condition specific neural circuits in motor cortex that could be affected differentially by disease, or be used in different forms of natural behaviour. However, there is substantial interindividual variability in the specificity of these protocols. Perhaps in the future it will be possible, with the advances currently being made to model the electrical fields induced in individual brains, to develop forms of stimulation that can reliably target more specific populations of neurones, and open up the internal circuitry of the motor cortex for study in behaving humans. [ABSTRACT FROM AUTHOR]

While studies have shown that the application of transcranial direct current stimulation (tDCS) has been beneficial in the stimulation of cortical activity and treatment of neurological disorders in humans, open questions remain regarding the placement of electrodes for optimal targeting of currents for a given functional area. Given the difficulty of obtaining in vivo measurements of current density, modeling of conventional and alternative electrode montages via the finite element method has been utilized to provide insight into tDCS montage performance. It has been shown that extracephalic montages might create larger total current densities in deeper brain regions, specifically in white matter as compared to an equivalent cephalic montage. Extracephalic montages might also create larger average vertical current densities in the primary motor cortex and in the somatosensory cortex. At the same time, the horizontal current density either remains approximately the same or decreases. The metrics used in this paper include either the total local current density through the entire brain volume or the average vertical current density as well as the average horizontal current density for every individual lobe/cortex. [ABSTRACT FROM PUBLISHER]

Objectives Electrode impedance increases following implantation and undergoes transitory reduction with onset of electrical stimulation. The studies in this paper measured the changes in access resistance and polarization impedance in vivo before and following electrical stimulation, and recorded the time course of these changes. Design Impedance measures recorded in (a) four cats following 6 months of cochlear implant use, and (b) three cochlear implant recipients with 1.5–5 years cochlear implant experience. Results Both the experimental and clinical data exhibited a reduction in electrode impedance, 20 and 5% respectively, within 15–30 minutes of stimulation onset. The majority of these changes occurred through reduction in polarization impedance. Cessation of stimulation was followed by an equivalent rise in impedance measures within 6–12 hours. Conclusions Stimulus-induced reductions in impedance exhibit a rapid onset and are evident in both chronic in vivo models tested, even several years after implantation. Given the impedance changes were dominated by the polarization component, these findings suggest that the electrical stimulation altered the electrode surface rather than the bulk tissue and fluid in the cochlea. [ABSTRACT FROM AUTHOR]

Noncompressible hemorrhage is currently the most common cause of preventable death in battlefield and in civilian trauma injuries. Tourniquets, specialized wound dressings, and hemorrhage-inhibiting biomaterials are not sufficiently effective in arrest of noncompressible hemorrhage and often cause collateral tissue damage. An effective, easy-to-use, portable device is needed to reduce blood loss in trauma patients immediately following injury and to maintain hemorrhage control up to several hours—until the injured is evacuated to a medical facility. We developed a miniature electrical stimulator to induce vascular constriction and, thereby, reduce hemorrhage. Vasoconstriction of the rat femoral arteries and veins was studied with pulse durations in the range of 1 μs to 10 ms and repetition rate of 10 Hz. Pulse amplitude of 20 V, duration of 1 ms, and repetition rate of 10 Hz were found sufficient to induce rapid constriction down to 31 ± 2% of the initial diameter, which could be maintained throughout a two-hour treatment. Within one minute following treatment termination the artery dilated back to 88 ± 3% of the initial diameter, providing rapid restoration of blood perfusion. Histology indicated no damage to the vessel wall and endothelium seven days after stimulation. The same treatment reduced the blood loss following complete femoral artery resection by 68 ± 11%, compared to untreated vessels. Very low power consumption during stimulation (<10 mW per 1.6 mm electrode) allows miniaturization of the stimulator for portable battery-powered operation in the field to control the blood loss following vascular trauma. [ABSTRACT FROM PUBLISHER]

Defibrillation is one of the most successful and widely recognized applications of electrotherapy. Yet the historical road to its first successful application in a patient and the innovative adaptation to an implantable device is marred with unexpected turns, political and personal setbacks, and public and scientific condemnation at each new idea. Driven by dedicated scientists and ever-advancing creative applications of new technologies, from electrocardiography to high density mapping and computational simulations, the field of defibrillation persevered and continued to evolve to the life-saving tool it is today. In addition to critical technological advances, the history of defibrillation is also marked by the plasticity of the theory of defibrillation. The advancing theories of success have propelled the campaign for reducing the defibrillation energy requirement, instilling hope in the development of a painless and harmless electrical defibrillation strategy. [ABSTRACT FROM PUBLISHER]

Copyright of Revista Salud UIS is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Study Design: A randomized prospective study. Purpose: To assess postoperative analgesic requirements after Phyback therapy preemptively in patients undergoing lumbar stabilization. Overview of Literature: Frequency Rhythmic Electrical Modulation System is the latest method of preemptive analgesia. Methods: Forty patients were divided into two groups. Patients who were to receive tramadol were allocated to "group A" and those who were to receive Phyback therapy were allocated to "group B." In patients with a visual analog scale score of >4 or a verbal rating scale score of >2, 75 mg of diclofenac IM was administered. The amount of analgesic consumption, the bolus demand dosage, and the number of bolus doses administered were recorded. Patient satisfaction was evaluated using the visual analog patient satisfaction scale. Results: There were statistically significant differences in the visual analog scale and verbal rating scale scores in the fourth, sixth, 12th, and 24th hours. The number of bolus infusions was significantly lower in group B. The amount of analgesic consumption was higher in group A. There was a significant difference between the two groups in the number of bolus infusions and the total amount of analgesic consumption, and this comparison showed better results for group B. Conclusions: Application of Phyback therapy reduced postoperative opioid consumption and analgesic demand, and it contributed to reducing patients' level of pain and increased patient satisfaction. Moreover, the application of preemptive Phyback therapy contributed to reducing preoperative pain which may have reduced patient anxiety. [ABSTRACT FROM AUTHOR]

This paper analyses some main areas of intervention to improve cognitive capacities: educational programs, psy-chopharmacology, brain-computer interface, electric stimulation of the brain, nanotechnology; it studies the possibilities these methods offer as well as possible ethical and medical problems. The problems related to the use of these procedures are the occurrence of undesirable effects in the shot-term or long-term, the question of equity -i.e. the possible disadvantage of people that have not been "improved"- and the problem of personal identity. The author advocates for an ethical limitation of scientific research in this field. [ABSTRACT FROM AUTHOR]

The harmonic impedance spectra (HIS) of a time-varying bioimpedance Z(ω, t) is a new tool to better understand and describe complex time-varying biological systems with a distinctive periodic character as, for example, cardiovascular and respiratory systems. In this paper, the relationship between the experimental setup and the identification framework for estimating Z(ω, t) is set up. The theory developed applies to frequency response based impedance measurements from noisy current–voltage observations. We prove theoretically and experimentally that a voltage source (VS) and a current source (CS) analogue front end-based measurement lead, respectively, to a closed-loop and an open-loop HIS identification problem. Next, we delve into the estimation of the HIS by treating Z(ω, t), on the one hand, as a linear time-invariant (LTI) system within a short time window; and, on the other hand, as a linear periodically time-varying (PTV) system within the entire measurement interval. The LTI approach is based on the short-time Fourier transform (STFT), while the PTV approach relies on the information that is present in the skirts of the voltage and/or current spectra. In addition, direct and indirect methods are developed for estimating the HIS by using simple as well as more sophisticated techniques. Ultimately, the HIS and their uncertainty bounds are estimated from real measurements conducted on a periodically varying dummy impedance. [ABSTRACT FROM AUTHOR]

Objective: To analyze the efficacy and safety of cortical and subcortical electrical stimulation CSES and awake surgery to approach purely subcortical tumors in highly functional locations, particularly in guiding the choice of the best transcortical path. Patients and methods: Prospective analysis of the surgical, neurological, and radiological outcome of patients harboring supratentorial, subcortically located brain tumors or vascular malformations who are operated on through awake surgery and CSES. Functional magnetic resonance (fMRI; either sensory-motor or language, based on the location) was performed in order to confirm the proximity to functional cortical areas. Major white matter tracts were investigated by MRI diffusion tensor fiber tracking (DTI-ft). The Rankin modified score was chosen to express the pre and postoperative functional neurological status. Immediate postoperative MRI was used to evaluate the extent of resection. Results: Seventeen patients were selected. The main distance of the tumors from the cortical surface was 18.2 mm (range 9-48mm). Neuronavigation was used to show the most direct route to the tumor (transsulcal or transgyral), but CSES was fundamental to adapt the surgical corridor to the functional topography both cortically and subcortically. If the transgyral route was chosen, CSES helped to detect a non-eloquent area. When a transsulcal route was preferred, CSES documented the presence or absence of function in the deep sulcus. The transient postoperative morbidity was 76.4%, but at last follow-up (range 4-20 months), all the patients regained preoperative status and 2 improved. Postoperative MRI demonstrated complete resection in all cases. Conclusions: Approaching purely subcortical tumors requires microsurgical skills, but in eloquent areas, functional topography monitoring is mandatory to allow safe surgery. CSES in an awake patient is a method that produces very good results in terms of resection and neurological outcome. [ABSTRACT FROM AUTHOR]

In chronic experiments on rabbits, the effect of electric stimulation of the hunger center in the lateral hypothalamus on myoelectric activity of the fundal and antral parts of the stomach was studied under conditions of hunger and satiation in the absence of food. Stimulation of the lateral hypothalamus in rabbits subjected to 24-h food deprivation and in previously fed rabbits produced incessant seeking behavior, which was followed by reorganization of the structure of temporal organization of slow wave electric activity of muscles of the stomach body and antrum specific for hungry and satiated animals. Increased hunger motivation during electric stimulation of the lateral hypothalamus manifested in the structure of temporal organization of slow wave electric activity of the stomach body and antrum muscles in rabbits subjected to 24-h food deprivation in the replacement of bimodal distribution of slow wave periods to a trimodal type typical of 2-day deprivation, while transition from satiation to hunger caused by electric stimulation of the lateral hypothalamus was associated with a shift from monomodal distributions of slow wave periods to a bimodal type typical of 24-h deprivation. Reorganization of the structure of temporal organization of slow wave electric activity of the stomach body and antrum muscles during electric stimulation of the lateral hypothalamus was determined by descending inhibitory influences of food motivational excitation on activity of the myogenic pacemaker of the lesser curvature of the stomach. [ABSTRACT FROM AUTHOR]

Abstract: The goal of this manuscript is to present a new methodology for real time analysis of time-varying electrical bioimpedance data. The approach assumes that the Fricke–Morse model of living tissues is meaningful and valid within the measured frequency range (10kHz to 1MHz). The parameters of this model are estimated in the whole frequency range with the presented method based on differential impedance analysis (DIA). The numerical accuracy of the developed approach has been validated and compared to complex nonlinear least square (CNLS) approach through simulations and also with experimental data from in vivo time-varying human lung tissue bioimpedance. The new developed method has demonstrated a promising performance for fast and easily interpretable information in real time. [Copyright &y& Elsevier]

Introduction: the use of electrical stimulation (ES) in the treatment of denervated muscles has been studied as it assists in the late reinnervation and minimizes muscle atrophy. Purpose: this study assessed the ES through the symmetric sinusoidal alternating current in the maintenance of the morphological aspects of the experimentally denervated Extensor digitorum longus (EDL) and Soleus muscles. Method: Forty Wister rats were divided into four experimental groups (n = 10) : initial control group (ICG), final control group (FCG), denervated group (DG) and denervated and stimulated group (DSG). ES was first applied in the soleus and EDL muscle 48 hours after nerve injury, the applications took place three times per week for forty-five days. Cross-sections were stained with HE to perform the morphometric analysis of the muscle fibers. We used the analysis of variance (one-way - ANOVA) followed by the Tukey test (p = 0.05) for statistical analysis. Results: the animals belonging to group D and DE showed a decrease in the cross-sectional area (CSA) when compared to FCG. However, the group DE had muscular atrophy minimized, as there was a statistically significant difference when compared to D, both for EDL and soleus muscles. Conclusion: the ES was effective in maintaining the morphological aspects of the EDL and soleus muscles, minimizing muscle atrophy. This may be a useful treatment for the peripheral nerve injuries. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the short-term effects of staged InterStim® implantation on activities of daily living (ADL) and pain. Methods: This prospective study assessed women undergoing staged InterStim® implantation. The Older Americans Resources and Services Program Multidimensional Functional Assessment Questionnaire asked participants about their ability to complete activities without help or what help they needed following stage I lead placement and stage II neurostimulator implantation. Narcotic use and a visual analog scale (VAS) for pain were recorded daily. Results: Thirty-eight women underwent stage I with 33 (86.8 %) progressing to stage II. On stage I postoperative day (POD) 2, more women required help shopping compared with baseline (40 vs 17 %, p < 0.004). The median pain score increased on Stage I POD1 ( P < 0.001) and the use of narcotics increased on POD1 and 2 compared with baseline (50 % vs 14 %, p = 0.001). The same trends were seen following stage II. Conclusions: Staged InterStim® implantation has minimal impact on ADL, pain or narcotic requirements. [ABSTRACT FROM AUTHOR]

Neuromuscular electrical stimulation (NMES) is commonly used by physiotherapists for pain relief, stimulation of denervated or disused muscles, and the promotion of wound healing. The purpose of this review is to discuss the applications of NMES in intensive care unit (ICU) patients according to the current research evidence. The first application is the use of NMES in ICU acquired weakness with evidence indicating significant benefits, such as preservation of muscle mass, prevention of polyneuromyopathy and improvement of muscle performance. Secondly, NMES has been proved to be effective in preventing pressure ulcers and accelerating wound healing through mechanisms which are clearly demonstrated by many experimental and clinical studies. However, very few studies have examined the effect of electrical stimulation in pressure ulcers of long term hospitalized ICU patients. Lastly, NMES in ICU can be applied in the form of functional electrical stimulation (FES), a well known technique used to mobilize patients with permanent neurological deficits, such as stroke and spinal cord injury. Current evidence in this area is reviewed and future research is proposed. [ABSTRACT FROM AUTHOR]

The article disucsses physicians' use of electricity in medicine in 18th century Paris, France. An overview of electricity's status as a medical technology, including electrical machines' use in treating paralysis, is provided. An overview of the physician and ornithologist Pierre Mauduyt de La Varenne, including his use of electricity for therapeutic purposes at his home, is provided.

Electrical impedance myography (EIM) is a technique for the evaluation of neuromuscular diseases, including amyotrophic lateral sclerosis and muscular dystrophy. In this study, we evaluated how alterations in the size and conductivity of muscle and thickness of subcutaneous fat impact the EIM data, with the aim of identifying an optimized electrode configuration for EIM measurements. Finite element models were developed for the human upper arm based on anatomic data; material properties of the tissues were obtained from rat and published sources. The developed model matched the frequency-dependent character of the data. Of the three major EIM parameters, resistance, reactance, and phase, the reactance was least susceptible to alterations in the subcutaneous fat thickness, regardless of electrode arrangement. For example, a quadrupling of fat thickness resulted in a 375% increase in resistance at 35 kHz but only a 29% reduction in reactance. By further optimizing the electrode configuration, the change in reactance could be reduced to just 0.25%. For a fixed 30 mm distance between the sense electrodes centered between the excitation electrodes, an 80 mm distance between the excitation electrodes was found to provide the best balance, with a less than 1% change in reactance despite a doubling of subcutaneous fat thickness or halving of muscle size. These analyses describe a basic approach for further electrode configuration optimization for EIM. [ABSTRACT FROM PUBLISHER]

Cutaneous afferent activities recorded by a nerve cuff electrode have been used to detect the stance phase in a functional electrical stimulation system for foot drop correction. However, the implantation procedure was difficult, as the cuff electrode had to be located on the distal branches of a multi-fascicular nerve to exclude muscle afferent and efferent activities. This paper proposes a new gait phase detection scheme that can be applied to a proximal nerve root that includes cutaneous afferent fibers as well as muscle afferent and efferent fibers. To test the feasibility of this scheme, electroneurogram (ENG) signals were measured from the rat sciatic nerve during treadmill walking at several speeds, and the signal properties of the sciatic nerve were analyzed for a comparison with kinematic data from the ankle joint. On the basis of these experiments, a wavelet packet transform was tested to define a feature vector from the sciatic ENG signals according to the gait phases. We also propose a Gaussian mixture model (GMM) classifier and investigate whether it could be used successfully to discriminate feature vectors into the stance and swing phases. In spite of no significant differences in the rectified bin-integrated values between the stance and swing phases, the sciatic ENG signals could be reliably classified using the proposed wavelet packet transform and GMM classification methods. [ABSTRACT FROM AUTHOR]

Transdermal amplitude modulated signal (TAMS) is a novel electrical stimulus which has been recently introduced for the treatment of overactive bladder (OAB) syndrome. It has been suggested that it has advantages over conventional waveforms by providing more effective penetration of the skin to enhance the efficacy of therapy. As there is no literature which supports this, we performed this study to evaluate potential advantages of the TAMS signal for electrical stimulation of subcutaneous nerves as compared to conventional stimuli. The stimuli were applied on forearms of ten healthy volunteers and electrical parameters of stimuli and sensation measurements were recorded. None of the recorded electrical parameters showed significant differences (paired t-test p ≥ 0.250) between the TAMS and conventional waveforms. Similarly, the mean sensation recorded at motor threshold level and at 50% of maximal motor response level showed no differences (paired t-test p = 0.242 and p = 0.687 respectively). It is unlikely, based on the results of this study, that TAMS provides any enhancement of the efficacy of conventional stimuli. We would recommend that further studies are carried out to clearly demonstrate in man what, if any, advantages the TAMS waveform has over conventional stimulation before it is widely deployed into clinical practice. [ABSTRACT FROM AUTHOR]

Abstract: Objective: To find out whether tubal sterilization leads to loss of ovarian reserve, we assessed the hormonal and ultrasonographic parameters of ovarian reserve in women who underwent laparoscopic tubal sterilization by bipolar electrodesiccation and transection. Study design: In this preliminary study, laparoscopic tubal sterilization was performed on 49 healthy women who had voluntarily requested elective surgical sterilization. Among the current ovarian reserve indicators, in the early proliferative phases, preoperative (baseline) and postoperative (third month) serum follicle-stimulating hormone (FSH), estradiol (E2), and anti-Mullerian hormone (AMH) levels, ovarian volume, and antral follicle counts (AFCs) were determined. Analysis of these hormonal and ultrasonographic parameters of ovarian reserve preoperatively and postoperatively was the main outcome measure. Results: Preoperative and third-month postoperative FSH, LH, E2, and AMH levels did not reveal statistically significant differences (p =0.101, p =0.180, p =0.254, and p =0.079; respectively). The ultrasonographic indicators of ovarian reserve did not change in terms of total ovarian volume and total AFC (p =0.793 and p =0.098, respectively). Conclusions: Short-term follow-up study results revealed a slight but non-significant change in the current ovarian reserve markers, especially in the AMH levels. [Copyright &y& Elsevier]

Abstract: Functional electrical stimulation is commonly used to correct drop foot following stroke or multiple sclerosis. This technique is successful for many patients, but previous studies have shown that a significant minority have difficulty identifying correct sites to place the electrodes in order to produce acceptable foot movement. Recently there has been some interest in the use of ‘virtual electrodes’, the process of stimulating a subset of electrodes chosen from an array, thus allowing the site of stimulation to be moved electronically rather than physically. We have developed an algorithm for automatically determining the best site of stimulation and tested it on a computer linked to a small, battery-powered prototype stimulator with 64 individual output channels. Stimulation was delivered via an 8×8 array adhered to the leg by high-resistivity self-adhesive hydrogel. Ten participants with stroke (ages 53–71 years) and 11 with MS (ages 40–80 years) were recruited onto the study and performed two walks of 10m for each of the following conditions: own setup (PS), clinician setup (CS), automated setup (AS) and no stimulation (NS). The PS and CS conditions used the participant''s own stimulator with two conventional electrodes; the AS condition used the new stimulator and algorithm. Outcome measures were walking speed, foot angle at initial contact and the Borg Rating of Perceived Exertion. Mean walking speed with no stimulation was 0.61m/s; all FES setups significantly increased speed relative to this (AS p <0.05, PS p <0.01, CS p <0.01). Speed for PS (0.72m/s) was faster than both AS (0.65m/s, p <0.01) and CS (0.68m/s, p <0.05). Frontal plane foot orientation at heel-strike was more neutral for AS (0.3° everted) than in the NS (11.2° inverted, p <0.01), PS (4.5° inverted, p <0.05) and CS (3.1° inverted, p <0.05) conditions. Dorsiflexion angles for AS (4.2°) were larger than NS (−3.0°, p <0.01), not different to PS (4.3°, p >0.05) and less dorsiflexed than CS (6.0°, p <0.05). This proof of principle study has demonstrated that automated setup of an array stimulator produces results broadly comparable to clinician setup. Slower walking speed for automated and clinician setups compared to the participants’ own setup may be due to the participants’ lack of familiarity with responses different to their usual setups. Automated setup using the method described here seems sufficiently reliable for future longer-term investigation outside the laboratory and may lead to FES becoming more viable for patients who, at present, have difficulty setting up conventional stimulators. [Copyright &y& Elsevier]

Electrocardiograms (ECGs) are widely used by clinicians to identify the functional status of the heart. Thus, there is considerable interest in automated systems for real-time monitoring of arrhythmia. However, intra- and inter-patient variability as well as the computational limits of real-time monitoring poses significant challenges for practical implementations. The former requires that the classification model be adjusted continuously, and the latter requires a reduction in the number and types of ECG features, and thus, the computational burden, necessary to classify different arrhythmias. We propose the use of adaptive learning to automatically train the classifier on up-to-date ECG data, and employ adaptive feature selection to define unique feature subsets pertinent to different types of arrhythmia. Experimental results show that this hybrid technique outperforms conventional approaches and is therefore a promising new intelligent diagnostic tool. [ABSTRACT FROM AUTHOR]

Detection of the moment when a muscle begins to activate on the basis of EMG signal is important task for a number of biomechanical studies. In order to provide high accuracy of EMG onset detection, we developed novel method, that give results similar to that obtained by an expert. By means of this method, EMG is processed in two stages. The first stage gives rough estimation of EMG onset, whereas the second stage performs local, precise searching. The method was applied to support signal processing in biomechanical study concerning effect of body position on EMG activity and peak muscle torque stabilizing spinal column under static conditions. [ABSTRACT FROM AUTHOR]

Copyright of Studia Universitatis Babes-Bolyai, Educatio Artis Gymnasticae is the property of Babes-Bolyai University, Cluj-Napoca, Romania and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We relate the fundamental stages of the long road leading to the discovery of electricity and its uses in cardiology. The first observations on the electromagnetic phenomena were registered in ancient texts; many Greek and Roman writers referred to them, although they provided no explanations. The first extant treatise dates back to the XIII century and was written by Pierre de Maricourt during the siege of Lucera, Italy, by the army of Charles of Anjou, French king of Naples. There were no significant advances in the field of magnetism between the appearance of this treatise and the publication of the study De magnete magneticisque corporibus (1600) by the English physician William Gilbert. Scientists became increasingly interested in electromagnetic phenomena occurring in certain fish, i.e., the so-called electric ray that lived in the South American seas and the Torpedo fish that roamed the Mediterranean Sea. This interest increased in the 18th century, when condenser devices such as the Leyden jar were explored. It was subsequently demonstrated that the discharges produced by ''electric fish'' were of the same nature as those produced in this device. The famous ''controversy'' relating to animal electricity or electricity inherent to an animal's body also arose in the second half of the 18th century. The school of thought of the physicist Volta sustained the principle of a single electrical action generated by metallic contact. This led Volta to invent his electric pile, considered as the first wet cell battery. Toward the middle of the XIX century, the disciples of the physiologist Galvani were able to demonstrate the existence of animal electricity through experiments exploring the so-called current of injury. On the path of Volta's approach, many characteristics of electricity were detailed, which ultimately led to their usage in the industrial field. The route followed by Galvani-Nobili-Matteucci led to the successes of Waller, Einthoven, etcetera, enabling the modern conquests of electro-vectorcardiography. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of the study was to investigate the effect of spinal shrinkage on the characteristic of flexion relaxation phenomenon in erector spinae muscle. Twelve male university students volunteered for this study. The spinal shrinkage was created with a load of 20% body weight on shoulder in 10min. Each performed three trials of lumbar flexion–extension with the cycle of 5s flexion and 5s extension in standing before and after shrinkage. Surface electromyography from right erector spinae muscle as well as trunk flexion performance was recorded synchronously in video camera. A one-way ANOVA with repeated measures was used to evaluate the effect of shrinkage. The results showed that there was a significant (p <0.001) stature change with mean magnitude of shrinkage 5.9mm. The erector spinae was active through a significantly larger angle during flexion and began activity significantly earlier during extension after shrinkage. It was concluded that shrinkage caused by prolonged compressive loading will elicit the change of flexion relaxation characteristic, which may be closely related to low back disorder. [Copyright &y& Elsevier]

Background: Electrical stimulation (ES) has been shown to promote nerve regeneration when it was applied to the proximal nerve stump. However, the possible beneficial effect of establishing a local electrical environment between a large nerve defect on nerve regeneration has not been reported in previous studies. The present study attempted to establish a local electrical environment between a large nerve defect, and examined its effect on nerve regeneration and functional recovery. Methodology/Findings: In the present study, a conductive scaffold was constructed and used to bridge a 15 mm sciatic nerve defect in rats, and intermittent ES (3 V, 20 Hz) was applied to the conductive scaffold to establish an electrical environment at the site of nerve defect. Nerve regeneration and functional recovery were examined after nerve injury repair and ES. We found that axonal regeneration and remyelination of the regenerated axons were significantly enhanced by ES which was applied to conductive scaffold. In addition, both motor and sensory functional recovery was significantly improved and muscle atrophy was partially reversed by ES localized at the conductive scaffold. Further investigations showed that the expression of S-100, BDNF (brain-derived neurotrophic factor), P0 and Par-3 was significantly up-regulated by ES at the conductive scaffold. Conclusions/Significance: Establishing an electrical environment with ES localized at the conductive scaffold is capable of accelerating nerve regeneration and promoting functional recovery in a 15 mm nerve defect in rats. The findings provide new directions for exploring regenerative approaches to achieve better functional recovery in the treatment of large nerve defect. [ABSTRACT FROM AUTHOR]

Background: Studies using vocoders as acoustic simulators of cochlear implants have generally focused on simulation of speech understanding, gender recognition, or music appreciation. The aim of the present experiment was to study the auditory sensation perceived by cochlear implant (CI) recipients with steady electrical stimulation on the most-apical electrode. Methodology/Principal Findings: Five unilateral CI users with contralateral residual hearing were asked to vary the parameters of an acoustic signal played to the non-implanted ear, in order to match its sensation to that of the electric stimulus. They also provided a rating of similarity between each acoustic sound they selected and the electric stimulus. On average across subjects, the sound rated as most similar was a complex signal with a concentration of energy around 523 Hz. This sound was inharmonic in 3 out of 5 subjects with a moderate, progressive increase in the spacing between the frequency components. Conclusions/Significance: For these subjects, the sound sensation created by steady electric stimulation on the most-apical electrode was neither a white noise nor a pure tone, but a complex signal with a progressive increase in the spacing between the frequency components in 3 out of 5 subjects. Knowing whether the inharmonic nature of the sound was related to the fact that the non-implanted ear was impaired has to be explored in single-sided deafened patients with a contralateral CI. These results may be used in the future to better understand peripheral and central auditory processing in relation to cochlear implants. [ABSTRACT FROM AUTHOR]

Background: A responsive electrical stimulation pattern based on our recently developed novel seizure prediction method was designed to suppress the penicillin-induced epileptic seizures. Methodology: Seizures were induced by Penicillin injection at rat cortex. A responsive electrical stimulation system was triggered prior to seizures predicted with phase synchronisation. Rats with induced seizures were stimulated by the electrical pulses at a responsive or 1 Hz periodic pattern of an open system. The effectiveness of stimulation on seizures suppression was assessed by measuring the average number and duration of seizures per hour. Results: The prediction algorithm reliably identified seizures in real time and triggered the responsive stimulation. This type of electrical stimulation dramatically suppressed seizure activity and the performance was better than the open stimulation system with fewer and shorter seizures. Conclusions: A responsive electrical stimulation system triggered by the phase synchronisation prediction is able to significantly suppress seizures. Significance: Responsive electrical stimulation could achieve superior treatment performance and reduce power consumption and side effects. [ABSTRACT FROM AUTHOR]

The aim of this review paper is to consider the application of neuromuscular electrical stimulation (NMES) to improve gait or upper limb function in children with cerebral palsy (CP). Although most NMES research has been directed at adults with neurological conditions, there is a growing body of evidence supporting its use in children with CP. In line with a recent meta-analysis, the use of electrical stimulation to minimise impairment and activity limitations during gait is cautiously advocated. A detailed commentary on one of the most common lower limb NMES applications, tibialis anterior stimulation (either with or without gastrocnemius stimulation) is given. Although there is a lack of randomised controlled trials and a predominance of mainly small studies, this review further concludes that the balance of available evidence is in favour of upper limb exercise NMES offering benefits such as increased muscle strength, range of motion and function in children with CP. The use of dynamic splinting with NMES has been shown to be more effective than either treatment on its own in improving function and posture. There is at present little published work to support the application of botulinum toxin type A to temporarily reduce muscle tone as an adjunct intervention to NMES in this population, although the presence of parallel applications to manage similar symptoms in other muscular disorders is noted. [ABSTRACT FROM AUTHOR]

The article discusses a study which investigated the functional and muscular effects of neuromuscular electrical stimulation (NMES) in patients with advanced chronic obstructive pulmonary disease (COPD). NMES training is compared to sham training. It concludes that NMES improved muscle cross-sectional area (CSA), which is associated with a more favorable muscle anabolic to catabolic balance.

Aim Faecal incontinence (FI) has a significant impact on quality of life. This study investigates whether stimulation of the dorsal genital nerve (DGN) improves FI symptoms. Method Ten female patients suffering from idiopathic FI (median age 60 years) were included in the study. Stimulation was applied twice daily for 3 weeks at the maximal tolerable stimulation amplitude (pulse width, 200 μs; pulse rate, 20 Hz). Patients kept a 3-week bowel diary prior to stimulation, during stimulation and after the final stimulation. FI severity scores, FI Severity Visual-Analogue Score (VAS), FI Quality of Life Score (FIQL), sphincter function and rectal volume tolerance were assessed at baseline, immediately after stimulation and 3 weeks after stimulation. Results Nine patients completed the study. The Wexner score ( P = 0.027) and the St Mark's score ( P = 0.035) improved after stimulation in seven and six of the patients and improvement was maintained 3 weeks after stimulation ( P = 0.048 and P = 0.049, respectively). The number of incontinent episodes was reduced in seven out of nine patients ( P = 0.025). Improvement was maintained for 3 weeks after stimulation ( P = 0.017). Subjective assessments of FI severity using the VAS score and the FIQl score did not improve during stimulation. Sphincter function and rectal volume tolerability were unaffected. Conclusion DGN stimulation reduced the number of FI episodes in most patients suffering from idiopathic FI. Sphincter function and rectal volume tolerability were not affected. DGN stimulation may represent a new treatment for idiopathic FI. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the reproducibility of a standardized technique of current perception threshold measurements with square wave and sine wave current, with monopolar and bipolar electrodes in a cohort of patients with overactive bladder (OAB) and healthy volunteers. Methods: We enrolled 6 female nulliparous healthy volunteers and 11 female patients with OAB. Current perception threshold measurements of the bladder were performed using several techniques. The same sequence was used for all 3 measurements performed at weekly intervals to assess the reproducibility. An intraclass correlation coefficient >0.75 was considered as very good reproducibility. Results: All the different stimulation forms were well tolerated by all participants and all experienced stimulation at 2.5-Hz and 95-Hz square wave current. The results with sine wave current showed less uniform results. The intraclass correlation showed the greatest reproducibility with bipolar stimulation at a current of 95 Hz. Sine wave current at 5 Hz and 250 Hz showed low reproducibility. Bipolar stimulation had significantly lower thresholds than monopolar stimulation (P < .0001). No significant differences were found between the healthy subjects and the patients with OAB for the 4 settings. Conclusion: In the healthy volunteers and patients with OAB, the determination of the current perception threshold in the bladder using a standardized method is feasible and well tolerated, with both bipolar and monopolar stimulation. In our study, square wave current showed strong reproducibility at weekly intervals at 2.5 Hz and 95 Hz. However, sinusoid current gave weak reproducibility. [ABSTRACT FROM AUTHOR]

Neck/shoulder pain has previously been linked to repetitive work and muscle fatigue. We have shown that asymptomatic people performing repetitive upper limb tasks display signs of shoulder fatigue and of whole-body compensatory strategies. However, the role played by the proprioceptive system in the production of these compensatory strategies has not been studied. A group of asymptomatic adults ( n = 18) performed a repetitive pointing task at shoulder height to fatigue. Before and after fatigue, they performed two position sense tasks, eyes closed: a single-joint task where they abducted their shoulder to the perceived horizontal and a multi-joint task, where they stood and placed their finger at the perceived location of a target in front of them at shoulder height. After fatigue, subjects made larger shoulder errors by raising their elbow higher above the horizontal (~+1.3 cm) than before fatigue; however, their finger position accuracy was not changed, despite all subjects performing the movement in less time (~−0.18 s) while fatigued. There were no gender differences in shoulder or finger position accuracy before or after fatigue; however, there were gender differences in the perceived finger-target location and in the temporal characteristics of the finger movement toward the target. Results suggest that healthy individuals are able to develop strategies to compensate for fatigue-induced deficits at one joint to maintain the endpoint accuracy of a multi-joint task constant. Gender differences in movement strategies and perception of endpoint location may play parts in the previously reported gender differences in work-related neck/shoulder symptoms. [ABSTRACT FROM AUTHOR]

The article discusses a study which stimulated normal and diabetic rabbits by skin electrode on the abnormal bladder projection area. The study used three levels of exporting voltage in the stimulation. Results showed attenuated electric signals from both groups, particularly in a group of rabbits with diabetes. The study also demonstrated a positive correlation between vesical pressure and signal.

Abstract: To examine the region specificity within the rectus femoris (RF) for knee extension and hip flexion force directions, three force components around the ankle were measured during intramuscular electrical stimulation applied to six parts of the RF: a proximal and medial part, a proximal and lateral part, a middle and medial part, a middle and lateral part, a distal and medial part, and a distal and lateral part. As a result, the exerted force directions in all of the subjects were variable in all regions, and the proximal region of the RF was the dominant contributor to the hip flexion moment. In addition, the force in the lateral region of the RF, rather than that in the medial region, denoted the lateral direction. These results suggest that divergent regions of muscle fibers within the RF are responsible for different functions in determining the force direction. [Copyright &y& Elsevier]

The article discusses the study on the electromyostimulation training in selected strength parameters. It tackles the effects of percutaneous electromyostimulation (EMS). It also explores the preconditions for generating a stimulus above the start of training with EMS. It provides analysis on the significant relationship of stimulation intensity and significant strength gains.

The peristimulus frequencygram (PSF) has recently been shown to illustrate postsynaptic potentials of motoneurones much more reliably than the peristimulus time histogram (PSTH). The aim of this investigation was to examine the profile of the postsynaptic potential (PSP) in soleus motoneurones in response to an H-reflex with and without accompanying M waves of different magnitude by using PSTH and PSF profiles of single motor units. Nine men and five women healthy subjects participated in this study. Electrical stimuli were delivered to the tibial nerve in the popliteal fossa. The reflex response of the soleus muscle was recorded using both surface electromyogram and single motor unit potentials. The PSTH analysis demonstrated that there were four different synaptic events following low-intensity stimulation of the tibial nerve: primary enhancement in firing probability (H-reflex or E1), primary reduction in firing probability (primary silent period or SP1), secondary reduction in firing probability (secondary silent period or SP2), and secondary enhancement in firing probability (E2). On the other hand, the PSF analysis indicated only two reflex responses, long-lasting enhancement in discharge rate including the H-reflex (LLE) and long-lasting decrease in discharge rate (LLD). The results of the two analyses methods are compared and contrasted. While the PSTH demonstrated that there was a silent period (SP1) immediately following the H-reflex, the PSF indicated an increase in discharge rate during the same period. The PSF also indicated that, during SP2 and E2, the discharge rate actually decreased (LLD). It was therefore suggested that LLD involved activation of several inhibitory pathways including the autogenic inhibition of units via the Golgi tendon organs. It was concluded that the PSF could indicate the details of the postsynaptic potentials and is very useful for bringing out previously unknown effects of electrical stimulation of muscle nerves. [ABSTRACT FROM AUTHOR]

Abstract: To clarify advantages of unilateral electrode placement as an optimisation technique for electroconvulsive therapy (ECT) for depression, aims were to meta-analyse unilateral ECT effects on cognitive performance relative to: (1) bitemporal electrode placement, (2) electrical dosage, and (3) time interval between final treatment and cognitive reassessment. Relevant electronic databases were systematically searched through May 2009, using the terms: "electroconvulsive therapy" and ["cogniti∗", "neuropsycholog∗", "memory", "attention", "executive", "spatial", or "intellectual"]. Inclusion criteria were: independent study of depressed patients receiving unilateral or bitemporal brief-pulse ECT; within-subjects design; use of objective cognitive assessments; available mean electrical dosage for unilateral samples. Standardized pre-post ECT weighted effect sizes were computed and pooled within 16 cognitive domains by a mixed-effects model. Thirty-nine studies (1415 patients) were meta-analysed. Up to three days after final treatment, unilateral ECT was associated with significantly smaller decreases in global cognition, delayed verbal memory retrieval, and autobiographical memory, compared to bitemporal ECT. Significant publication bias was found for autobiographical memory, favouring reporting of larger percentage loss. Higher unilateral ECT electrical dosage predicted larger decreases in verbal learning, delayed verbal memory retrieval, visual recognition, and semantic memory retrieval. When retested more than three days after completing ECT, no significant differences remained between the two electrode placements; for unilateral ECT, electrical dosage no longer predicted cognitive performance whereas increasing interval between final treatment and retesting predicted growing improvement in some variables. This interval is a more useful long-term predictor of cognitive function than electrode placement or electrical dosage following unilateral ECT. [Copyright &y& Elsevier]

Abstract: Objective: To investigate the synaptic potentials underlying reflex inhibition in gastrocnemius following electrical stimulation of the Achilles tendon using single motor unit recordings. Methods: Surface electromyography (SEMG) and single motor unit (SMU) action potentials were recorded from the medial head of left gastrocnemius muscle in eight healthy human subjects. The left Achilles tendon was stimulated electrically while subjects maintained a low contraction level sufficient to record one or two motor units. SMU responses were analysed using peri-stimulus time histogram (PSTH) and peri-stimulus frequencygram (PSF) techniques and compared with SEMG results. Results: A total of 22 SMU experiments were completed. In all trials, a large reflex inhibition (I1) was observed in both SEMG and PSTH followed by a later inhibition (I2). In 50% of trials, SEMG and PSTH showed that both I1 and I2 were followed by excitation (E1 and E2, respectively). PSF analysis showed only a prolonged reduction in SMU discharge rate. This inhibition had a latency of 38ms and duration of 130ms, extending into the E1 period in 14 units and more than 200ms extending into the E2 period in six units. Conclusions: PSF data suggest that tendon electrical stimulation results in a long-lasting inhibition, most likely through the autogenic inhibitory reflex pathway mediated by group I tendon afferents. Significance: These findings emphasise the importance of using both probability (SEMG, PSTH) and frequency (PSF) based techniques in error free estimation of synaptic potentials. [Copyright &y& Elsevier]

Electric-acoustic stimulation (EAS) was developed for individuals with a profound hearing loss in the high frequencies and a substantial residual low-frequency hearing (LFH). For this group of candidates, conventional hearing aids often neither provided sufficient amplification nor were they considered suitable for cochlear implantation due to the possible destruction of residual hearing capabilities. With EAS, combining electric stimulation with an ipsilateral acoustic stimulation, preservation of residual LFH and the development of a new speech processor uniting both strategies became essential. Over the last years, EAS has developed further and advanced in electrode design and surgery techniques. This paper summarizes the history of EAS and acknowledges the tremendous work of the many research groups who contributed to the success of EAS. Copyright © 2011 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]