Electrodes In Space Research Articles

Intrathecal placement of percutaneous spinal cord stimulation leads: illustrative cases.

Spinal cord stimulation (SCS), including the percutaneous placement of epidural stimulation leads, has been increasingly utilized to treat chronic pain. Although lead migration is a well-characterized complication, few studies have reported on malpositioned leads in the intrathecal space. Here, the authors discuss two cases of intrathecal lead placement necessitating surgical revision. This report is a two-case series on the inadvertent placement of percutaneous SCS leads in the intrathecal space. The authors describe the identification of malpositioned leads, describe the clinical presentation, characterize stimulation parameters, and report improvement following neurosurgical revision for each case. Two patients originally presenting with chronic low-back pain underwent percutaneous SCS lead implantation. Both patients presented with atypical pain symptoms in the acute to subacute postprocedural period, raising suspicion for malpositioned leads. Imaging was consistent with intrathecal malpositioning. Both patients underwent revision surgery resulting in symptomatic improvement. Indicators of malpositioned thoracic SCS leads in the intrathecal space include thoracoabdominal or flank pain exacerbated by movement, insufficient pain relief versus that in the SCS trial, very low electrode impedances, direct visualization on imaging, and lack of epidural lead visualization following laminectomy. Revision options include removal of the intrathecal leads and the surgical placement of a paddle electrode in the epidural space. https://thejns.org/doi/10.3171/CASE24275.

α-MnO2 composite with gold nanoparticles on carbon cloth modified with MOFs-derived porous carbon for flexible and activity-enhanced sodium-ion supercapacitors

Improving the catalytic activity of electrodes in a limited space is crucial to energy storage devices such as supercapacitors. Herein, the surface activity of the flexible electrode (Au-MnO2/CPCN@CC) is enhanced by combining gold particles (AuNPs) modified α-MnO2 with conductive porous carbon nanoflakes (CPCN) derived from the metal-organic framework (MOF) on carbon cloth (CC). The Au-MnO2/CPCN@CC electrode exhibits a higher specific capacity of 503.7 F/g at 0.125 mA/cm2 and retains 87.68% capacity after 10,000 cycles in 1 M Na2SO4, while the structure without AuNPs achieves 242.6 F/g and 61.07% capacity retention after 10,000 cycles. The high stability of Au-MnO2/CPCN@CC stems from the good pseudocapacitance ratio of 83.80% at 1 mV/s compared to 78.43% of MnO2/CPCN@CC and 40.88% of Au/CPCN@CC. The supercapacitor assembled with Au-MnO2/CPCN@CC as the positive electrode and activated carbon (AC) as the negative electrode in 1 M NaPF6 shows an excellent power density of 79.96 W/kg at 71.48 Wh/kg as well as 81.93% capacitance retention after 10,000 cycles. Density-functional theory (DFT) calculations of Au-MnO2/CPCN composite reveal a sodium-ion adsorption energy of 3.744 eV and a large DOS near Fermi level. Hence, Au nanoparticles (AuNPs) and MOFs-derived CPCN lead to enhanced surface electron transport of MnO2 and ultimately superior performance.

EFFICACY AND PHARMACOECONOMICS STUDY OF SPINAL CORD STIMULATION (SCS) CONDUCTED AT THE PAIN THERAPY HUB, SAN GIULIANO HOSPITAL ASL NAPOLI 2

EFFICACY AND PHARMACOECONOMICS STUDY OF SPINAL CORD STIMULATION (SCS) CONDUCTED AT THE PAIN THERAPY HUB, SAN GIULIANO HOSPITAL ASL NAPOLI 2

ID: 216932 High-Frequency Spinal Cord Stimulation Salvages Therapy in Failed Low-Frequency Treatment of Failed Back Surgery Syndrome

Spinal cord stimulator (SCS) is a Federal Drug Administration-approved treatment modality for treating failed back surgery syndrome (FBSS), complex regional pain syndrome (CRPS), and diabetic neuropathy (DN). Patients first must undergo an SCS trial by placing electrodes in the epidural space with a temporary external power source to determine if the patient achieves pain relief. The pulses generated by the SCS create paresthesias to interfere with the pain. If the trial is successful, a permanent SCS is implanted. Despite using paresthesias in low-frequency SCS treatment, many patients find this uncomfortable. To avoid using paresthesias with low frequency, a newer, higher frequency version using a waveform of 10 kHz at a subthreshold level can provide superior pain relief without paresthesias. Additionally, high-frequency SCS may be used to salvage therapy where low-frequency SCS has failed. Here, we present a case where we switched mid-trial from low-frequency to high-frequency SCS with lead placement revision salvaging the trial and improving the patient’s overall pain.

ID: 204152 Single Versus Dual Lead Spinal Cord Stimulation Trials

Spinal cord stimulation (SCS) has been used to treat chronic low back pain (LBP) since it was first proposed by Shealy et al. (1). SCS required placing electrodes in the posterior epidural space near the dorsal columns with electrical stimulation delivered at low-frequency 30-60 Hz (LFSCS) with concordant paresthesia elicited in the areas of pain (2). 10 kHz high-frequency spinal cord stimulation (HF10) was introduced and required no paresthesia mapping and used standardized reproducible epidural lead placement. Several studies have shown the clinical superiority of HF10 over LFSCS, including the two SENZA-RCTs(4,5). Since no paresthesia mapping is needed, we wanted to see if single lead trial would be comparable to standard dual lead trial.

Spinal Cord Stimulation Alleviates Pain Hypersensitivity by Attenuating Neuroinflammation in a Model of Painful Diabetic Neuropathy.

Painful diabetic neuropathy (PDN) is an intractable chronic pain condition affecting a growing number of adults in China. Spinal cord stimulation (SCS) has been employed in the treatment of PDN for several decades. However, the efficacy and underlying mechanisms of SCS are still inconclusive. In this study, we adopted an implantable pulse generator to deliver electrical stimulation (50 Hz, 200 us pulse width, 12 hours/day in 5 weeks) via a quadripolar electrode in the lumbar epidural space to treat pain hypersensitivity in the rat model of PDN. Electronic von Frey and Hargreaves tests were used to measure the responses to mechanical and heat stimuli, respectively. Quantitative PCR, western blotting, and enzyme-linked immunosorbent assay (ELISA) were adopted to explore the changes in neuroinflammation after SCS. SCS alleviated mechanical allodynia and heat hyperalgesia over a period of 3 weeks in diabetic rats. SCS completely suppressed neuropathy-induced Tlr4 and NFκB p65 elevation, resulting in the reduction of pain-promoting Il1β, Il6, and Tnfα proteins in the spinal cord dorsal horn. SCS may alleviate diabetic neuropathy-induced pain hypersensitivity via attenuating neuroinflammation in the spinal cord dorsal horn.

제한된 면적에서 심타식 접지봉의 경제성 및 안전전압 유지성능에 관한 연구

In this paper, in order to design an effective grounding electrode in a confined space, the application of a deep-drilled ground rod together with a mesh grounding electrode is proposed. The CDEGS program was used to calculate the maximum safe current of the earthing electrode for each case, and the performance and economic feasibility of the earthing electrode were compared and analyzed through this data. In addition, ground electrode characteristics according to frequency changes were also compared. As a result of the study, it was confirmed that the role of the vertical earth electrode is very important when designing the earth electrode in a small space, and that the deep-drilled earth rod can effectively reduce the area of the earth grid. However, it was found that the ability to secure the safety voltage of the vertical earth electrode was greatly reduced in the frequency domain.

Considerate motion imagination classification method using deep learning.

In order to improve the classification accuracy of motion imagination, a considerate motion imagination classification method using deep learning is proposed. Specifically, based on a graph structure suitable for electroencephalography as input, the proposed model can accurately represent the distribution of electroencephalography electrodes in non-Euclidean space and fully consider the spatial correlation between electrodes. In addition, the spatial-spectral-temporal multi-dimensional feature information was extracted from the spatial-temporal graph representation and spatial-spectral graph representation transformed from the original electroencephalography signal using the dual branch architecture. Finally, the attention mechanism and global feature aggregation module were designed and combined with graph convolution to adaptively capture the dynamic correlation intensity and effective feature of electroencephalography signals in various dimensions. A series of contrast experiments and ablation experiments on several different public brain-computer interface datasets demonstrated that the excellence of proposed method. It is worth mentioning that, the proposed model is a general framework for the classification of electroencephalography signals, which is suitable for emotion recognition, sleep staging and other fields based on electroencephalography research. Moreover, the model has the potential to be applied in the medical field of motion imagination rehabilitation in real life.

Spinal Cord Stimulation in Chronic Low Back Pain Syndrome: Mechanisms of Modulation, Technical Features and Clinical Application.

Chronic low-back pain (CLBP) is a common disease with several negative consequences on the quality of life, work and activity ability and increased costs to the health-care system. When pharmacological, psychological, physical and occupational therapies or surgery fail to reduce CLBP, patients may be a candidate for Spinal Cord Stimulation (SCS). SCS consists of the transcutaneous or surgical implantation of different types of electrodes in the epidural space; electrodes are then connected to an Implanted Pulse Generator (IPG) that generates stimulating currents. Through spinal and supraspinal mechanisms based on the “gate control theory for pain transmission”, SCS reduces symptoms of CLBP in the almost totality of well-selected patients and its effect lasts up to eight years in around 75% of patients. However, the evidence in favor of SCS still remains weak, mainly due to poor trial methodology and design. This narrative review is mainly addressed to those professionals that may encounter patients with CLBP failing conventional treatments. For this reason, we report the mechanisms of pain relief during SCS, the technical features and some clinical considerations about the application of SCS in patients with CLBP.

A New Surface Technique for Phrenic Nerve Conduction Study.

To report a new patient friendly and convenient technique for phrenic nerve conduction with alternative sites of stimulation and recording. Phrenic nerve conduction was performed in forty volunteers and ten patients of peripheral neuropathy. Active recording electrode was placed in tenth intercostal space 2.5 cm away from para-spinal muscles (mid-scapular line), reference electrode in eighth intercostal space just medial to subcostal margin with ground between stimulating and recording electrode. Stimulation was done at the level of crico-thyroid space near or under the posterior margin of sternocleidomastoid muscle. This new method was compared with existing ones. Data was analysed using SPSS 23 version. Correlation between height, weight, body mass index, age, and chest expansion was done using bi-variate correlation. Mean latency and amplitude of the study method were compared with other methods using MANNOVA test. Total of forty subjects were studied. Thirty-seven were male subjects. Mean age was 28.03 ± 9.63 years, height 168.0 ± 9.60 cm and chest expansion 3.53 ± 0.64 cm. Right sided phrenic nerve mean latency was 5.99 ± 0.629 ms and amplitude 1.088 ± 0.178 mV. Left sided phrenic nerve conductions showed mean latency of 6.02 ± 1.82 ms, amplitude of 1.092 ± 0.2912 mV. These standard deviations were smaller than what were observed with other methods suggesting increased consistency of our results. There was no correlation between phrenic nerve conduction with age, height, gender or chest expansion. This study method gave a better as well as consistent morphology, higher amplitude and required lower amount of current strength. It was superior to previously reported methods in consistency of normative data.

Controllable three-dimensional electrostatic lattices for manipulation of cold polar molecules

Engineering many-body systems of particles in lattices has attracted intense interest in the last few decades, thanks to their promising applications such as in quantum computation or topological matter. While lattices of different dimensions have been demonstrated with magnetic and/or optical fields, little work has been done upon three-dimensional (3D) electrostatic lattices to tame polar molecules. Here, we propose a 3D electrostatic lattice consisting of periodically distributed square-patterned electrodes in space, whose potentials reach tens of millikelvin and can be controlled easily. Detailed analysis and Monte Carlo simulations indicate that ${\mathrm{ND}}_{3}$ molecules in its $|J,KM\ensuremath{\rangle}=|1,\ensuremath{-}1\ensuremath{\rangle}$ state can be effectively trapped and evaporatively cooled. In addition, replacing the electrodes with different patterns enables realizing 3D electric lattices with new topological geometry (e.g., honeycomb or kagome). As a natural extension of the 3D optical and magnetic lattices, the 3D electrostatic lattice offers intriguing perspectives for cold chemistry, quantum simulation, and precision metrology.

Evaluation of NdBaCo2O5+δ oxygen electrode combined with negative expansion material for reversible solid oxide cells

The mismatch of thermal expansion between the oxygen electrodes and the electrolytes is still a critical issue, which leads to the degradation of performance for solid oxide cells (SOCs) or even the damage to cells during the long-term operation. Here, we propose a strategy to achieve complete thermomechanical compatibility between NdBaCo2O5+δ (NBC) electrode and other cell components by introducing NdMnO3-δ (NM), a negative thermal expansion (NTE) oxide. During the thermal cycling process, the negative expansion material alleviates the shear and tensile stresses of the NBC electrode in a three-dimensional space. Whereafter, the “buffer effect” significantly improves the thermal cycling stability of the composite electrode. The results of electrochemical impedance spectroscopy and microstructure observation also confirmed that the significant improvement in thermal stability is mainly related to a better bonding ability between the oxygen electrode and the electrolyte.

423 Efficacy of an Image-Based Programing Plan in Predicting the Final Stimulation Configuration and Directionality for Subthalamic Nucleus Deep Brain Stimulation

INTRODUCTION: Subthalamic nucleus stimulation (STN-DBS) is a well stablished therapy for Parkinson’s disease (PD). Initial programing of the DBS electrodes may take up to 2 hours in order to determine the contact(s) with the best and worse therapeutic response and thresholds for side effects. Furthermore novel directional electrodes have additional contacts that increase complexity and time to the selection. New image processing techniques allows reconstruction and visualisation of the DBS electrode and adjacent structures in a tridimensional space as well as modeling of the volume of tissue activation (VTA) which in turns helps to infer which contact(s) could be best for the stimulation. METHODS: Forty-four electrodes were evaluated; directional contacts were initially reviewed as a ring. The images were processed using two different methods 1) The spatial position and distance of each electrode contact was assessed in a normalized space with respect to the STN, motor portion of the STN (mSTN) and the corticospinal tract (CST) using the open source toolbox Lead-DBS; 2) The relation of the electrode contacts with the STN was visualized using the Boston Scientific GuideTM XT clinical software which is based on automatic anatomical segmentation. Both methods were independently used to select the best (positive) and worst (negative) stimulation contacts and then compared with the final stimulation plan. RESULTS: A chi-square analysis demonstrated a significant association between the IBP and the final therapeutic configuration (p<0.05). The test sensitivity was 95%-97.3%, specificity 85.7%-83.87%, positive predictive value 86.3%-87.8%, negative predictive value 94.7%-96.3%, and accuracy 90.2%-91.2% using the research and clinical methods respectively. In a subsequent analysis the selection of the directional contact(s) was investigated in 5 patients (6 electrodes) using current steering. In 89%-78% of the cases the contact(s) selected based on the IBP was part of the final configuration. CONCLUSION: An Imaged-based programing plan could be used as an initial guide to predict the best electrode configuration in order to reduce the programing time, this may translate in better use of hospital resources, improve the patient comfort and may avoid further adjustments in programing.

A subgaleal electrode array for neurostimulation allows the recording of relevant information in closed loop applications

BackgroundNeurostimulation is an emerging treatment option for patients resistant to pharmacotherapy and ineligible for neurosurgical intervention. Compared to intracranial stimulation placement of electrodes in the subgaleal space offers a minimally invasive option for long-term seizure monitoring for responsive systems. New methodIt was investigated, whether electrode contacts of a device being developed as a stimulation system placed in the subgaleal space are suited for recording of EEG activity for seizure detection. EEG was recorded intraoperatively in four participants participating in a clinical trial during the insertion of the device. Quantitative parameters like electrode impedance, signal amplitude ranges and amplitude spectra were determined. Epileptiform patterns in the recordings were compared to patterns occurring in scalp EEG prior to device implantation. ResultsElectrode impedances, amplitude ranges for artefact free intervals and intervals containing artefacts were determined. Spectral analysis showed typical properties of EEG recordings with high amplitude content at low frequencies and a peak in the alpha band. No major noise except at power line frequency disturbed the recordings. In two patients, typical epileptiform patterns could be identified having similar characteristics as their respective scalp EEG recordings prior to device implantation. Comparison with existing methodsNew and less invasive electrode system compared to existing solutions for responsive neurostimulation. ConclusionsThe subgaleal electrode system allows for high quality EEG recordings even in an hostile unfavorable environment like an operation theatre. For the design of a signal acquisition unit of a responsive system using subgaleal electrodes, specifications could be obtained.

Full-needle geometry: application in a high-voltage corona discharge model with large-scale space

Corona discharge is widely used in many fields, such as drying, temperature control, propulsion, combustion-supporting, etc. In order to solve the problem of the small calculation space of the existing needle electrode discharge model, in the previous work, we proposed a hybrid method based on the combination of hydrodynamic fluid model and ion flow transport equations to study the corona discharge characteristics of the needle electrode in a large-scale space. However, as the voltage increases, the discharge source of the needle electrode changes from a single source (needle tip) to multiple sources (needle tip and needle body). The half-needle geometry used in the hydrodynamic fluid model ignores the needle body, causing the hybrid model to fail to converge under high voltage conditions. Therefore, we propose a full-needle geometry to replace the half-needle geometry in the hydrodynamic fluid model to expand the voltage range of the hybrid model. The calculation results show that the full-needle geometry can converge to the high-voltage hybrid model. The upper limit of the calculated voltage is increased from 20.9 kV to 41 kV, and the research voltage range has been increased by nearly two times. In addition, a needle-ball electrode device was adopted to verify the accuracy of the model. This research not only expands the calculation voltage range of the hybrid model, but also implies the potential of the hybrid model to be used in the multi-source discharge model.

Using the MoBI motion capture system to rapidly and accurately localize EEG electrodes in anatomic space.

During mobile brain/body imaging (MoBI) experiments, electroencephalography and motion capture systems are used in concert to record high temporal resolution neural activity and movement kinematics while participants perform demanding perceptual and cognitive tasks in a naturalistic environment. A typical MoBI setup involves positioning multi‐channel electrode caps based on anatomical fiducials as well as experimenter and participant intuition regarding the scalp midpoint location (i.e., Cz). Researchers often use the “template” electrode locations provided by the manufacturer, however, the “actual” electrode locations can vary based on each participant's head morphology. Accounting for differences in head morphologies could provide more accurate clinical diagnostic information when using MoBI to identify neurological deficits in patients with motor, sensory, or cognitive impairments. Here, we asked whether the existing motion capture system used in a MoBI setup could be easily adapted to improve spatial localization of electrodes across participants without requiring additional or specialized equipment that might impede clinical adoption. Using standard electrode configurations, infrared markers were placed on a subset of electrodes and anatomical fiducials, and the remaining electrode locations were estimated using spherical or ellipsoid models. We identified differences in event‐related potentials between “template” and “actual” electrode locations during a Go/No‐Go task (p < 9.8e–5) and an object‐manipulation task (p < 9.8e–5). Thus, the motion capture system already used in MoBI experiments can be effectively deployed to accurately register and quantify the neural activity. Improving the spatial localization without needing specialized hardware or additional setup time to the workflow has important real‐world implications for translating MoBI to clinical environments.

Spinal cord stimulators and implications for anaesthesia

Spinal cord stimulators and implications for anaesthesia

Casuística do Serviço em Implante de Eletrodos de Estimulação Epidural para Dor Crônica Intratável: 8 casos no Amazonas

Introdução: A estimulação espinal (SCS) vem sendo utilizada no tratamento de pacientes portadores de dor crônica intratável mediantecolocação de eletrodos no espaço epidural posterior da medula. Objetivo: Este estudo objetiva analisar uma série de casos de pacientescom dor crônica intratável submetidos à implantação de eletrodo de estimulação espinal no estado do Amazonas. Métodos: Foramincluídos pacientes com diagnóstico de dor crônica intratável e indicação de implantação de eletrodo de estimulação espinal. Utilizousea Escala Analógica Visual (VAS) para avaliar a dor pré e pós-operatória. Resultados: A amostra deste estudo constituiu-se de 8pacientes. O VAS médio encontrado no pré e pós-operatório foi de 8,4 e 3,8, respectivamente. Não houve óbitos durante e após a cirurgiae 3 complicações foram observadas. Conclusão: A SCS mostrou ser eficaz no tratamento da dor crônica intratável. No entanto, novaspesquisas são fundamentais para a consolidação e expansão dessa modalidade de tratamento.

Математична модель ініціювання розрядного процесу у рідких органічних відходах

In connection with the rapid development of high-voltage pulse technology, the phenomenon of electrical breakdown in a liquid is of increasing interest. Depending on the purpose of the installation, the working chamber can have various sizes and shapes. To process the waste of pig-breeding complexes, we have developed an electropulse installation, the working chamber of which has a cylindrical shape, which allows us to simplify the modeling of processes that will occur during the breakdown of liquid in the chamber. The nature and sequence of the discharge processes of the installation depends on such parameters as the state of the electrodes, their shape of exacerbation, the length of the interelectrode gap, the viscosity of the liquid in the chamber, and the presence of impurities. The use of a high-voltage spark as a “working tool” became the first stage of a complex technological process in which a liquid-insulating working medium. The article gives a generalized scheme of the experimental setup, the questions of mathematical modeling of the optimal operating modes of the electric pulse installation are considered. The features of constructing a mathematical model of the electropulse conversion of energy in liquid are considered. Considerable attention is paid to the process of operation of an electric pulse installation, where the current technological mechanism is pressure pulses that emit in the channel of high voltage discharges in an organic liquid. The effectiveness of the impact of pulses is spatially limited and decreases sharply with increasing distance from the axis of the channel and therefore it must be adjusted during the processing of the liquid. In the calculation mathematical model it is necessary to take into account factors affecting the parameters of the pressure pulse in the liquid and the position of the electrodes in space. The article presents the equations of a linearized mathematical model of the processes that occur in the discharge channel of the working body of the electric pulse installation. Key words: mathematical model, electric pulse installation, liquid organic waste

A dielectric breakdown model for an electrode along an interface between two piezoelectric materials

A plane strain problem for an interface electrically charged thin electrode in a bimaterial piezoelectric space is considered. Remote in-plane mechanical loading and an electrical field parallel to the electrode faces are applied. The known solution of this problem demonstrates the electromechanical field singularities at the electrode tips. To remove these singularities the dielectric breakdown model is applied. Using the presentations of electromechanical quantities via sectional analytic functions the Riemann-Hilbert problem with discontinuous right side is formulated and solved exactly. The dielectric breakdown zone lengths are found from the electric field finiteness at the end points of these zones. It is shown that this length depends on the external electric field and the electrode net charge. The variations of electromechanical characteristics along the electrode and its continuation are presented in graphical form. Particular cases of an uncharged electrode and homogeneous material are considered and compared with previously obtained results. A verification of the obtained solutions by means of the ABAQUS code is carried out and good agreement of analytical and numerical results is revealed.