Electrode Position Research Articles

Impact of cochlear detailed morphology on insertion results and intracochlear trauma of a slim pre-curved electrode array: a micro-CT study.

This study aimed to evaluate the impact of detailed cochlear dimensions, assessed using micro-CT (µCT) imaging, on insertion outcomes and associated trauma with a new slim, precurved electrode array. Eleven temporal bone specimens underwent implantation of a 22-electrode slim precurved array via the round window. High-resolution µCT scans post-implantation enabled visualization of cochlear structures and electrode positioning. Combination with subsequent scans taken after electrodes removal, we analyzed angular insertion depth (AID), insertion length, number of electrodes inserted, cochlear dimensions (specifically cochlear duct length (CDL), basal turn diameter, scala tympani dimension), and intracochlear trauma of fine structures. Statistical analyses were performed to correlate cochlear detailed dimensions and morphology with insertion outcomes and trauma. The mean AID was 351.82°, and the mean insertion length was 21.07mm. CDL showed positive correlations with AID and insertion length. Basal turn diameter (value B) positively correlated with AID and insertion length, unlike value A. Middle-basal turn (M/B) relationships (angle and height) significantly influenced insertion depth. The cochleae with smaller M/B heights and specific angles were more susceptible to insertion trauma. Larger basal turn diameters correlated with increased trauma and electrode translocation into the scala vestibuli. This study highlights the importance of precise cochlear measurements in predicting and optimizing cochlear implant outcomes. Specific cochlear dimensions and anatomical shapes were identified as critical factors affecting insertion depth, trauma risk, and electrode positioning. Utilizing micro-CT provided detailed insights into cochlear anatomy and insertion outcomes, offering valuable data for advancing cochlear implant technology and surgical practices.

Temperature-triggered liquid metal actuators for fluid manipulation by leveraging phase transition control

ABSTRACT Small-scale pumps for controlling microfluidics have promising applications in drug delivery and chemical assays. Liquid metal (LM) demonstrates excellent flow pumping performance due to its simple structure and the electrocapillary effect under an electric field. However, LM droplets risk escaping from constrained structures, which can lead to pump failure. Temperature regulation is also a critical parameter in optimizing chemical reactions in fluidic systems, however, integrating it into a compact system remains challenging. Here, we develop a temperature-triggered gallium-based actuator (TTGA) by introducing a gallium (Ga) droplet wetted on a copper (Cu) plate as the core element for flow actuation. The Cu plate prevents the Ga droplet from escaping the chamber and significantly increases the flow rate. By leveraging the electrochemical method to inhibit the supercooling effect of Ga, the TTGA enables activation/deactivation for flow actuation at different temperatures. We investigate the impact of electrode position, solution concentration, and applied voltage on TTGA’s pumping efficiency. By dynamically tuning the Ga droplet’s temperature to control phase transition, TTGA allows for accurate flow actuation control. Furthermore, placing Ga and eutectic Ga-indium (EGaIn) droplets in different channels enables the expected flow divergence for fluids with different temperatures. The development of TTGA presents new opportunities in microfluidics and biomedical treatment.

Improving quantitative neuromuscular monitoring: an education initiative on stimulating electrode placement.

Quantitative neuromuscular monitoring reduces the incidence of residual neuromuscular block, but broad acceptance of monitoring has been elusive despite recommendations for quantitative monitoring for decades. Acceptance of quantitative monitoring may, in part, be related to the quality of the data from monitoring systems. This evaluation explored proper stimulating electrode positioning for electromyographic (EMG) monitoring, the impact of an educational intervention on electrode positioning and anesthesia provider (anesthesiologist, resident, anesthetist) confidence in the monitoring data from the device. In a single-center, observations of EMG electrode placement by anesthesia technicians, in 55 adult elective surgery patients were made by an independent observer. Separately, the anesthesia provider satisfaction with EMG derived data was recorded after reversal of neuromuscular block. An educational intervention then occurred on proper electrode positioning, including prior observations of electrode positioning, and prior anesthesia provider satisfaction with the EMG derived data. After the intervention, stimulating electrode position was observed with an additional 60 patients and anesthesia provider satisfaction with the data was again ascertained. The educational intervention significantly increased the proportion of ideal ulnar nerve groove electrode positioning from 74.5% to 95% (P < 0.003) and ideal wrist crease positioning (distal electrode within 2cm of crease) from 61.8% to 96.7% (P < 0.001). Anesthesia provider confidence with EMG derived information during anesthesia delivery, increased from 67 to 90% after the education (P = 0.005). There was a significant relationship between correct stimulating electrode placement and anesthesia provider confidence in the EMG derived data on neuromuscular block status. An educational intervention to improve EMG electrode positioning proved meaningful. It increased anesthesia provider confidence in the EMG derived data during anesthesia case management.

Effect of Electrode Positioning on Electrokinetic Remediation of Contaminated Soft Clay with Surface Electrolyte.

Soft clay contamination is an increasingly global issue with significant implications for land development and human health. Electrokinetic remediation (EKR) has demonstrated significant potential for cleaning contaminated soils. It is crucial to develop efficient processes that minimize environmental impact and reduce costs. A series of citric acid (CA)-enhanced EKR tests were conducted using a novel experimental setup, with the electrolyte positioned above the soil surface, to examine the impact of four different electrode arrangements on the effectiveness of EKR. The position of the electrode end had a significant impact on the migration of ions in the anolyte and catholyte, which in turn affected the volume reduction in the anolyte, the magnitude of the current, and the migration of heavy metals. The electrode arrangement mode c (electrodes suspended in the electrolytes) can enhance the migration of the anolyte and reduce the drainage of the soil, making it an effective measure for improving the removal rate of heavy metals. After the heavy metal remediation is complete, the bearing capacity of the soil should be increased. Changing the electrode arrangement to mode d (anode suspended in the anolyte, a very small part of the cathode inserted into the soil) is an effective measure for reducing the soil water content and improving soil strength.

CONTINUOUS SCORING OF AUTISM SPECTRUM DISORDER PATIENTS BY ANALYZING THEIR EEG SIGNALS

Clinical manifestations and standard psychological tests have been widely used to diagnose autism spectrum disorder (ASD) patients and evaluate their severity level. The gold-standard criterion to diagnose ASD patients is the childhood autism rating scale (CARS), which is a qualitative questionnaire that is filled out through a systematic interview while no physiological test/record is performed to determine this score. To make the diagnosis process quantitative, electroencephalography (EEG) signals have been repeatedly analyzed to differentiate healthy subjects from ASD patients. However, the precise relationship between the abnormal behavior of EEG signals and different ASD severity levels is not well investigated. Here, we use CARS to qualitatively determine the severity level of 14 autistic children, who voluntarily enrolled in our study. We recorded their EEG signals from 19 scalp channels when they were awake in the idle state and elicited three informative features including approximation entropy, multiscale entropy and sample entropy in successive time frames. Among the three measures of entropy, the last one exhibits the highest sensitivity, where its correlation coefficient (CC) exceeds 0.7, on the electrode positions T6 (CC [Formula: see text] 0.74), P4 (CC [Formula: see text] 0.76) and Cz (CC [Formula: see text] 0.75). Results of sample entropy in channels Cz-versus-Pz and P4-versus-FP2 show that a simple K-nearest neighbor classifier can provide 93% classification accuracy among patients with mild, moderate and severe ASD levels. Comparing the proposed method to the conventional ones, we also extracted power spectral density features from the channels but they failed to identify the ASD severity level with an acceptable accuracy.

3D ultrasound guidance for radiofrequency ablation in an anthropomorphic thyroid nodule phantom

BackgroundThe use of two-dimensional (2D) ultrasound for guiding radiofrequency ablation (RFA) of benign thyroid nodules presents limitations, including the inability to monitor the entire treatment volume and operator dependency in electrode positioning. We compared three-dimensional (3D)-guided RFA using a matrix ultrasound transducer with conventional 2D-ultrasound guidance in an anthropomorphic thyroid nodule phantom incorporated additionally with temperature-sensitive albumin.MethodsTwenty-four phantoms with 48 nodules were constructed and ablated by an experienced radiologist using either 2D- or 3D-ultrasound guidance. Postablation T2-weighted magnetic resonance imaging scans were acquired to determine the final ablation temperature distribution in the phantoms. These were used to analyze ablation parameters, such as the nodule ablation percentage. Further, additional procedure parameters, such as dominant/non-dominant hand use, were recorded.ResultsNonsignificant trends towards lower ablated volumes for both within (74.4 ± 9.1% (median ± interquartile range) versus 78.8 ± 11.8%) and outside of the nodule (0.35 ± 0.18 mL versus 0.45 ± 0.46 mL), along with lower variances in performance, were noted for the 3D-guided ablation. For the total ablation percentage, 2D-guided dominant hand ablation performed better than 2D-guided non-dominant hand ablation (81.0% versus 73.2%, p = 0.045), while there was no significant effect in the hand comparison for 3D-guided ablation.Conclusion3D-ultrasound-guided RFA showed no significantly different results compared to 2D guidance, while 3D ultrasound showed a reduced variance in RFA. A significant reduction in operator-ablating hand dependence was observed when using 3D guidance. Further research into the use of 3D ultrasound for RFA is warranted.Relevance statementUsing 3D ultrasound for thyroid nodule RFA could improve the clinical outcome. A platform that creates 3D data could be used for thyroid diagnosis, therapy planning, and navigational tools.Key PointsTwenty-four in-house-developed thyroid nodule phantoms with 48 nodules were constructed.RFA was performed under 2D- or 3D-ultrasound guidance.3D- and 2D ultrasound-guided RFAs showed comparable performance.Real-time dual-plane imaging may offer an improved overview of the ablation zone and aid electrode positioning.Dominant and non-dominant hand 3D-ultrasound-guided RFA outcomes were comparable.Graphical

Targeting Method for rTMS for Treating Depression in Japanese Patients: A Comparison of the Standard, F3, and Neuronavigation Approaches

Introduction: The left dorsolateral prefrontal cortex (lDLPFC) is a commonly targeted brain region for repetitive transcranial magnetic stimulation (rTMS) for depression. The lDLPFC has been identified using the “5-cm rule.” However, identification of the lDLPFC may deviate from the ideal stimulation site localized by neuronavigation. Therefore, we aimed to compare this method with other methods and examine the relationship between deviation from the ideal stimulation site and treatment effects. While most existing studies have focused on participants of European descent, this study focused on Japanese participants. Methods: The study participants were 16 patients who underwent rTMS and had the stimulus location identified using the 5-cm method. The lDLPFC was identified by the F3 electrode position and neuronavigation in addition to the 5-cm rule, and these locations were compared. We then performed a correlation analysis of the distance between the sites identified by the 5-cm method and by neuronavigation, as well as changes in scores on the 17-item Hamilton Depression Scale (HAMD-17). Results: The lDLPFC identified by the F3 site and neuronavigation was approximately 3 cm more anterolateral than that identified by the 5-cm method. A significant correlation was found between the distance between the sites identified by the 5-cm method and neuronavigation and the rate of change in HAMD-17 scores. Conclusion: The ideal stimulation site may be approximately 3 cm anterior to the site identified by the 5-cm method, and stimulation of the F3 site may be a valid alternative to the 5-cm method.

Electrical stimulation improves the efficiency of treating typical reclaimed water in biofilters

ABSTRACT To conduct advanced treatment on reclaimed water with a low C/N ratio and a low content of biodegradable organic matter, this paper established an electrically coupled biological filter system (biofilter-microbial electrolysis cell, BF-MEC). Through two-stage influent, the influence of electrical stimulation and electrochemical structure on the nitrogen and carbon removal of the system was explored, and the following results were obtained. The optimal externally applied voltage for the BF-MEC system is 0.55 V. The optimal structure of the BF-MEC system is an electrode spacing of 100 mm, and the optimal electrode position is when the electrode is located at the bottom of the system. Compared with the BF system, in the first stage, the removal rates of chemical oxygen demand, total ammonia nitrogen (TAN), and total nitrogen (TN) in the optimal structure BF-MEC system are increased by 13.4, 118.1, and 273.65%, respectively. In the second stage, COD, TAN, and TN removal rates are increased by up to 277.98, 115, and 722.98, respectively. The optimal electrode position is when the electrode is located at the lower part of the system. At this time, the microbial community is more abundant, the microbial activity and lifespan are longer, and the system efficiency is optimal. optimal.

Machine learning explains response variability of deep brain stimulation on Parkinson’s disease quality of life

Improving health-related quality of life (QoL) is crucial for managing Parkinson’s disease. However, QoL outcomes after deep brain stimulation (DBS) of the subthalamic nucleus (STN) vary considerably. Current approaches lack integration of demographic, patient-reported, neuroimaging, and neurophysiological data to understand this variability. This study used explainable machine learning to analyze multimodal factors affecting QoL changes, measured by the Parkinson’s Disease Questionnaire (PDQ-39) in 63 patients, and quantified each variable’s contribution. Results showed that preoperative PDQ-39 scores and upper beta band activity (>20 Hz) in the left STN were key predictors of QoL changes. Lower initial QoL burden predicted worsening, while improvement was associated with higher beta activity. Additionally, electrode positions along the superior-inferior axis, especially relative to the z = −7 coordinate in standard space, influenced outcomes, with improved and worsened QoL above and below this marker. This study emphasizes a tailored, data-informed approach to optimize DBS treatment and improve patient QoL.

Attention improvement to transcranial alternating current stimulation at gamma frequency over the right frontoparietal network: a preliminary report.

Applying transcranial alternating current stimulation (tACS) at 40 Hz to the frontal and parietal regions, either unilaterally (left or right) or bilaterally, can improve cognitive dysfunctions. This study aimed to explore the influence of tACS at gamma frequency over right fronto-parietal (FP) region on attention. The analysis is based on retrospective data from a clinical intervention. We administered test of variables of attention (TOVA; visual mode) to 44 participants with various neuropsychiatric diagnoses before and after 12 sessions of tACS treatment. Alternating currents at 2.0 mA were delivered to the electrode positions F4 and P4, following the 10-20 EEG convention, for 20 mins in each session. We observed significant improvement across 3 indices of the TOVA, including reduction of variability in reaction time (p = 0.0002), increase in d-Prime (separability of targets and non-targets; p = 0.0157), and decrease in commission error rate (p = 0.0116). The mean RT and omission error rate largely remained unchanged. Artificial injection of tACS at 40 Hz over right FP network may improve attention function, especially in the domains of consistency in performance, target/non-target discrimination, and inhibitory control.

Improvement in uniformity of co‐linear pulsed electric field treatment chamber by sub‐electrodes and its optimization

AbstractThe uniformity of performance parameters such as electric field and temperature for a co‐linear pulsed electric field (PEF) processing system is one of main factors affecting the processing effect and quality of liquid food. We have proposed a co‐linear PEF treatment chamber configuration with sub‐electrodes to improve the uniformity and processing efficiency. We have first examined how the position of the sub‐electrodes alone affects the uniformity of the performance parameters. Then, we have investigated the variation of the uniformity while changing simultaneously the electrode radius, inter‐electrode gap, and position of sub‐electrodes. As a result, we have found that the most uniform field could be obtained when the electrode radius is 5.5 mm, the inter‐electrode gap is 15 mm, and the sub‐electrodes situate at the middle of the chamber. In this chamber, the region between 95% and 105% of the average electric field covers 83%, which shows much improvement compared to the formers' results, 69.5% and 76%, respectively. Also, the optimal treatment chamber provides greater average electric field under the same voltages as the voltages reported by the formers.Practical applicationsA novel treatment chamber with sub‐electrodes is proposed for pulsed electric fields food processing. The improved treatment design was obtained by changing position of sub‐electrodes, inner radius of electrodes and distance between electrodes. The more uniform electric field was obtained in treatment region. The temperature distribution was more uniformed by increasing flow rates and uniformed electric field strength. The treatment throughput was increased by sub‐electrodes.

Agreement of measurement of body composition with seven alternative electrode positions on the hand compared to the standard protocol with single-frequency 50 khz bioelectrical impedance in healthy young adults

Agreement of measurement of body composition with seven alternative electrode positions on the hand compared to the standard protocol with single-frequency 50 khz bioelectrical impedance in healthy young adults

EEG electrodes and where to find them: automated localization from 3D scans

Objective.The accurate localization of electroencephalography (EEG) electrode positions is crucial for accurate source localization. Recent advancements have proposed alternatives to labor-intensive, manual methods for spatial localization of the electrodes, employing technologies such as 3D scanning and laser scanning. These novel approaches often integrate magnetic resonance imaging (MRI) as part of the pipeline in localizing the electrodes. The limited global availability of MRI data restricts its use as a standard modality in several clinical scenarios. This limitation restricts the use of these advanced methods.Approach.In this paper, we present a novel, versatile approach that utilizes 3D scans to localize EEG electrode positions with high accuracy. Importantly, while our method can be integrated with MRI data if available, it is specifically designed to be highly effective even in the absence of MRI, thus expanding the potential for advanced EEG analysis in various resource-limited settings. Our solution implements a two-tiered approach involving landmark/fiducials localization and electrode localization, creating an end-to-end framework.Main results.The efficacy and robustness of our approach have been validated on an extensive dataset containing over 400 3D scans from 278 subjects. The framework identifies pre-auricular points and achieves correct electrode positioning accuracy in the range of 85.7% to 91.0%. Additionally, our framework includes a validation tool that permits manual adjustments and visual validation if required.Significance.This study represents, to the best of the authors' knowledge, the first validation of such a method on a substantial dataset, thus ensuring the robustness and generalizability of our innovative approach. Our findings focus on developing a solution that facilitates source localization, without the need for MRI, contributing to the critical discussion on balancing cost effectiveness with methodological accuracy to promote wider adoption in both research and clinical settings.

Comparative analysis of electroencephalogram (EEG) data gathered from the frontal region with other brain regions affected by attention deficit hyperactivity disorder (ADHD) through multiresolution analysis and machine learning techniques

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by repeated patterns of hyperactivity, impulsivity, and inattention that limit daily functioning and development. Electroencephalography (EEG) anomalies correspond to changes in brain connection and activity. The authors propose utilizing empirical mode decomposition (EMD) and discrete wavelet transform (DWT) for feature extraction and machine learning (ML) algorithms to categorize ADHD and control subjects. For this study, the authors considered freely accessible ADHD data obtained from the IEEE data site. Studies have demonstrated a range of EEG anomalies in ADHD patients, such as variations in power spectra, coherence patterns, and event-related potentials (ERPs). Some of the studies claimed that the brain’s prefrontal cortex and frontal regions collaborate in intricate networks, and disorders in either of them exacerbate the symptoms of ADHD. , Based on the research that claimed the brain’s prefrontal cortex and frontal regions collaborate in intricate networks, and disorders in either of them exacerbate the symptoms of ADHD, the proposed study examines the optimal position of EEG electrode for identifying ADHD and in addition to monitoring accuracy on frontal/ prefrontal and other regions of brain our study also investigates the position groupings that have the highest effect on accurateness in identification of ADHD. The results demonstrate that the dataset classified with AdaBoost provided values for accuracy, precision, specificity, sensitivity, and F1-score as 1.00, 0.70, 0.70, 0.75, and 0.71, respectively, whereas using random forest (RF) it is 0.98, 0.64, 0.60, 0.81, and 0.71, respectively, in detecting ADHD. After detailed analysis, it is observed that the most accurate results included all electrodes. The authors believe the processes can detect various neurodevelopmental problems in children utilizing EEG signals.

Levodopa / opicapone as a complement to STN-DBS in clinical practice. A retrospective single-centre analysis.

ObjectiveDeep brain stimulation of the subthalamic nucleus (STN-DBS) is a well-established treatment option in Parkinson's disease with motor and non-motor fluctuations allowing for postoperative reduction of dopaminergic medication. However, evidence is scarce on optimal medication adjustments following STN-DBS implantation. Opicapone allows for long-lasting inhibition of the catechol-O-methyltransferase (COMT) thereby enabling more constant dopaminergic stimulation compared to levodopa alone. However, especially COMT inhibitors are regularly discontinued after STN-DBS surgery. In this single-centre retrospective analysis, we aimed to analyse the clinical phenotype of patients selected for opicapone treatment following STN-DBS implantation and to define clinical determinants of patients requiring more intense dopamine-stabilising strategies after STN-DBS implantation. MethodsA patient cohort treated with STN-DBS + levodopa + opicapone (n = 16) was compared to an age-matched control cohort without opicapone treatment at baseline before and ≥ 5 months post-surgery. As main outcomes we assessed the MDS-UPDRS III and IV scores and reduction of the cumulative dopaminergic medication quantified by the levodopa equivalent dosages (LED). ResultsWhilst the MDS-UPDRS III (median [min – max]) in patients with STN-DBS as well as anatomical electrode positions did not differ significantly between the opicapone 20 [4–40] and control cohort 14 [1–44], the patients selected for opicapone treatment showed a significantly higher degree of dyskinesias already preoperatively as reflected by a UPDRS-IV A subscore of 2 [0–4] compared to controls 0 [0–4]. Postoperatively, the opicapone cohort showed stronger motor fluctuations MDS-UPDRS IV 6 [0–14] compared to the controls 0 [0−10], albeit without statistical significance. Moreover, the opicapone cohort showed significantly less reduction of dopaminergic medication (−36.4 % vs. -46.2 % in the control cohort) following STN-DBS implantation independent from the intake of dopamine agonists. ConclusionThese results indicate a clinical phenotype characterised by more motor fluctuations requiring a more stable dopamine replacement therapy to address the patients' disease biology. In these cases, levodopa + COMT inhibition by opicapone represents a therapeutic approach but determination of the potential clinical benefit requires further prospective studies.

Augmented Reality in Extratemporal Lobe Epilepsy Surgery.

Background: Epilepsy surgery for extratemporal lobe epilepsy (ETLE) is challenging, particularly when MRI findings are non-lesional and seizure patterns are complex. Invasive diagnostic techniques are crucial for accurately identifying the epileptogenic zone and its relationship with surrounding functional tissue. Microscope-based augmented reality (AR) support, combined with navigation, may enhance intraoperative orientation, particularly in cases involving subtle or indistinct lesions, thereby improving patient outcomes and safety (e.g., seizure freedom and preservation of neuronal integrity). Therefore, this study was conducted to prove the clinical advantages of microscope-based AR support in ETLE surgery. Methods: We retrospectively analyzed data from ten patients with pharmacoresistant ETLE who underwent invasive diagnostics with depth and/or subdural grid electrodes, followed by resective surgery. AR support was provided via the head-up displays of the operative microscope, with navigation based on automatic intraoperative computed tomography (iCT)-based registration. The surgical plan included the suspected epileptogenic lesion, electrode positions, and relevant surrounding functional structures, all of which were visualized intraoperatively. Results: Six patients reported complete seizure freedom following surgery (ILAE 1), one patient was seizure-free at the 2-year follow-up, and one patient experienced only auras (ILAE 2). Two patients developed transient neurological deficits that resolved shortly after surgery. Conclusions: Microscope-based AR support enhanced intraoperative orientation in all cases, contributing to improved patient outcomes and safety. It was highly valued by experienced surgeons and as a training tool for less experienced practitioners.

Understanding error rejection of differential impedance spectroscopy for the in situ characterization of highly conductive fluids

Abstract Differential impedance spectroscopy (DIS) can offer distinct advantages over conventional impedance spectroscopy (IS), particularly for the in situ characterization of highly conductive, corrosive fluids. To enhance the understanding of DIS and determine the conditions under which this method is preferable over conventional IS with fixed electrode positions, error calculations were performed. Two scenarios were analyzed, one accounting solely for random instrument errors and the other including random errors as well as systematic errors from a serial offset impedance. Our analyses reveal that while permittivity measurements of highly conductive media remain challenging regardless of whether a conventional or differential impedance approach is used, DIS enables highly accurate conductivity measurements across a wide frequency and conductivity range. Studying different cell dimensions with equal cell constants revealed that despite the increased influence of systematic errors at small scales, conductivity can still be accurately measured, underscoring the applicability of DIS for microfluidic applications. Other potential parasitic effects, such as those arising from the electromagnetic skin effect, stray capacitances, electrode size, and temperature gradients, are discussed, providing a comprehensive framework for sample characterization with DIS.

Enhanced network synchronization connectivity following transcranial direct current stimulation (tDCS) in bipolar depression: Effects on EEG oscillations and deep learning-based predictors of clinical remission

AimTo investigate oscillatory networks in bipolar depression, effects of a home-based tDCS treatment protocol, and potential predictors of clinical response. Methods20 participants (14 women) with bipolar disorder, mean age 50.75 ± 10.46 years, in a depressive episode of severe severity (mean Montgomery-Åsberg Rating Scale (MADRS) score 24.60 ± 2.87) received home-based transcranial direct current stimulation (tDCS) treatment for 6 weeks. Clinical remission defined as MADRS score < 10. Resting-state EEG data were acquired at baseline, prior to the start of treatment, and at the end of treatment, using a portable 4-channel EEG device (electrode positions: AF7, AF8, TP9, TP10). EEG band power was extracted for each electrode and phase locking value (PLV) was computed as a functional connectivity measure of phase synchronization. Deep learning was applied to pre-treatment PLV features to examine potential predictors of clinical remission. ResultsFollowing treatment, 11 participants (9 women) attained clinical remission. A significant positive correlation was observed with improvements in depressive symptoms and delta band PLV in frontal and temporoparietal regional channel pairs. An interaction effect in network synchronization was observed in beta band PLV in temporoparietal regions, in which participants who attained clinical remission showed increased synchronization following tDCS treatment, which was decreased in participants who did not achieve clinical remission. Main effects of clinical remission status were observed in several PLV bands: clinical remission following tDCS treatment was associated with increased PLV in frontal and temporal regions and in several frequency bands, including delta, theta, alpha and beta, as compared to participants who did not achieve clinical remission. The highest deep learning prediction accuracy 69.45 % (sensitivity 71.68 %, specificity 66.72 %) was obtained from PLV features combined from theta, beta, and gamma bands. ConclusionstDCS treatment enhances network synchronization, potentially increasing inhibitory control, which underscores improvement in depressive symptoms. Baseline EEG-based measures might aid predicting clinical response.

Microstructural and mechanical characterization of chromium carbide layers obtained on 100Cr6 and X200Cr12 steels by conversion

Carbides and Nitrides of transition metals are widely used due to their interesting properties. Several deposition methods and techniques can be used to produce carbide and nitride coatings. The choice of how to make the deposit depends on several parameters such as, the conditions of use of these deposits, the thickness to be produced, the adhesion between the substrate the deposit, and the cost. In this work, hard coatings of chromium carbide were produced by a conversion treatment on 100Cr6 and X200Cr12 steels. The conversion treatment consists of electrode position of chromium on the surface of 100Cr6 and X200Cr12 steels followed by diffusion annealing treatment at 1000 and 1100 °C for holding times of 1 and 2 hours. The obtained results show that, for all the conversion treatments carried out in this work, there was formation of chromium carbides layer on the surface of steel. However, it should be noted that the nature of the constituting phases of the formed layer depends on the temperature of the diffusion annealing treatment and the duration at this temperature. It should also be noted that the X-ray diffraction analysis has allowed us to show the existence of chromium oxide in addition to chromium carbides. The microhardness profile and the scratch test show that the X200Cr12 steel sample shows better results.These properties are usually obtained by expensive methods such as PVD, CVD, while we can obtain them by easy and inexpensive methods.

Landmark registration in CT for lung model approximation in EIT

Abstract For the visualization of pulmonary ventilation with Electrical Impedance Tomography (EIT), most devices rely on generalized reconstruction models. Yet, fixed thorax dimensions, predetermined electrode locations, and standard lung shapes lead to multiple sources of EIT imaging distortion. The following work compares reconstructions of a library model, a practical model based on landmark fitting, and a detailed model based on manual segmentation. CT images of five pigs were segmented into torso surface, electrode positions, and lung borders. Practical models were created with reduced data, registration, and fitting. Detailed models were created by using the complete segmentation data. After EIT reconstruction and tidal image calculation, the overlap of CT lung segmentation and ventilated voxel was calculated. Compared with the results of a standardized model, the practical model reached an average ventilation/segmentation-overlap difference of an additional 12 %, and the detailed model achieved an average difference of 10 %. In conclusion, the shift of reconstructed impedance towards the segmented lung region is similar in both models when compared to the standard model, while the practical model requires a considerably less amount of information.