Oscilloscope Research Articles

Critical care nurses' knowledge and attitudes towards using ventilator waveform monitoring to detect patient-ventilator asynchrony: A cross-sectional online survey.

Patient-ventilator asynchrony (PVA) is a condition that commonly affects patients who are mechanically ventilated. PVA happens when the patient's own breathing effort and the ventilator preset settings are out of sync. Ventilator waveform monitoring is viewed as a difficult undertaking, even for experienced practitioners, despite being a non-invasive and reliable tool for diagnosing PVA. To assess the knowledge levels and attitudes of critical care nurses (CCNs) regarding the use of ventilator waveform monitoring to detect PVA. A cross-sectional online survey was conducted in three intensive care units (ICUs) in Alexandria, Egypt. The questionnaire consisted of four parts to evaluate CCNs' level of knowledge and attitude regarding ventilator waveform monitoring and assess their ability to detect PVA. Of the 137 CCNs approached, 101 CCNs completed the survey, resulting in a 73.7% response rate. Most nurses (88.1%) demonstrated poor knowledge levels and negative attitudes (93.1%) towards using waveform monitoring to detect PVA. A significant relationship was found between nurses' knowledge of ventilator waveform monitoring and their participation in previous training programmes on mechanical ventilation (MV; p = .031). Additionally, nurses' attitudes towards ventilator waveform monitoring were significantly associated with their level of education (p = .002) and attendance in previous courses on waveform analysis (p = .020). A majority of CCNs have poor knowledge and negative attitudes regarding ventilator waveform monitoring. Previous training in MV and attendance courses on ventilator waveform analysis showed a significant correlation between nurses' level of knowledge and attitudes regarding ventilator waveform monitoring. Assessment of CCNs' knowledge and attitudes regarding ventilator waveform monitoring for detecting patient-ventilator asynchrony (PVA) informs the development of future educational programmes, ultimately aiding in the delivery of prompt and high-quality care.

Longitudinal Wave Defect Detection Technology Based on Ablation Mechanism

For laser ultrasound in the thermoelastic mechanism, excitation of ultrasonic body wave signal is weak, it is not easy to realize the detection of deep defects inside the workpiece. While the ablation mechanism produces a high and practical ultrasonic signal-to-noise ratio, this paper is based on the generation mechanism of laser ablation excitation of ultrasonic waves, the establishment of laser ultrasound in the ablation mechanism in the aluminum plate excitation and propagation of ultrasonic numerical model, through the solution, obtained the ultrasonic acoustic field map, discussed the ablation mechanism of the laser ultrasonic body wave acoustic field directionality. Additionally, the preliminary verification of the validity of the model is presented. Then, in order to explore the application potential of high signal-to-noise ratio longitudinal waves in defect detection, defects of different depths are preset in the model for simulation calculations, and waveform and acoustic field analyses are performed on the simulation results to study the ultrasonic propagation paths inside the member and the interaction with the defects, and the transverse position and depth of the internal defects are judged by using B-scan imaging. Finally, experimental validation is carried out. The experimental results are highly consistent with the simulation model, and the defect experiments can qualitatively determine the location of internal defects and verify the practicality and accuracy of the model.

Dual-initiation ruptures in the 2024 Noto earthquake encircling a fault asperity at a swarm edge.

To reveal the connections between the 2024 moment magnitude (Mw) 7.5 Noto earthquake in Japan and the seismicity swarms that preceded it, we investigated its rupture process through near-source waveform analysis and source imaging techniques, combining seismic and geodetic datasets. We found notable complexity in the initial rupture stages. A strong fault asperity, which remained unbroken in preceding seismic swarms, slowed down the rupture. Then, a second rupture initiated at the opposite edge of the asperity, and the asperity succumbed to double-pincer rupture fronts. The failure of this high-stress drop asperity drove the earthquake into a large-scale event. Our observations help unravel the crucial role of fault asperities in controlling swarm migration and rupture propagation and underscore the need for detailed seismological and interdisciplinary studies to assess seismic risk in swarm-prone regions.

Seismic source analysis and directivity of the November 2021 Fin doublet earthquake in southern Iran: challenges and findings

Studying the source characteristics of doublet or multiple earthquake sequences presents significant challenges in seismology, especially with short time intervals between events. On November 14, 2021, a doublet earthquake (Mw 6.0 and Mw 6.1) occurred near Fin city, southern Iran, within a span of less than two minutes and 10 km apart. We employed the Kinematic Waveform Inversion (KIWI) procedure to determine the point and extended source parameters of these events, using a multistep inversion approach for stable solutions. Our analysis highlighted the directivity of the earthquakes: the first event exhibited bilateral directivity, causing a rupture area that reached the surface, while the second event showed unilateral westward directivity, supported by waveform amplitude differences observed at various stations. This directivity analysis plays an essential role in seismic hazard studies. Our findings regarding the source parameters of these recent doublet earthquakes in the Fin region align well with regional geological trends and fault patterns. However, retrieving the main fault plane for the second earthquake was challenging due to the complexities of the waveform. Moment tensor decomposition revealed significant non-double-couple components for the second event, indicating the complexity inherent in analyzing doublet events. This study underscores the critical role of precise waveform analysis and robust inversion techniques in understanding complex seismic events.

The data acquisition system of the LZ dark matter detector: FADR

The Data Acquisition System (DAQ) for the LUX-ZEPLIN (LZ) dark matter detector is described. The signals from 745 PMTs, distributed across three subsystems, are sampled with 100-MHz 32-channel digitizers (DDC-32s). A basic waveform analysis is carried out on the on-board Field Programmable Gate Arrays (FPGAs) to extract information about the observed scintillation and electroluminescence signals. This information is used to determine if the digitized waveforms should be preserved for offline analysis.The system is designed around the Kintex-7 FPGA. In addition to digitizing the PMT signals and providing basic event selection in real time, the flexibility provided by the use of FPGAs allows us to monitor the performance of the detector and the DAQ in parallel to normal data acquisition.The hardware and software/firmware of this FPGA-based Architecture for Data acquisition and Realtime monitoring (FADR) are discussed and performance measurements are described.

Human in vivo baseline intrarenal pressure, peristaltic activity and response to ureteric stenting.

To assess human in vivo intrarenal pressure (IRP) and peristaltic activity at baseline and after ureteric stent placement, using a narrow calibre pressure guidewire placed retrogradely in the renal pelvis. A prospective, multi-institutional study recruiting consenting patients undergoing ureteroscopy was designed with ethical approval. Prior to ureteroscopy, the urinary bladder was emptied and the COMET™ II pressure guidewire (Boston Scientific) was advanced retrogradely via the ureteric orifice to the renal pelvis. Baseline IRPs were recorded for 1-2 min. At procedure completion, following ureteric stent insertion, IRPs were recorded for another 1-2 min. Statistical analysis of mean baseline IRP, peristaltic waveforms and frequency of peristaltic contractions was performed, thereby analysing the influence of patient variables and ureteric stenting. A total of 100 patients were included. Baseline mean (±SD) IRP was 16.76 (6.4) mmHg in the renal pelvis, with maximum peristaltic IRP peaks reaching a mean (SD) of 25.75 (17.9) mmHg. Peristaltic activity generally occurred in a rhythmic, coordinated fashion, with a mean (SD) interval of 5.63 (3.08) s between peaks. On univariate analysis, higher baseline IRP was observed with male sex, preoperative hydronephrosis, and preoperative ureteric stenting. On linear regression, male sex was no longer statistically significant, whilst the latter two variables remained significant (P = 0.004; P < 0.001). The mean (SD) baseline IRP in the non-hydronephrotic, unstented cohort was 14.19 (4.39) mmHg. Age, α-blockers and calcium channel blockers did not significantly influence IRP, and no measured variables influenced peristaltic activity. Immediately after ureteric stent insertion, IRP decreased (mean [SD] 15.18 [5.28] vs 16.76 [6.4] mmHg, P = 0.004), whilst peristaltic activity was maintained. Human in vivo mean (SD) baseline IRP is 14.19 (4.39) mmHg in normal kidneys and increases with both hydronephrosis and preoperative ureteric stenting. Mean (SD) peristaltic peak IRP values of 25.75 (17.9) mmHg are reached in the renal pelvis every 3-7 s and maintained in the early post-stent period.

Peak vertical ground reaction force used to identify sub-groups of individuals with differing biomechanical gait profiles post-anterior cruciate ligament reconstruction.

Lesser peak vertical ground reaction force (vGRF) has been widely reported among individuals with anterior cruciate ligament reconstruction (ACLR). Peak vGRF remains less than uninjured controls and relatively stable during the first year following ACLR. However, it is unknown whether there are subgroups of individuals exhibiting consistently greater peak vGRF in the first 6-months following ACLR and if individuals with consistently greater peak vGRF exhibit kinematic and kinetic gait differences compared to individuals with low vGRF. The purpose of this study was to determine if distinct clusters exist based upon magnitude of peak vGRF 2- and 6-months post-ACLR. Subsequently, we explored between cluster differences in vGRF, knee flexion angle, and sagittal and frontal plane knee kinetics throughout stance between clusters. Forty-three individuals (58.1%female, 21.4 ± 4.4 years-old, 95.3% patellar-tendon autograft) completed five gait trials at their habitual walking speed 2- and 6-months post-ACLR. A single K-means cluster analysis was used to identify clusters of individuals based on peak vGRF at 2- and 6-months post-ACLR. Functional waveform analyses were used to compare gait outcomes between clusters with and without controlling for gait speed and age. We identified two clusters that included a subgroup with high vGRF (n = 16) and low vGRF (n = 27). The cluster with high vGRF demonstrated greater vGRFs, knee flexion angles, and knee extension moments during early stance as compared to the low vGRF cluster 2- and 6-months post-ACLR. Individuals with peak vGRF ≥1.02 times body-weight 2-months post-ACLR had 35.4 times greater odds of being assigned to the high vGRF cluster.

Reliable Stenosis Detection Based on Thrill Waveform Analysis Using Non-Contact Arteriovenous Fistula Imaging.

Hemodialysis therapy is an extracorporeal circulation treatment that serves as a substitute for renal function. In Japan, patients receive this efficient four-hour treatment, three times per week, allowing them to maintain a social life nearly equivalent to that of healthy individuals. Before the treatment, two punctures are performed to establish extracorporeal circulation, and a high blood flow rate is essential to ensure efficient therapy. Specialized blood vessels created through arteriovenous fistula (AVF) surgery are utilized to achieve high blood flow rates. Although the AVF allows safe and efficient dialysis treatment, AVF stenosis leads to a serious problem in dialysis. To early detect this abnormal blood flow, auscultation and palpation methods are widely used in hospitals. However, these methods can only provide qualitative judgment of the AVF condition, so the results cannot be shared among other doctors and staff. Additionally, since the conventional methods require contact with the skin, some issues require consideration regarding infection and low reproducibility. In our previous study, we proposed an alternative method for auscultation using non-contact optical imaging technology. This study aims to construct a reliable AVF stenosis detection method using Thrill waveform analysis based on the developed non-contact device to solve the problem with the contact palpation method. This paper demonstrates the performance validation of the non-contact imaging in the normal AVF group (206 total data, 75 patients, mean age: 69.1 years) and in the treatable stenosis group (107 total data, 17 patients, mean age: 70.1 years). The experimental results of the Mann-Whitney U test showed a significant difference (p=0.0002) between the normal and abnormal groups, which indicated the effectiveness of the proposed method as a new possible alternative to palpation.

Abstract Mo043: Advanced waveform analysis of the electrocardiogram signals using complementary signal processing techniques to investigate the response to a QTc prolonging drug vs control including food effect.

Background: Thorough QT studies using Electrocardiogram data, are a well-established method for testing the pro-arrhythmic propensity of drugs performed during drug development. ECG analysis is currently reduced to simplified biomarkers, such as rate, intervals and amplitudes. However, ECG waveforms are complex and generally sampled with high fidelity 125-1000 Hz. Our novel mathematical method, Symmetric Projection Attractor Reconstruction analyses the morphology and variability of such waveforms, using every data point to generate a new, faithful 2D waveform representation termed an attractor. Moxifloxacin know QT prolonging medicine and has been shown to cause a mean increase of the QTc interval of 10–14 mS after a single dose of 400 mg. Separately, studies have shown that meals can alter QT interval as well as altering the pharmacokinetic profile of moxifloxacin itself with gender and ethnicity impacting individual responses. In-depth knowledge of these physiological factors could support safer medicines development and clinical use. Purpose: This project investigated the feasibility of SPAR analysis of ECG signals to detect drug induced changes which a higher degree of sensitivity, to support safety evaluation during medicines development Methods: High resolution triplicate 12 lead ECG time-series data from a Phase one study of healthy human volunteers cross over of placebo, moxifloxacin or moxifloxacin + food was retrospectively analysed using SPAR at 0,1 and 6 hours. MATLAB bespoke software tool was used to perform SPAR analyses to transform ECG time-series into corresponding attractors. Corresponding single point measurements were previously obtained as part of the original Phase one study. Results: Initial evaluation of attractors revealed high inter-individual variation, consistent with previous SPAR ECG analysis. Nevertheless, we identified changes in subjects receiving Moxifloxacin +/- food vs placebo control. These changes were not as evident in previously obtained QT intervals. Conclusion: This pilot study illustrates that SPAR is highlighting changes on the ECG in fasted and fed states that are less obvious from QT data alone. Further evaluation of the whole dataset to identify generalisable SPAR features, and their comparison with existing markers is now necessary. The individualised nature of ECGs and corresponding attractors indicates the method may have highest utility in personalised medicine.

Stroke Volume and Stroke Volume Variation, but not Cardiac Index Is Associated With Survival of Majorly Burned Patients in Early Burn Shock.

Adequate fluid therapy is crucial to maintain organ function after burn trauma. Major burns lead to a systemic response with fluid loss and cardiac dysfunction. To guide fluid therapy, measurement of cardiac pre- and afterload is helpful. Whereas cardiac function is usually measured after admission to intensive care unit (ICU), in this study, hemodynamic monitoring was performed directly after arrival at hospital. We conducted a prospective cohort study with inclusion of 19 patients (male/female 13/6, 55 ± 18 years, mean total body surface area 36 ± 19%). Arterial waveform analysis (PulsioFlexProAqt®, Getinge) was implemented immediately after admission to hospital to measure cardiac pre- and afterload and to guide resuscitation therapy. Cardiac parameters 3.75 (2.67-6.0) h after trauma were normal regarding cardiac index (3.45 ± 0.82) L/min/m², systemic vascular resistance index (1749 ± 533) dyn sec/cm5 m2, and stroke volume (SV; 80 ± 20) mL. Stroke volume variation (SVV) was increased (21 ± 7) % and associated with mortality (mean SVV survivors vs nonsurvivors 18.92 (±6.37) % vs 27.6 (±5.68) %, P = .017). Stroke volume was associated with mortality at the time of ICU-admission (mean SV survivors vs nonsurvivors 90 (±20) mL vs 50 (±0) mL, P = .004). Changes after volume challenge were significant for SVV (24 ± 9 vs19 ± 8%, P = .01) and SV (68 ± 24 vs 76 ± 26 mL, P = .03). We described association of SVV and SV with survival of severely burned patients in an observational study. This indicates high valence of those parameters in the early postburn period. The use of an autocalibrated device enables a very early monitoring of parameters relevant to burn shock survival.

Comparison of clot waveform analysis with or without adjustment between prothrombin time and activated partial thromboplastin time assays to assess in vitro effects of direct oral anticoagulants

BackgroundClot waveform analysis (CWA) reportedly enhances the interpretation of clotting time measurement. This study aimed to compare CWA between prothrombin time (PT) and activated partial thromboplastin time (APTT) assays for better understanding how to apply CWA for assessing effects of direct oral anticoagulants (DOACs). MethodsSamples were prepared by spiking plasma with rivaroxaban, apixaban, edoxaban, or dabigatran. To compensate the influence of fibrinogen, CWA parameters were adjusted by unifying maximum changes in transmittance in clotting reaction curves detected by the optical system. ResultsNon-adjusted PT-CWA parameters unexpectedly rose at low drug concentrations but declined at high drug concentrations while adjusted PT-CWA parameters exhibited dose-dependent decrease. Both non-adjusted and adjusted APTT-CWA parameters showed dose-dependent decrease. Adjusted CWA parameters were applicable to Hill plot analysis. All DOACs exhibited Hill coefficients indicating positively cooperative effects regarding most adjusted PT-CWA parameters. Regarding adjusted APTT-CWA parameters, rivaroxaban, apixaban, and edoxaban exhibited Hill coefficients indicating no or negatively cooperative effects. The observed differences between PT-CWA and APTT-CWA suggested the implication of thrombin positive feedback in DOAC effects. ConclusionThe results revealed distinct features of DOAC effects in extrinsic and intrinsic pathways. To ascertain the clinical implication, further studies using clinical samples are needed.

Beyond the debut: unpacking six years of Hypotension Prediction Index software in intraoperative hypotension prevention - a systematic review and meta-analysis.

Intraoperative hypotension (IOH) during general anesthesia is associated with higher morbidity and mortality, although randomized trials have not established a causal relation. Historically, our approach to IOH has been reactive. The Hypotension Prediction Index (HPI) is a machine learning software that predicts hypotension minutes in advance. This systematic review and meta-analysis explores whether using HPI alongside a personalized treatment protocol decreases intraoperative hypotension. A systematic search was performed in Pubmed and Scopus to retrieve articles published from January 2018 to February 2024 regarding the impact of the HPI software on reducing IOH in adult patients undergoing non-cardio/thoracic surgery. Excluded were case series, case reports, meta-analyses, systematic reviews, and studies using non-invasive arterial waveform analysis. The risk of bias was assessed by the Cochrane risk-of-bias tool (RoB 2) and the Risk Of Bias In Non-randomised Studies (ROBINS-I). A meta-analysis was undertaken solely for outcomes where sufficient data were available from the included studies. 9 RCTs and 5 cohort studies were retrieved. The overall median differences between the HPI-guided and the control groups were - 0.21 (95% CI:-0.33, -0.09) - p < 0.001 for the Time-Weighted Average (TWA) of Mean Arterial Pressure (MAP) < 65mmHg, -3.71 (95% CI= -6.67, -0.74)-p = 0.014 for the incidence of hypotensive episodes per patient, and - 10.11 (95% CI= -15.82, -4.40)-p = 0.001 for the duration of hypotension. Notably a large amount of heterogeneity was detected among the studies. While the combination of HPI software with personalized treatment protocols may prevent intraoperative hypotension (IOH), the large heterogeneity among the studies and the lack of reliable data on its clinical significance necessitate further investigation.

Study on the Anti-Interference Performance of Substrate-Free PEDOT:PSS ECG Electrodes

Substrate-free electrodes are promising dry electrodes for long-term physiological electrical signal monitoring due to their ultra-thinness, conformal contact, and stable skin–electrode impedance. However, the response of substrate-free electrodes to various disturbances during electrocardiogram (ECG) monitoring and the corresponding optimization needs to be investigated. This paper investigates the specific effects of various influencing factors on skin–electrode impedance and ECG during electrocardiogram (ECG) detection. The research utilizes substrate-free poly(3,4-ethylenedioxythiophene)/poly(styrene-sulfonate) (PEDOT:PSS) electrodes. The investigation employs several methods, including skin–electrode impedance comparison, ECG waveform analysis, spectrum analysis, and signal-to-noise ratio (SNR) evaluation. To avoid the impact of physiological state differences in subjects at different times, relevant data were only compared with the same group of experiments conducted in the same period. The results demonstrate that the substrate-free conformal contact PEDOT:PSS electrode has more stable skin–electrode impedance and could obtain a more stable ECG than partial contact electrodes (the SNR of the partial contact and conformal contact electrodes are 1.2768 ± 4.0299 dB and 7.2637 ± 1.4897 dB, respectively). Furthermore, the ECG signal quality of the substrate-free conformal contact PEDOT:PSS electrode was independent of the electrode area and shape (the SNRs of the large, medium, and small electrodes are 4.0447 ± 0.4616 dB, 3.9115 ± 0.5885 dB, and 4.1556 ± 0.5557 dB, respectively; the SNRs of the circular, square, and triangular electrodes are 9.2649 ± 0.6326 dB, 9.2471 ± 0.6806 dB, and 9.1514 ± 0.6875 dB, respectively), showing high signal acquisition capability that is the same as microneedle electrodes and better than fabric electrodes. The results of clothing friction effects show that skin–electrode impedance stability was important for ECG stability, while the impedance value was not (the SNRs of friction and non-friction electrodes are 2.4128 ± 7.0784 dB and 9.2164 ± 0.6696 dB, respectively). Moreover, the skin–electrode impedance maintains stability even at a high breathing frequency, but the ECG signal fluctuates at a high breathing frequency. This experiment demonstrates that even when the skin–electrode impedance remains stable, the ECG signal can still be susceptible to interference from other factors. This study suggests that substrate-free PEDOT:PSS that could form conformal contact with the skin has higher skin–electrode impedance stability and could measure a high ECG signal even with a small electrode area, demonstrating its potential as dry ECG electrodes, but the interference from other physiological electrical signals may require better circuit design.

Model-less multi-input analysis of pulmonary blood flow using deep learning convolution

The study investigates two categories of perfusion-based pulmonary blood flow analysis: model-based and model-less methods. The model-based approach yields plausible results, but requires strict parameter settings and presents challenges in handling. On the other hand, the model-less approach is simpler but limited to a single input analysis, necessitating an inverse problem to estimate the impulse response from input–output relationships. To overcome these limitations, this article proposes a model-less method that combines simplicity and accuracy, enabling multi-input system analysis and aiming for standardized analysis. They leverage deep learning convolution to directly estimate the impulse response, allowing for multi-input analysis. Comparative experiments demonstrate that the proposed method is easy to implement and exhibits a low estimation error within the measured signal-to-noise ratio (SNR) range, even though it is sensitive to noise. Furthermore, the proposed method is evaluated through waveform analysis, specifically Delay and Dispersion in Experiment 1, where it is compared with conventional methods. In Experiment 2, blood flow analysis is performed on a patient with a defect in the left pulmonary artery. The results indicate high convergence, independence from input waveforms, and effective analysis of cases with vascular stenosis. Moreover, the method enables multi-input system analysis, consistently yielding results consistent with medical findings, even for patients with left pulmonary artery defects.

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In this article, we investigated the solitary wave solutions of the KdV–mKdV equation using Hirota’s bilinear method. Closed-form analytical single and multiple solitary wave solutions were obtained. Through qualitative methods and the analysis of solitary waveforms, we discovered that in addition to sech-type solitary waves, the system also contains Sech2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{Sech}^{2}$$\\end{document}-type solitary waves. By employing the trial functions method, we obtained a single Sech2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{Sech}^{2}$$\\end{document}-type solitary wave and verified its existence and stability using the split-Step Fourier Transform method. Furthermore, we use the collision of two Sech2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{Sech}^{2}$$\\end{document}-type single solitary waves to excite a stable Sech2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{Sech}^{2}$$\\end{document}-type double solitary wave. Similarly, we excite a stable triple solitary wave with three Sech2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{Sech}^{2}$$\\end{document}-type single solitary waves. This method can also be used to excite stable multiple solitary waves. It is shown that these solitary wave solutions enrich the dynamic behavior of the KdV–mKdV equation and provide methods for solving Sech2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ ext{Sech}^{2}$$\\end{document}-type solitary waves, which hold significant theoretical value.

Improvement of linearity in trap-rich substrates for radio frequency applications: Which of donor and acceptor trap is the best?

This paper investigates the effect of volume traps intentionally introduced into a silicon-on-insulator (SOI) substrate by inserting a layer of polysilicon beneath buried oxide. In radio frequency applications, this type of substrate, referred to as trap-rich, is known to considerably reduce the generation of harmonics resulting from the parasitic non-linear charge dynamics introduced by the substrate handler under the buried oxide. This analysis focuses on a test vehicle in the form of an integrated coplanar waveguide on two types of substrates, namely, high-resistivity SOI substrates with and without a trap-rich layer. From a modeling point of view, a simulation methodology is implemented in order to convert the 3D simulation of the coplanar waveguide into a 2D treatment that takes into account the wave propagation effect associated with the distributed nature of the transmission line. As a first step, this modeling strategy is implemented to reproduce the effect of increasing substrate resistivity on 2nd and 3rd harmonic reductions, leading to an excellent agreement with experimental data. Building on this validation of the simulation method, we have opted to simulate the non-linear response of the transmission line on the SOI trap-rich substrate by simplifying the trap distribution model. To avoid the adoption of unverified and strongly process-dependent trap distributions across the bandgap, a midgap monovalent trap density has been introduced, either acceptor or donor density. A monovalent density of acceptor traps with a concentration of 1016 cm−3 and a carrier lifetime of 0.1 ns has been shown to reproduce the experimental data very accurately with a substantial reduction in 2nd and 3rd harmonics. A detailed analysis of the displacement current waveforms explains the beneficial role of acceptor traps compared with donor traps.

Evaluation of renal resistive index and new biomarkers in post-hepatitis C cirrhosis patients for developing kidney injury

Background In liver cirrhosis, hemodynamic changes in splanchnic and systemic circulations are involved. Indeed, no established laboratory markers for altered renal hemodynamics in cirrhosis were implicated. The duplex Doppler waveform analysis of intrarenal arteriolar vessels is considered a noninvasive estimate of renovascular impedance and renal arterial vasoconstriction. In particular, the renal resistive index (RRI) is considered as the best reliable indicator of renal blood flow in patients with different diseases. The study aimed to evaluate RRI, serum and urinary cystatin C, beta-trace protein, liver fatty acid protein, and kidney injury molecule-I as noninvasive indicators of altered renal hemodynamics in patients with cirrhosis with normal urea and creatinine. Patients and methods A case–control study included 60 patients with post-hepatitis C virus (HCV) cirrhosis and 40 healthy controls. Serum and urinary biomarkers were measured. Renal color Doppler duplex was used to evaluate RRI. Results Mean serum and urinary biomarkers in HCV patients were significantly higher than controls. Moreover, the RRI was higher in patients than in controls with P value less than 0.001. Rising levels of urea, high direct bilirubin, and hypoprothrombinemia with high serum kidney injury molecule 1 and RRI were significant independent predictors for subsequent kidney injury. Conclusion Urinary kidney injury molecule 1 is a reliable, sensitive, and specific biomarker for the prediction of kidney injury among HCV cirrhotic patients with an obvious superior test performance and specificity to e other biomarkers. An increase in serum kidney injury molecule 1 and RRI were associated with poor prognosis.

Central venous pressure waveform analysis during sleep/rest: a novel approach to enhance intensive care unit post-extubation monitoring of extubation failure.

This pilot study aimed to investigate the relation between cardio-respiratory parameters derived from Central Venous Pressure (CVP) waveform and Extubation Failure (EF) in mechanically ventilated ICU patients during post-extubation period. This study also proposes a new methodology for analysing these parameters during rest/sleep periods to try to improve the identification of EF. We conducted a prospective observational study, computing CVP-derived parameters including breathing effort, spectral analyses, and entropy in twenty critically ill patients post-extubation. The Dynamic Warping Index (DWi) was calculated from the respiratory component extracted from the CVP signal to identify rest/sleep states. The obtained parameters from EF patients and patients without EF were compared both during arbitrary periods and during reduced DWi (rest/sleep). We have analysed data from twenty patients of which nine experienced EF. Our findings may suggest significantly increased respiratory effort in EF patients compared to those successfully extubated. Our study also suggests the occurrence of significant change in the frequency dispersion of the cardiac signal component. We also identified a possible improvement in the differentiation between the two groups of patients when assessed during rest/sleep states. Although with caveats regarding the sample size, the results of this pilot study may suggest that CVP-derived cardio-respiratory parameters are valuable for monitoring respiratory failure during post-extubation, which could aid in managing non-invasive interventions and possibly reduce the incidence of EF. Our findings also indicate the possible importance of considering sleep/rest state when assessing cardio-respiratory parameters, which could enhance respiratory failure detection/monitoring.

A Study on the Operation Characteristics of Arc Fault Detection Device under Arc Generation

According to the National Fire Agency's statistics in South Korea, the number of fires caused by electrical factors is increasing every year. Residual current devices and molded case circuit breakers are used to prevent electrical fires, but it is difficult to prevent electrical fires caused by arc generation. To prevent electrical fires caused by arc generation, studies on arc fault detection devices (AFDDs) and product development for commercial purposes are being conducted. However, the performance of AFDDs under real-life conditions has not been sufficiently verified. In this study, we conducted experiments on three types of AFDDs to verify their performance when a series arc is generated. Moreover, we performed arc waveform measurement and analysis. For the series arc test, we used a series arc generator based on the KS C IEC 62606 standard. We conducted arc-breaking experiments of the AFDDs with resistive and inductive loads and performed waveform measurement and analysis of the arc voltage and current.

Evaluating Factor VIII Concentrates Using Clot Waveform Analysis.

Background/Objectives: FVIII reagent activity varies across different assays, as well as activated partial thromboplastin time (APTT) reagents. The hemostatic ability of various FVIII reagents was examined via clot waveform analysis (CWA). Methods: APTT was measured using 12 APTT reagents, a small amount of tissue factor-induced FIX activation (sTF/FIXa) and a small amount of thrombin time (sTT) in order to examine 10 FVIII reagents and reference plasma (RP) using CWA. FVIII activity was measured using CWA-APTT, a chromogenic assay, or CWA-sTT. Results: Although the peak time (PT) and peak height (PH) of the CWA-APTT were markedly different in different FVIII reagents using several APTT reagents, the PTs of CWA-APTT were generally normal or shortened and the PHs of CWA-APTT were generally lower than those of RP. The FVIII activity varied, as evaluated using APTT, and was higher when using the CWA-sTT method than the APTT or chromogenic methods. CWA-sTT showed an elevated second peak of first DPH in all FVIII reagents, and both CWA-sTF/FIXa and CWA-sTT were enhanced using APTT reagents. Conclusions: Our evaluation of the hemostatic ability of FVIII reagents varied among APTT reagents. CWA-sTT can be used to further evaluate the hemostatic ability of an FVIII concentrate based on thrombin burst.