Impending Failure Research Articles

Brief communication: Monitoring impending slope failure with very high-resolution spaceborne synthetic aperture radar

Abstract. We demonstrate how high spatial and temporal resolution spaceborne synthetic aperture radar (SAR) imagery can improve slope deformation monitoring. We process ICEYE data over the Brienz/Brinzauls slope instability in the Swiss Alps, where a catastrophic failure occurred on 15 June 2023. Image correlation applied to retrieve surface velocities shows results comparable to in situ measurements. Pre- and post-failure acquisitions used to map areas invaded by debris and to compute associated volumetric changes are in good agreement with photogrammetric data. This study sets the baseline for new-generation satellite SAR data aimed at providing timely information in landslide early warning scenarios.

Clinical value of multiple sensors contributing to a composite heart failure ICD monitoring index

Abstract Background The HeartLogic algorithm integrates data from various implantable defibrillator (ICD) sensors to predict impending heart failure (HF) decompensation. The algorithm computes worsening in its sensors and weighs them based on a risk level. These sensors include accelerometer-based first (S1) and third (S3) heart sounds, intrathoracic impedance (TI), respiration rate (RR), the ratio of respiration rate to tidal volume (RSBI), and night heart rate (NHR). Objective This study assessed the relative worsening of ICD sensors at the onset of HeartLogic alerts, their association with patient characteristics and subsequent outcomes. Methods The HeartLogic feature was activated in 568 ICD patients (410 with CRT-D) across 26 centers, with a median follow-up of 26 months [25th–75th percentile: 16–37]. Results During the follow-up, 1200 HeartLogic alerts were recorded in 370 patients. The sensor with the highest worsening (SHW) at the alert onset was S3 (27% of alerts), followed by S3/S1 (25%), TI (16%), RR (15%), and NHR (11%), RSBI (6%). Patients with atrial fibrillation (AF) at implantation and those with chronic kidney disease (CKD) had higher alert prevalence (AF 84% vs. no-AF 58%, CKD 72% vs. no-CKD 59%; both p <0.05) and higher alert rates (AF 1.51/patient-year vs. no-AF 0.88/patient-year, CKD 1.30/patient-year vs. no-CKD 0.89/patient-year; both p <0.05). AF patients had alerts with every sensor as SHW, while CKD patients had alerts primarily with TI, RR, and RSBI as SHW (Figure). In 85% of cases among 247 patients with >1 alert, the SHW changed between successive alerts. Of the 88 (7%) alerts resulting in HF hospitalizations or deaths, a greater proportion featured RR or RSBI (11%) and NHR (11%) as SHW, followed by heart sounds (5%) (both p <0.05). Clinical events were more common with the first alert (12.6%) than subsequent alerts (5.2%, p <0.001). Conclusion HeartLogic alerts are predominantly associated with the highest worsening in heart sounds. Nevertheless, recurrent alerts often involve other sensors, suggesting varied HF progression mechanisms and potential divergent outcomes. The frequency of alerts and the pattern of worsening in ICD sensors are linked to patient characteristics.

Respiratory failure and rhabdomyolysis caused by severe hypokalemia in a young female with hypertension: a rare critical condition in primary aldosteronism

BackgroundThe two classic manifestations of primary aldosteronism are hypertension and hypokalemia. However, acute respiratory failure due to hypokalemia in primary hyperaldosteronism is rare.Case presentationThe patient was a 27-year-old female who presented with drowsiness and weakness in all extremities. She had been diagnosed with hypertension three years prior, with irregular follow-up, and had a history of preeclampsia one year later. She exhibited high blood pressure and severe hypokalemia (2 mEq/L), leading to respiratory depression and impending respiratory arrest. Consequently, the patient was intubated and transferred to the intensive care unit (ICU). She also developed rhabdomyolysis. Blood pressure tests, including hormonal tests (aldosterone: 13.2 ng/dL, plasma renin activity: 0.32 ng/mL/h), were conducted. Due to the high aldosterone-renin ratio, an abdominopelvic computed tomography (CT) scan was performed. The CT scan revealed a 14 × 12 mm round mass with a washout value above 60%, consistent with an adrenal adenoma, leading to a diagnosis of primary aldosteronism. The patient was discharged after stabilization, and one and a half months after ICU admission, a laparoscopic left adrenalectomy was successfully performed without post-operative complications. Histopathology showed encapsulated hypertrophy of the adrenal cortex with a predominance of large clear cells, confirming the diagnosis of adrenal adenoma. At the most recent follow-up, the patient had normal potassium levels, was normotensive without any medications, and exhibited no alarming signs or symptoms.ConclusionRespiratory depression to the extent of impending respiratory failure and rhabdomyolysis as a result of hypokalemia in primary aldosteronism are extremely rare. In this patient, who developed respiratory depression due to resistant hypokalemia, timely investigation of secondary causes and diagnosis of adrenal adenoma were crucial. The surgery provided definitive treatment for the patient’s blood pressure and prevented the recurrence of life-threatening complications.

Analysis of signals from air conditioner compressors with ordinal patterns and machine learning

Most machines are equipped with devices that monitor their operation. Air conditioners, in particular, are routinely monitored through various measurements. A desirable outcome of this monitoring is identifying when the device will likely require maintenance. In this study, we present the use of Ordinal Patterns, a symbolic transformation of time series, which allows for the visual assessment of the type of operation. Ordinal Patterns are chosen because they can transform intricate time series into simple and intuitive symbolic representations. The technique is visually appealing, generating points on a plane whose positions reveal hidden dynamics. This approach makes it easier to identify recurring or abnormal patterns in machine operations that may indicate wear or impending failure. Additionally, Ordinal Patterns allow for precise and understandable visualization of operational data, making interpreting results more accessible for professionals who may not be experts in data analysis. We compare two machines under different operational conditions with six measured variables. We analyze the expressiveness of the Ordinal Patterns and identify those variables that best differentiate the two machines. Furthermore, we incorporate machine learning algorithms, such as Artificial Neural Networks, Support Vector Machines, and Decision Trees, to evaluate and validate the effectiveness of Ordinal Patterns as discriminative features. Integrating machine learning methods with a symbolic transformation offers a robust approach for the early and accurate diagnosis of potential failures, enhancing the predictive maintenance of air conditioning equipment.

12618 A Rare Case Of Diabetic Ketoacidosis Leading To Severe Hypertriglyceridemia-induced Necrotizing Pancreatitis

Abstract Disclosure: E.R. Perez Roman: None. D.A. Lopez Rodriguez: None. K. Ramirez Gorbea: None. M. Sanchez Cordero: None. Y. Garcia Cruz: None. Acute pancreatitis is an acute inflammatory process of the pancreas that if left untreated can become complicated resulting in multiple organ damage and a fatal outcome in approximately 10%-40% of patients. There are well-known causes that can lead to pancreatitis such as alcohol, hereditary disorders, cholelithiasis, prior pancreatitis, and medications. Less frequently, it can be related to poorly controlled diabetes mellitus and diabetic ketoacidosis (DKA), given that in a state of low or deprived insulin, there is a breakdown of triglycerides into toxic fatty acids by pancreatic lipases; this lipotoxicity can result in the development of acute pancreatitis. We present a case of a 50-year-old woman with a past medical history of untreated hyperlipidemia and previous pancreatitis who was transferred to our institution with acute epigastric pain radiating to the back, nausea, and persistent vomiting. Upon arrival, blood glucose was 299 mg/dL, HbgA1c of 11.4%, lactic acid of 3.6 mmol/L, hypocalcemia of 6.0 mg/dl, hypoalbuminemia, and elevated pancreatic enzymes, amylase 869 U/L and lipase 2,493 U/L. The lipid panel was remarkable for total cholesterol of 1,085 mg/dL and triglycerides of 4,369mg/dL. Abdominopelvic CT scan confirmed acute pancreatitis with extensive peripancreatic and regional mesenteric edema. This patient was treated with aggressive IV fluid resuscitation and treated for DKA as per protocol. Despite prompt treatment, the patient rapidly deteriorated, developing pulmonary effusions and impending respiratory failure requiring mechanical ventilation. Her hyperglycemia was challenging to control and in the setting of severe hypertriglyceridemia, insulin requirements were higher, as intravenous insulin is useful in patients with concomitant findings, in the absence of plasmapheresis availability. Despite the marked reduction of triglyceride to 978 mg/dL and a decrease in pancreatic enzymes, multiorgan failure developed. Unfortunately, the patient died. Repeated abdominopelvic CT imaging revealed the progression of the disease to necrotizing pancreatitis involving the pancreatic head, uncinate process, and neck of the pancreas with evidence of a small hypodense lesion at the level of the tail of the pancreas. This case emphasizes the importance of prompt recognition of acute pancreatitis secondary to uncontrolled hyperglycemia with concomitant severe hypertriglyceridemia since it can lead to a worse clinical outcome as seen in our patient who developed rapid progression to necrotizing pancreatitis. It is paramount not to delay treatment with aggressive fluid resuscitation, continuous insulin infusion, and if available, plasmapheresis; as these treatment strategies in conjunction can be life-saving. Presentation: 6/3/2024

Mechanical properties and acoustic emission characteristics of basalt fiber reinforced cemented silty sand subjected to freeze–thaw cycles

Freeze–thaw (F–T) cycling poses a significant challenge in seasonally frozen zones, notably affecting the mechanical properties of soil, which is a critical consideration in subgrade engineering. Consequently, a series of unconfined compressive strength tests were conducted to evaluate the influence of various factors, including fiber content, fiber length, curing time, and F–T cycles on the unconfined compression strength (UCS) of fiber-reinforced cemented silty sand. In parallel, acoustic emission (AE) testing was conducted to assess the AE characteristic parameters (e.g., cumulative ring count, cumulative energy, energy, amplitude, RA, and AF) of the same material under F–T cycles, elucidating the progression of F–T-induced damage. The findings indicated that UCS initially increased and then declined as fiber content increased, with the optimal fiber content identified at 0.2%. UCS increased with prolonged curing time, while increases in fiber length and F–T cycles led to a reduction in UCS, which then stabilized after 6 to 10 cycles. Stable F–T cycles resulted in a strength loss of approximately 30% in fiber-reinforced cemented silty sand. Furthermore, AE characteristic parameters strongly correlated with the stages of damage. F–T damage was segmented into three stages using cumulative ring count and cumulative energy. An increase in cumulative ring count to 0.02 × 104 times and cumulative energy to 0.03 × 104 mv·μs marked the emergence of critical failure points. A sudden shift in AE amplitude indicated a transition in the damage stage, with an amplitude of 67 dB after 6 F–T cycles serving as an early warning of impending failure.

Deep‐Learning Analysis of Fracture Networks Leading to System‐Size Failure in Rocks

AbstractFracture networks in rocks and other geomaterials form by seismic and aseismic damage processes that could lead to system‐size failure. Here, we use a multi‐view convolutional neural network model to predict the stress proximity to macroscopic failure of experimentally deformed rock samples using two‐dimensional images. Models are trained on time series of fractures observed in rock samples through dynamic in situ synchrotron X‐ray tomography experiments. The results demonstrate that deep learning models outperform traditional estimates based on fracture density, increasing the accuracy of the predictions. Furthermore, the models provide insights into fundamental characteristics of fracture patterns that may provide precursory information on impending material failure. The trained deep learning models estimate the angle of the fracture plane relative to the principal loading direction, which is a key factor contributing to shear failure. The predicted angle of the fracture plane, in the range of 10°–30° with respect to the direction of maximum compressive stress, is consistent with the established failure criteria used in rock mechanics.

Progression of Femoral Osteolytic Metastases after Intramedullary Nailing and Subsequent Salvage Techniques.

Intramedullary nailing insertion from the proximal-to-distal femur is frequently performed for impending and complete pathological femur fractures due to osteolytic metastases. After nailing through cancer-laden bone, residual chemotherapy- and/or radiation-resistant tumor may progress. Progression of osteolysis risks future nail failure or pathological fractures. This study assesses the incidence of cancer progression following intramedullary nailing in a femur-only cohort and describes a percutaneous rod-retaining salvage technique. A single-institution, retrospective study was conducted to identify adult patients who underwent intramedullary nailing for femoral osteolytic lesions for complete or impending nail failure from 2016 to 2023. Progression was defined as enlargement of the pre-existing lesion and/or appearance of new lesions on radiographs. Surgical outcomes were assessed with a combined pain and functional score. A total of 113 patients (median age 66.8 years (IQR = 16.4); median follow-up 6.0 months (IQR = 14.5)) underwent intramedullary nailing. Sixteen patients (14.2%) exhibited post-nailing cancer progression. Pre- and postoperative radiation and chemotherapy did not decrease the odds of cancer progression. Three patients underwent initial open surgical salvage consisting of proximal femur replacement arthroplasty, and six patients did not receive salvage due to poor surgical candidacy or patient choice. Seven patients (median follow-up 10.7 months (IQR = 12.9)) received percutaneous salvage. In this group, pain and functional scores improved by 4.0 points (p = 0.0078) at two-week postoperative follow-up and 2.0 points (p = 0.0312) at the most recent follow-up (mean follow-up 13.0 ± 9.4 months). All three nonambulatory patients became ambulatory, and six patients were able to ambulate independently without walking aids. No major complications were reported 30 days postoperatively. Progression of femoral osteolytic metastases may occur following intramedullary nailing. Continued monitoring of the entire femur is needed to maintain improved functional status and to prevent catastrophic progression of pre-existing lesions or appearance of new lesions. In patients with more proximal metastases only, the customary practice of bringing a long nail from the proximal femur to distal metaphysis should be reconsidered. Furthermore, there is concern of mechanical transport of cancer cells during guide wire insertion, reaming, and rod insertion through cancer laden bone to cancer free distal bone.

Thin-Film Embedded Sensors for Battery Health Monitoring

Hybrid or all-electric aircraft are being developed as the next generation of aircraft to both allow new forms of aviation and decrease environmental impact. Since these types of aircraft are based on high-capacity battery technology, safe operation of these batteries becomes increasingly important. In particular, the potential for battery failure due to uncontrolled chemical reactions resulting in thermal runaway, catastrophic failure, and battery fires must be addressed in order for such battery technology to have the level of safety needed for standard aviation implementation. Efforts to ensure battery safety often involve engineering solutions that seek to contain rather than prevent such events by early detection. Such approaches increase the system weight and decrease the power per unit mass provided by the battery system. Existing methods for measuring battery parameters to determine the battery state-of-health are limited. These methods include electrical measurements of the cell current and/or voltage output as well as temperature measurements taken externally on the cell surface. Such external temperature measurements are limited in their ability to provide early warning of impending battery failure. In response, an effort to develop sensors operating internal to battery for health monitoring has been ongoing in the NASA Sensor-based Prognostics to Avoid Runaway Reactions & Catastrophic Ignition (SPARRCI) project [1]. The basic approach associated with this sensor work is the deposition of thin film sensors on the battery separator located between the anode and cathode of the battery. These thin film sensors are then monitored to determine changes in battery parameters and health. Microfabrication techniques are employed to minimize the overall impact of the sensors on battery operation through the implementation of sensors with minimal size, weight, and power consumption. The thickness of the films, which are fabricated through physical vapor deposition (sputtering), are on the order of thousands of angstroms and can have minimal surface area. Thin film sensors for system health management have been implemented for a many decades on complex components for aerospace applications [2,3]. However, the application of thin films of this type on a battery separator for internal battery monitoring applications has not previously been demonstrated to our knowledge. This paper describes the development of sensors for the internal battery monitoring through the use of thin film sensor technology. Thin metal films were successfully deposited on a battery separator polymer material with good adherence and electrical continuity. Multiple types of sensors have been deposited, as well as lead connections from the sensor to the edge of the separator material. The ability of these thin film sensors immersed in electrolyte to perform multiple types of battery parameter measurements has been demonstrated. For example, a multiparameter sensor system measured multiple properties simultaneously inside of a pouch cell over a wide temperature range. Further, real time measurement of interior temperature changes in a battery pouch cell with an integrated interior temperature sensor was demonstrated. These changes include detecting a fault in the battery (shorting) in situ with rapid response time (less than a minute) corresponding to a more limited response by a temperature sensor mounted externally. Other aspects of monitoring battery health were also explored, such as real-time measurement of simulated dendrite growth/metal deposition by sensor on separator material demonstrated. Future efforts will include improvements in the durability of the sensor structure to allow introduction of the approach into standard battery fabrication techniques. Overall, this work is a step forward in providing a method to prevent catastrophic battery failures and provide a foundation for safer, lighter, and higher energy batteries for the electric aircraft industry.[1] B. DeMattia, Daniel Perey, John Lawson, and Gary Hunter, “Advanced Battery Health Approaches for Electric Aircraft”, Energy & Mobility Technology, Systems, and Value Chain Conference & Expo, Cleveland, OH, Sept. 23, 2023.[2] John D. Wrbanek, and Gustave C. Fralick, “Thin Film Physical Sensor Instrumentation Research and Development at NASA Glenn Research Center”, 52nd International Instrumentation Symposium Cleveland, OH, May 2006, NASA TM-2006-214395[3] Lawrence G. Matus (2015) “Instrumentation for Aerospace Applications: Electronic-Based Technologies”, Journal of Aerospace Engineering 26 (2) https://doi.org/10.1061/(ASCE)AS.1943-5525.0000302

(Invited) Hydrogen Detection Strategies to Support H2@Scale--the NREL Sensor Laboratory

Hydrogen represents a major pathway to decarbonize and stabilize the national and international energy industry and select manufacturing markets. To facilitate the development of hydrogen markets, the US Department of Energy initiated H2@Scale to bring together stakeholders to advance affordable hydrogen production, transport, storage, and utilization to increase revenue opportunities in multiple energy sectors. One major impediment to hydrogen implementation is cost. To expedite the use of hydrogen in energy and other markets, the United States announced in 2021 the Hydrogen Shot, which seeks to reduce the cost of clean hydrogen by 80% to $1 per 1 kilogram in 1 decade ("1 1 1"). As the cost of hydrogen drops, new applications will emerge that will require unique configurations of existing equipment and infrastructure, and eventually lead to advances in the generation and utilization of hydrogen. As the hydrogen economy expands, sensors and detection methods will need to adapt to changing infrastructure demands to address the primary targets of health & safety, emissions monitoring, and process control. The NREL Sensor Laboratory is playing a pivotal role in advancing the use of hydrogen sensors and detection methodologies in each of these categories to support DOE’s mission for safe and efficient utilization in emerging markets. Health & safety monitors are required to ensure that operators and facilities can react to unintended hydrogen releases, either as GH2, LH2, or as a constituent of blends (e.g., natural gas or ammonia). Current detection methodologies focus on safety applications to detect near its lower flammable limit (4 vol %), and typically include point sensors in applications such as fixed or mobile detectors (e.g., personal gas monitors). Methodologies amenable for area detection include acoustic, emerging optical imaging methods, and flame detectors.Comparable detection strategies can be utilized for emissions monitoring and quantization, however few methods can simultaneously cover both low (emissions) and high (health & safety) levels. Deployment of emission level detectors will be required to 1) reduce product loss through small but potentially significant leaks from an environmental or cost perspective, 2) reduce downtime of high demand systems by early identification of eminent system failures (leaks through pump or compressor seals indicative of impending failure), and 3) address potential emission monitoring requirements that may be set by regulating bodies. The first two points should be adopted by industry to reduce the cost-of-goods-sold.The third main category for hydrogen detection relates to process control and may be advantageous for many existing applications. Two main applications are emerging. For example, the purity requirements for hydrogen that is dispensed from refueling systems for hydrogen fuel cell electric vehicles (FCEV) is rigorously regulated by the Standard SAE J2719, which prescribes maximum allowable levels of multiple impurities in the hydrogen fuel and must be verified by a regulatory body. Hydrogen contaminant detectors (HCD) integrated to the fueling station can assure this compliance. HCDs must be able operate in 100% H2 backgrounds and be able to distinguish between multiple contaminants at low ppm to low ppb levels.Secondly, as a strategy to decarbonize the natural gas grid, there are proposals to blend hydrogen with natural gas. This blending will affect transport applications (pipeline infrastructure), stationary combustion systems (turbines), and consumer and commercial appliances. In the short-term, hydrogen levels up to 20% are proposed. Variations in the hydrogen level can have dramatic impact on the combustion process and on the potential response of safety sensors. These mixtures may be regulated so that the concentration at a delivery point must be monitored with high precision. However, routine maintenance may introduce background gases such as ambient air (with water) or maintenance gases (introduced with welding processes or adhesive outgassing.) Therefore, the detection methodology must be robust enough to recover or respond to various contaminants.Several reviews can be found in literature addressing sensing and detection technologies, including their limitations and applications. However, for most applications, limitations can be alleviated by combining various detection techniques either through system integration or implementation of machine learning methods (artificial intelligence). Many detection methods already implement some sort of senor fusion, i.e., integrated temperature and humidity sensors allow for compensation methods of point sensors to increase the accuracy and precision of detectors through a wide range of environmental conditions. Similarly, sensing arrays (electronic noses) may implement intelligent algorithms to quantify multiple gasses present in a sample, or simply to identify a single gas in a mixture.In this presentation, we will discuss several applications, highlight their current approach for hydrogen detection, and suggest detection strategies to supplement their limitations.

Optimal timing of staged percutaneous coronary intervention after subintimal tracking and re-entry: Rationale and design of the subintimal tracking and re-entry with deferred stenting study.

Ten to fifteen percent of chronic total occlusion (CTO) percutaneous coronary interventions (PCIs) are unsuccessful in contemporary practice. Subintimal tracking and re-entry (STAR) (one form of "investment procedure") with staged reattempt and stenting may further increase the ultimate success and safety of CTO as a bailout strategy. The optimal timing for staged stenting after STAR is unknown. We designed a six-center, prospective randomized trial with a planned enrollment of 150 patients where STAR is utilized in case of impending failure. The primary aim is to evaluate the optimal timing of the staged PCI after STAR by randomizing the timing to earlier (5-7 weeks) versus later (12-14 weeks) staged PCI. The primary endpoint of the study is the technical success rate of the staged procedure. The secondary endpoints include: (1) the rate of thrombolysis in myocardial infarction 3 flow at the start of staged intervention, (2) rate of partial technical and procedural success of the staged procedure, (3) rate of in-hospital and 12-month major cardiac and cerebrovascular adverse events, and (4) change in patient-reported quality at 30 days, 6 months, and 12 months assessed by Seattle Angina Questionnaire. This study will ascertain the optimal timing of staged stenting after bail-out STAR approach in contemporary CTO PCI (ClinicalTrials.gov NCT05089864).

Identifying impending failure in heterogeneous materials: A study on acoustic emission time series

In the present paper, precursors to identify impending failure in heterogeneous materials are investigated by analyzing Acoustic Emission (AE) time series. Three main approaches are considered: (1) long-range correlations using the Hurst (H) analysis, (2) Natural Time (NT) analysis, and (3) a proposed Method of Critical Fluctuations-Based (MCF-B) approach. The above approaches are employed to data collected from an experimental AE test on a concrete cubic specimen subjected to an axial compression loading. The results indicate that: persistent long-range correlations tend towards near-random behavior prior to imminent failure; critical regions, characterized by the convergence of natural time parameters, show a direct correlation with imminent increments in the acoustic emission activity and the structure's collapse; the proposed MCF-B approach as precursor, is capable to identify critical states, being the results in agreement with those from NT and Hurst analysis.

Failure analysis and Mechanical Behaviour of A60 steel Bollards Used In Port Infrastructure

The failure mechanisms and mechanical properties of bollards present significant risks in port and maritime engineering thereby calling for a thorough investigation into these aspects. This study highlights the significance of elements like tensile strength shear stress and service loads while examining the difficulties related to metal bollard failures. This paper presents a case study on A60 steel bollards that combines numerical simulations with experimental testing using Catia and Mathcad software. The results reveal that even as the mechanical houses adjust with A60 steel standards, under accurate ambit and a hundred-ton load, compactness and shear stresses exceed the limit attrition of the bollard. The acceptable strain considerably surpasses the adaptable limit, advertence impending failure. The analysis recommends layout adjustments, presenting a higher array of the annular part of the demonstrated bollard and a safety factor of at least 1. 5 to boost the bollard attrition and forestall hurt under a hundred-ton load. This research contributes advantageous insights into bollard layout, acclamation real- global demanding situations, and promoting safety in maritime infrastructure.

The diaphragmatic electrical activity during spontaneous breathing trial in patients with mechanical ventilation: physiological description and potential clinical utility

BackgroundsIncreased respiratory drive has been demonstrated to correlate with weaning failure, which could be quantified by electrical activity of the diaphragm (EAdi). We described the physiological process of EAdi-based parameters during the spontaneous breathing trial (SBT) and evaluated the change of EAdi-based parameters as potential predictors of weaning failure.MethodsWe conducted a prospective study in 35 mechanically ventilated patients who underwent a 2-hour SBT. EAdi and ventilatory parameters were continuously measured during the SBT. Diaphragm ultrasound was performed before the SBT and at the 30 min of the SBT. Three EAdi-based parameters were calculated: neuro-ventilatory efficiency, neuro-excursion efficiency and neuro-discharge per min.ResultsOf the thirty 35 patients studied, 25 patients were defined as SBT success, including 22 patients weaning successfully and 3 patients reintubated. Before the SBT, neuro-excursion efficiency differed significantly between two groups and had the highest predictive value for SBT failure (AUROC 0.875, p < 0.01). Early increases in EAdi were observed in SBT, which are more prominent in SBT failure group. One minute, changes in EAdi and neuro-discharge per min also predicted weaning outcome (AUROCs 0.944 and 0.918, respectively).ConclusionsEAdi-based parameters, especially neuro-excursion efficiency and changes in neuro-discharge per min, may detect impending weaning failure earlier than conventional indices. EAdi monitoring provides physiological insights and a more tailored approach to facilitate successful weaning. Further research should validate these findings and explore the utility of combined EAdi and diaphragm ultrasound assessment in weaning ICU patients from mechanical ventilation.Trial RegistrationRegistered at ClinicalTrials.gov on 20 September 2022 (Identifier: NCT05632822).

Predicting the failure of rock using critical slowing down theory on acoustic emission characteristics

The joint surfaces and size affect the mechanical behavior and failure precursors of shale. Therefore, this paper studies the mechanical behavior, the response characteristics of acoustic emission (AE) and critical slowing down (CSD) characteristics of AE for shale with different joint surfaces and size. The results show that with an increase in the number of joint surfaces and the size of the sample, the crack initiation stress, uniaxial compressive strength (UCS), peak strain, and fractal dimension decrease. During the plastic stage, the occurrence of a sharp rise in AE ringing count, RA, a low-frequency, high-amplitude AE signal, and a rapid drop in AF can be characteristics of impending sample failure. Variance and autocorrelation coefficients can be used to characterize the CSD phenomenon. The optimal window length and lag step are determined to be 400 and 100, respectively. The CSD characteristics of the autocorrelation coefficient and the variance of multi-AE parameters are obtained. The variance-based early warning time provides short-term early warning, while the autocorrelation coefficient-based early warning time provides early warning. The research results can provide theoretical references for the mechanical design and failure prediction of underground rock engineering.

Neonatal somatic oxygenation and perfusion assessment using near-infrared spectroscopy : Part of the series on near-infrared spectroscopy by the European Society of Paediatric Research Special Interest Group "Near-Infrared Spectroscopy".

In this narrative review, we summarize the current knowledge and applications of somatic near-infrared spectroscopy (NIRS), with a focus on intestinal, renal, limb, and multi-site applications in neonates. Assessing somatic oxygenation at various body locations in neonates may aid in the understanding of underlying pathophysiology of organ injury. Considering cerebral autoregulation may be active to protect the brain during systemic circulatory failure, peripheral somatic oxygenation may potentially provide an early indication of neonatal cardiovascular failure and ultimate hypoxemic injury to vital organs including the brain. Certain intestinal oxygenation patterns appear to be associated with the onset and course of necrotizing enterocolitis, whereas impaired renal oxygenation may indicate the onset of acute kidney injury after various types of hypoxic events. Peripheral muscle oxygenation measured at a limb may be particularly effective in the early prediction of shock in neonates. Using multi-site NIRS may complement current approaches and clinical investigations to alert for neonatal tissue hypoxemia, and potentially even guide management. However, somatic NIRS has its inherent limitations in regard to accuracy. Interpretation of organ-specific values can also be challenging. Last, currently there are limited prospective intervention studies, and clinical benefits need to be examined further, after the clarification of critical threshold-values. IMPACT: The assessment of somatic oxygenation using NIRS may contribute to the prediction of specific diseases in hemodynamically challenged neonates. Furthermore, it may give early warning signs for impending cardiovascular failure, and impaired cerebral circulation and oxygenation. We present a comprehensive overview of the literature on applications of NIRS to various somatic areas, with a focus on its potential clinical applicability, including future research directions. This paper will enable prospective standardized studies, and multicenter collaboration to obtain statistical power, likely to advance the field.

Diethylene glycol poisoning from transcutaneous absorption: Case report

Introduction: Diethylene glycol (DEG) has been implicated in several cases of poisoning over the years. The most common mechanism of poisoning is accidental or deliberate ingestion of anti-freezer; however, poisoning from transcutaneous absorption is extremely rare. Treatment is not well defined but fomepizole or ethanol can be an effective antidote specially if started early. Furthermore, early hemodialysis will reduce the burden of toxic metabolites. Case report: Here, we report a rare case of diethylene glycol poisoning from transcutaneous absorption. Our patient presented complaining of gastrointestinal and renal symptoms. Initial laboratory results showed values consistent with acute kidney injury and metabolic acidosis. Therefore, hemodialysis was started right away. On the 7th day of admission, the patient started showing features suggestive of impending respiratory failure which prompted a transfer to intensive care unit (ICU) for mechanical ventilation. After ICU admission, the patient’s family reported previously concealed history of the patient applying brake fluid, a substance containing diethylene glycol, as traditional remedy for rash. Unfortunately, at that time, the antidote for diethylene glycol poisoning was not available in our country, Ethiopia. Hence, supportive treatment alone was given. Regrettably, the patient died on the 12th day of ICU admission. Conclusion: This case represents the unique clinical aspects of DEG poisoning. It also underscores the importance of suspecting DEG poisoning in acute renal failure patients with poor response to hemodialysis. Furthermore, taking detailed history will provide the initial clue to consider DEG poisoning. Lastly, further study should be done to identify factors that determine the occurrence of DEG poisoning from cutaneous brake fluid exposure.

Clinical impact of remote heart failure management using the multiparameter ICD HeartLogic alert

Introduction and objectivesThe multiparametric implantable cardioverter-defibrillator HeartLogic index has proven to be a sensitive and timely predictor of impending heart failure (HF) decompensation. We evaluated the impact of a standardized follow-up protocol implemented by nursing staff and based on remote management of alerts. MethodsThe algorithm was activated in HF patients at 19 Spanish centers. Transmitted data were analyzed remotely, and patients were contacted by telephone if alerts were issued. Clinical actions were implemented remotely or through outpatient visits. The primary endpoint consisted of HF hospitalizations or death. Secondary endpoints were HF outpatient visits. We compared the 12-month periods before and after the adoption of the protocol. ResultsWe analyzed 392 patients (aged 69±10 years, 76% male, 50% ischemic cardiomyopathy) with implantable cardioverter-defibrillators (20%) or cardiac resynchronization therapy defibrillators (80%). The primary endpoint occurred 151 times in 86 (22%) patients during the 12 months before the adoption of the protocol, and 69 times in 45 (11%) patients (P<.001) during the 12 months after its adoption. The mean number of hospitalizations per patient was 0.39±0.89 pre- and 0.18±0.57 postadoption (P<.001). There were 185 outpatient visits for HF in 96 (24%) patients before adoption and 64 in 48 (12%) patients after adoption (P<.001). The mean number of visits per patient was 0.47±1.11 pre- and 0.16±0.51 postadoption (P<.001). ConclusionsA standardized follow-up protocol based on remote management of HeartLogic alerts enabled effective remote management of HF patients. After its adoption, we observed a significant reduction in HF hospitalizations and outpatient visits.

Interface evolution of lithium metal anodes in all-solid-state batteries via mechanical–electrochemical investigations

All-solid-state Li metal batteries (ASSLMBs) have garnered attention owing to the high-energy density and low redox potential of Li metal anodes. However, the practical applications of ASSLMBs are hindered by issues such as the volume effect of Li anodes and Li dendrite growth. In this study, a combined method of stacking pressure analysis, interface morphology observation, and electrochemical impedance spectroscopy was used to investigate the electrochemical failure of Li symmetric batteries based on the Li6PS5Cl electrolyte at areal capacities of 0.5, 1, and 3 mAh cm−2. The results indicated that ASSLMBs with areal capacities >1 mAh cm−2 exhibited a continuous decrease in the stacking pressure. As Li dendrites/dead Li and pores/cracks increased, stacking pressure variations of >0.1 MPa per cycle and a stacking pressure change rate > 0.2 MPa h−1 were observed, indicating impending battery failure owing to interface detachment. These findings provide new insights into the interface evolution of Li anodes of ASSLMBs and emphasize the importance of electrochemical–mechanical measurements in studying Li anode interfaces of ASSLMBs.

The physiology of venoarterial extracorporeal membrane oxygenation - A comprehensive clinical perspective.

Venoarterial extracorporeal membrane oxygenation (VA ECMO) has become a standard of care for severe cardiogenic shock, refractory cardiac arrest and related impending multiorgan failure. The widespread clinical use of this complex temporary circulatory support modality is still contrasted by a lack of formal scientific evidence in the current literature. This might at least in part be attributable to VA ECMO related complications, which may significantly impact on clinical outcome. In order to limit adverse effects of VA ECMO as much as possible an indepth understanding of the complex physiology during extracorporeally supported cardiogenic shock states is critically important. This review covers all relevant physiological aspects of VA ECMO interacting with the human body in detail. This, to provide a solid basis for health care professionals involved in the daily management of patients supported with VA ECMO and suffering from cardiogenic shock or cardiac arrest and impending multiorgan failure for the best possible care.