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1.
Sensors (Basel) ; 21(17)2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34502720

RESUMO

Scientific and technological advances in the field of rotatory electrical machinery are leading to an increased efficiency in those processes and systems in which they are involved. In addition, the consideration of advanced materials, such as hybrid or ceramic bearings, are of high interest towards high-performance rotary electromechanical actuators. Therefore, most of the diagnosis approaches for bearing fault detection are highly dependent of the bearing technology, commonly focused on the metallic bearings. Although the mechanical principles remain as the basis to analyze the characteristic patterns and effects related to the fault appearance, the quantitative response of the vibration pattern considering different bearing technology varies. In this regard, in this work a novel data-driven diagnosis methodology is proposed based on deep feature learning applied to the diagnosis and identification of bearing faults for different bearing technologies, such as metallic, hybrid and ceramic bearings, in electromechanical systems. The proposed methodology consists of three main stages: first, a deep learning-based model, supported by stacked autoencoder structures, is designed with the ability of self-adapting to the extraction of characteristic fault-related features from different signals that are processed in different domains. Second, in a feature fusion stage, information from different domains is integrated to increase the posterior discrimination capabilities during the condition assessment. Third, the bearing assessment is achieved by a simple softmax layer to compute the final classification results. The achieved results show that the proposed diagnosis methodology based on deep feature learning can be effectively applied to the diagnosis and identification of bearing faults for different bearing technologies, such as metallic, hybrid and ceramic bearings, in electromechanical systems. The proposed methodology is validated in front of two different electromechanical systems and the obtained results validate the adaptability and performance of the proposed approach to be considered as a part of the condition-monitoring strategies where different bearing technologies are involved.


Assuntos
Algoritmos , Vibração , Cerâmica , Análise de Falha de Equipamento , Modalidades de Fisioterapia
2.
Comput Intell Neurosci ; 2021: 2221702, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34394334

RESUMO

Data-driven intelligent prognostic health management (PHM) systems have been widely investigated in the area of defective bearing signals. These systems can provide precise information on condition monitoring and diagnosis. However, existing PHM systems cannot identify the accurate degradation trend and the current fault types simultaneously. Given that different fault types have various effects on the mechanical system, the corresponding maintenance strategies also vary. Then, choosing the appropriate maintenance strategy according to the future fault type can reduce the maintenance cost of the equipment operation. Therefore, a multifeature information health index (MIHI) must be developed to trace various bearing degradation trends with various types of faults simultaneously. This paper reports a new quasi-orthogonal sparse project algorithm that can mutually convert the degraded processing feature vector sets (such as spectrum) for each type of fault to orthogonal approximate spatial straight lines. The algorithm builds a MIHI through the spectrum of current state measured points. The MIHI is then transformed by a quasi-orthogonal sparse project algorithm to trace the various bearing degradation trends and recognize the fault type simultaneously. The case study of bearing degradation data demonstrates that this approach is effective in assessing the various degradation trends of different fault types.


Assuntos
Algoritmos , Análise de Falha de Equipamento
3.
Sensors (Basel) ; 21(15)2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34372204

RESUMO

Models trained with one system fail to identify other systems accurately because of domain shifts. To perform domain adaptation, numerous studies have been conducted in many fields and have successfully aligned different domains into one domain. The domain shift problem is caused by the difference of distributions between two domains, which is solved by reducing this difference. Source domain data are labeled and used for training the models to extract the features while the target domain data are unlabeled or partially labeled and only used for aligning. Bearings play important roles in rotating machines, so many artificial intelligent models have been developed to diagnose bearings. Bearing diagnosis has also faced a domain shift problem due to various operating conditions such as experimental environment, number of balls, degree of defects, and rotational speed. Cross-domain fault diagnosis has been successfully performed when the systems are the same but operating conditions are different. However, the results are poor when diagnosing different bearing systems because the characteristics of the signals such as specific frequencies depend on the specifications. In this paper, the pre-processing method was used for improving the diagnosis without prior knowledge such as fault frequencies. The signals were first transformed to a common pattern space before entering the models. To develop and to validate the proposed method for different domains, vibration signals measured from two ball-bearing systems (Case Western Reserve University datasets and Paderborn University datasets) were used. One dimensional CNN models were utilized for verification of the proposed method and the results of the models using raw datasets and pre-processed datasets were compared. Even though each of the ball-bearing systems have their own specifications, using the proposed method was very helpful for domain adaptation, and cross-domain fault diagnosis was performed with high accuracy.


Assuntos
Algoritmos , Inteligência Artificial , Análise de Falha de Equipamento , Humanos , Modalidades de Fisioterapia , Vibração
4.
Sensors (Basel) ; 21(15)2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34372246

RESUMO

In this research, the aim is to investigate an adaptive digital twin algorithm for fault diagnosis and crack size identification in bearings. The main contribution of this research is to design an adaptive digital twin (ADT). The design of the ADT technique is based on two principles: normal signal modeling and estimation of signals. A combination of mathematical and data-driven techniques will be used to model the normal vibration signal. Therefore, in the first step, the normal vibration signal is modeled to increase the reliability of the modeling algorithm in the ADT. Then, to help challenge the complexity and uncertainty, the data-driven method will solve the problems of the mathematically based algorithm. Thus, first, Gaussian process regression is selected, and then, in two steps, we improve its resistance and accuracy by a Laguerre filter and fuzzy logic algorithm. After modeling the vibration signal, the second step is to design the data estimation for ADT. These signals are estimated by an adaptive observer. Therefore, a proportional-integral observer is then combined with the proposed technique for signal modeling. Then, in two stages, its robustness and reliability are strengthened using the Lyapunov-based algorithm and adaptive technique, respectively. After designing the ADT, the residual signals that are the difference between original and estimated signals are obtained. After that, the residual signals are resampled, and the root means square (RMS) signals are extracted from the residual signals. A support vector machine (SVM) is recommended for fault classification and crack size identification. The strength of the proposed technique is tested using the Case Western Reserve University Bearing Dataset (CWRUBD) under diverse torque loads, various motor speeds, and different crack sizes. In terms of fault diagnosis, the average detection accuracy in the proposed scheme is 95.75%. In terms of crack size identification for the roller, inner, and outer faults, the proposed scheme has average detection accuracies of 97.33%, 98.33%, and 98.33%, respectively.


Assuntos
Lógica Fuzzy , Máquina de Vetores de Suporte , Algoritmos , Análise de Falha de Equipamento , Humanos , Reprodutibilidade dos Testes
5.
Sensors (Basel) ; 21(12)2021 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-34203066

RESUMO

The reliable and cost-effective condition monitoring of the bearings installed in water pumps is a real challenge in the industry. This paper presents a novel strong feature selection and extraction algorithm (SFSEA) to extract fault-related features from the instantaneous power spectrum (IPS). The three features extracted from the IPS using the SFSEA are fed to an extreme gradient boosting (XBG) classifier to reliably detect and classify the minor bearing faults. The experiments performed on a lab-scale test setup demonstrated classification accuracy up to 100%, which is better than the previously reported fault classification accuracies and indicates the effectiveness of the proposed method.


Assuntos
Algoritmos , Água , Análise de Falha de Equipamento
6.
Sensors (Basel) ; 21(12)2021 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-34199163

RESUMO

In this paper, an explainable AI-based fault diagnosis model for bearings is proposed with five stages, i.e., (1) a data preprocessing method based on the Stockwell Transformation Coefficient (STC) is proposed to analyze the vibration signals for variable speed and load conditions, (2) a statistical feature extraction method is introduced to capture the significance from the invariant pattern of the analyzed data by STC, (3) an explainable feature selection process is proposed by introducing a wrapper-based feature selector-Boruta, (4) a feature filtration method is considered on the top of the feature selector to avoid the multicollinearity problem, and finally, (5) an additive Shapley explanation followed by k-NN is proposed to diagnose and to explain the individual decision of the k-NN classifier for debugging the performance of the diagnosis model. Thus, the idea of explainability is introduced for the first time in the field of bearing fault diagnosis in two steps: (a) incorporating explainability to the feature selection process, and (b) interpretation of the classifier performance with respect to the selected features. The effectiveness of the proposed model is demonstrated on two different datasets obtained from separate bearing testbeds. Lastly, an assessment of several state-of-the-art fault diagnosis algorithms in rotating machinery is included.


Assuntos
Algoritmos , Vibração , Inteligência Artificial , Análise de Falha de Equipamento
7.
J Occup Environ Hyg ; 18(6): 265-275, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33989113

RESUMO

The COVID-19 pandemic has caused a high demand for respiratory protection among health care workers in hospitals, especially surgical N95 filtering facepiece respirators (FFRs). To aid in alleviating that demand, a survey of commercially available filter media was conducted to determine whether any could serve as a substitute for an N95 FFR while held in a 3D-printed mask (Stopgap Surgical Face Mask from the NIH 3D Print Exchange). Fourteen filter media types and eight combinations were evaluated for filtration efficiency, breathing resistance (pressure drop), and liquid penetration. Additional testing was conducted to evaluate two filter media disinfection methods in the event that the filters were reused in a hospital setting. Efficiency testing was conducted in accordance with the procedures established for approving an N95 FFR. One apparatus used a filter-holding device and another apparatus employed a manikin head to which the 3D-printed mask could be sealed. The filter media and combinations exhibited collection efficiencies varied between 3.9% and 98.8% when tested with a face velocity comparable to that of a standard N95 FFR at the 85 L min-1 used in the approval procedure. Breathing resistance varied between 10.8 to >637 Pa (1.1 to > 65 mm H2O). When applied to the 3D-printed mask efficiency decreased by an average of 13% and breathing resistance increased 4-fold as a result of the smaller surface area of the filter media when held in that mask compared to that of an N95 FFR. Disinfection by dry heat, even after 25 cycles, did not significantly affect filter efficiency and reduced viral infectivity by > 99.9%. However, 10 cycles of 59% vaporized H2O2 significantly (p < 0.001) reduced filter efficiency of the media tested. Several commercially available filter media were found to be potential replacements for the media used to construct the typical cup-like N95 FFR. However, their use in the 3D-printed mask demonstrated reduced efficiency and increased breathing resistance at 85 L min-1.


Assuntos
COVID-19/prevenção & controle , Desinfecção/normas , Contaminação de Equipamentos/prevenção & controle , Teste de Materiais/normas , Respiradores N95/virologia , Exposição Ocupacional/prevenção & controle , Pandemias/prevenção & controle , Poluentes Ocupacionais do Ar/análise , Análise de Falha de Equipamento/estatística & dados numéricos , Guias como Assunto , Humanos , Exposição por Inalação/análise , SARS-CoV-2
8.
Am J Med ; 134(9): 1170-1174, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33864761

RESUMO

BACKGROUND: Pseudohyperchloremia results in a very low or negative anion gap. Historically, the most common cause of this artifact was bromide poisoning. Bromide salts have been removed from most medications and bromism has become very uncommon. More recently, the introduction of chloride ion selective sensing electrodes (Cl-ISE) has generated a new cause of pseudohyperchloremia-salicylate poisoning. We describe 5 such patients and quantitate the error generated by this measurement artifact. METHODS: The magnitude of artifactual hyperchloremia generated by high salicylate levels was quantified in 5 patients by measuring chloride concentration with several Cl-ISEs from different manufacturers and with Cl-ISEs of different "ages," and comparing these results to measurements with a chloridometer (coulometric titration), which is free of the salicylate artifact. RESULTS: Cl-ISEs from different manufacturers generated a wide range of artifactual chloride concentration elevation. Furthermore, the same Cl-ISE generated increasingly severe pseudohyperchloremia as it was repeatedly reused over time and "aged." CONCLUSIONS: Salicylate interferes with measurement of the blood chloride concentration when a Cl-ISE is used. The severity of this artifact is related to the salicylate level, the specific Cl-ISE, and the "age" of the electrode. Toxic blood salicylate levels can generate marked pseudohyperchloremia, and consequently, an artifactual very small or negative anion gap. The large anion gap metabolic acidosis typical of salicylate poisoning is masked by this artifact. Salicylate has become the most common cause of pseudohyperchloremia, and physicians should immediately consider salicylate poisoning whenever the combination of hyperchloremia and a very small or negative anion gap is reported by the laboratory.


Assuntos
Acidose , Aspirina/envenenamento , Cloretos , Eletrodos Íon-Seletivos/normas , Salicilatos , Equilíbrio Ácido-Base , Desequilíbrio Ácido-Base/induzido quimicamente , Desequilíbrio Ácido-Base/diagnóstico , Desequilíbrio Ácido-Base/terapia , Acidose/sangue , Acidose/induzido quimicamente , Acidose/diagnóstico , Acidose/terapia , Artefatos , Cloretos/análise , Cloretos/sangue , Análise de Falha de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Assistência ao Paciente/métodos , Salicilatos/sangue , Salicilatos/envenenamento , Tentativa de Suicídio
9.
Clin Biochem ; 93: 112-118, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33882283

RESUMO

INTRODUCTION: The aim of this study was to evaluate the analytical performance of the Kite Biotechnology Oral fluid (OF) screening test device, which is used for roadside screening of cannabis, opiates, amphetamines, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), cocaine and benzodiazepines by comparing samples with matched plasma samples, analysed via liquid chromatography-tandem mass spectrometry (LC-MS/MS) for confirmation. METHODS: OF and plasma samples were obtained simultaneously from a total of 100 subjects. OF samples were analysed by OF screening test based on immunochromatography. The OF screening test cut-off values were 50 ng/mL for amphetamines (d-amphetamine) and methamphetamine/MDMA (d-methamphetamine), 30 ng/mL for cocaine (benzoylecgonine), 40 ng/mL for opiates (morphine), 20 ng/mL for benzodiazepines (nordazepam), and 25 ng/mL for cannabis (Δ9-tetrahydrocannabinol). LC-MS/MS method validation was performed according to the CLSI C62-A recommendations with the following parameters: matrix effect, lower limit of quantification (LLOQ), linearity, intra-day and inter-day precision and accuracy. RESULTS: The overall specificity, accuracy and negative predictive values (NPV) were acceptable and met the DRUID standard of >80%. The OF screening test device showed good sensitivity for cocaine, amphetamines and opiates, whereas it indicated poor sensitivity for methamphetamine/MDMA (66.7%) and failed to detect cannabis and benzodiazepines. CONCLUSION: The present study is the first report to evaluate the Kite Biotechnology OF screening test device. The diagnostic performance of the OF screening test device was acceptable for opiates, cocaine and amphetamines, but it was insufficient for methamphetamine/MDMA, benzodiazepines and cannabis because of sensitivity issues.


Assuntos
Imunoensaio/instrumentação , Imunoensaio/métodos , Saliva/química , Detecção do Abuso de Substâncias/instrumentação , Detecção do Abuso de Substâncias/métodos , Anfetaminas/análise , Cocaína/análogos & derivados , Cocaína/análise , Confiabilidade dos Dados , Dirigir sob a Influência , Dronabinol/análise , Análise de Falha de Equipamento , Feminino , Toxicologia Forense/instrumentação , Toxicologia Forense/métodos , Humanos , Drogas Ilícitas/análise , Masculino , Metanfetamina/análise , Morfina/análise , Nordazepam/análise , Plasma/química , Valor Preditivo dos Testes , Espectrometria de Massas em Tandem
10.
J Mech Behav Biomed Mater ; 119: 104472, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33813334

RESUMO

Wear remains a significant challenge in the design of orthopedic implants such as total hip replacements. Early elastohydrodynamic lubrication modeling has predicted thicker lubrication films in hip replacement designs with compliant polycarbonate polyurethane (PCU) bearing materials compared to stiffer materials like ultra-high molecular weight polyethylene (UHMWPE). The predicted thicker lubrication films suggest improved friction and wear performance. However, when compared to the model predictions, experimental wear studies showed mixed results. The mismatch between the model and experimental results may lie in the simplifying assumptions of the early models such as: steady state conditions, one dimensional rotation and loading, and high viscosities. This study applies a 3D-transient elastohydrodynamic model based on an ISO standard gait cycle to better understand the interaction between material stiffness and film thickness in total hip arthroplasty material couples. Similar to previous, simplified models, we show that the average and central film thickness of PCU (∼0.4µm) is higher than that of UHMWPE (∼0.2µm). However, in the 3D-transient model, the film thickness distribution was largely asymmetric and the minimum film thickness occurred outside of the central axis. Although the overall film thickness of PCU was higher than UHMWPE, the minimum film thickness of PCU was lower than UHMPWE for the majority of the gait cycle. The minimum film thickness of PCU also had a larger range throughout the gait cycle. Both materials were found to be operating between boundary and mixed lubrication regimes. This 3D-transient model reveals a more nuanced interaction between bearing material stiffness and film thickness that supports the mixed results found in experimental wear studies of PCU hip implant designs.


Assuntos
Prótese de Quadril , Poliuretanos , Análise de Falha de Equipamento , Fricção , Lubrificação , Teste de Materiais , Peso Molecular , Cimento de Policarboxilato , Polietilenos , Desenho de Prótese
11.
Am J Surg ; 221(6): 1121-1126, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33745689

RESUMO

BACKGROUND: We compared surgical device malfunction reports in the Food and Drug Administration (FDA) public Manufacturer and User Facility Device Experience (MAUDE) with those in the FDA nonpublic Alternative Summary Reporting (ASR). METHODS: General surgery device product code categories in MAUDE and ASR from 1999 to 2018 were identified. Changes in the rates of categories and adverse events were evaluated by Poisson regression. RESULTS: There were 283,308 (72%) general surgical device malfunctions in MAUDE and 109,954 (28%) in ASR. Reports increased annually in ASR versus MAUDE, particularly for surgical staplers and clip devices (p < 0.05). ASR contained approximately 80% of these reports; MAUDE 20%. In MAUDE, 42.9% of surgical device malfunctions and 20.2% of stapler/clip malfunctions resulted in patient injury or death. ASR listed no injury or death information. CONCLUSIONS: ASR contained a significant portion of surgical device malfunctions hidden from public scrutiny. Access to such data is essential to safe surgical care.


Assuntos
Falha de Equipamento/estatística & dados numéricos , Instrumentos Cirúrgicos/efeitos adversos , Bases de Dados Factuais , Análise de Falha de Equipamento , Humanos , Estudos Retrospectivos , Estados Unidos , United States Food and Drug Administration
12.
PLoS One ; 16(3): e0246905, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33647055

RESUMO

Rolling bearing fault diagnosis is one of the challenging tasks and hot research topics in the condition monitoring and fault diagnosis of rotating machinery. However, in practical engineering applications, the working conditions of rotating machinery are various, and it is difficult to extract the effective features of early fault due to the vibration signal accompanied by high background noise pollution, and there are only a small number of fault samples for fault diagnosis, which leads to the significant decline of diagnostic performance. In order to solve above problems, by combining Auxiliary Classifier Generative Adversarial Network (ACGAN) and Stacked Denoising Auto Encoder (SDAE), a novel method is proposed for fault diagnosis. Among them, during the process of training the ACGAN-SDAE, the generator and discriminator are alternately optimized through the adversarial learning mechanism, which makes the model have significant diagnostic accuracy and generalization ability. The experimental results show that our proposed ACGAN-SDAE can maintain a high diagnosis accuracy under small fault samples, and have the best adaptation performance across different load domains and better anti-noise performance.


Assuntos
Análise de Falha de Equipamento/métodos , Redes Neurais de Computação , Rotação
14.
J Artif Organs ; 24(2): 234-242, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33449228

RESUMO

We evaluated the clinical and radiographic outcomes of femoral head penetration and total hip arthroplasties with untreated and poly (2-methacryloyloxyethyl phosphorylcholine) (PMPC)-grafted highly cross-linked polyethylene (HXLPE) acetabular liners against 26-, 28-, and 32-mm cobalt-chromium alloy femoral heads 3 years after the index surgery. Three combinations of the articulating surfaces were evaluated in the present study: untreated or PMPC-grafted HXLPE liner against 26- or 28-mm femoral heads (n = 16, 24) [control (26 or 28 mm) and PMPC (26 or 28 mm)] and PMPC-grafted HXLPE liner against 32-mm femoral heads (n = 64) [PMPC (32 mm)]. The clinical outcomes improved at 3 years postoperatively for the groups. No periprosthetic osteolysis or acetabular component migration was detected, and no revision surgery was performed among the groups. The steady-state wear rate of the PMPC (26 or 28 mm) group (0.021 mm/year) was lower than that of the control (26 or 28 mm) group (- 0.015 mm/year); the steady-state wear was under the clinical threshold. In contrast, the steady-state wear rate of the PMPC (32 mm) group (-0.006 mm/year) showed no significant difference when compared to that of the PMPC (26 or 28 mm) group (p < 0.01). The results obtained in the present study clearly demonstrate that PMPC-grafting onto an HXLPE surface improved the wear resistance of acetabular liners, even when coupled with larger femoral heads. Although further follow-up evaluations are required, PMPC-grafted HXLPE acetabular liners may be a promising approach to extend the longevity of artificial joints.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Fosforilcolina/análogos & derivados , Polietileno/química , Ácidos Polimetacrílicos/química , Desenho de Prótese , Adulto , Idoso , Idoso de 80 Anos ou mais , Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/instrumentação , Artroplastia de Quadril/métodos , Artroplastia de Quadril/estatística & dados numéricos , Análise de Falha de Equipamento , Feminino , Cabeça do Fêmur/química , Cabeça do Fêmur/cirurgia , Seguimentos , Prótese de Quadril/efeitos adversos , Prótese de Quadril/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Fosforilcolina/química , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Falha de Prótese/etiologia , Reoperação/estatística & dados numéricos , Resultado do Tratamento
15.
Biomed Pharmacother ; 136: 111288, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33493869

RESUMO

Heart valve replacement is a very effective method to treat severe valvular stenosis or valvular insufficiency. The valve can be divided into the mechanical valve and biological valve according to the main materials of the valve leaflets. The former has good durability, but the patients need to take anticoagulants all their lives, otherwise, thrombosis will occur; the latter has good blood compatibility, and only 3-6 months of postoperative anticoagulation is required, but its durability is lower than the former. Compared with a traditional valve used materials, the fabric composite valve leaflets have both mechanical valve and biological valve advantages, i.e. it can have both good blood compatibility and excellent fatigue resistance. This material is comprised of the internal fabric layer and bilateral external polyurethane layers jointed with adhesive, and it can adjust the flexibility, wear-resistance and fatigue resistance of the valve leaflet through adjusting the thickness of the outer polyurethane protective layer, the weaving method, the fiber diameter and the surface density of the inner ultra-high molecular weight polyethylene (UHMWPE) fabric. In this article, we tested the long-term durability of a fabric composite with its property close to the valve leaflet made of bovine pericardium, to evaluate the material performance loss under long-term fatigue and the wear degree of this material with different polyurethane layer thicknesses. As many as two hundred million cycles of fatigue test and the hydrodynamic performance test before and after the fatigue test proved that the material could withstand a service life of at least five years without structural failure or functional degradation. According to the SEM images after the experiment, it can be predicted that this material can achieve a longer fatigue life.


Assuntos
Próteses Valvulares Cardíacas , Polietilenos/química , Poliuretanos/química , Análise de Falha de Equipamento , Teste de Materiais , Desenho de Prótese , Falha de Prótese , Estresse Mecânico , Resistência à Tração , Fatores de Tempo
16.
Enferm Clin ; 31 Suppl 1: S78-S83, 2021 Feb.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-32768261

RESUMO

AIM: Personal protective equipment (PPE), including respirators, is essential in a pandemic like COVID-19, which has required, on many occasions, the reuse of material due to its shortage. The aim of this review is to summarize available evidence on the reuse and extended use of filtering facepiece respirator. METHOD: Scoping review. Search through natural language in PUBMED and Centers, Agencies and Organizations for Disease Control. Limited to articles published between 2010-2020 in English and Spanish. RESULTS: 83 articles were located, 14 were selected, plus 5 recommendations. The topics included in this study are classified in 7 sections: expiration, extended use and reuse of masks, handling techniques, sealing, physical-psychological effects and compliance, contamination and decontamination of respirators. CONCLUSIONS: The reuse of masks is not recommended by official organizations or manufacturers, and is only accepted in extraordinary cases, such as pandemics. The studies are characterized by having small samples, using different models of respirators adjusting their recommendation to the model.


Assuntos
COVID-19/prevenção & controle , Reutilização de Equipamento/normas , Máscaras/normas , SARS-CoV-2 , COVID-19/epidemiologia , Descontaminação , Desinfecção/métodos , Desinfecção/normas , Equipamentos Descartáveis/normas , Contaminação de Equipamentos/prevenção & controle , Desenho de Equipamento , Análise de Falha de Equipamento/métodos , Filtração/instrumentação , Filtração/normas , Guias como Assunto , Humanos , Respiradores N95/normas , Pandemias , Fatores de Tempo
18.
J Thromb Thrombolysis ; 51(4): 966-970, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33026569

RESUMO

Coronavirus disease 2019 (COVID-19) appears to be associated with increased arterial and venous thromboembolic disease. These presumed abnormalities in hemostasis have been associated with filter clotting during continuous renal replacement therapy (CRRT). We aimed to characterize the burden of CRRT filter clotting in COVID-19 infection and to describe a CRRT anticoagulation protocol that used anti-factor Xa levels for systemic heparin dosing. Multi-center study of consecutive patients with COVID-19 receiving CRRT. Primary outcome was CRRT filter loss. Sixty-five patients were analyzed, including 17 using an anti-factor Xa protocol to guide systemic heparin dosing. Fifty-four out of 65 patients (83%) lost at least one filter. Median first filter survival time was 6.5 [2.5, 33.5] h. There was no difference in first or second filter loss between the anti-Xa protocol and standard of care anticoagulation groups, however fewer patients lost their third filter in the protocolized group (55% vs. 93%) resulting in a longer median third filter survival time (24 [15.1, 54.2] vs. 17.3 [9.5, 35.1] h, p = 0.04). The rate of CRRT filter loss is high in COVID-19 infection. An anticoagulation protocol using systemic unfractionated heparin, dosed by anti-factor Xa levels is reasonable approach to anticoagulation in this population.


Assuntos
Biomarcadores Farmacológicos/análise , COVID-19 , Terapia de Substituição Renal Contínua , Estado Terminal/terapia , Monitoramento de Medicamentos/métodos , Heparina , Filtros Microporos/efeitos adversos , Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Coagulação Sanguínea/efeitos dos fármacos , COVID-19/sangue , COVID-19/fisiopatologia , COVID-19/terapia , Protocolos Clínicos , Terapia de Substituição Renal Contínua/efeitos adversos , Terapia de Substituição Renal Contínua/métodos , Relação Dose-Resposta a Droga , Análise de Falha de Equipamento , Fator Xa/análise , Feminino , Heparina/administração & dosagem , Heparina/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , SARS-CoV-2
19.
Clin Oral Investig ; 25(1): 169-177, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32488488

RESUMO

OBJECTIVES: To determine the effect of the location of the canal curvature on the fatigue resistance of WaveOne (WO), WaveOne Gold (WOG), Reciproc (Rec), and Reciproc Blue (RecB) files, and to examine the phase transformation behaviors of the reciprocating file systems. MATERIAL AND METHODS: The instruments were subjected to fatigue testing in five artificial canals with a curvature of 60° angle and a 3-mm radius. The location of the curvature was unique for each canal. Each file was inserted 16 mm into the canal and operated until fracture occurred. The time to fracture was recorded and the length of the fragment was measured. Differential scanning calorimetry was used to characterize the thermal behavior of the files. The number of cycles to failure was analyzed using two-way analysis of variance and the post hoc Tukey test. The Kruskal-Wallis test was used to compare the mean fragment lengths between groups. RESULTS: The instruments had significantly lower fatigue resistance in canals with curvatures in the middle and coronal canals compared with those with apical curvatures (p < 0.05). At all tested curvature locations, RecB had superior fatigue resistance compared with WO and Rec (p < 0.05). There were no significant differences between WOG and Rec in canals with curvatures in the middle and coronal canals. The DSC thermograms for RecB exhibit a single exothermic peak during cooling but double endothermic peaks during heating indicating that a two-step phase transformation from martensite to R-phase to austenite takes place. CONCLUSIONS: The reciprocating instruments experience decreased cyclic fatigue resistance when operated in canals with coronal- and middle-third curvatures when compared with curvatures in the apical-third. Instrumenting coronally positioned curvatures with reciprocating files needs to be performed with caution. CLINICAL RELEVANCE: The location of the root canal's curvature influences the fracture resistance of rotary files that are used with reciprocating movements. Therefore, caution needs to be exercised when using reciprocating instruments in canals with coronal or middle curvatures.


Assuntos
Instrumentos Odontológicos , Preparo de Canal Radicular , Desenho de Equipamento , Análise de Falha de Equipamento , Titânio
20.
Strahlenther Onkol ; 197(3): 198-208, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32561941

RESUMO

BACKGROUND AND PURPOSE: High-dose 6­MV radiotherapy may cause cardiac implantable electronic devices (CIEDs) to malfunction. To assess CIED malfunctions resulting from direct exposure up to 10 Gy, 100 pacemakers (PMs) and 40 implantable cardioverter-defibrillators (ICDs) were evaluated. MATERIALS AND METHODS: CIEDs underwent baseline interrogation. In ICDs, antitachycardia therapies were disabled via the programmer while the detection windows were left enabled. A computed tomography (CT) scan was performed to build the corresponding treatment plan. CIEDs were "blinded" and randomized to receive single doses of either 2, 5, or, 10 Gy via a 6-MV linear accelerator (linac) in a water phantom. Twenty-two wireless telemetry-enabled CIEDs underwent a real-time session, and their function was recorded by the video camera in the bunker. The CIEDs were interrogated after exposure and once monthly for 6 months. RESULTS: During exposure, regardless of dose, 90.9% of the CIEDs recorded electromagnetic interference, with 6 ICDs (27.3%) reporting pacing inhibition and inappropriate arrhythmia detections. After exposure, a backup reset was observed in 1 PM (0.7% overall, 1% among PMs), while 7 PMs (5% overall, 7% among PMs) reported battery issues (overall immediate malfunction rate was 5.7%). During follow-up, 4 PMs (2.9% overall; 4% among PMs) and 1 ICD (0.7% overall; 2.5% among ICDs) reported abnormal battery depletion, and 1 PM (0.7% overall; 1% among PMs) reported a backup reset (overall late malfunction rate was 4.3%). CONCLUSION: Apart from transient electromagnetic interference, last-generation CIEDs withstood direct 6­MV exposure up to 10 Gy. Permanent battery or software errors occurred immediately or later only in less recent CIEDs.


Assuntos
Desfibriladores Implantáveis/efeitos adversos , Falha de Equipamento , Marca-Passo Artificial/efeitos adversos , Dosagem Radioterapêutica , Análise de Falha de Equipamento , Humanos , Radioterapia/efeitos adversos
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