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2.
Clin Transl Gastroenterol ; 12(2): e00314, 2021 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-33620880

RESUMO

INTRODUCTION: During the coronavirus disease 2019 (COVID-19) pandemic, endoscopists have high risks of exposure to exhaled air from patients during gastroscopy. To minimize this risk, we transformed the oxygen mask into a fully closed negative-pressure gastroscope isolation mask. This study aimed to evaluate the effectiveness, safety, and feasibility of use of this mask during gastroscopy. METHODS: From February 28, 2020, to March 10, 2020, 320 patients undergoing gastroscopy were randomly assigned into the mask group (n = 160) or conventional group (n = 160). Patients in the mask group wore the isolation mask during gastroscopy, whereas patients in the conventional group did not wear the mask. The adenosine triphosphate fluorescence and carbon dioxide (CO2) concentration in patients' exhaled air were measured to reflect the degree of environmental pollution by exhaled air. Patients' vital signs, operation time, and adverse events during endoscopy were also evaluated. RESULTS: Four patients were excluded because of noncooperation or incomplete data. A total of 316 patients were included in the final analysis. The difference between the highest CO2 concentration around patients' mouth and CO2 concentration in the environment was significantly decreased in the mask group compared with the conventional group. There was no significant difference in the adenosine triphosphate fluorescence, vital signs, and operation time between the 2 groups. No severe adverse events related to the isolation mask, endoscopy failure, or new coronavirus infection during follow-up were recorded. DISCUSSION: This new isolation mask showed excellent feasibility of use and safety compared with routine gastroscopy during the COVID-19 pandemic.


Assuntos
/transmissão , Gastroscopia/efeitos adversos , Máscaras/virologia , Isoladores de Pacientes/virologia , Trifosfato de Adenosina/metabolismo , Adulto , /epidemiologia , Dióxido de Carbono/análise , Estudos de Casos e Controles , Desenho de Equipamento/métodos , Expiração/fisiologia , Estudos de Viabilidade , Feminino , Fluorescência , Gastroscopia/métodos , Humanos , Masculino , Máscaras/efeitos adversos , Máscaras/estatística & dados numéricos , Pessoa de Meia-Idade , Duração da Cirurgia , Estudos Prospectivos , Segurança , Resultado do Tratamento
3.
J Infect Dev Ctries ; 15(1): 51-57, 2021 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-33571145

RESUMO

BACKGROUND: COVID-19 is a global pandemic. The virus spreads through respiratory droplets and close contact. Therefore, the availability of personal protective equipment (PPE) for healthcare professionals is essential. 3D printing technology could represent a valid option to ameliorate PPE shortages. METHODOLOGY: Custom-made face mask were designed on the basis of facial scan and then 3D-printed. The whole protocol is executed with freeware software and only required a 3D printer. Six healthcare workers wore the device weekly thus expressing a judgment regarding quality of work, respiratory and skin comfort. RESULTS: The estimated total cost of a single mask is approximately 5 USD. The virtual design of a complete mask lasted 68 minutes on average. Most healthcare workers rated comfort as very good. CONCLUSIONS: Based on the encouraging results obtained, we can confidently confirm that custom-made masks are novel and useful devices that may be used in the fight against COVID-19.


Assuntos
/prevenção & controle , Desenho de Equipamento/métodos , Máscaras/normas , Impressão Tridimensional , Desenho de Equipamento/instrumentação , Feminino , Pessoal de Saúde/estatística & dados numéricos , Humanos , Masculino , Máscaras/economia , Impressão Tridimensional/economia
4.
Int J Pharm ; 595: 120243, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33484923

RESUMO

Cardiovascular diseases constitute a number of conditions which are the leading cause of death globally. To combat these diseases and improve the quality and duration of life, several cardiac implants have been developed, including stents, vascular grafts and valvular prostheses. The implantation of these vascular prosthesis has associated risks such as infection or blood clot formation. In order to overcome these limitations medicated vascular prosthesis have been previously used. The present paper describes a 3D printing method to develop medicated vascular prosthesis using fused deposition modelling (FDM) technology. For this purpose, rifampicin (RIF) was selected as a model molecule as it can be used to prevent vascular graft prosthesis infection. Thermoplastic polyurethane (TPU) and RIF were combined using hot melt extrusion (HME) to obtain filaments containing RIF concentrations ranging between 0 and 1% (w/w). These materials are capable of providing RIF release for periods ranging between 30 and 80 days. Moreover, TPU-based materials containing RIF were capable of inhibiting the growth of Staphylococcus aureus. This behaviour was observed even for TPU-based materials containing RIF concentrations of 0.1% (w/w). TPU containing 1% (w/w) of RIF showed antimicrobial properties even after 30 days of RIF release. Alternatively, these methods were used to prepare dipyridamole containing TPU filaments. Finally, using a dual extrusion 3D printer vascular grafts containing both drugs were prepared.


Assuntos
Antibacterianos/farmacocinética , Sistemas de Liberação de Medicamentos/métodos , Poliuretanos/química , Rifampina/farmacocinética , Tecnologia Farmacêutica/métodos , Células Sanguíneas/efeitos dos fármacos , Prótese Vascular/efeitos adversos , Preparações de Ação Retardada/química , Dipiridamol/farmacocinética , Liberação Controlada de Fármacos , Desenho de Equipamento/métodos , Células Endoteliais da Veia Umbilical Humana , Humanos , Inibidores da Agregação de Plaquetas/farmacocinética , Poliuretanos/uso terapêutico , Impressão Tridimensional , Infecções Estafilocócicas/etiologia , Infecções Estafilocócicas/prevenção & controle , Staphylococcus aureus/efeitos dos fármacos , Trombose/etiologia , Trombose/prevenção & controle
5.
Anal Chem ; 93(4): 2570-2577, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33461290

RESUMO

Oxygen concentration varies tremendously within the body and has proven to be a critical variable in cell differentiation, proliferation, and drug metabolism among many other physiological processes. Currently, researchers study the gas's role in biology using low-throughput gas control incubators or hypoxia chambers in which all cells in a vessel are exposed to a single oxygen concentration. Here, we introduce a device that can simultaneously deliver 12 unique oxygen concentrations to cells in a 96-well plate and seamlessly integrate into biomedical research workflows. The device inserts into 96-well plates and delivers gas to the headspace, thus avoiding undesirable contact with media. This simple approach isolates each well using gas-tight pressure-resistant gaskets effectively creating 96 "mini-incubators". Each of the 12 columns of the plate is supplied by a distinct oxygen concentration from a gas-mixing gradient generator supplied by two feed gases. The wells within each column are then supplied by an equal flow-splitting distribution network. Using equal feed flow rates, concentrations ranging from 0.6 to 20.5% were generated within a single plate. A549 lung carcinoma cells were then used to show that O2 levels below 9% caused a stepwise increase in cell death for cells treated with the hypoxia-activated anticancer drug tirapirizamine (TPZ). Additionally, the 96-well plate was further leveraged to simultaneously test multiple TPZ concentrations over an oxygen gradient and generate a three-dimensional (3D) dose-response landscape. The results presented here show how microfluidic technologies can be integrated into, rather than replace, ubiquitous biomedical labware allowing for increased throughput oxygen studies.


Assuntos
Desenho de Equipamento/instrumentação , Desenho de Equipamento/métodos , Técnicas Analíticas Microfluídicas/instrumentação , Oxigênio , Impressão Tridimensional/instrumentação , Células A549 , Técnicas de Cultura de Células/instrumentação , Humanos
6.
J Acoust Soc Am ; 149(1): 66, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33514153

RESUMO

During the COVID-19 outbreak, the auscultation of heart and lung sounds has played an important role in the comprehensive diagnosis and real-time monitoring of confirmed cases. With clinicians wearing protective clothing in isolation wards, a potato chip tube stethoscope, which is a secure and flexible substitute for a conventional stethoscope, has been used by Chinese medical workers in the first-line treatment of COVID-19. In this study, an optimal design for this simple cylindrical stethoscope is proposed based on the fundamental theory of acoustic waveguides. Analyses of the cutoff frequency, sound power transmission coefficient, and sound wave propagation in the uniform lossless tube provide theoretical guidance for selecting the geometric parameters for this simple cylindrical stethoscope. A basic investigation into the auscultatory performances of the original tube and the optimal tube with proposed dimensions was conducted both in a semi-anechoic chamber and in a quiet laboratory. Both experimental results and front-line doctors' clinical feedback endorse the proposed theoretical optimization.


Assuntos
Acústica , Auscultação/normas , Desenho de Equipamento/normas , Estetoscópios/normas , Acústica/instrumentação , Auscultação/instrumentação , Auscultação/métodos , /fisiopatologia , Desenho de Equipamento/instrumentação , Desenho de Equipamento/métodos , Humanos , Sons Respiratórios/fisiologia , Sons Respiratórios/fisiopatologia
7.
Enferm Clin ; 31 Suppl 1: S73-S77, 2021 Feb.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-33487530

RESUMO

The main element of personal protective equipment against the SARS-CoV-2 pandemic are masks, which protect against droplets and aerosols that can remain suspended in the air. The objective of this study is to summarize the existing evidence on the filtration of different materials for the manufacture of masks. A scoping review or exploratory review has been carried out in the PubMEd and Scopus databases, using the terms "respirator", "mask", "facemask", "material", and "tissue", combined with Boolean operators. The results show some of the materials used for the manufacture of masks, both surgical masks and medium-high filtration masks, as well as materials used for the manufacture of household masks. As a conclusion, it is necessary to know the characteristics of the different materials as well as their properties to guarantee an adequate use according to the specific needs in each context, being fundamental the application of particle filtration systems as well as support materials that comply with current recommendations.


Assuntos
/prevenção & controle , Máscaras/normas , /epidemiologia , Celulose/normas , Desenho de Equipamento/métodos , Filtração/instrumentação , Filtração/normas , Pessoal de Saúde , Humanos , Máscaras/provisão & distribução , Pandemias , Equipamento de Proteção Individual/provisão & distribução , Polipropilenos/normas , Eletricidade Estática , Têxteis/normas
8.
Methods Mol Biol ; 2147: 3-18, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32840806

RESUMO

The design of optimized scaffolds for tissue engineering and regenerative medicine is a key topic of current research, as the complex macro- and micro-architectures required for scaffold applications depend not only on the mechanical properties but also on the physical and molecular queues of the surrounding tissue within the defect site. Thus, the prediction of optimal features for tissue engineering scaffolds is very important, for both its physical and biological properties.The relationship between high scaffold porosity and high mechanical properties is contradictory, as it becomes even more complex due to the scaffold degradation process. Biomimetic design has been considered as a viable method to design optimum scaffolds for tissue engineering applications. In this research work, the scaffold designs are based on biomimetic boundary-based bone micro-CT data. Based on the biomimetic boundaries and with the aid of topological optimization schemes, the boundary data and given porosity is used to obtain the initial scaffold designs. In summary, the proposed scaffold design scheme uses the principles of both the boundaries and porosity of the micro-CT data with the aid of numerical optimization and simulation tools.


Assuntos
Materiais Biomiméticos/síntese química , Desenho Assistido por Computador , Desenho de Equipamento/métodos , Engenharia Tecidual/instrumentação , Tecidos Suporte , Materiais Biomiméticos/química , Biomimética/métodos , Osso e Ossos/fisiologia , Simulação por Computador , Humanos , Modelos Anatômicos , Porosidade , Medicina Regenerativa/instrumentação , Medicina Regenerativa/métodos , Resistência ao Cisalhamento , Resistência à Tração , Engenharia Tecidual/métodos , Tecidos Suporte/química , Microtomografia por Raio-X
9.
PLoS One ; 15(12): e0244463, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33373392

RESUMO

Advances in additive manufacturing enable the production of tailored lattice structures and thus, in principle, coronary stents. This study investigates the effects of process-related irregularities, heat and surface treatment on the morphology, mechanical response, and expansion behavior of 316L stainless steel stents produced by laser powder bed fusion and provides a methodological approach for their numerical evaluation. A combined experimental and computational framework is used, based on both actual and computationally reconstructed laser powder bed fused stents. Process-related morphological deviations between the as-designed and actual laser powder bed fused stents were observed, resulting in a diameter increase by a factor of 2-2.6 for the stents without surface treatment and 1.3-2 for the electropolished stent compared to the as-designed stent. Thus, due to the increased geometrically induced stiffness, the laser powder bed fused stents in the as-built (7.11 ± 0.63 N) or the heat treated condition (5.87 ± 0.49 N) showed increased radial forces when compressed between two plates. After electropolishing, the heat treated stents exhibited radial forces (2.38 ± 0.23 N) comparable to conventional metallic stents. The laser powder bed fused stents were further affected by the size effect, resulting in a reduced yield strength by 41% in the as-built and by 59% in the heat treated condition compared to the bulk material obtained from tensile tests. The presented numerical approach was successful in predicting the macroscopic mechanical response of the stents under compression. During deformation, increased stiffness and local stress concentration were observed within the laser powder bed fused stents. Subsequent numerical expansion analysis of the derived stent models within a previously verified numerical model of stent expansion showed that electropolished and heat treated laser powder bed fused stents can exhibit comparable expansion behavior to conventional stents. The findings from this work motivate future experimental/numerical studies to quantify threshold values of critical geometric irregularities, which could be used to establish design guidelines for laser powder bed fused stents/lattice structures.


Assuntos
Desenho Assistido por Computador , Desenho de Equipamento/métodos , Teste de Materiais/métodos , Stents Metálicos Autoexpansíveis , Aço Inoxidável/química , Doença das Coronárias/cirurgia , Procedimentos Endovasculares/instrumentação , Análise de Elementos Finitos , Humanos , Estresse Mecânico
10.
PLoS One ; 15(12): e0244963, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33378363

RESUMO

The COVID-19 pandemic disrupted the world in 2020 by spreading at unprecedented rates and causing tens of thousands of fatalities within a few months. The number of deaths dramatically increased in regions where the number of patients in need of hospital care exceeded the availability of care. Many COVID-19 patients experience Acute Respiratory Distress Syndrome (ARDS), a condition that can be treated with mechanical ventilation. In response to the need for mechanical ventilators, designed and tested an emergency ventilator (EV) that can control a patient's peak inspiratory pressure (PIP) and breathing rate, while keeping a positive end expiratory pressure (PEEP). This article describes the rapid design, prototyping, and testing of the EV. The development process was enabled by rapid design iterations using additive manufacturing (AM). In the initial design phase, iterations between design, AM, and testing enabled a working prototype within one week. The designs of the 16 different components of the ventilator were locked by additively manufacturing and testing a total of 283 parts having parametrically varied dimensions. In the second stage, AM was used to produce 75 functional prototypes to support engineering evaluation and animal testing. The devices were tested over more than two million cycles. We also developed an electronic monitoring system and with automatic alarm to provide for safe operation, along with training materials and user guides. The final designs are available online under a free license. The designs have been transferred to more than 70 organizations in 15 countries. This project demonstrates the potential for ultra-fast product design, engineering, and testing of medical devices needed for COVID-19 emergency response.


Assuntos
/terapia , Desenho de Equipamento/métodos , Respiração Artificial/instrumentação , Ventiladores Mecânicos/efeitos adversos , Animais , Humanos , Respiração Artificial/métodos , Mecânica Respiratória/fisiologia , Taxa Respiratória/fisiologia , Suínos
11.
S Afr Med J ; 0(0): 13162, 2020 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-33334390

RESUMO

BACKGROUND: Given the global shortage of N95 filtering facepiece respirators (FFP2 in Europe) during the COVID-19 pandemic, KN95 masks (Chinese equivalent of the N95 and FFP2) were imported and distributed in South Africa (SA). However, there are hardly any published independent safety data on KN95 masks. OBJECTIVES: To evaluate the seal, fit and filtration efficiency of several brands of KN95 masks marketed for widespread use in SA healthcare facilities, using standardised testing protocols. METHODS: The verifiability of manufacturer and technical details was first ascertained, followed by evaluation of the number of layers comprising the mask material. The testing protocol involved a directly observed positive and negative pressure user seal check, which if passed was followed by qualitative fit testing (sodium saccharin) in healthy laboratory or healthcare workers. Quantitative fit testing (3M) was used to validate the qualitative fit testing method. The filtration efficacy and integrity of the mask filter material were evaluated using a particle counter-based testing rig utilising aerosolised saline (expressed as filtration efficacy of 0.3 µm particles). Halyard FLUIDSHIELD 3 N95 and 3M 1860 N95 masks were used as controls. RESULTS: Twelve KN95 mask brands (total of 36 masks) were evaluated in 7 participants. The mask type and manufacturing details were printed on only 2/12 brands (17%) as per National Institute of Occupational Safety and Health and European Union regulatory requirements. There was considerable variability in the number of KN95 mask layers (between 3 and 6 layers in the 12 brands evaluated). The seal check pass rate was significantly lower in KN95 compared with N95 masks (1/36 (3%) v. 12/12 (100%); p<0.0001). Modification of the KN95 ear-loop tension using head straps or staples, or improving the facial seal using Micropore 3M tape, enhanced seal test performance in 15/36 KN95 masks evaluated (42%). However, none of these 15 passed downstream qualitative fit testing compared with the control N95 masks (0/15 v. 12/12; p<0.0001). Only 4/8 (50%) of the KN95 brands tested passed the minimum filtration requirements for an N95 mask (suboptimal KN95 filtration efficacy varied from 12% to 78%, compared with 56% for a surgical mask and >99% for the N95 masks at the 0.3 µm particle size). CONCLUSIONS: The KN95 masks tested failed the stipulated safety thresholds associated with protection of healthcare workers against airborne pathogens such as SARS-CoV-2. These preliminary data have implications for the regulation of masks and their distribution to healthcare workers and facilities in SA.


Assuntos
Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Teste de Materiais/métodos , Exposição Ocupacional/prevenção & controle , /epidemiologia , Desenho de Equipamento/métodos , Desenho de Equipamento/normas , Análise de Falha de Equipamento , Humanos , Gestão da Segurança/organização & administração , África do Sul/epidemiologia
12.
Biomed Instrum Technol ; 54(5): 346-351, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33049766

RESUMO

Electroencephalography (EEG) is a sensitive and weak biosignal that varies from person to person. It is easily affected by noise and artifacts. Hence, maintaining the signal integrity to design an EEG acquisition system is crucial. This article proposes an analog design for acquiring EEG signals. The proposed design consists of eight blocks: (1) a radio-frequency interference filter and electro-static discharge protection, (2) a preamplifier and second-order high-pass filter with feedback topology and an unblocking mechanism, (3) a driven right leg circuit, (4) two-stage main and variable amplifiers, (5) an eight-order anti-aliasing filter, (6) a six-order 50-Hz notch filter (optional), (7) an opto-isolator circuit, and (8) an isolated power supply. The maximum gain of the design is approximately 94 dB, and its bandwidth ranges from approximately 0.18 to 120 Hz. The depth of the 50-Hz notch filter is -35 dB. Using this filter is optional because it causes EEG integrity problems in frequencies ranging from 40 to 60 Hz.


Assuntos
Amplificadores Eletrônicos , Eletroencefalografia , Artefatos , Fontes de Energia Elétrica , Desenho de Equipamento/métodos
13.
BMC Res Notes ; 13(1): 421, 2020 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-32894167

RESUMO

OBJECTIVE: The advent of new technologies has made it possible to explore alternative ventilator manufacturing to meet the worldwide shortfall for mechanical ventilators especially in pandemics. We describe a method using rapid prototyping technologies to create an electro-mechanical ventilator in a cost effective, timely manner and provide results of testing using an in vitro-in vivo testing model. RESULTS: Rapid prototyping technologies (3D printing and 2D cutting) were used to create a modular ventilator. The artificial manual breathing unit (AMBU) bag connected to wall oxygen source using a flow meter was used as air reservoir. Controlled variables include respiratory rate, tidal volume and inspiratory: expiratory (I:E) ratio. In vitro testing and In vivo testing in the pig model demonstrated comparable mechanical efficiency of the test ventilator to that of standard ventilator but showed the material limits of 3D printed gears. Improved gear design resulted in better ventilator durability whilst reducing manufacturing time (< 2-h). The entire cost of manufacture of ventilator was estimated at 300 Australian dollars. A cost-effective novel rapid prototyped ventilator for use in patients with respiratory failure was developed in < 2-h and was effective in anesthetized, healthy pig model.


Assuntos
Desenho de Equipamento/métodos , Respiração Artificial/instrumentação , Ventiladores Mecânicos/provisão & distribução , Anestesia Geral/métodos , Animais , Infecções por Coronavirus/terapia , Volume de Reserva Expiratória/fisiologia , Feminino , Humanos , Volume de Reserva Inspiratória/fisiologia , Modelos Biológicos , Pandemias , Pneumonia Viral/terapia , Impressão Tridimensional/instrumentação , Respiração Artificial/economia , Respiração Artificial/métodos , Taxa Respiratória/fisiologia , Suínos , Volume de Ventilação Pulmonar/fisiologia , Ventiladores Mecânicos/economia
14.
PLoS One ; 15(9): e0239008, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32956410

RESUMO

This paper presents analysis, design and experimentation of a high voltage DC power supply (HVDCPS) with power factor correction based on LLC resonant converter. For power factor correction improvement, the proposed topology has an input rectifier with two filter capacitors, two inductors with a bus capacitor (Cbus) and a resonant tank. To prevent the reverse current flow towards the source diodes (D9 & D10) are employed. A couple of power switches are inserted in a single leg that makes a half-bridge network. To form an LLC resonance circuit, a capacitor and two inductors are connected to the primary winding of the high voltage transformer (HVT). To rectify the high frequency and high voltage, a full-bridge rectifier is inserted to secondary side of high voltage transformer (HVT). The secondary diodes always get on and off under zero current switching (ZCS) due to discontinuous conduction mode of proposed topology. It is found that due to power factor correction, less cost, lower losses and smaller size, the proposed topology achieves several major improvements over the conventional high voltage power supply. To obtain zero voltage switching (ZVS) the converter operate in a narrow frequency range. The output voltage can be varied or regulate through pulse width modulation of power switches. Due to ZVS and ZCS, the proposed topology has minimum switching losses and therefore higher efficiency. To verify the feasibility of the proposed topology a prototype is being implemented and verified by simulation & experimental results for 1.5KV prototype of the proposed topology. The results make sure the achievement, good efficiency and successful operation of the proposed topology.


Assuntos
Fontes de Energia Elétrica/tendências , Desenho de Equipamento/instrumentação , Desenho de Equipamento/métodos , Simulação por Computador , Capacitância Elétrica
15.
PLoS One ; 15(9): e0239297, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32941538

RESUMO

The mismatch between students' anthropometric measures and school furniture dimensions have been investigated in many countries. In Iran, collegians spend at least a quarter of the day hours at university in the sitting position, so it is essential to evaluate furniture mismatch among university students. In Iranian universities, the use of chairs with an attached table is widespread, while the study of mismatches in these chairs among the collegian community is rare. This study was aimed to compare and rank different classroom furniture types based on the mismatch between collegians' anthropometric measures and the dimensions of classroom furniture among Industrial Engineering students by developing a Multi-Criteria Decision Making approach in an integrated Methodology. The sample consisted of 111 participants (71 males, 40 females). Ten anthropometric measures were gathered, together with eight furniture dimensions for four types of chairs. Mismatch analyses were carried out using mismatch equations, and the Simple Additive Weighting method was used as a base method to solve the decision-making problem. The results indicated that Underneath Desk Height and Seat to Desk Clearance showed the highest levels of the match, while Seat Width presents the highest levels of low mismatch. According to the results, Type 1 and Type 3 were the best current classroom furniture. The Sensitivity Analysis was performed in two ways: changing the weights of criteria in nine scenarios and comparing the results with five other MCDM methods. The proposed MCDM approach can be used widely in furniture procurement processes and educational environments.


Assuntos
Algoritmos , Pesos e Medidas Corporais/estatística & dados numéricos , Desenho de Equipamento/métodos , Decoração de Interiores e Mobiliário/normas , Estudantes/estatística & dados numéricos , Universidades , Adolescente , Tomada de Decisões , Feminino , Humanos , Masculino , Adulto Jovem
16.
PLoS One ; 15(9): e0239608, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32970768

RESUMO

Electro-mechanical brakes (EMBs) are the future of braking systems, particularly in commercial vehicles. Therefore, it is important to design a simple EMB scheme and establish its clamping force control strategy to satisfy the demands of commercial vehicle braking systems. This study proposes a pneumatic disc-brake-based EMB for an electric bus. Its working principle was established, and the system model was analyzed. Subsequently, the hidden Markov models (HMMs) of driver decelerate and brake intentions were built and recognized based on the analytic hierarchy process (AHP). Given the time-consuming behavior of the proposed EMB to eliminate brake clearance due to the leverage effect of the arm and motor performance limitation, a clamping force control strategy factoring in the driver intentions was developed to improve the response performance without changing the structure or size of the EMB. Furthermore, simulation analyses were performed using MATLAB/Simulink. The results confirmed that under the action of a step and 5 Hz triangular sawtooth signals, the clamping force output from the EMB corresponds well with the target signal. The clamping force gradually increases when approaching the target without overshoot and jitter during the process. The overall clamping force response time is decreased by approximately 0.25 s under the driver emergency brake than the conventional control method. Hence, the response performance of the EMB is improved.


Assuntos
Automóveis/normas , Simulação por Computador , Desaceleração , Intenção , Condução de Veículo/psicologia , Desenho de Equipamento/métodos , Humanos
17.
Rev Esp Anestesiol Reanim ; 67(8): 417-424, 2020 10.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-32891414

RESUMO

BACKGROUND AND OBJECTIVE: There is a shortage of supplies for the protection of professionals during the COVID-19 pandemic. 3D printing offers the possibility to compensate for the production of some of the equipment needed. The objective is to describe the role of 3D printing in a health service during the COVID-19 pandemic, with an emphasis on the process to develop a final product ready to be implemented in the clinical environment. METHODS: A working group was formed between the healthcare administration, clinicians and other public and private institutions in Cantabria, Spain coordinated by the Valdecilla Virtual Hospital. The process included receiving the printing proposals, learning about the printing resources in the region, selecting the devices, creating a team for each project, prototyping, evaluation and redesign, manufacturing, assembly and distribution. RESULTS: The following supplies are produced: 1) devices that help protect providers: face protection screens (2,400 units), personalized accessories for photophores (20 units) and ear-protection forks for face-masks (1,200 units); 2) products related to the ventilation of infected patients: connectors for non-invasive ventilation systems; and 3) oral and nasopharyngeal swabs (7,500 units) for the identification of coronavirus carriers with the aim of designing action protocols in clinical areas. CONCLUSIONS: 3D printing is a valid resource for the production of protective material for professionals whose supply is reduced during a pandemic.


Assuntos
Betacoronavirus , Infecções por Coronavirus/prevenção & controle , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Máscaras , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Impressão Tridimensional , Ventiladores Mecânicos , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/epidemiologia , Cuidados Críticos , Desenho de Equipamento/métodos , Humanos , Máscaras/provisão & distribução , Equipamento de Proteção Individual , Pneumonia Viral/epidemiologia , Espanha , Centros de Atenção Terciária
18.
Appl Opt ; 59(25): 7585-7595, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32902458

RESUMO

We present evidence-based design principles for three different UV-C based decontamination systems for N95 filtering facepiece respirators (FFRs) within the context of the SARS-CoV-2 outbreak of 2019-2020. The approaches used here were created with consideration for the needs of low- and middle-income countries (LMICs) and other under-resourced facilities. As such, a particular emphasis is placed on providing cost-effective solutions that can be implemented in short order using generally available components and subsystems. We discuss three optical designs for decontamination chambers, describe experiments verifying design parameters, validate the efficacy of the decontamination for two commonly used N95 FFRs (3M, #1860 and Gerson #1730), and run mechanical and filtration tests that support FFR reuse for at least five decontamination cycles.


Assuntos
Filtros de Ar , Descontaminação/instrumentação , Desenho de Equipamento/métodos , Máscaras , Raios Ultravioleta , Filtros de Ar/microbiologia , Filtros de Ar/virologia , Reutilização de Equipamento , Umidade , Ozônio/síntese química , Ozônio/toxicidade , Temperatura , Raios Ultravioleta/efeitos adversos
19.
J Laryngol Otol ; 134(8): 735-738, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32718361

RESUMO

BACKGROUND: Coronavirus disease 2019 is an international pandemic. One of the cardinal features is acute respiratory distress syndrome, and proning has been identified as beneficial for a subset of patients. However, proning is associated with pressure-related side effects, including injury to the nose and face. METHOD: This paper describes a pressure-relieving technique using surgical scrub sponges. This technique was derived based on previous methods used in patients following rhinectomy. CONCLUSION: The increased use of prone ventilation has resulted in a number of referrals to the ENT team with concerns regarding nasal pressure damage. The described technique, which is straightforward and uses readily available materials, has proven effective in relieving pressure in a small number of patients.


Assuntos
Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pressão/efeitos adversos , Decúbito Ventral/fisiologia , Respiração Artificial/métodos , Tampões de Gaze Cirúrgicos/normas , Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/transmissão , Infecções por Coronavirus/virologia , Desenho de Equipamento/métodos , Traumatismos Faciais/prevenção & controle , Humanos , Nariz/lesões , Nariz/cirurgia , Posicionamento do Paciente/métodos , Pneumonia Viral/epidemiologia , Pneumonia Viral/transmissão , Pneumonia Viral/virologia
20.
A A Pract ; 14(8): e01264, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32643906

RESUMO

Approximately 30% of health care workers (HCWs) fail the respirator fit test. Evidence suggests that addressing face leaks in the 3M respirator enhances its fit and improves its efficacy. Between March 31 and April 9, 2020, HCWs who failed fit tests for 3M 1860 and 1860S respirators were invited to retest with an adhesive modification of the 3M respirator. Sixty-eight percent of HCWs who failed the fit test with their first-choice respirator passed with a modified adhesive respirator. To increase the efficacy and safety of 3M respirators, ineffective face seals need substantial improvement in design.


Assuntos
Betacoronavirus , Infecções por Coronavirus/prevenção & controle , Desenho de Equipamento/métodos , Pessoal de Saúde , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Dispositivos de Proteção Respiratória/estatística & dados numéricos , Adesivos , Adulto , Feminino , Humanos , Masculino , Projetos Piloto
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