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1.
Int J Mol Sci ; 23(21)2022 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-36362036

RESUMO

Nitride film played an essential role as an excellent diffusion barrier in the semiconductor field for several decades. In addition, interest in next-generation memories induced researchers' attention to nitride film as a new storage medium. A Pt/AlN/TaN device was investigated for resistive random-access memory (RRAM) application in this work. Resistive switching properties were examined in the AlN thin film formed by atomic layer deposition (ALD). The unique switching feature conducted under the positive voltage was investigated, while the typical bipolar switching was conducted under the application of negative voltage. Good retention and DC, and pulse endurances were achieved in both conditions and compared to the memory performances. Finally, the electronic behaviors based on the unique switching feature were analyzed through X-ray photoelectron spectroscopy (XPS) and the current-voltage (I-V) linear fitting model.


Assuntos
Dispositivos de Armazenamento em Computador , Semicondutores , Eletrônica , Espectroscopia Fotoeletrônica
2.
ACS Appl Mater Interfaces ; 13(8): 10639-10649, 2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33606512

RESUMO

Two-dimensional (2D) materials based artificial synapses are important building blocks for the brain-inspired computing systems that are promising in handling large amounts of informational data with high energy-efficiency in the future. However, 2D devices usually rely on deposited or transferred insulators as the dielectric layer, resulting in various challenges in device compatibility and fabrication complexity. Here, we demonstrate a controllable and reliable oxidation process to turn 2D semiconductor HfS2 into native oxide, HfOx, which shows good insulating property and clean interface with HfS2. We then incorporate the HfOx/HfS2 heterostructure into a flash memory device, achieving a high on/off current ratio of ∼105, a large memory window over 60 V, good endurance, and a long retention time over 103 seconds. In particular, the memory device can work as an artificial synapse to emulate basic synaptic functions and feature good linearity and symmetry in conductance change during long-term potentiation/depression processes. A simulated artificial neural network based on our synaptic device achieves a high accuracy of ∼88% in MNIST pattern recognition. Our work provides a simple and effective approach for integrating high-k dielectrics into 2D material-based memory and synaptic devices.


Assuntos
Dispositivos de Armazenamento em Computador , Háfnio/química , Sulfetos/química , Biomimética/métodos , Condutividade Elétrica , Eletrônica , Redes Neurais de Computação , Oxirredução , Semicondutores , Sinapses/química
3.
ACS Appl Mater Interfaces ; 13(1): 1057-1064, 2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33378176

RESUMO

Inverse photoconductance is an uncommon phenomenon observed in selective low-dimensional materials, in which the electrical conductivity of the materials decreases under light illumination. The unique material property holds great promise for biomedical applications in photodetectors, photoelectric logic gates, and low-power nonvolatile memory, which remains a daunting challenge. Especially, tunable photoconductivity for biocompatible materials is highly desired for interfacing with biological systems but is less explored in organic materials. Here, we report nanofibers self-assembled with cyclo-tyrosine-tyrosine (cyclo-YY) having voltage-regulated inverse photoconductance and photoconductance. The peptide nanofibers can be switched back and forth by a bias voltage for imitating biological sensing in artificial vision and memory devices. A peptide optoelectronic resistive random access memory (PORRAM) device has also been fabricated using the nanofibers that can be electrically switched between long-term and short-term memory. The underlying mechanism of the reversible photoconductance is discussed in this paper. Due to the inherent biocompatibility of peptide materials, the reversible photoconductive nanofibers may have broad applications in sensing and storage for biotic and abiotic interfaces.


Assuntos
Dipeptídeos/química , Nanofibras/química , Peptídeos Cíclicos/química , Dispositivos de Armazenamento em Computador , Computadores Moleculares , Dipeptídeos/efeitos da radiação , Condutividade Elétrica , Nanofibras/efeitos da radiação , Peptídeos Cíclicos/efeitos da radiação
4.
PLoS One ; 15(9): e0238115, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32915812

RESUMO

This work provides an in-depth computational performance study of the parallel finite-difference time-domain (FDTD) method. The parallelization is done at various levels including: shared- (OpenMP) and distributed- (MPI) memory paradigms and vectorization on three different architectures: Intel's Knights Landing, Skylake and ARM's Cavium ThunderX2. This study contributes to prove, in a systematic manner, the well-established claim within the Computational Electromagnetic community, that the main factor limiting FDTD performance, in realistic problems, is the memory bandwidth. Consequently a memory bandwidth threshold can be assessed depending on the problem size in order to attain optimal performance. Finally, the results of this study have been used to optimize the workload balancing of simulation of a bioelectromagnetic problem consisting in the exposure of a human model to a reverberation chamber-like environment.


Assuntos
Algoritmos , Campos Eletromagnéticos , Osso e Ossos/fisiologia , Dispositivos de Armazenamento em Computador , Sistemas Computacionais , Humanos , Rim/fisiologia , Fígado/fisiologia , Modelos Teóricos , Software
5.
Adv Mater ; 32(37): e2001249, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32725925

RESUMO

DNA-based data storage has attracted attention because of its higher physical density of the data and longer retention time than those of conventional digital data storage. However, previous DNA-based data storage lacked index features and the data quality of storage after a single access was not preserved, obstructing its industrial use. Here, DNA micro-disks, QR-coded micro-sized disks that harbor data-encoded DNA molecules for the efficient management of DNA-based data storage, are proposed. The two major features that previous DNA-based data-storage studies could not achieve are demonstrated. One feature is accessing data items efficiently by indexing the data-encoded DNA library. Another is achieving write-once-read-many (WORM) memory through the immobilization of DNA molecules on the disk and their enrichment through in situ DNA production. Through these features, the reliability of DNA-based data storage is increased by allowing selective and multiple accession of data-encoded DNA with lower data loss than previous DNA-based data storage methods.


Assuntos
Dispositivos de Armazenamento em Computador , DNA , Armazenamento e Recuperação da Informação/métodos
6.
Mol Syst Biol ; 16(3): e9401, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32141239

RESUMO

Synthetic genetic circuits offer the potential to wield computational control over biology, but their complexity is limited by the accuracy of mathematical models. Here, we present advances that enable the complete encoding of an electronic chip in the DNA carried by Escherichia coli (E. coli). The chip is a binary-coded digit (BCD) to 7-segment decoder, associated with clocks and calculators, to turn on segments to visualize 0-9. Design automation is used to build seven strains, each of which contains a circuit with up to 12 repressors and two activators (totaling 63 regulators and 76,000 bp DNA). The inputs to each circuit represent the digit to be displayed (encoded in binary by four molecules), and output is the segment state, reported as fluorescence. Implementation requires an advanced gate model that captures dynamics, promoter interference, and a measure of total power usage (RNAP flux). This project is an exemplar of design automation pushing engineering beyond that achievable "by hand", essential for realizing the potential of biology.


Assuntos
Escherichia coli/genética , Processamento de Sinais Assistido por Computador/instrumentação , Biologia Sintética/instrumentação , Algoritmos , Inteligência Artificial , Dispositivos de Armazenamento em Computador , Desenho de Equipamento
7.
PLoS One ; 15(3): e0229645, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32119705

RESUMO

Solid-state drives (SSDs) that do not have internal dynamic random-access memory (DRAM) are being widely spread for client SSD and embedded SSD markets in recent years because they are cheap and consume less power. Obviously, their performance is lower than conventional SSDs because they cannot exploit advantages of DRAM in the controller. However, this problem can be alleviated by using host memory buffer (HMB) feature of Non-Volatile Memory Express (NVMe), which allows SSDs to utilize the DRAM of host. In this paper, we show that commercial DRAM-less SSDs clearly exhibit worse I/O performance than SSDs with internal DRAM, but this can be improved by using the HMB feature. We also present methods that reveal how the host memory buffer is used in commercial DRAM-less SSDs to improve I/O performance. Through extensive experiments, we conclude that DRAM-less SSDs evaluated in this study mainly exploit the host memory buffer as an address mapping table cache rather than a read cache or write buffer to improve I/O performance.


Assuntos
Periféricos de Computador/tendências , Dispositivos de Armazenamento em Computador/tendências , Computadores/tendências , Algoritmos , Periféricos de Computador/economia , Periféricos de Computador/estatística & dados numéricos , Dispositivos de Armazenamento em Computador/estatística & dados numéricos
8.
Molecules ; 25(3)2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31979354

RESUMO

Organic nonvolatile transistor memory with synthetic polypeptide derivatives as dielectric was fabricated by a solution process. When only poly (γ-benzyl-l-glutamate) (PBLG) was used as dielectric, the device did not show obvious hysteresis in transfer curves. However, PBLG blended with PMMA led to a remarkable increase in memory window up to 20 V. The device performance was observed to remarkably depend on the blend ratio. This study suggests the crystal structure and the molecular alignment significantly affect the electrical performance in transistor-type memory devices, thereby provides an alternative to prepare nonvolatile memory with polymer dielectrics.


Assuntos
Desenho de Equipamento/métodos , Nanoestruturas/química , Peptídeos/química , Ácido Poliglutâmico/análogos & derivados , Polímeros/química , Polimetil Metacrilato/química , Transistores Eletrônicos , Dicroísmo Circular , Dispositivos de Armazenamento em Computador , Eletricidade , Microscopia de Força Atômica , Ácido Poliglutâmico/química , Propriedades de Superfície , Difração de Raios X
9.
Macromol Rapid Commun ; 41(3): e1900542, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31880040

RESUMO

A compatible organic/inorganic nanocomposite film for a stretchable resistive memory device with high performance is demonstrated using poly(4-vinylpyridine)-block-poly(propyl methacrylate) (P4VP-b-PPMA) with zinc oxide (ZnO) nanoparticle. The PPMA soft segment is designed for reducing the rigidity of the active layer, while the P4VP block serves as a charge-trapping component to induce conductive filament and also a compatible moiety for inorganic nanoparticles through hydrogen bonding. The experimental results show that the P4VP-b-PPMA-based electrical memory device exhibits write-once-read-many-times memory behavior and an excellent ON/OFF current ratio of over 105 with a stable turn-on voltage (Vset ) around -2.0 V and stable memory behavior upon stretching up to 60% strain. On the other hand, P4VP-b-PPMA/ZnO nanocomposite film switches the memory characteristic to the dynamic random access memory behavior. The stretchable memory device prepared from the nanocomposite film can have a stretching durability over 40% strain and up to 1000 times cycling stretch-relaxation test. This work demonstrates a new strategy using nanocomposite films with tunable electrical characteristics and enhanced mechanical properties for stretchable electrical devices.


Assuntos
Dispositivos de Armazenamento em Computador , Eletrônica/métodos , Nanocompostos/química , Polímeros/química , Condutividade Elétrica , Eletricidade , Eletrônica/instrumentação , Metacrilatos/química , Compostos Orgânicos/química , Polímeros/análise , Piridinas/química , Óxido de Zinco/química
10.
J Phys Chem Lett ; 10(24): 7745-7752, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31773960

RESUMO

Logic gate functions built with nonvolatile resistive switching and thermoresponsive memory based on biologic proteins were investigated. The "NAND" and "NOR" functions of logic gates in soya protein devices have been built at room temperature by their nonvolatile ternary WORM resistive switching behaviors. Furthermore, heating the devices from room temperature to 358 K results in a switch from tristable state to bistable state WORM resistive switching behavior, indicating that the thermoresponsiveness can be efficiently memorized. The biologic transient nonvolatile memory device consisting of soya protein is illustrated. This device exhibits a long data retention time (104 s) and significant HRS/LRS ratio (∼105); the transient response of the current to voltage of an as-fabricated device is also explored. The soya protein based memory device on a gelatin film substrate is also assessed to validate the feasibility of degradation and biological compatibility for the implantable biological electronic device, that is, innoxious and avirulent to the human body. This can offer alternative avenues for exploring prospective bioelectronic devices.


Assuntos
Dispositivos de Armazenamento em Computador , Desenho de Equipamento/instrumentação , Proteínas de Plantas/química , Soja/química , Condutividade Elétrica , Eletrodos , Gelatina/química , Temperatura
11.
Sci Rep ; 9(1): 16141, 2019 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-31695093

RESUMO

Bio - molecules detection and their quantification with a high precision is essential in modern era of medical diagnostics. In this context, the memristor device which can change its resistance state is a promising technique to sense the bio - molecules. In this work, detection of the Bovine Serum Albumin (BSA) protein using resistive switching memristors based on TiO2 and TiO2 + graphene oxide (GO) is explored. The sensitivity of BSA detection is found to be 4 mg/mL. Both the devices show an excellent bipolar resistive switching with an on/off ratio of 73 and 100 respectively, which essentially demonstrates that the device with GO, distinguishes the resistance states with a high precision. The enhanced performance in the GO inserted device (~ 650 cycles) is attributed to the prevention of multi-dimensional and random growth of conductive paths.


Assuntos
Bovinos/sangue , Dispositivos de Armazenamento em Computador , Soroalbumina Bovina/análise , Adsorção , Animais , Desenho de Equipamento , Grafite , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Sensibilidade e Especificidade , Eletricidade Estática , Titânio
12.
Gigascience ; 8(10)2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31648300

RESUMO

BACKGROUND: Gene homology type classification is required for many types of genome analyses, including comparative genomics, phylogenetics, and protein function annotation. Consequently, a large variety of tools have been developed to perform homology classification across genomes of different species. However, when applied to large genomic data sets, these tools require high memory and CPU usage, typically available only in computational clusters. FINDINGS: Here we present a new graph-based orthology analysis tool, SwiftOrtho, which is optimized for speed and memory usage when applied to large-scale data. SwiftOrtho uses long k-mers to speed up homology search, while using a reduced amino acid alphabet and spaced seeds to compensate for the loss of sensitivity due to long k-mers. In addition, it uses an affinity propagation algorithm to reduce the memory usage when clustering large-scale orthology relationships into orthologous groups. In our tests, SwiftOrtho was the only tool that completed orthology analysis of proteins from 1,760 bacterial genomes on a computer with only 4 GB RAM. Using various standard orthology data sets, we also show that SwiftOrtho has a high accuracy. CONCLUSIONS: SwiftOrtho enables the accurate comparative genomic analyses of thousands of genomes using low-memory computers. SwiftOrtho is available at https://github.com/Rinoahu/SwiftOrtho.


Assuntos
Genômica/métodos , Algoritmos , Proteínas de Bactérias/genética , Análise por Conglomerados , Dispositivos de Armazenamento em Computador , Genoma Bacteriano
13.
Artigo em Inglês | MEDLINE | ID: mdl-31454944

RESUMO

This article explores the performance optimizations of an embedded database memory management system to ensure high responsiveness of real-time healthcare data frameworks. SQLite is a popular embedded database engine extensively used in medical and healthcare data storage systems. However, SQLite is essentially built around lightweight applications in mobile devices, and it significantly deteriorates when a large transaction is issued such as high resolution medical images or massive health dataset, which is unlikely to occur in embedded systems but is quite common in other systems. Such transactions do not fit in the in-memory buffer of SQLite, and SQLite enforces memory reclamation as they are processed. The problem is that the current SQLite buffer management scheme does not effectively manage these cases, and the naïve reclamation scheme used significantly increases the user-perceived latency. Motivated by this limitation, this paper identifies the causes of high latency during processing of a large transaction, and overcomes the limitation via proactive and coarse-grained memory cleaning in SQLite.The proposed memory reclamation scheme was implemented in SQLite 3.29, and measurement studies with a prototype implementation demonstrated that the SQLite operation latency decreases by 13% on an average and up to 17.3% with our memory reclamation scheme as compared to that of the original version.


Assuntos
Dispositivos de Armazenamento em Computador/normas , Bases de Dados Factuais/normas , Registros Eletrônicos de Saúde/normas , Análise de Falha de Equipamento/estatística & dados numéricos , Guias como Assunto , Armazenamento e Recuperação da Informação/normas , Dispositivos de Armazenamento em Computador/estatística & dados numéricos , Bases de Dados Factuais/estatística & dados numéricos , Registros Eletrônicos de Saúde/estatística & dados numéricos , Humanos , Armazenamento e Recuperação da Informação/estatística & dados numéricos
14.
Cells ; 8(5)2019 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-31126166

RESUMO

As a typical biomedical detection task, nuclei detection has been widely used in human health management, disease diagnosis and other fields. However, the task of cell detection in microscopic images is still challenging because the nuclei are commonly small and dense with many overlapping nuclei in the images. In order to detect nuclei, the most important key step is to segment the cell targets accurately. Based on Mask RCNN model, we designed a multi-path dilated residual network, and realized a network structure to segment and detect dense small objects, and effectively solved the problem of information loss of small objects in deep neural network. The experimental results on two typical nuclear segmentation data sets show that our model has better recognition and segmentation capability for dense small targets.


Assuntos
Núcleo Celular , Aprendizado Profundo , Processamento de Imagem Assistida por Computador/métodos , Dispositivos de Armazenamento em Computador , Amarelo de Eosina-(YS)/química , Hematoxilina/química , Humanos , Modelos Logísticos , Microscopia de Fluorescência , Modelos Biológicos , Coloração e Rotulagem
15.
Sci Rep ; 9(1): 4318, 2019 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-30867495

RESUMO

The advent of Nanopore sequencing has realised portable genomic research and applications. However, state of the art long read aligners and large reference genomes are not compatible with most mobile computing devices due to their high memory requirements. We show how memory requirements can be reduced through parameter optimisation and reference genome partitioning, but highlight the associated limitations and caveats of these approaches. We then demonstrate how these issues can be overcome through an appropriate merging technique. We incorporated multi-index merging into the Minimap2 aligner and demonstrate that long read alignment to the human genome can be performed on a system with 2 GB RAM with negligible impact on accuracy.


Assuntos
Genoma Humano/genética , Genômica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Algoritmos , Dispositivos de Armazenamento em Computador , Humanos , Sequenciamento por Nanoporos/métodos , Análise de Sequência de DNA/métodos , Software
16.
Carbohydr Polym ; 214: 213-220, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30925991

RESUMO

Nowadays the development of natural biomaterials as promising building polymers for flexible, biodegradable, biocompatible and environmentally friendly electronic devices is of great interest. As the most common natural polymers, cellulose and its derivatives have the potential to be applied in the devices owing to the easy processing, nontoxicity and biodegradability. Here, write-once-read-many-times resistive switching devices based on biodegradable carboxymethyl cellulose-graphene oxide (CMC-GO) nanocomposite are demonstrated for the first time. The hybridization sites formed by the gelation of CMC and GO molecules contribute to the excellent memory behaviors. When compared with devices base on pure GO and CMC, the device with the Al/CMC-GO/Al/SiO2 structure exhibits brilliant write-once-read-many-times (WORM) switching characteristics such as high ON/OFF current ratio of ˜105, low switching voltage of 2.22 V, excellent stability and durability. What's more, the device shows high flexibility and good resistive switching behaviors even with soft PET substrate (Al/CMC-GO/Al/PET structure). This newly designed cellulose-graphene oxide-based polymer nanocomposites are quite cheap and easy processed for large scale manufacturing of memory devices and can further contribute to future biodegradable data storage applications such as portable stretchable displays, wearable electronics and electronic skins in the coming age of artificial intelligence.


Assuntos
Carboximetilcelulose Sódica/química , Dispositivos de Armazenamento em Computador , Equipamentos e Provisões Elétricas , Grafite/química , Nanocompostos/química , Alumínio/química , Carboximetilcelulose Sódica/síntese química , Eletrodos , Grafite/síntese química , Dióxido de Silício/química
17.
IEEE Trans Biomed Eng ; 66(10): 2809-2822, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30714907

RESUMO

OBJECTIVE: This paper presents a data-driven method for estimating the memory order (the average length of the statistical dependence of a given sample on previous samples) of a recorded electrocorticography (ECoG) sequence. METHODS: The proposed inference method is based on the relationship between the loss in predicting the next sample in a time-series and the dependence of this sample on the previous samples. Specifically, the memory order is estimated to be the number of past samples that minimize the least squares error (LSE) in predicting the next sample. To deal with the lack of an analytical model for ECoG recordings, the proposed method combines a collection of different predictors, thereby achieving LSE at least as low as the LSE achieved by each of the different predictors. RESULTS: ECoG recordings from six patients with epilepsy were analyzed, and the empirical cumulative density functions (ECDFs) of the memory orders estimated from these recordings were generated, for rest as well as pre-ictal time intervals. For pre-ictal time intervals, the electrodes corresponding to the seizure-onset-zone were separately analyzed. The estimated ECDFs were different between patients and between different types of blocks. For all the analyzed patients, the estimated memory orders were on the order of tens of milliseconds (up to 100 ms). SIGNIFICANCE: The proposed method facilitates the estimation of the causal associations between ECoG recordings, as these associations strongly depend on the recordings' memory. An improved estimation of causal associations can improve the performance of algorithms that use ECoG recordings to localize the epileptogenic zone. Such algorithms can aid doctors in their pre-surgical planning for the surgery of patients with epilepsy.


Assuntos
Algoritmos , Dispositivos de Armazenamento em Computador , Eletrocorticografia/métodos , Epilepsia/fisiopatologia , Humanos , Análise dos Mínimos Quadrados , Modelos Lineares , Planejamento de Assistência ao Paciente , Valor Preditivo dos Testes
18.
Sci Rep ; 8(1): 11160, 2018 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-30042433

RESUMO

The Resistive RAM (RRAM) technology is currently in a level of maturity that calls for its integration into CMOS compatible memory arrays. This CMOS integration requires a perfect understanding of the cells performance and reliability in relation to the deposition processes used for their manufacturing. In this paper, the impact of the precursor chemistries and process conditions on the performance of HfO2 based memristive cells is studied. An extensive characterization of HfO2 based 1T1R cells, a comparison of the cell-to-cell variability, and reliability study is performed. The cells' behaviors during forming, set, and reset operations are monitored in order to relate their features to conductive filament properties and process-induced variability of the switching parameters. The modeling of the high resistance state (HRS) is performed by applying the Quantum-Point Contact model to assess the link between the deposition condition and the precursor chemistry with the resulting physical cells characteristics.


Assuntos
Dispositivos de Armazenamento em Computador , Condutividade Elétrica , Impedância Elétrica , Háfnio/análise , Háfnio/química , Óxidos/análise , Óxidos/química , Transistores Eletrônicos , Algoritmos , Carbono/análise , Carbono/química , Cristalização , Temperatura Alta , Sistemas Microeletromecânicos , Microscopia Eletrônica de Transmissão , Modelos Teóricos , Oxigênio/análise , Espectroscopia Fotoeletrônica , Difração de Raios X
19.
Respir Care ; 63(9): 1139-1146, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29921607

RESUMO

BACKGROUND: Remote monitoring is increasingly used in patients who receive home mechanical ventilation. The average volume assured pressure support mode is a target volume pressure preset mode that delivers a given tidal volume (VT) within a range of controlled inspiratory pressures. In a mode such as this, it is important to verify that the VT value retrieved from the ventilator SD card is accurate. METHODS: A lung model was set with C (Compliance) 0.075 L/cm H2O and RI (Inspiratory resistance)-RE (Expiratory resistance) 15-25 cm H2O/L/s (model 1) or with C 0.050 L/cm H2O and RI 6 cm H2O/L/s (model 2) and 6 cm H2O effort. Three home-care ventilators (A40, PrismaST30, and Vivo40) were set to average volume assured pressure support mode with 0.3 and 0.6 L VT each at PEEP 5 and 10 cm H2O, and were connected to the lung model with and without nonintentional leak. The reference airway pressure and flow were measured by a data logger. VT was expressed in body temperature and pressure saturated. We assessed the difference in VT between the ventilator SD card and a data logger relative to set VT and factors associated with its magnitude. RESULTS: For A40, PrismaST30, and Vivo40, the adjusted mean VT differences between the ventilator SD card and the data logger were -0.053 L (95% CI -0.067 to -0.039 L) (P < .001), -0.002 L (95%CI -0.022 to 0.019 L) (P = .86), and -0.067 L (95% CI -0.007 to 0.127 L) (P = .03), respectively. The partial Spearman correlation coefficients between the ventilator SD card and a data logger were 0.89 (P < .001), 0.59 (P < .001), and 0.78 (P < .001), respectively to the ventilators. The relative variations in measured VT from the set VT were 16.0, -12.0, and 6.7% for the ventilator SD card, and were -2.5, -7.5, and -27.2% for the data logger, respectively. The discrepancy in ventilator between SD card and data logger were influenced by PEEP for the PrismaST30 ventilator, nonintentional leak for the Vivo40 ventilator and PEEP, nonintentional leak, and underlying disease, the effect of each depending on the levels of the other factors, for the A40 ventilator. CONCLUSIONS: In the 3 home-care ventilators, the ventilator SD card underestimated VT. Factors involved in this difference differed among the ventilators.


Assuntos
Respiração com Pressão Positiva/estatística & dados numéricos , Testes de Função Respiratória/normas , Telemetria/normas , Volume de Ventilação Pulmonar , Ventiladores Mecânicos/estatística & dados numéricos , Resistência das Vias Respiratórias , Dispositivos de Armazenamento em Computador , Humanos , Pulmão/fisiopatologia , Modelos Anatômicos , Respiração com Pressão Positiva/instrumentação , Reprodutibilidade dos Testes , Testes de Função Respiratória/métodos , Telemetria/instrumentação , Telemetria/métodos
20.
Radiat Prot Dosimetry ; 181(1): 30-33, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29901765

RESUMO

The CD/DVDs used as radon (222Rn) and thoron (220Rn) detectors can provide a sufficiently sensitive and cost-efficient option for passive radiation monitoring in underground mines. This note presents results of measurements made under real environmental conditions by CD/DVDs. Comparison with conventional diffusion chambers was made and good correspondence was observed. Correlation between 222Rn and 220Rn was studied by CD/DVDs and no signs for any correlation were observed. Dedicated study in a mine gallery showed that CD/DVDs can be successfully used for the purposes of ventilation diagnostics by identifying sources of air contaminated with radon.


Assuntos
Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Dispositivos de Armazenamento em Computador , Física Médica , Mineração , Radônio/análise , CD-ROM , Humanos , Monitoramento de Radiação , Tecnologia Radiológica , Ventilação
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