OBJECTIVE: To study the influence of disposable respiratory filter on the results of impulse oscillometery. METHODS: 90 healthy subjects were randomly selected and impulse oscillometery results were taken repeatedly through disposable respiratory filter and control device. All results were statistically analyzed. RESULTS: When using the disposable respiratory filter, respiratory impedance (Zrs) and resistance at all frequency (R5Hz-R35Hz) were significantly increased compared with the control device (P<0.01). The two measurements had a significant linear correlation (P<0.01) and a regression equation was established. The disposable respiratory filter did not exist in statistic difference to response frequency (Fres) and the elastic resistance (X5Hz-X15Hz) at all frequency(P>0.05). CONCLUSIONS The disposable respiratory filter can be used when testing pulmonary compliance, chest wall disease and obstruction outside the airway in impulse oscillometery system to avoid infection and ensure quality.
Airway Resistance ; Filtration/instrumentation* ; Humans ; Oscillometry

OBJECTIVEThe objective of this study was to investigate the aspiratory resistance, filtration penetration and their influence factors of N95 filtering-facepiece respirators used widely in China.

METHODSThe total of 6 brands and 21 models of N95 filtering-facepiece respirators which are certified and big sales on the market. The aspiratory resistance and filtration efficiency filter penetration were measured while air pump ran from 10 L/min to 100 L/min using differential pressure gauge and the PortaCount, respectively.

RESULTSThe filtration penetrations for 2 of the 21 models were lower than 95%, and the qualified rate for all models was 90.47%. The filtration penetrations gradually decreased when ventilation flow of air pump increased. The negative correlation was observed between filtration penetration and ventilation flow (r(2) = 0.711, P < 0.05). The resistances of all 21 models of N95 respirators met the requirements of the national standard. The aspiratory resistance started to elevate with the increasing of ventilation flow, and a positive correlation between both (r(2) = 0.878, P < 0.05). Significant differences of filtration penetration and aspiratory resistance were observed among between different brands (P < 0.05) although no differences of filtration penetration existed among different models of one brand (P > 0.05). But the differences of the aspiratory resistance among different models of one brand were statistically significant (P < 0.05).

CONCLUSIONThe aspiratory resistances of all N95 filtering-facepiece respirators used in this study met the requirements of the national standard. And the qualified ratio of filtration penetration of all models was higher than 90%. The influencing factors of aspiratory resistance included materials, size and ventilation flow. And influencing factors for filtration penetration were materials and ventilation flow.

Air Pollutants, Occupational ; China ; Equipment Design ; Filtration ; instrumentation ; Masks ; standards ; Materials Testing ; Respiratory Protective Devices ; standards

OBJECTIVETo compare the membrane filtration process of four membrane modules namely, FMX rotating disk flat membrane module, hollow fiber membrane module, tubular membrane module and filter cup membrane module, with traditional Chinese medicine compound Huanglian Jiedu decoction as the experimental subject.

METHODUnder the same experimental operating conditions, the four membrane modules in membrane filtration process of Huanglian Jiedu decoction were compared in terms flux, resistance distribution, transmittance of index components and membrane fouling.

RESULT AND CONCLUSIONThree membrane modules in the dynamic filtration form--FMX rotating disk flat membrane module, hollow fiber membrane module and tubular membrane module had more advantages than filter cup membrane module in the static dead-end filtration form in terms of permeate flux, transmittance of index components and membrane fouling. However, FMX membrane module that made the fluid in a strong vortex status had better performance than hollow fiber membrane and tubular membrane module in permeate flux and membrane fouling.

Biofouling ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; Filtration ; instrumentation ; Membranes, Artificial ; Permeability

The high-pass filter which is designed to overcome the polarization voltage in the ECG measurements can affect the measurement of the ST-segment; but the accuracy of the ST-segment will have an impact on the diagnosis and treatment of heart diseases. This paper used the ECG detection platform to test the effect of the high-pass filter at different frequency and studied the effect of the high-pass filter on the ST segment to ensure proper use of different application modes.
Electrocardiography ; instrumentation ; methods ; Filtration

PURPOSE: A charcoal filter attached within the anesthetic circuit has been shown to efficiently adsorb halothane or isoflurane, thus hastening anesthetic recovery in low or minimal flow system. This study was intended to demonstrate whether the charcoal filter enhances the recovery time from sevoflurane anesthesia using a semi-closed circuit system. MATERIALS AND METHODS: Thirty healthy patients scheduled for elective surgery under sevoflurane anesthesia were randomly assigned to the charcoal filter or control group. Upon completion of surgery, the end-tidal concentration of sevoflurane was maintained at 2.0 vol%. A charcoal filter was attached to the expiratory limb of the breathing circuit of charcoal filter group subjects. After sevoflurane was discontinued, ventilation was controlled with the same minute volume as the intra-operative period at a fresh gas flow rate of 5 L.min(-1) with 100% O2. The elimination kinetics of sevoflurane from end-tidal concentration, Bispectral index and times of eye opening and extubation were obtained. RESULTS: The exponential time constant (tau) of alveolar sevoflurane concentration in the charcoal filter group was significantly shorter than that in the control group (1.7+/-0.5 vs. 2.5+/-1.1 min, p=0.008). The charcoal filter hastened rapid eye opening (11.1+/-3.8 vs. 14.8+/-3.0 min, p=0.007) and extubation (11.9+/-3.9 vs. 15.3+/-3.2 min, p=0.014), compared to the control group. CONCLUSION: A charcoal filter enhances the recovery from sevoflurane anesthesia with a semi-closed rebreathing circuit.
Adult ; Anesthesia/methods ; *Anesthesia Recovery Period ; Anesthesiology/instrumentation ; Anesthetics, Inhalation/chemistry/*pharmacology ; Charcoal/*chemistry ; Filtration/*methods ; Humans ; Methyl Ethers/chemistry/*pharmacology ; Middle Aged ; Time Factors

OBJECTIVETo separate essential oil of Caryophyllix flos from oil-in-water emulsion, and to enrich the essential oil by microfiltration (MF).

METHODUsing membrane flux and removal rate of COD as the indicatrixes, the membrane material as well as the operating conditions containing pressure, surface speed, temperature were optimized.

RESULTThe results showed that QWLM membrane of hydrophilic is the proper membrane, and the best operating conditions was at 0.06 MPa, 60 degrees C, and 150 r min(-1) stir speed.

CONCLUSIONIt can be concluded that MF is a reasonable way to enrich essential oil of C. flox.

Emulsions ; chemistry ; Filtration ; instrumentation ; methods ; Membranes, Artificial ; Oils, Volatile ; chemistry ; isolation & purification ; Plant Oils ; chemistry ; isolation & purification ; Syzygium ; chemistry

A new viral sampling concentration device was designed which was equipped with a new cationic filter membrane-Nanoceram suitable for field sampling. Norovirus Genegroup II was detected from environmental water with the aid of this device. The effects on virus recovery of prefiltration, various second-concentration methods, and different eluants were investigated through pre-experiment. The concentration optimized process, and the optimal concentration process were then determined. The results showed that the prefiltration had a profound effect on virus recovery, and two second-concentration method: PEG-NaC1 precipitation and celite adsorption, had almost the same concentration effects. The Na2 HPO4 solution of 0.15 mol/L was selected as the final eluant to elute the adsorbed Nuorovirus from the celite. The virus recovery of Nanoceram was determined to be 3.02%. Finally, successful detection of Norovirus GII in sewage from Yangqiao River, Fengtai District, Beijing was acheived. All these data had shown that the Naneceram filter concentration method could concentrate Norovirus from environmental water with a steady effects.
Filtration ; instrumentation ; methods ; Fractional Precipitation ; instrumentation ; methods ; Genotype ; Norovirus ; classification ; genetics ; isolation & purification ; Rivers ; virology ; Water Microbiology

Through five experiments, such as "Circle", "square", "side that does not shake", "burning edge", "filter", this paper discussed the effect of different experimental methods of polypropylene fiber liquid filtration membrane particles shedding. The results show that: the particles falling off the edge of the polypropylene fiber Double-sided liquid filtration membrane are very important and must be considered off the evaluation of particle pollution.
Equipment Failure ; Filtration ; instrumentation ; methods ; Particle Size ; Polypropylenes

OBJECTIVEIt aims to investigate the changes in composition and structure of bacterial communities developing on biological activated carbon (BAC) particles, and the bacterial functions.

METHODA pilot plant had been in service for 180 days, aiming to develop bacterial communities on activated carbon naturally. After 180 days of operation, the bacterial communities were determined by denaturing gradient gel electrophoresis (DGGE) analyses of PCR-amplified 16S rRNA genes. The study on community composition and the phylogenetic relationships of the organisms was complemented by a sequence analysis of cloned PCR products from 16S rRNA genes. Gas chromatography-mass (GC-MS) measurement was used to determine organic chemical composition of inflow and outflow water on the 300th day. TOC and NH(4)(+)-N were also tested in this experiment.

RESULTSIt showed that the stable bacterial structure did not develop on BAC particles until the 9th month during running time of the BAC filter. The communities were finally dominated by Pseudomonas sp., Ba-cillus sp., Nitrospira sp., and an uncultured bacterium. Stable bacterial communities played an important role in removal of NH(4)(+)-N and total organic carbon (TOC). Results from gas chromatography-mass (GC-MS) showed that 36 kinds of chemicals in feed water were eliminated, and concentrations of 5 kinds of chemicals decreased. These chemicals served as nutrients for the dominant bacteria.

CONCLUSIONThe findings from the study suggested that the stability of microbial structure was beneficial for improving NH(4)(+)-N and TOC removal efficiencies. The dominant bacteria had the advantage of biode-grading a wide range of organic chemicals and NH(4)(+)-N.

Ammonia ; chemistry ; Bacteria ; classification ; genetics ; Biofilms ; Carbon ; chemistry ; Filtration ; instrumentation ; methods ; Microscopy, Electron, Scanning ; Pilot Projects ; Waste Disposal, Fluid ; instrumentation ; methods ; Water Microbiology ; Water Purification ; instrumentation ; methods ; Water Supply ; standards

Several digital filtering techniques for correcting baseline drift from ECG signals are presented. A bidirectional filter is introduced, which can cantain baseline drift their filtering performance and realization methods are compared.
Electrocardiography ; instrumentation ; methods ; Filtration ; instrumentation ; Signal Processing, Computer-Assisted ; instrumentation