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

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

The membrane separation is a new practical technique with wide applications. This paper introduces the course of its development, theorem and feature, and the usage of its module. Its application in the research and production is reviewed. Its existent questions in the applications presently are analyzed and the relevant resolvents are brought forward.
Filtration ; instrumentation ; methods ; Hemofiltration ; instrumentation ; Micropore Filters ; Technology, Pharmaceutical ; instrumentation ; methods ; Ultrafiltration ; instrumentation ; methods

This study was aimed to investigate the effect of leukocyte depletion by filtration on the quality of apheresis platelets. 20 units of donor apheresis platelets were randomly selected and were preserved with agitation at 20 - 24 degrees C for 24 - 96 hours, then were filtered on polyester flatbed filters. The platelet concentration, mean platelet volume (MPV), volume of apheresis platelets, leukocyte count, pH value, lactate dehydrogenase (LDH) concentration, K(+) concentration and CD62p expression level on surface of platelet membrane, were detected before and after filtration, as well as the rate of leukocyte depletion and platelet loss were calculated. The results showed that the leukocyte count after filtration was remarkably lower than that before filtration (p < 0.001), and the rate of leukocyte depletion was 99.97%. Platelet loss was approximately 8%, and obviously lower than that of the national standard (p < 0.001). MPV, pH value, K(+) and LDH concentration were not significantly different before and after filtration. Compared with platelets before filtration, CD62p expression level after filtration slightly decreased (p > 0.05). CD62p expression on surface of platelet membrane in perfusion fluid obtained from filter plate was obviously higher than that before filtration (p < 0.05). MA of platelet after filtration slightly decreased (p > 0.05). It is concluded that leukocyte and partial activated platelets can be removed efficiently by using polyester flatbed filters, and platelet loss is very low. Filtration does not adversely affect coagulation activity of the platelets in vitro. Apheresis platelets after filtration can fulfil quality requirements to prevent infection of cytomegalovirus and HLA alloimmunization.
Filtration ; Humans ; Leukapheresis ; instrumentation ; Platelet Count ; Plateletpheresis ; instrumentation ; methods

Worldwide, several regions suffer from water scarcity and contamination. The infiltration and subsurface storage of rain and river water can reduce water stress. Artificial groundwater recharge, possibly combined with bank filtration, plant purification and/or the use of subsurface dams and artificial aquifers, is especially advantageous in areas where layers of gravel and sand exist below the earth's surface. Artificial infiltration of surface water into the uppermost aquifer has qualitative and quantitative advantages. The contamination of infiltrated river water will be reduced by natural attenuation. Clay minerals, iron hydroxide and humic matter as well as microorganisms located in the subsurface have high decontamination capacities. By this, a final water treatment, if necessary, becomes much easier and cheaper. The quantitative effect concerns the seasonally changing river discharge that influences the possibility of water extraction for drinking water purposes. Such changes can be equalised by seasonally adapted infiltration/extraction of water in/out of the aquifer according to the river discharge and the water need. This method enables a continuous water supply over the whole year. Generally, artificially recharged groundwater is better protected against pollution than surface water, and the delimitation of water protection zones makes it even more save.
Filtration ; Fresh Water ; analysis ; Water Purification ; instrumentation ; methods ; Water Supply

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

Biomass and microbial activity in backwashing processes of a biofilter for tertiary treatment were investigated. The microbial groups revealed new distribution along the biofilter depth after low flow rate backwashing for a short time. Then the start-up process was accelerated by backwashing. The biomass profile and microbial activity profile both varying with depth before and after backwashing, can be mathematically described by quadratic equations. Using the profiles, the difference of oxygen demand can be calculated to determine the airflow rate during backwashing. Combined with the difference between biofilters and rapid gravity filters, analysis of biomass and microbial activity can determine more accurately the required airflow rate during backwashing.
Biomass ; Environmental Microbiology ; Filtration ; instrumentation ; methods ; Oxygen ; metabolism ; Sewage ; microbiology ; Water Purification ; instrumentation ; methods

The aim of this study was to observe the difference in respect to the leukocyte reduction efficiency and quality of fresh-frozen plasma (FFP) from filtered whole blood between two types of in-line filters wherein only filter materials were surface modified by the two methods respectively. Whole blood was kept in refrigerator and filtered within 6 h of collection at ambient temperature. Samples were taken pre- and post filtration for analysis of WBC numbers, coagulation factors and complement activation (n = 8 for each type of filter). All filtered units contained < 2. 5 x 10(6) residual leucocytes. RBCs recovery was over 93%. No significant difference between group A and B was seen. But group B appeared to take longer time for filtration than did group A (9'29" vs. 8'01"). Neither group A nor group B showed statistically significant losses of total protein, album, IgG, IgM, fibrin, factors VIII, IX, vWF and C3 (P > 0.05). Factor V, XI and AT-III decreased significantly in two group filters. Group B showed more significant losses of IgA content and factor V activity than did group A, which appeared to be related to the difference in surface character between group A and group B filters. These two types of filters could remove leukocytes effectively, and no significant changes were observed in the quality of FFP from the filtered whole blood. It is presumed that the filter material with better bio-compatibility will give a high recovery of plasma protein and coagulation factors after filtration.
Blood Coagulation Factors ; metabolism ; Filtration ; instrumentation ; methods ; Humans ; Leukocyte Count ; Leukocyte Reduction Procedures ; instrumentation ; methods

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

Pseudomonas sp. ZD8 isolated from contaminated soil was immobilized with platane wood chips to produce packing materials for a novel biofilter system utilized to control restaurant emissions. The effects of operational parameters including retention time, temperature, and inlet gas concentration on the removal efficiency and elimination capacity were evaluated. Criteria necessary for a scale-up design of the biofilter was established. High and satisfactory level of rapeseed oil smoke removal efficiency was maintained during operation and the optimal retention time was found to be 18 s corresponding to smoke removal efficiency greater than 97%. The optimal inlet rapeseed oil smoke loading was 120 mg/(m(3) x h) at the upper end of the linear correlation between inlet loading and elimination capacity.
Air Pollutants ; isolation & purification ; Biodegradation, Environmental ; Cells, Immobilized ; Filtration ; instrumentation ; methods ; Microscopy, Electron, Scanning ; Oils ; metabolism ; Pseudomonas ; metabolism ; ultrastructure ; Restaurants ; Smoke ; Temperature ; Time Factors ; Waste Management ; instrumentation ; methods