An introduction of an intelligent testing instrument for medical electrical equipment security is given in this article. The realization of its testing functions is based on a single-chip processor, the high-voltage control circuit and the relay combination network technology. It can be used to test security parameters such as the continuous leakage current, patient auxiliary current, dielectric strength and protective earth impedance. It is suitable for the medical electricity security testing of Kind I, II and Type B, BF, CF (internal power supply) medical electrical equipments.
Electricity ; Equipment Design ; Equipment Failure Analysis ; instrumentation ; methods ; Equipment Safety ; instrumentation ; methods ; Software Design

According to the structural characteristics of spiral CT systems and our experiences, some relevant solutions to common malfunctions in daily maintenance are suggested.
Computers ; Equipment Design ; Equipment Failure ; Equipment Failure Analysis ; methods ; Humans ; Maintenance ; Tomography, Spiral Computed ; instrumentation

The AB 7300 Real-time PCR Systems in our hospital have been detected malfunction for three times in a short term. The detection indicated the major reason for the malfunction attributed to the fuse of the solder of the COVER at the same position with the serial number 4344490 D1. This article explicitly introduces how to detect and maintain this equipment. It serves as a good reference for colleagues. Meanwhile the author raises five issues for further exploration and discussion.
Equipment Failure Analysis ; Maintenance ; methods ; Polymerase Chain Reaction ; instrumentation ; methods

Based on the structure and principle of transducers for medical ventilators, this paper analyzes the causes of transducers' failures, and introduces some corresponding calibration methods. Besides, some suggestions about how to reduce different kind of transducer failures are put forward.
Calibration ; Equipment Failure ; Equipment Failure Analysis ; methods ; standards ; Equipment Safety ; methods ; Maintenance ; Respiration, Artificial ; instrumentation ; Transducers ; Ventilators, Mechanical

The aim of this study was to compare the accuracy of four different methods for measuring wear using an apparatus that simulates known amounts of three dimensional wear. Wear was measured using the manual methods reported by Charnley, Livermore, Dorr and Wan and the computerized method reported by Devane. Only the method reported by Devane measured the three-dimensional (superior and anterior) wear with a reasonable accuracy, with a mean measurement error of 0.21 mm. With superior wear alone, Charnley's method underestimated the extent of wear by 16.6%, with a mean error of 0.35 mm; Livermore's method estimated wear to within 9.5%, with a mean error of 0.16 mm; Devane's method estimated wear to within 9.5%, with a mean error of 0.15 mm; and Dorr's method underestimated wear by 25.4%, with a mean error of 0.56 mm. Dorr's method was modified as a result of the experimental tests. The clinical application of the new method showed comparable data to that using the Devane method. In conclusion, this new method can be used to estimate the average wear in groups of patients accurately.
Equipment Failure Analysis/instrumentation/methods ; *Hip Prosthesis ; Human ; *Polyethylene ; *Prosthesis Failure ; Stress, Mechanical

This article introduces a new testing method for mammographic x-ray equipments. The films placed around the x-ray tube assembly are exposured to find the location of leakage radiation and then the accurate testing for the leakage radiation of the mammographic x-ray equipment is carried out with a radiation dosimeter.
Equipment Design ; Equipment Failure Analysis ; Female ; Humans ; Mammography ; instrumentation ; methods ; Quality Control ; Radiation Dosage ; Radiation Protection ; instrumentation ; methods ; Radiometry ; instrumentation ; methods

Ni-Ce(0.8)Sm(0.2)O(1.9) (Ni-SDC) cermet was selected as anode material for reduced temperature (800 degrees C) solid oxide fuel cells in this study. The influence of NiO powder fabrication methods for Ni-SDC cermets on the electrode performance was investigated so that the result obtained can be applied to make high-quality anode. Three kinds of NiO powder were synthesized with a fourth kind being available in the market. Four types of anode precursors were fabricated with these NiO powders and Ce(0.8)Sm(0.2)O(1.9) (SDC), and then were reduced to anode wafers for sequencing measurement. The electrical conductivity of the anodes was measured and the effect of microstructure was investigated. It was found that the anode electrical conductivity depends strongly on the NiO powder morphologies, microstructure of the cermet anode and particle sizes, which are decided by NiO powder preparation technique. The highest electrical conductivity is obtained for anode cermets with NiO powder synthesized by NiCO(3).2Ni(OH)(2).4H(2)O or Ni(NO(3))(2).6H(2)O decomposition technique.
Electric Impedance ; Electric Power Supplies ; Electrochemistry ; instrumentation ; methods ; Electrodes ; Equipment Design ; Equipment Failure Analysis ; Nickel ; chemistry ; Powders ; Surface Properties

A naphtha catalytic reforming unit with four reactors in series is analyzed. A physical model is proposed to describe the catalytic reforming radial flow reactor. Kinetics and thermodynamics equations are selected to describe the naphtha catalytic reforming reactions characteristics based on idealizing the complex naphtha mixture by representing the paraffin, naphthene, and aromatic groups by single compounds. The simulation results based above models agree very well with actual operation unit data.
Alkanes ; analysis ; chemistry ; Catalysis ; Chemical Industry ; instrumentation ; methods ; Computer Simulation ; Computer-Aided Design ; Equipment Design ; Equipment Failure Analysis ; methods ; Hydrocarbons, Aromatic ; chemical synthesis ; Models, Chemical

Artificial knee joint simulation test is an important form in the research and evaluation of prosthetic material and design. Natural knee joint could not be tested by conventional instruments because of complex motion and load in movement. Simulation test designed for artificial knee is needed. At present, two kinds of simulation, namely simplification method and complete simulation, are widely used. Complete simulation can be used for simultaneous evaluation of material and design of prosthesis, whereas simplification method is only useful in evaluating the material of prosthesis. In international standards, there are already two protocols for artificial knee joint experiment, namely load control and displacement control. This paper also reviews the evaluation criteria and measurement standards for artificial knee joint simulation test, and then envisages the researches in future.
Arthroplasty, Replacement, Knee ; instrumentation ; Computer Simulation ; Computer-Aided Design ; Equipment Failure Analysis ; methods ; Humans ; Knee Prosthesis ; Prosthesis Design ; methods

The natural ventilation widely used in greenhouses has advantages of saving energy and reducing expense. In order to provide information for climate control of greenhouse, a model was developed to predict the variation of air temperature in the naturally ventilated greenhouse equipped with insect-proof screen. Roof ventilation and combined roof and sidewall ventilation were considered in the model. This model was validated against the results of experiments conducted in the greenhouse when the wind was parallel to the gutters. The model parameters were determined by the least squares method. In the used model, effects of wind speed and window opening height on the air temperature variation were analyzed. Comparison between two types of ventilation showed that there existed a necessary ventilation rate which results in air temperature decrease in natural ventilation under special climatic conditions. In our experiments when wind speed was less than 3.2 ms(-1), wind had a more gradual effect on greenhouse temperature for roof ventilation, compared with combined roof and sidewall ventilation, which had greater air temperature decrease than roof ventilation only.
Air Conditioning ; instrumentation ; methods ; Air Movements ; Computer Simulation ; Computer-Aided Design ; Equipment Design ; Equipment Failure Analysis ; methods ; Insect Control ; instrumentation ; methods ; Models, Theoretical ; Plant Development ; Plastics ; Rheology ; instrumentation ; methods ; Temperature ; Wind