Objective To compare the performance of novel Ag/AgCl pulverized electrodes with conventional Ag/AgCl coating electrodes in cerebral application of Electrical Impedance Tomography(EIT).Methods Based on the EIT system developed by our group,raw data were measured on a phantom and an adult volunteer,with Ag/AgCl coating electrodes and pulverized electrodes,respectively.The performances of electrode systems were evaluated in contact impedance and two other figures(the high-frequency SNR,HFSNR;the low-frequency SNR,LFSNR).Results Ag/AgCl pulverized electrode plays a better performance in resisting noise and keeping stabilization.Conclusion Ag/AgCl pulverized electrode develops the needs of imaging and monitoring human brains in EIT more availably.

Objective To provide the hardware system of EIT with an excellent direct current(DC) power source. Methods The spectrums of the outputs of DC power source and the driving source were analyzed by means of Spectrum Analyzer- E4408B when EIT system was respectively powered by battery, linear power source and switching power source. Based on the numbers and power levels of the spurs of the three power sources and the numbers and power levels of the interferences within the driving source, the influence of the three power sources on the error of measuring was estimated. Meanwhile the EIT system did data acquisition, the overall signal-to-noise-ratio(SNR) of the three power sources at the 18 frequencies were calculated and the influence of the three power sources on the error of measuring was judged. Results With respect to the numbers and power levels of the interferences within the driving source when EIT was powered respectively by the three power sources, the battery output 6 interferences, the highest power of which achieved -78.25 dBm; the linear power source output 6 interferences, the highest power of which achieved -67.11 dBm; the switching power source output 15 interferences, the highest power of which achieved -35.83 dBm. The overall SNRs of the battery at the 18 driving frequencies were higher than that of the linear power source, and the overall SNRs of the linear power source were higher than that of the switching power source. Conclusion The power mode of battery is the best for the hardware of EIT among the three power sources.

Objective To investigate the effect of the bletilla striata polysaccharide on the expression of ovarian vascular endothelial growth factor(VEGF) and serum malondialdehyde(MDA)and endometrial morphology in rat during perimenopause period.Methods The animal model of perimenopause rats was established by unforced aging.A total of 40 female SD rats(12~14 months old)were randomly divid-ed into four groups:Chinese medicine low(0.5 g/kg),medium(1 g/kg),high(2 g/kg) dosage group and the elder model group.The rats were given with corresponding drugs for 8 weeks.The content changes of ovarian VEGF protein was detected by western blot;serum MDA con-tent was detected by thiobarbituric acid;the morphology of endometrium in rats was observed by HE staining.Results Eight weeks later, compared with the elder model group,the VEGF protein expression in Chinese medicine low,medium,high dosage group increased,the serum MDA content in Chinese medicine low,medium,high,dosage group reduced,the differences were statistically significant( P<0.01),with dose dependence.Endometrial thickening and glandular increasing with the increase of dose.Conclusion Bletilla striata polysaccharide can upregulate the expression of VEGF protein,and down regulate the level of serum MDA,which improves the uterine function so as to delay the process of perimenopause in rats.

Adult ; Hepatitis B ; prevention & control ; Humans ; Immunity, Active ; Liver Transplantation ; immunology ; methods ; Male ; Postoperative Complications ; prevention & control

Objective To establish a human-head phantom with realistic skull anatomy and resistivity distribution in order to provide an accurate experimental platform for brain electrical impedance tomography(EIT).Methods Firstly a skull model with 3-layer structure was constructed with double-nozzle 3D printer,and every layer had its specific resistivity verified on the accuracy. Then brain parenchyma with its resistivity was modelled using 3D printer and cerebrospinal fluid and scalp were mimicked using NaCl solution;after the whole phantom was assembled,imaging test using EIT was performed.Results The skull model was similar to the realistic one in terms of anatomy and resistivity distribution;the EIT experiment on the new phantom showed similar results to simulation.Conclusion The proposed phantom has realistic skull anatomy,resistivity distribution and multi-layer anatomical structure, which reflects the features of skull resistivity and thus is suitable for experiments on brain EIT.

Objective To propose a method for accurately controlling the resistivity of 3D printing materials to facilitate to establish a human-head volume conductor model.Methods Two kinds of ABS/CB composite conductive printing materials covering the resistivity ranges of parenchymal and skull were selected through resistivity measurement and analysis. The correlation between the proportions and resistivities of the two kinds of ABS/CB materials and the empirical formula on the correlation between the resistivity and proportion was obtained through exponential function fitting. Results The selected ABS/CB composite material behaved well in frequency stability and time stability,and the obtained empirical formula had high-correlation coefficient.Conclusion Accurate control of 3D printing model resistivity is realized,and it's facilitated to gain 3D printing material with the same resistivity as those of skull and parenchymal.

Objective To analyze the difference of teaching modes of course of digital signal processing for the undergraduates and postgraduates.Methods The teaching modes were compared from the aspects of educational objective,teaching content, teaching method,examination mode and etc.Results Differentiated teaching modes contributed to the satisfactory education of the undergraduates and postgraduates. Conclusion The differentiated teaching modes for the undergraduates and postgraduates provide references for the high-level education in universities and colleges of science and technology. [Chinese Medical Equipment Journal,2018,39(5):87-89,102]

Objective:To measure the kinetic parameters of murine plasma albumin synthesis by deuterated water (2H2O).Methods:Twenty SD rats received 2H2O-labelled intraperitoneal injection and drinking.At the end of the 1st,3rd,5th,6th,10th week,every 4 rats was respectively sacrificed by cardiac puncture for blood collection.Plasma albumin was purified by trichloroacetic acid and ethanol,identified by SDS-PAGE and hydrolyzed by hydrochloric acid.The alanine in albumin and plasma was separated,purified and derived.The deuterium enrichments of alanyl unit in albumin and alanine in plasma were determined by GC-MS.The fractional synthesis rate of albumin and synthetic dynamic equation were calculated.Results:The fractional synthesis rate of plasma albumin was 15.3％/w,and synthetic dynamic equation was ft =1.256 × (1-e-0.153t).Conclusion:The kinetic parameters of plasma albumin synthesis can be measured by 2H2O labeling method,which can be applied in the study of physiological and pathological metabolic mechanism.

Objective To put forward a method for 3D electrical impedance finite element joint modeling and simulation using COMSOL for visual modeling and Visual C++ for programming.Methods A model was established with COMSOL,and then transformed into a.stl file and introduced into Visual C++ simulation platform.Delaunay tetrahedral mesh generation algorithm was used for finite element meshing,calculation and simulation,and joint modeling and simulation were realized finally.Results Simulation result showed that the method could be used to introduce COMSOL model and complete 3D finite element simulation.Conclusion The method proves its compatibility with the models generated by multi software and practicability for joint modeling and simulation.

OBJECTIVETo determine the operation procedure of total hip arthroplasty (THA) for Crowe type-IV developmental dysplasia of hip and its relationship with nerve injury.

METHODSA consecutive series of 39 THAs was performed for Crowe type-IV developmental dysplasia of hip in 35 patients (all female). The mean age of the patients at the time of surgery was 46 years (range 36 - 56 years). Thirty-five hips in 31 patients were followed up. The average follow-up period of the whole series was 4 years (range 1 - 8 years). All procedures were carried out through a lateral-posterior approach. In 33 of 35 hips, the cup was inserted in the "true" acetabulum. All the prostheses used were cementless, except for 5 cemented femoral stems in 5 patients. Each patient was evaluated clinically and by radiographs before the operation and during the follow-up period, according to the Harris hip score (HHS).

RESULTSNone of the cups and stems were revised for aseptic loosening, dislocation or infection during the follow-up period. The mean preoperative HHS was 43 compared with the postoperative HHS of 87. The mean amount of postoperative leg lengthening was 5 cm (range 4 - 6 cm).

CONCLUSIONSThe reconstruction of the hip at the level of the "true" acetabulum through a lateral-posterior approach is a safe and effective procedure of THA for Crowe type-IV developmental dysplasia of hip in adults. Acute leg lengthening of less than 6 cm could not cause nerve injury.

Adult ; Arthroplasty, Replacement, Hip ; methods ; Female ; Follow-Up Studies ; Hip Dislocation, Congenital ; surgery ; Humans ; Middle Aged ; Treatment Outcome