1.Development of a portable low-frequency electronic pulse analgesia apparatus based on single-chip microprocessor
Chinese Medical Equipment Journal 2004;0(08):-
In this paper, a novel portable low-frequency electronic pulse analgesia apparatus is introduced, which is based on a novel single-chip microprocessor, switching power supply without transformer and OTL power output amplifier. Through this apparatus, multi-group low-frequency electronic pulses can be produced to simulate the same effects as acupuncture. This apparatus has an observably curative effect for dysmenorrhea.
2.A Modified Kernel-based Fuzzy C-Means Algorithm For Images Segmentation
Chinese Medical Equipment Journal 2004;0(09):-
Objective To segment brain magnetic resonance (MR) images corrupted by noises. Methods We presented a novel Fuzzy C-Means (FCM) algorithm for image segmentation. The algorithm was by modifying the objective function in the conventional FCM. Firstly,by using kernel method,the original Euclidean distance in the FCM was replaced by a kernel-induced distance. Then,a spatial penalty term was added to the objective function to compensate the influence of the neighboring pixels on the center pixel. Results Segmentation results on a four-class synthetic image corrupted by salt & pepper noise shows that the new algorithm is less speckled and smoother. The new algorithm is applied to simulation MR images and is shown to have less misclassification rate than the other FCM-based methods. Conclusion The results of experiments show that the proposed algorithm is more robust to noise than other FCM-based methods.
3.Distribution and Drug-resistance of Stenotrophomonas maltophilia
Sufei YU ; Xuefei YANG ; Tingting LI
Chinese Journal of Nosocomiology 2006;0(05):-
OBJECTIVE To get knowledge of the distribution and drug-resistance of Stenotrophomonas maltophilia in our hospital and improve the level of diagnosis and treatment.METHODS The automatic drug sensitive test and the paper spreads medicine sensitive test were carried on to 162 strains of S.(maltophilia) with the index of the VITEK system.RESULTS In all clinical samples,S. maltophilia isolated from phlegm was the most(90%),then was from secretion and swab.The majority of 162 strains were multidrug resistant.But to the(trimethoprim)-sulfamethoxazole and ciprofloxacin,the drug resistance was low((20.4%) and 22.2%,respectively).CONCLUSIONS S.maltophilia is the prevalent pathogen of nosocomial infection in ICU.And most of it are(isolated) from phlegm.So use antibiotics correctly,(reduce) invasive examinations or treatments and strengthen drug-resistant monitoring,are helpful to prevent and control S.maltophilia nosocomial infection.
4.Application of wireless transfer technology to medical instrument development
Xuefei YU ; Guangwen LU ; Zhe LI
Chinese Medical Equipment Journal 1989;0(02):-
In many medical instrumentation systems, there exists a long distance between manipulation platform and host unit. Wireless data transferring between the platform and the host could be a feasible way to set parameters. This paper introduces wireless transmitter and receiver circuit based on encoder chip PT2262 and decoder chip PT22720, and presents some typical applications in medical instrument development.
5.Morphological changes of spinal motorneurons by early treatment after explosive injury of spinal cord
Jie YU ; Zhuojing LUO ; Xuefei ZHANG
Orthopedic Journal of China 2006;0(16):-
[Objective]To study therapeutic effect of different medicines on motorneuron of spinal cord after explosive injury of spinal cord.[Method]Thirty-six rabbits were randomly divided into model group(group A,n= 12),the dexamethasone experiment group(group B,n= 12) and the methylprednisolone experiment group(group C,n=12),all rabbits were made explosive wound by 0.9 g cyclotrimethylene trinitramine,group A injection NS after blast, group B injection dexamethasone and group C injection methylprednisolone,6 and 24 hours after specimen had been taken out,then morphological change and quantity of the spinal motorneurons be observed under light microscopes.[Result]The reversible change of the neurons of rabbits happened after six hours,after 24 hours,the died motoneuron increase obviously, some rabbits remedied with dexamethasone and methylprednisolone after explosive injury in group B and C,quantity of the died motorneuron marked significant difference than that in the control group(P0.05).[Conclusion]Glycocotical stdroid can protect spinal cord motoneurons after explosive injury of spinal cord.In the experiment,there is no preponderance in early treatment of explosive injury of spinal cord between methylprednisolone and dexamethasone.
6.Development of Temperature Control System for Hyperthermia Based on PWM
Xianfeng LIU ; Xuefei YU ; Guangwen LU ; Daming PENG ; Jiaxi YU
Chinese Medical Equipment Journal 2004;0(07):-
Objective To develop a hyperthermia temperature control system for the treatment of pelvic inflammatory disease. Methods Temperature was controlled by using PWM method based on a single chip computer. The system was heated by using heating wire. In the whole cycle of T, the heating wire's work time was divided into three different stages according to different temperature of system: in the lower temperature, the duty cycle of the heating wire's work time was 100%; when the system temperature entered to a certain stage, a control variable was obtained through the PID algorithm which was used to compare the difference between the current temperature and the temperature requirements. The control variable determined the duty cycle of the heating wire's work time: the more close to the temperature required for the temperature of system, the duty cycle of the heating wire's work time was more close to 0; if the temperature exceeded a predetermined value, then the heating wire would not heat in the whole cycle. Results The accuracy of the temperature control system was ?0.2 ℃, the overshoot of the temperature control system was ?0.3 ℃, and the response time of the temperature control system was 500 seconds. Conclusion The temperature control method has high precision, small overshoot, and the right response time, which can meet the requirements of constant temperature of hyperthermia treatment. Besides, it is simple and cheap.
7.Inhibition of Coriaria Sinica Maxim’ s extract on burn wound infections with common three kinds of resistant bacteria
Debin HUANG ; Zehua HU ; Zhaofen YU ; Xuefei CHEN ; Jin HUANG
Chinese Pharmacological Bulletin 2016;32(10):1388-1394
Aim To explore the inhibition of Sinica Maxim′s extract( CSME) on resistant infections of burn wounds,such as the methicillin-resistant staphylococcus aureus ( MRSA ) , resistant pseudomonas aeruginosa (RPA) and resistant escherichia coli(RECO). Meth-ods The resistant strains were cultured by MH agar plates. After resistance genes of quality control strains were extracted and appraised, such as mecA, mexB, merA, qacE△1-sull, tnpU/A and mexB, etc, and then,some projects of CSME were detected,such as the antibacterial spectrum, the minimum inhibitory con-centration(MIC), different concentrations of sensitive rate and inhibition curves, etc. Finally, these results were compared with the inhibitory effects of some anti-biotics to determine the sensitivity rates of CSME. Re-sults The MIC of CSME was 62. 5 ,125 ,250 g · L-1 respectively on the MESA, RPA and RECO. The inhi-bition rates of CSME appeared concentration-dependent on these three kinds of resistant bacteria,and the inhi-bition rates of the multi-concentration CSME on RECO were significantly lower than on MRSA and RPA ( P<0. 05). While in MIC,the resistance rates of MRSA on carbenicillin, cefazolin, erythromycin were significant-ly higher than those of CSME(P<0. 05); The inhibi-tion zones of CSME were significantly smaller than those of ceftriaxone, cefepime, imipenem, but greater than those of other antibiotics( P<0. 05 ); The inhibi-tion zones of CSME on RPA were significantly smaller than those of carbenicillin, and greater than those of other antibiotics ( P <0. 05 ) . The inhibition zones of CSME on RECO were significantly smaller than those of ceftriaxone,cefepime,imipenem,ciprofloxacin,nitro-furazone,and greater than those of other antibiotics ( P<0. 05 ) . Conclusions CSME has a significant inhi-bition on burn wound infection with these three kinds of resistant bacteria,such as MRSA,RPA and RECO. It is prompted that CSME could become one of the effective drugs to control burn wound infections with multi-re-sistant strains.
8.Comparative study of self-ligating brackets and conventional brackets:direction and progress
Yu LIU ; Peijun WANG ; Shan ZHOU ; Xuefei BAI
Chinese Journal of Tissue Engineering Research 2014;(25):4068-4072
BACKGROUND:The self-ligating bracket is superior to the conventional bracket in orthodontic treatment, but there are a lot of controversies. At present, researchers have different views on the function of self-ligating brackets. OBJECTIVE:To summarize the comparative study of self-ligating brackets and conventional brackest with the direction and development in recent years. METHODS:A computer-based search of PubMed (2000-2014) and CNKI (2000-2014) databases was done for relevant articles, using the key words of “self-ligating brackets; conventional orthodontic brackets” in English and Chinese, respectively. RESULTS AND CONCLUSION:Self-locking brackets saves chair side time, which has been confirmed and accepted. There are different views for the issue that self-ligating brackets can reduce friction in orthodontic treatment. It is widely accepted that, the self-ligating brackets using thin round wire had less friction than the conventional brackets; whether the friction of self-ligating brackets in the closed gap and fineness adjustment stages is less than the conventional brackets stil remains unclear, which need further clinical comparative studies. The self-ligating brackets showed no significant difference with the conventional brackets in arch expansion, reducing anchorage loss and root adsorption. The majority of relevant studies is performedin vitro, and cannot exactly simulate the dental conditions. A large-size experiment with the uniform criteria for therapeutic efficacy is needed to objectively evaluate self-ligating brackets.
9.Heat treatment effect on the fatigue fracture cycle of buccal multiloop
Xuefei BAI ; Peijun WANG ; Shiqian XU ; Lu HOU ; Yu LIU
Chinese Journal of Tissue Engineering Research 2014;(47):7597-7602
BACKGROUND:Buccal Multiloop Removable Appliance can interceptively correct mutiple adolescent malocclusions. But the clinical problem of Buccal Multiloop fatigue fracture is not solved yet. How to prolong the fatigue fracture cycle is stil in the research stage. OBJECTIVE: To study the effect of different temperature of heat treatment on the Buccal Multiloop fatigue fracture cycle, thereby to select a relatively optimal method to enhance the fatigue fracture cycle. METHODS: Thirty-five left HL-2 Buccal Mltiloops were divided into seven groups according to different ways of heat treatment. Each group consisted of five samples. They were an untreated group, three pre-bending groups (320, 420, 520℃ heat treatment before bending) and three post-bending groups (320, 420, 520℃ heat treatment after bending). The dental stainless steel wires and Buccal Multiloop were respectively treated by low-temperature annealing. The data were recorded and evaluated after the samples tested by the 3D Simulating Movement of TMJ Testing Machine. The features of fatigue fracture were observed by scanning electron microscope. RESULTS AND CONCLUSION: The mean values of the Buccal Multiloop fatigue fracture cycle from largest to smalest were as folows: 520℃ pre-bending group > 420℃ pre-bending group > 320℃ pre-bending group > untreated group > 520℃ post-bending group > 320℃ post-bending group > 420℃ post-bending group. The fatigue fracture cycle of Buccal Multiloop made of the dental stainless steel wires after 520℃ annealing treatment was longer than others. By the observation of scanning electron microscope, the fracture crack extension area had the tendency to expand, transient interruption was delayed and the tissue structure became more uniform.
10.Development of programming cardiac trigger apparatus and its application to myocardial contrast echocardiography
Zhe LI ; Daogang ZHA ; Guangwen LU ; Xuefei YU ; Hao CHEN
Chinese Medical Equipment Journal 1989;0(04):-
This paper introduces a programming cardiac trigger apparatus used for the study of quantitative measurement of myocardial blood flow with myocardial contrast echocardiography.The design of hardware circuit based on MCU and the scheme of software based on Keil C51 are mainly discussed.With stable and reliable working,this apparatus provides a kind of technical support for the study of quantitative measurement of myocardial blood flow with continuous intravenous injection of sonicated microbubbles.