1.Research on quality control and calibration period of medical monitor
China Medical Equipment 2015;(7):57-59
Objective:To do research on quality control and calibration period of medical monitor, to assure that the medical monitor is being its best performance and to provide a stable and consistency medical diagnostic images for doctors.Methods: Based on DICOM and AAPM-TG18 calibration standards and using luminance meter and monitor calibration software, our hospital implemented detection and correction quarterly to nine medical monitors. At the same time we tested the brightness response data of medical monitor continuously for 55 weeks and recorded the various brightness with the change of time, then we did some work in statistic analysis and curve fitting using MATLAB software.Results: The performance parameters of our hospital medical monitors are in AAPM-TG18 specified range and the display characteristics are also consistent with the DICOM standard; The change of brightness quarterly of medical monitor is 0~25cd/m2 which is accorded with the function of DICOM GSDF. Conclusion: In order to ensure the accuracy of the impact of image diagnosis system, it’s reasonable and effective to do medical monitors quarterly testing based on brightness response curve.
2.Quality control analysis and application of CT equipment
China Medical Equipment 2016;13(10):24-28,29
Objective:We propose a quality control plan which is suitable for the actual situation of our hospital and keep our CT equipment in a normal working condition, so that we can get the best image quality.Methods: According to “GB 17589-2011 Specification for quality assurance testing of X-ray computed tomography apparatus”, we can get quality testing data of GE Lightspeed VCT from different time.Results: The indicators in quarterly testing meet the requirements, and have little difference with ideal value. Meanwhile the testing indicators have no significant change after calibration. The indicators in half year testing meet the requirements, and have large difference with ideal value. Meanwhile the testing indicators have significant change after calibration. Conclusion: According to the test results, combined with the daily use of experience, we carry out the quality control program for the actual situation of our hospital. It reduces the failure rate of the equipment, and improves the picture quality of CT equipment.
3.Research on the principle and application of high voltage of the Elekta accelerator
China Medical Equipment 2014;(9):64-66
Objective:Through getting acknowledge of the High-voltage of medical linear accelerator, it makes it possible for the relative medical workers to do a quick reaction to the repairmen and maintenance to the accelerator, and to maintain the machine to a good performance efficiently. While through understanding the application situation and development of accelerator, we could do a better choice at the terms of choosing an accelerator for hospital which meet the basic requirements and accuracy.Methods: Using the block diagram to introduce the main part of High-voltage of medical linear accelerator, and especially introduce the charging pinciple of charging transformer and the charge and discharge of PFN. The accelerator plays a vital fuction at radiation therapy, and we introduce the accelerator application in various fields and the development situation of technology application.Results: It’s significant to know the working principle of High- voltage as it’s helpful to ensure whether the machine works normal or not and to diagnose faults in it.Conclusion: In addition, through understanding the application situation and the development of accelerator, we could choose an appropriate accelerator for our hospital.
4.Study of electrocardiograph in differential diagnosis of pulmonary embolism
Clinical Medicine of China 2008;24(4):341-343
Objective To explore the characteristics,application and significance of electrocardiogragh (ECG)in diagnosis and differential diagnosis of pulmonary embolism(PE)by contrasting the ECG of PE and several diseases with similiar clinical features.Methods A total of 364 cases were enrolled in this study,including 197 cases of PE,70 cares of coronary artery disease(CAD)with congestive heart failure(CHF),47 cases of essential hypertension(EH)with CHF,and 50 cases of acute lung injury/acute respiratory distress syndrome(ALI/ARDS).The ECG of these 364 PE cases were analyzed.Results The rates of axle right drift,lockward rotation,right bundle branch block and pulmonary P wave,V1 lead s-wave were higher than control groups,with significant difference.Bates of S1Q3T3,disposition of T wave in chest lead were the highest in PE group,with significant difference.Conclusion The main appearances of ECG in PE patients hint the heavy load of right ventricular and coronary ischemia.Perhaps S1Q3T3 is the appearance of axle right drift.The sensitivity and speciality of every feature is not good enough to diagnosis or differential diagnosis;dynamic observation of ECG is of great significance to the diagnosis of PE.
5.Vagal effects on atrial fibrillation thresholds of pulmonary veins after autonomic denervation
Peng LIU ; Jihong GUO ; Haicheng ZHANG
Chinese Journal of Practical Internal Medicine 2006;0(20):-
Objective To investigate vagal effects on atrial fibrillation(AF)thresholds at different sites of pulmonary veins after autonomic denervation.Methods In 10 mongrel dogs,the cervical vagal trunks were isolated bilaterally and decentralized from Oct 2004 to May 2005.The ansae subclaviae were exposed bilaterally as they exited from the stellate ganglia,doubly ligated,and cut.Local rapid electrical stimulation(S1S1=80 ms,impulse duration 0.5 ms)was performed to right appendage(RAA)、left appendage(LAA)、left atrium(LA)and different sites of 4 pulmonary veins.AF threshold was determined at each site in the baseline state,during bilateral cervical vagal stimulation(VNS,12.5 Hz,impulse duration 0.5 ms,stimulation voltage 5~8 V)and during infusion of atropine.Results During VNS,a lower AF threshold was observed at all sites,especially at distal of 4 pulmonary veins(P0.05).Conclusion Vagal nerve not only contributes to the maintenance of AF originating from pulmonary veins,but also greatly promotes the initiation of AF.
6.T-type calcium channel effects on atrial electrical remodelling and an approach to its mechanisms during atrial fibrillation
Yuansheng LIU ; Jihong GUO ; Haicheng ZHANG
Chinese Journal of Practical Internal Medicine 2000;0(12):-
Objective To inquire into T-type calcium channel effects on atrial electrical remodelling and its mechanisms during atrial fibrillation.Methods Animal experiment was performed in Peking University Pepole's Hospital from Feb.2002 to Oct.2006.Fifteen adult cross-bred dogs were used in the experiment.Ten dogs underwent continuous rapid atrial pacing(500 beats/min)for twenty-four weeks to create persistent atrial fibrillation.In five rapidly-paced dogs,50mg pure powder/day of mibefradil dihydrochloride was given from the second day after pacemaker implantation and continued until the twenty-fourth week.A group of size-matched dogs(n=5)without being given mibefradil was used as a pure atrial fibrillation group.Another group of size-matched dogs(n=5)without pacemaker implantation was used as a control group.Atrial fibrillation duration was determined by electrophysiological study.Canine atrial myocytes were isolated by enzymatic dissociation and intracellular Ca2+ cytosolic transient was studied with confocal imaging.Results (1)The preoperation atrial effective refractory period was 280/90~110 ms.In the twenty-fourth week after rapid atrial pacing,atrial effective refractory period was obviously extended(2000/1400~1700 ms)in the T-type Ca2+ channel blocker group compared with the preoperation one.In the twenty-fourth week,the induced rate of persistent atrial fibrillation was 75% in atrial fibrillation group,whereas the persistent atrial fibrillation occurred in only one case(20%)in the T-type Ca2+ channel blocker group.(2)Intracellular Ca2+ concentration of atrial myocytes was unremarkably changed in control group after blocking L-type Ca2+ channel(1.17?0.09 OD ratio),whereas the intracellular Ca2+ concentration was obviously enhanced(2.35?1.05 OD ratio)(P
7.Preexcitation syndrome with tachycardia-bradycardia syndrome:Clinical analysis
Jihong GUO ; Yuan XU ; Haicheng ZHANG
Chinese Journal of Practical Internal Medicine 2001;0(05):-
Objective To investigate the association between syncope and transient suppression of sinoatrial node in patients with preexcitation syndrome and paroxysmal supraventricular tachycardia (PSVT).Methods Twelve patients (male 8,female 4;age range:19-49 years) were enrolled due to WPW(Wolff-Parkinson-White) syndrome and syncope when the tachycardia terminated.The function of sinoatrial node was evaluated with clinical electrophysiologic study,and then radiofrequency catheter ablation (RFCA) or antitachycardia pacemaker were optimized for the patients with a follow-up of 2 to 5 years.Results Electrocardiographic features of the 12 patients were: ventricular preexcitation (type A in 7 and type B in 5) and long pause when tachycardias ended up.Electrophysiologic study revealed the function of sinoatrial node was normal.Four patients received antitachycardia pacing therapy,5 underwent RFCA,and 3 received both.The 2 to 5 years follow-up found no relapse of PSVT associated syncope.Conclusion Transient suppression of sinoatrial node might explain the mechanism of syncope with preexcitation and PSVT.However,the reason why such a small group of patients differ from the majority of preexcited cases in clinical course remains to be unsettled.The first choice of prevention and treatment for these patients should be eliminating PSVT.Conventional pacemaker implantation for preventing syncope seems to be unnecessary.
8.Kidney sparing operation in the surgical treatment of calculous pyonephrosis
Yuanfeng RUAN ; Qinghua ZHANG ; Haicheng LI
Chinese Journal of Urology 2001;0(10):-
Objective To investigate the feasibility of kidney sparing operation in the surgical treatment of calculous pyonephrosis. Methods 31 cases of calculous pyonephrosis were treated by nephrolithotomy or ureterolithotomynephropyelostomy with a double J catheter stent in the ureter.23 cases have been followed up and evaluate. Results The renal function returned to some extent in 78.3%(18/23).However,renal atrophy was observed in 21.7%(5/23) one year after and stone recurrence in 13%(3/23). Conclusions Calculous pyonephrosis of short course on reliving the obstruction would cause the return of renal blood circulation and renal function in near 80.0% of the cases.Thickness of the remaining renal cortex might not be the sole parameter to keep the kidney or not.To save the kidney in calculous pyonephrosis of short course might be feasible.
10.Phase Ⅱ rehabilitation/prevention of brain tumor: effect of the HSV-TK/ACV system mediated by cationic lipsome on the proliferative activity of human glioma cells
Jun SU ; Yan YU ; Xuexin ZHANG ; Hong XIAO ; Haicheng YANG
Chinese Journal of Tissue Engineering Research 2005;9(14):232-233
BACKGROUND: Gene therapy is a popular topic in domestic and overseas studies on biological therapy for brain tumor.OBJECTIVE: By using a newly constructed eukaryotic expression vector of pCR3-TK, the effect of the HSV-TK/ACV system on the proliferative activity of human glioma cells was investigated.DESIGN: Experimental study based on cells.SETTING: Department of neurosurgery and department of oncology in a university hospital.MATERIALS: The study was conducted at the National Key Laboratory of Veterinary Biotechnology of Harbin Veterinary Research Institute from January to April in 2004. The eukaryotic expression vector of pCR3-TK was constructed by the author. The TJ905 strain was a gift from professor Pu Pei-yu, who worked in the Neurology Institute of Tianjin city. The nontransfected cells and the cells transfected with pCR3-Uni vector were set as controls.METHODS: By using Lipofectamine(a cationic liposome), the pCR3-Uni vector and the recombinant pCR3-TK plasmid(inserted with HSV-TK gene)were transfected into the human glioma cell strain-TJ905. Then the positive clones were picked out and were given ACV(50 mg/L) . Totally 72 hours later, the cover slips were collected and silver staining for nucleolus organizer regions(AgNORs) was performed.MAIN OUTCOME MEASURES: After the ACV treatment and AgNORs staining, the numbers of silver-stained granules in TJ905 cells with or without transfections were counted respectively.RESULTS: In those cells transfected with HSV-TK gene, after ACV treatment, a significant decreasing in proliferative activity could be observed, and the average numbers of the silver-stained granules in cells transfected with pCR3-Uni or pCR3-TK were 14.33 and 6.67 respectively( P < 0.01).CONCLUSION: As an easy-to-operate method, AgNOR counting is helpful for the studies on the proliferative activity of cells and the investigations into the potential anti-tumor mechanism of the HSV-TK/ACV system.