End-tidal carbon dioxide tension or concentration monitoring is characterized with noninvasive,convenient and fast reaction,which Can be continuously monitored and dynamically displayed On electrocardiogram monitor.The technique has been extensively applied in the operation room,intensive care unit and emergency room.

Zhisou powder is a famous TCM prescription of Qing dynasty great physician Cheng Zhongling in treating cough caused by exogenous pathogenic factor.Author respects ancient TCM prescriptions,but don't adhere to it.Author believes that with proper modification of the prescription based on correct syndrome differentiation,Zhisou powder is effective for various kinds of cough including acute and chronic cases,and is satisfactory for good clinical result.This article mainly introduces author's experience in treating various kinds of cough which embodies the holism concept and thought of treatment based on syndrome differentiation in TCM.

Objective To study the distribution and changes of the purulent meningitis in gender,age,region,season and pathogens in children during the past 20 years.Methods All the basic clirical features of purulent meningitis patients less than 17 years old in Children's Hospital of Chongqing Medical University from Jan.1993 to Jan.2013 were analyzed retrospectively.A total of 1 855 patients were divided into 2 groups according to their date of admission.Group A included 666 patients admitted from Jan.1993 to Dec.2002,and group B included 1 189 cases admitted from Jan.2003 to Jan.2013.Then,they were divided into 5 groups according to their ages,including neonate group,＞ 1 month-1 year old aoup,＞ 1-3 years old group,＞ 3-10 years old group,＞ 10-17 years old group.Results Of the 1 855 cases,there were 1 054 cases (56.82％) admitted in the spring and summer,and 1 123 cases (60.54％) were younger than 1 year of age.The ratio of male to female cases was 1.82 to 1.00 and that of country patients to urban patients was 1.40 to 1.00.The distributions were female patients (443 cases,37.26％),urban patients (517 cases,43.48％),and the ratio of patients admitted in the autumn (265 cases,22.29％) and patients younger than 1 year of age (606 cases,50.97％) in group B,which were significantly higher than those [215 cases (32.28％),256 cases (38.44％),102 cases (15.32％),272 cases (40.84％)] of group A (x2 =4.62,4.47,25.51,25.52,all P ＜ 0.05).The predominant isolated bacteria from cerebrospinal fluid were coagulase negative staphylococcus (43/196 cases,21.94％),Streptococcus pneumoniae (32/196 cases,16.33％),Neisseria meningitidis (17/196 cases,8.67％) and Escherichia coli (15/196 cases,7.65％).Coagulase negative staphylococcus and Escherichia coli both accounted for higher rates of pathogenic bacteria in 1 year old than that of pathogenic bacteria more than 1 year old (x2 =4.57,14.37,all P ＜ 0.05),while Streptococcus pneumoniae and Neisseria meningitidis both had higher rates of pathogenic bacteria more than 1 year old and more than 3 years old,respectively (x2 =14.93,19.76,all P ＜ 0.05).Onfly cases in group B with Streptococcus pneumoniae were higher than those in group A (x2 =11.78,P ＜ 0.05),while the other common bacteria in each age group were of no difference between group A and group B.Conclusions There had been some changes in the epidemiological distribution of purulent meningitis during the past 20 years.The main risk factors were male in gender,patients in rural areas,onset in the spring or summer and infants in early age.The predominant isolated bacteria from cerebrospinal fluid were some opportunistic pathogens,including coagulase negative staphylococcus,Streptococcus pneumoniae,and Escherichia coli.Streptococcus pneumoniae meningitis was increased during the past 10 years.

Objective To investigate reasonable method of deciding internal target volume (ITV) by comparing physical phantom volumes (including moving volume) with reconstruction volumes of spiral CT scanning.Methods The various-volume wax blocks which were labeled No.1-9 were made and put on the respiratory motion simulator.The range of motion was set 2.5 cm and frequency 18 beats/min.All blocks were scanned 10 times continuously and imported into the Eclipse TPS.All blocks volumes were calculated and then compared with the true physical volumes and paired t-test.Results The reconstruction volumes of 1-9 blocks were bigger than their stationary volumes (121.77 cm3 vs.103.14 cm3,P =0.038),but significantly smaller than their moving volumes (121.77 cm3 vs.161.75 cm3,P =0.045).The results can be gotten in different volume block scanning.The relative deviation of reconstruction volumes and the moving volumes tends to increase as the stationary physical volume decreases.Conclusions As to moving targets,conventional spiral CT scanning speed is too fast to collect all volume information of targets.So the one-time-scanning volume does not represent the ITV.

Objective To measure the distortion of digital images generated by radiotherapy simula-tor,and to study the appropriate method of correction. Methods The grid correction plate and Microsoft Visual C + + 6.0 were used for correction. The area error and boundary maximum displacement error of dig-ital images before and after correction were calculated. The post-correction images were compared with film images to evaluate the correction method. Results The area error was 0.31% - 12.36%, and the bounda-ry displacement error was more than 0 -6 mm for 4 cm ×4 cm - 12 cm × 12 cm radiation field before correc-tion. For commonly used radiation field(12 cm × 12 cm) ,the post-correction area error and the boundary displacement error were 0.48% and 0.46 mm,respectively. Conclusions The least square and polynomi-al fitting correction method can fulfill the requirement of conventional radiotherapy.

Objective To study the effect of various methods determining lung volume and fraction dose on the lung dose-volume parameters for lung cancer patients. Methods Twenty patients with lung cancer were rantdomly enrolled into our study and the plan of three dimensional eonformal radiation therapy(3DCRT)was designed by Varian Eclipse TPS.The lung volumes and the dose-volume parameters were measured under CT value of-300- -980, -400- -980 and -500- -980.Under CT value of -400- -980,total lung volumes were confirmed.The dose-volume parameters of V30,V20,V10 and mean lung dose(MLD)were reevaluated after GTV,CTV and PTV were subtracted from the total lung volumes and when the fraction dose was elevated from 2.0 Gy to 10.0 Gy. Results When the CT value ranged from-300--980 to-500--980,the median reduction of the total lung volumes(-9.10%)was significantly higher than that of V30,V20,V10 and MLD(-3.18%,-1.13%,0.82%and-0.79%,respectively).When the total lung volume was fixed at CT value of-400--980,the alterations of V30,V20,V10 and MLD became more apparent as the increase of the subtracted lung volume,among which the alteration of V30 was most significant while V10 the least.Among five cases with a fixed total dose of 60 Gy and PTV less than 140 cm3,the V30,V20,V10 and MLD were increased to a similar extent(about 40%)when the fraction dose was increased from 2.0 Gy to 10.0 Gy.MLD was increased(36%)when the fraction dose was above 6.0 Gy. Conclusions When CT value ranges from-300- -980 to-500- -980,the total lung volume is influenced most.The alteration of V30,being statistically significant,might have some significance but is not enough to determine the plan of radiotherapy clinically.The alteration of V20、V10 and MLD is not statistically significant.When the overlapped target volume is subtracted from the total lung volumes,the alteration of V30 is the most sign:tifhcant while V10 the least.The fraction dose,being the most consuming factor(＞10%)when comparing with the CT valHe and targeted volume,can significantly influence the dose-volume parameter.

In the present work, Monte Carlo simulations were employed to study the characteristics of the dose distribution of high energy electron beam in the presence of uniform transverse magnetic field. The simulations carried out the transport processes of the 30 MeV electron beam in the homogeneous water phantom with different magnetic field. It was found that the dose distribution of the 30 MeV electron beam had changed significantly because of the magnetic field. The result showed that the range of the electron beam was decreased obviously and it formed a very high dose peak at the end of the range, and the ratio of maximum dose to the dose of the surface was greatly increased. The results of this study demonstrated that we could change the depth dose distribution of electron beam which is analogous to the heavy ion by modulating the energy of the electron and magnetic field. It means that using magnetic fields in conjunction with electron radiation therapy has great application prospect, but it also has brought new challenges for the research of dose algorithm.
Algorithms ; Electrons ; Humans ; Magnetic Fields ; Monte Carlo Method ; Phantoms, Imaging ; Radiation Dosage

Objective: To explore the position change of the setup reference markers on the sternum due to the change of hands grip position. Methods: Six hands grip positions were simulated for 8 patients and the set-up reference points marked on the sternum skin were compared while the hands grasped different positions of the hands. Results: The setup markers on the sternum were deviated by all five hands grip positions. The maximum deviated distance was 14mm. Conclusion: The change of the hands grip position can affect the position of setup reference markers on the sternum of the patients and thus the isocenter of plan may be aligned to the wrong area.

Objective To compare the results of CT/MRI registration by using two different marker materials. Methods CT and MR transversal images (using electric wire and thin tube filled with lohexol injection as matching points respectively) were obtained from nine cases with brain tumor. Another CT and MR transversal images were also obtained by using the cod-liver oil capsule filled with gadopentetate dimeglumine injection as matching points with the same scanning position. The images were transferred to the TPS for image registration and the effect was evaluated. Results The CT/MRI CRE range for using different kinds of marker material was 0.16-0.28cm,while was 0.06-0.16cm for using the same marker material. Conclusion Comparing with the method using different kinds of material,the method using the same spherical material can get better results in CT/MRI registration.

The hybrid pencil beam model (HPBM) is an effective algorithm for calculating electron dose distribution in radiotherapy. The mean energy distribution of incident electron beam in phantom is one of the factors that affect the calculation accuracy of HPBM, especially in field edge areas near the end of the electron range. A new fitted formula based on Monte Carlo (MC) simulation data for electron beams with energy range of 6-20 MeV in the homogeneous water phantom is proposed in this paper. The precision of the fitted formula within the scope of the energy was evaluated by comparing the electron dose distribution of ECWG measured data with that obtained from HPBM which took the mean electron energy that calculated by the fitted formula and the existed empirical formula, respectively. The results showed that the accuracy of dose distribution that obtained by the mean electron energy calculated with the fitted formula increased about 1%.
Algorithms ; Electrons ; Humans ; Monte Carlo Method ; Phantoms, Imaging ; Radiotherapy Planning, Computer-Assisted ; Water