Objective To propose an improved C-means segment method based on Gibbs random field accelerated by GPU.Methods The parallel computation of pixel shades was used to take the place of the classical point-by-point method of CPU.By this way,the efficiency was higher than merely using the CPU computation.Results The efficiency of computation was improved over 400%.The load of CPU was reduced and the effect of accelerator was obvious.Conclusion The improved C-means segment method based on Gibbs random field accelerated by GPU enhances the clinical application of image segmentation,the computer rate of which is improved distinctly and closely to real time.[Chinese Medical Equipment Journal,2008,29(2):6-9]

Objective To determine the median effective target effect-site concentration (EC50) of sufentanil when intraoperative wake-up test was successful in patients undergoing scoliosis surgery.Methods Ninety ASA Ⅰ or Ⅱ patients,aged 18-64 yr,with body mass index ＜ 30 kg/m2,scheduled for scoliosis surgery under sevoflurane and sufentanil anesthesia,were randomly divided into Ⅰ-Ⅵ groups (n =15 each).Anesthesia was induced with sufentanil,etomidate and cisatracurium,and maintained with sevoflurane,sufentanil and cisatracurium.The patients were tracheal intubated and mechanically ventilated.Before the wake-up test,infusion of cisatracurium was stopped and the end-tidal concentration of sevoflurane was adjusted to 0.The EC50 was determined by the K(a)rber method.The target effect-site concentration of sufentanil was set at 0.19 ng/ml in group Ⅰ,0.18 ng/ml in group Ⅱ and gradually decreased in decrements of 0.01 ng/ml.The wake-up test was performed 5 min later.The EC50 and 95 ％ confidence interval of sufentanil were calculated by the K(a)rber method.Results EC50 of sufentanil obtained was 0.164 ng/ml and 95％ confidence interval of sufentanil obtained was 0.157-0.172 ng/ml when the wake-up test was successful.Conclusion The EC50 of sufentanil is 0.164 ng/ml when the intraoperative wake-up test is successful in the patients undergoing scoliosis surgery.

The remote monitoring and alarming system of the level & pressure of the liquid-oxygen tank employes two microprocessors and remote control technique to fulfill its functions.With a cable and a video connection wire involved,the system is simple,safe,reliable and lightingproof.

Objective To explore the formation process of vacuum pressure differential of micro power negative pressure technology to facilitate its clinical application.MethodsThe formation of negative pressure differential and changes of negative pressure values in enclosure space were studied which was formed by liquid aspiration after the compressive polyvinyl alcohol foam material was enclosed.Micro power negative pressure technology was applied to the treatment of the right ear necrosis patient after focal cleaning,and the efficacy was observed.Results Medical adhesive film was raised gradually during the expansion of polyvinyl alcohol foam due to liquid aspiration,and then the enclosure space extended increasingly to form local vacuum negative pressure.The range of maximal negative pressure was between-110 and-200 Pa,and the mean maximal negative pressure value was-132.7 Pa.Micro power negative pressure technology behaved well in healing the wound.Conclusion Micro power negative pressure technology gains advantages in reliability and easy operation over other technologies and products,and may be a new choice for healing of refractory wounds.

Objective To evaluate the effect of dexmedetomidine on intraoperative wake-up test in patients undergoing scoliosis surgery.Methods Sixty ASA Ⅰ patients,aged 13-18 yr,scheduled for elective scoliosis surgery,were randomly divided into 2 groups (n =30 each) ∶ sufentanil group (group S) and dexmedetomidine combined with sufentanil group (group DS).Anesthesia was induced with sufentanil,etomidate and cisatracurium,and maintained with target-controlled inhalation of sevoflurane combined with target-controlled infusion of sufentanil in both groups.In group DS,dexmedetomidine 0.2 μg·kg-1 · h-1 was infused during operation,while the equal volume of normal saline was given instead in group S.Before the wake-up test,cisatracurium infusion was stopped,the end-tidal concentration of sevoflurane was adjusted to 0,and the target effect-site concentration of sufentanil was adjusted to 0.1 and 0.08 ng/ml in groups S and DS,respectively.The wake-up test was performed 5 min later.The wake-up time and bucking/restlessness and cardiovascular events during the wake-up test were recorded.The occurrence of intraoperative awareness was recorded in the patients who were followed up after operation.Results No cardiovascular events occurred during the wake-up test in group DS.The wake-up time was significantly shorter and the incidences of cardiovascular events and bucking/restlessness were significantly lower in group DS than in group S (P ＜ 0.05).No intraoperative awareness occurred in the patients.Conclusion Dexme-detomidine can be used for intraoperative wake-up test in patients undergoing scoliosis surgery,with shorter wakeup time,stable hemodymamics and fewer adverse reactions.

Objective To investigate the effect of dexmedetomidine combined anesthesia on postoperative delirium in the elderly patients undergoing hip joint replacement.Methods One hundred and sixty ASA Ⅱ or Ⅲ patients,aged 75-85 yr,with a body mass index of 20-25 kg/m2,scheduled for elective total hip joint replacement under general anesthesia,were randomly divided into 2 groups (n =80 each):sevoflurane-fentanyl control group (group C) and dexmedetomidine-sevoflurane-fentanyl group (group D).Dexmedetomidine was intravenously infused at 0.2 μg· kg-1 · h-1 until the end of operation after a loading dose of 0.6μg/kg over 15 min before induction of anesthesia in group D,while the equal volume of normal saline was infused in group C.Anesthesia was induced with iv injection of fentanyl 2-4 μg/kg and etomidate 0.1-0.3 mg/kg at 5 min after the end of administration of the loading dose.Tracheal intubation was facilitated with cisatracurium 0.15 mg/kg and the patients were mechanically ventilated.Anesthesia was maintained with target-controlled inhalation of sevoflurane (the end-tidal concentration 1％-3％) and intermittent iv boluses of fentanyl 0.05 mg.BIS was maintained at 40-60 during operation.The consumption of etomidate,fentanyl,and sevoflurane,agitation during emergence from anesthesia,and postoperative delirium within 24 h after operation were recorded.Results Compared with group C,the consumption of etomidate,fentanly,and sevoflurane was significantly reduced and the incidences of agitation during emergence from anesthesia and postoperative delirium within 24 h after operation were significantly decreased in group D (P ＜0.05).Conclusion Dexmedetomidine combined anesthesia can reduce the occurrence of postoperative delirium in the elderly patients undergoing hip joint replacement.

Objective To investigate the risk factors for postoperative delirium in patients undergoing spine operation under total intravenous anesthesia. Methods Two hundred patients undergoing elective spine operation were included in this study. Patients' perioperative informations were recorded. The diagnosis of delirium was based on Confusion Assessment Method (CAM). The patients were divided into 2 groups according to the occurrence of delirium within 3 days after operation: postoperative delirium group and no postoperative delirium group. Multivariate logistic regression was used to analyze the risk factors for postoperative delirium. Results Postoperative delirium developed in 39 patients during the first three postoperative days. The incidence of postoperative delirium was 19.5%. The logistic stepwise regression analysis indicated that the risk factors for delirium included age, intraoperative blood loss and alcohol abuse. Conclusion Age, large amount of intraoperative blood loss and alcohol abuse are risk factors for postoperative delirium in patients undergoing spine operation under total intravenous anesthesia.

Objective to establish an ethical assessment system in the admittance of the limitative medical technologies.Method:literature review and Delphi method are employed to adjust and set the structure,index numbers,and index weights of ethical assessment system of the limitative medical technologies.Result:An ethical assessment system in the admittance of the limitative medical technologies was established,which included 3 primary indices,11 secondary indices and 35 tertiary indices.There were 4 qualitative levels with different weights in tertiary indices,based on which the global grade and proposed-admittance criterion were obtained.Conclusion:Establishment of ethical assessment system in the admittance of the limitative medical technologies provides an ethical evidence for the assessment of clinical admittance of the limitative medical technologies with qualitative and quantitative approaches and class-setting evidence.

Objective To investigate the risk factors for postoperative delirium in patients undergoing noncardiac surgery. Methods From September-December 2009, 480 patients undergoing elective noncardiac surgery were included in this study. The criteria for enrolment of the patients in this study were (1) age ≥ 65 yr,(2) age ＜ 65 yr if associated with coronary artery disease, hypertension, diabetes mellitus, brain injury, cerebral hemorrhage, cerebral infarct, emphysema, chronic bronchitis; duration of operation ≥ 3 h and intraoperative blood loss was expected to exceed 20% of blood volume. The diagnosis of delirium was based on Confusion Assessment Method (CAM). Multivariate logistic regression was used to analyze the risk factors for postoperative delirium.Results Postoperative delirium developed in 79 patients during the first three postoperative days. The incidence of postoperative delirium was 16.5%. The logistic stepwise regression analysis indicated that the risk factors for delirium included advanced age, method of anesthesia, long operation, postoperative pain, emphysema and alcholic. Conclusion Age, method of anesthesia, long operation, postoperative pain, emphysema and alcholic are risk factors for postoperative delirium in patients undergoing noncardiac surgery.

Objective To investigate the effect of the intraoperative wake-up test on the postoperative delirium in patients undergoing scoliosis operation under analgesia with sufentanil. Methods Sixty ASA Ⅰ or Ⅱ patients , aged 12-60 yr, scheduled for scoliosis surgery, were randomly divided into 2 groups ( n = 30 each) : control group (group C) and intraoperative wake-up test group (group W) . The intraoperative wake-up test was not performed during operation in group C. Anesthesia was induced with target-controlled infusion of sufentanil with the target effect-site concentration set at 0.5 ng/ml and iv injection of propofol 1-2 nig/kg. As soon as the patients lost consciousness, tracheal intubation was facilitated with 0.15 mg/kg cisatracurium besylate. The patients were mechanically ventilated. Anesthesia was maintained with target-controlled inhalation of sevoflurane (target end-tidal concentration 0. 8%-1. 5%), target-controlled infusion of sufentanil (target effect-site concentration 0.2-0.3 ng/ml) and iv infusion of cisatracurium besylate 0.1 mg- kg-1·h-1 . In group W, the patients underwent the intraoperative wake-up test. Postoperative analgesia was provided with sufentanil. The occurrence of intraoperative awareness and postoperative delirium was recorded. Results No significant difference was found in the incidences of intraoperative awareness and postoperative delirium between the two groups. Conclusion The intraoperative wake-up test is not the risk factor for postoperative delirium in patients undergoing scoliosis surgery under analgesia with sufentanil, and inhibition of perioperative pain and intraoperative awareness by analgesia with sufentanil may be involved in the mechanism.