A new diamond-based variable spring-mass model has been proposed in this study. It can realize the deformation simulation for different organs by changing the length of the springs, spring coefficient and initial angle. The virtual spring joined in the model is used to provide constraint and to avoid hyperelastic phenomenon when excessive force appears. It is also used for the calculation of force feedback in the deformation process. With the deformation force feedback algorithm, we calculated the deformation area of each layer through screening effective particles, and contacted the deformation area with the force. This simplified the force feedback algorithm of traditional spring-particle model. The deformation simulation was realized by the PHANTOM haptic interaction devices based on this model. The experimental results showed that the model had the advantage of simple structure and of being easy to implement. The deformation force feedback algorithm reduces the number of the deformation calculation, improves the real-time deformation and has a more realistic deformation effect.
目的 探讨胆道镜在探查十二指肠损伤中的临床价值。方法 回顾性分析我院2001年3月至2011年2月期间收治的28例十二指肠损伤患者应用胆道镜探查的临床资料。结果 开腹后直视十二指肠球部损伤7例，胆道镜探查发现其中3例合并水平部损伤，2例合并降部与水平部交界处损伤。直视下未见十二指肠损伤患者中胆道镜探查发现十二指肠损伤21例，其中降部5例，水平部6例，降部与水平部交界处3例，升部2例，十二指肠多处伤5例。按Lucas分级，Ⅰ级4例，Ⅱ级12例，Ⅲ级7例，Ⅳ级5例。Ⅰ级损伤患者中3例在胆道镜下未见血肿继续增大，局部损伤未行处理；1例血肿压迫十二指肠导致肠腔狭窄，在胆道镜引导下避开肠系膜血管，切开肠系膜行血肿清除及止血术。Ⅱ级损伤患者中6例在胆道镜引导下避开肠系膜血管切开肠系膜行全层缝合。其他病例分别采用十二指肠破口空肠Roux-en-Y吻合术（Ⅱ级3例，Ⅲ级1例）、十二指肠空肠端端吻合术（Ⅱ级1例，Ⅲ级3例）、十二指肠空肠Roux-en-Y吻合术（Ⅱ级2例，Ⅲ级2例，Ⅳ级1例）、Graham简化术（Ⅲ级1例，Ⅳ级4例），术后通过空肠切口处放置十二指肠内引流。术后发生并发症12例，其中肠瘘2例，胰瘘2例，肠梗阻3例，腹腔脓肿2例，胰腺脓肿3例。死亡3例，治愈25例。结论 在十二指肠损伤患者中应用胆道镜探查，可以确切诊断十二指肠受损情况，防止漏诊，也可以在胆道镜引导下行相应部位的处理。
ObjectiveTo explore the clinical value of modified Soave procedure with stapler for the treatment of Hirschsprung disease. MethodsThe clinical data of 26 patients with Hirschsprung disease adimitted in No.477 hospital from January 2002 to December 2010 were analyzed retrospectively. All the patients underwent modified Soave operation with rectal mucosa and proximal intestine stapled end-to-end. ResultsAll operations were successful without anastomotic leakage, aponeurosis of investment infection, and colonitis. Increased stool frequency presented in two cases, which were cured with astringents on day 15 and 30 after operation, respectively. Mild fecal contamination was in one case. All cases were followed up between 3 months to 60 months, with an average 32 months, without incontinence and constiptation. ConclusionModified Soave procedure with stapler is safe and effective for the treatment of Hirschsprung disease in elder children and adult.
Objective To investigate the influence on the postoperative recovery for giving either total parenteral nutrition （TPN） or early enteral nutrition (EEN) to patients with gastric cancer after total gastrectomy. Methods Eighty-six patients with gastric cancer undergone total gastrectomy were divided into TPN group (n=31) and EEN group (n=55). Patients in TPN group received TPN support via vena cava (internal jugular vein or subclavian vein), while patients in EEN group received early feeding through the naso-intestinal tube, which was placed during operation, and volume of enteral nutrition (fresubin) was increased daily, full enteral nutrition was expected on day 3-5. Nutrition status after operation, postoperative plasma albumin (Alb), the time of passing gas or stool, the time of oral intake, hospital stay and any postoperative complications were recorded and analyzed. Results There were no significant differences between two groups (Pgt;0.05) in postoperative plasma Alb level, the time of passing gas or stool, postoperative complications rate or hospital stay. However, in the TPN group, the time of oral intake was shorter than that in EEN group (P=0.004). Conclusions Both TPN and EEN are the suitable nutritional methods for patients with gastric cancer after total gastrectomy, and with no detectable difference. For patients with high risk, such as severe malnutrition, naso-intestinal tube should be placed for EEN.
Brain functional network changes over time along with the process of brain development, disease, and aging. However, most of the available measurements for evaluation of the difference (or similarity) between the individual brain functional networks are for charactering static networks, which do not work with the dynamic characteristics of the brain networks that typically involve a long-span and large-scale evolution over the time. The current study proposes an index for measuring the similarity of dynamic brain networks, named as dynamic network similarity (DNS). It measures the similarity by combining the “evolutional” and “structural” properties of the dynamic network. Four sets of simulated dynamic networks with different evolutional and structural properties (varying amplitude of changes, trend of changes, distribution of connectivity strength, range of connectivity strength) were generated to validate the performance of DNS. In addition, real world imaging datasets, acquired from 13 stroke patients who were treated by transcranial direct current stimulation (tDCS), were used to further validate the proposed method and compared with the traditional similarity measurements that were developed for static network similarity. The results showed that DNS was significantly correlated with the varying amplitude of changes, trend of changes, distribution of connectivity strength and range of connectivity strength of the dynamic networks. DNS was able to appropriately measure the significant similarity of the dynamics of network changes over the time for the patients before and after the tDCS treatments. However, the traditional methods failed, which showed significantly differences between the data before and after the tDCS treatments. The experiment results demonstrate that DNS may robustly measure the similarity of evolutional and structural properties of dynamic networks. The new method appears to be superior to the traditional methods in that the new one is capable of assessing the temporal similarity of dynamic functional imaging data.