Objective To investigate the clinical effect of the DaVinci robot system and laparoscopic radical gastrectomy. Methods Propensity score matching and retrospective cohort study were adopted. Data of 446 patients who underwent robotic or laparoscopic radical gastrectomy in the Department of Gastrointestinal Surgery, Xijing Hospital, the First Affiliated Hospital of Air Force Military Medical University from January 2014 to April 2021 were collected. Among them, 174 cases underwent robotic and 272 cases underwent laparoscopic surgery. Using the method of propensity score matching, 133 cases were selected from robotic operation group and laparoscopic operation group respectively as the research object. The perioperative indexes of the two groups were compared. Kaplan-Meier survival analysis was used to draw the survival curve and calculate the survival rate. Cox regression model was used to analyze the risk factor of prognosis. Results There was no significant difference in baseline data between the robotic surgery group and the laparoscopic surgery group after propensity score matching (P>0.05). The operative time of the two groups [(236.47±50.32) min vs. (230.64±44.51) min, t=1.000, P=0.318], the number of lymph nodes dissected [(23.32±6.58) vs. (23.95±6.03), t=–0.826, P=0.410], the time of first anal exhaust [(3.46±0.77) days vs. (3.38±0.75) days, t=0.882, P=0.378], and the length of postoperative hospital stay [(6.98±2.84) days vs. (6.94±3.61) days, t=0.094, P=0.925] were similar, the differences were not statistically significant. Compared with the laparoscopic surgery group, the robotic surgery group had less intraoperative bleeding [(83.76±58.23) mL vs. (116.54±58.58) mL, t=–4.577, P<0.001], but the total hospitalization expenses was higher [(10.04±1.92) ten-thousand Yuan vs. (6.80±1.27) ten-thousand Yuan, t=16.211, P<0.001]. The incidence of postoperative complications between the two groups (χ2=0.057, P=0.812) and Clavien-Dindo classification of complications (Z=–0.440, P=0.965) were similar between the two groups, the differences were not statistically significant. The 3-year survival situation was similar between the two groups (P=0.356). Body mass index [RR=0.803, 95%CI (0.698, 0.924), P=0.002], TNM-staging [Ⅱ -stage vs.Ⅰ -stage, RR=4.152, 95%CI (1.121, 15.385), P=0.033; Ⅲ -stage vs.Ⅰ -stage, RR=5.476, 95%CI (1.458, 20.558), P=0.012] and postoperative complications [with vs. without, RR=3.262, 95%CI (1.283, 8.293), P=0.013] were prognostic factors for 3-year survival. Conclusion Compared with laparoscopic radical gastrectomy, robotic radical gastrectomy has the same short-term and long-term prognosis.
For the transportation process of rescuing wounded personnel on naval vessels, a new type of shoulder type exoskeleton stretcher for individual soldier was designed in this paper. The three-dimensional model of the shoulder type exoskeleton stretcher for individual soldier was constructed using three dimensional modeling software. Finite element analysis technique was employed to conduct statics simulation, modal analysis, and transient dynamics analysis on the designed exoskeleton stretcher. The results show that the maximum stress of the exoskeleton stretcher for walking on flat ground is 265.55 MPa, which is lower than the allowable strength of the fabrication material. Furthermore, the overall deformation of the structure is small. Modal analysis reveals that the natural frequency range of the exoskeleton stretcher under different gait conditions is 1.96 Hz to 28.70 Hz, which differs significantly from the swing frequency of 1 Hz during walking. This indicates that the designed structure can effectively avoid resonance. The transient dynamics analysis results show that the maximum deformation and stress of exoskeleton stretcher remain within the safety range, which meets the expected performance requirements. In summary, the shoulder type exoskeleton stretcher for individual soldier designed in this study can solve the problem of requiring more than 2 people to carry for the existing stretcher, especially suitable for narrow spaces of naval vessels. The research results of this paper can provide a new solution for the rescue of wounded personnel on naval vessels.