目的探讨腹腔镜胆总管切开取石术后T管的处理方法。方法1997年7月-2004年10月，我院行腹腔镜胆总管切开取石（laparoscopic common bile duct exploration，LCBDE）、置T管治疗肝外或肝外合并肝内胆管结石420例。明确有胆总管结石后，...目的探讨腹腔镜胆总管切开取石术后T管的处理方法。方法1997年7月-2004年10月，我院行腹腔镜胆总管切开取石（laparoscopic common bile duct exploration，LCBDE）、置T管治疗肝外或肝外合并肝内胆管结石420例。明确有胆总管结石后，胆总管切开取石，胆总管一期缝合或置T管。结果胆总管切开取石一期缝合27例（6．4％），置T管393例（93．6％）。术中取尽结石236例（56．2％），术后胆道镜取石184例（43．8％）。209例术后3-4周行经T管胆道造影，无残余结石，拔除T型管。420例随访3个月-6年。平均47．5月，3例复发。结论腹腔镜胆总管切开取石术后T管拔管时间，T管造影无残留结石拔管时间应3—4周，T管造影有残留结石，应于术后6周胆道镜取石后拔管，均闭管2周。展开更多
Active debris removal(ADR) technology is an effective approach to remediate the proliferation of space debris, which seriously threatens the operational safety of orbital spacecraft. This study aims to design a contro...Active debris removal(ADR) technology is an effective approach to remediate the proliferation of space debris, which seriously threatens the operational safety of orbital spacecraft. This study aims to design a controller for a dual-arm space robot to capture tumbling debris, including capture control and detumbling control. Typical space debris is considered as a non-cooperative target, which has no specific capture points and unknown dynamic parameters. Compliant clamping control and the adaptive backstepping-based prescribed trajectory tracking control(PTTC)method are proposed in this paper. First, the differential geometry theory is utilized to establish the constraint equations, the dynamic model of the chaser-target system is obtained by applying the Hamilton variational principle, and the compliance clamping controller is further designed to capture the non-cooperative target without contact force feedback. Next, in the post-capture phase,an adaptive backstepping-based PTTC is proposed to detumble the combined spacecraft in the presence of model uncertainties. Finally, numerical simulations are carried out to validate the feasibility of the proposed capture and detumbling control method. Simulation results indicate that the target detumbling achieved by the PTTC method can reduce propellant consumption by up to24.11%.展开更多
文摘目的探讨腹腔镜胆总管切开取石术后T管的处理方法。方法1997年7月-2004年10月，我院行腹腔镜胆总管切开取石（laparoscopic common bile duct exploration，LCBDE）、置T管治疗肝外或肝外合并肝内胆管结石420例。明确有胆总管结石后，胆总管切开取石，胆总管一期缝合或置T管。结果胆总管切开取石一期缝合27例（6．4％），置T管393例（93．6％）。术中取尽结石236例（56．2％），术后胆道镜取石184例（43．8％）。209例术后3-4周行经T管胆道造影，无残余结石，拔除T型管。420例随访3个月-6年。平均47．5月，3例复发。结论腹腔镜胆总管切开取石术后T管拔管时间，T管造影无残留结石拔管时间应3—4周，T管造影有残留结石，应于术后6周胆道镜取石后拔管，均闭管2周。
基金supported by the National Natural Science Foundation of China(Nos.61725303 and 61803312)。
文摘Active debris removal(ADR) technology is an effective approach to remediate the proliferation of space debris, which seriously threatens the operational safety of orbital spacecraft. This study aims to design a controller for a dual-arm space robot to capture tumbling debris, including capture control and detumbling control. Typical space debris is considered as a non-cooperative target, which has no specific capture points and unknown dynamic parameters. Compliant clamping control and the adaptive backstepping-based prescribed trajectory tracking control(PTTC)method are proposed in this paper. First, the differential geometry theory is utilized to establish the constraint equations, the dynamic model of the chaser-target system is obtained by applying the Hamilton variational principle, and the compliance clamping controller is further designed to capture the non-cooperative target without contact force feedback. Next, in the post-capture phase,an adaptive backstepping-based PTTC is proposed to detumble the combined spacecraft in the presence of model uncertainties. Finally, numerical simulations are carried out to validate the feasibility of the proposed capture and detumbling control method. Simulation results indicate that the target detumbling achieved by the PTTC method can reduce propellant consumption by up to24.11%.
