Missile interception problem can be regarded as a two-person zero-sum differential games problem,which depends on the solution of Hamilton-Jacobi-Isaacs(HJI)equa-tion.It has been proved impossible to obtain a closed-f...Missile interception problem can be regarded as a two-person zero-sum differential games problem,which depends on the solution of Hamilton-Jacobi-Isaacs(HJI)equa-tion.It has been proved impossible to obtain a closed-form solu-tion due to the nonlinearity of HJI equation,and many iterative algorithms are proposed to solve the HJI equation.Simultane-ous policy updating algorithm(SPUA)is an effective algorithm for solving HJI equation,but it is an on-policy integral reinforce-ment learning(IRL).For online implementation of SPUA,the dis-turbance signals need to be adjustable,which is unrealistic.In this paper,an off-policy IRL algorithm based on SPUA is pro-posed without making use of any knowledge of the systems dynamics.Then,a neural-network based online adaptive critic implementation scheme of the off-policy IRL algorithm is pre-sented.Based on the online off-policy IRL method,a computa-tional intelligence interception guidance(CIIG)law is developed for intercepting high-maneuvering target.As a model-free method,intercepting targets can be achieved through measur-ing system data online.The effectiveness of the CIIG is verified through two missile and target engagement scenarios.展开更多
BACKGROUND Osteoid osteoma is a benign bone tumor with characteristic clinical symptomatology.The selected method for its treatment is percutaneous radiofrequency ablation.However,percutaneous cryoablation is an alter...BACKGROUND Osteoid osteoma is a benign bone tumor with characteristic clinical symptomatology.The selected method for its treatment is percutaneous radiofrequency ablation.However,percutaneous cryoablation is an alternative method with certain advantages.AIM To evaluate percutaneous computed tomography(CT)-guided cryoablation for the treatment of osteoid osteoma in young patients and adults.METHODS A total of 25 patients were treated with percutaneous CT-guided cryoablation for osteoid osteomas between October 2020 and March 2023 at a single institution.All patients were above 14-years-old(mean age,24-years-old),and all procedures were performed under local anesthesia.Of the 25 patients,8 were female and 17 were male.Tumor sites included the femur(n=9),medial malleolus(n=4),sacral ala(n=4),facets(n=4),humerus(n=3),and tibia(n=1).One cryoprobe was used in each procedure and,when possible,the lesion was covered by the ice-ball using an extraosseous position without penetrating the nidus.All necessary thermal protective techniques were used depending on the anatomical structure at risk.RESULTS All patients treated had complete response(100%clinical success rate)starting on the day of the procedure.Technical success was achieved in all cases.Visual analog scale(VAS)scores at 1 year were 0,compared to a mean VAS score of 8.5±1(SD)before the procedure.No recurrences were reported at the 1-year follow-up and no complications were observed.In 11/25 cases,an extraosseous position of the cryoprobe was used with less procedural time achieving technical and clinical success and no complications with less patient discomfort.All patients were discharged from the hospital on the same day as the procedure.CONCLUSION Cryoablation of osteoid osteomas is an efficacious and safe procedure with durable clinical results.Its greatest advantage is that the procedure can be performed under local anesthesia using an extraosseous position of the cryoprobe when possible.展开更多
Objective To explore the value of clinical application of a navigation system with three-dimensional(3D)imaging for thermal ablation of liver tumors.Methods The study cohort comprised 60 patients who underwent compute...Objective To explore the value of clinical application of a navigation system with three-dimensional(3D)imaging for thermal ablation of liver tumors.Methods The study cohort comprised 60 patients who underwent computer tomography-(CT)guided thermal ablation(radiofrequency or microwave ablation)of liver tumors in our department from August 2021 to October 2022.A random envelope method was used to allocate the study patients randomly to two groups of 30 patients each:a navigation and a control group.An intraoperative 3D imaging navigation system with CT guidance was used in the navigation group,whereas traditional CT guidance was used in the control group.During the thermal ablation process,the number of puncture needle adjustments,time to target puncture,and number of CT scans were recorded and compare between the two groups.Results The average number of punctures and needle adjustments was significantly lower in the navigation group(2.7±1.1 mins)than in the control group(4.9±3.7 mins).The average time taken to puncture the target was significantly shorter in the navigation group(11.3±4.2 mins)than in the control group(15.5±4.8 mins).There average number of CT scans was significantly smaller in the navigation group(4.5±1.6)than in the control group(8.4±4.5)(all P<0.05).Conclusion Use of an intraoperative 3D imaging navigation system in thermal ablation of liver tumors can improve the accuracy of tumor thermal ablation puncture and reduce the number of punctures,number of CT scans,and average puncture time.Such systems can play an important role in the clinic.展开更多
文摘Missile interception problem can be regarded as a two-person zero-sum differential games problem,which depends on the solution of Hamilton-Jacobi-Isaacs(HJI)equa-tion.It has been proved impossible to obtain a closed-form solu-tion due to the nonlinearity of HJI equation,and many iterative algorithms are proposed to solve the HJI equation.Simultane-ous policy updating algorithm(SPUA)is an effective algorithm for solving HJI equation,but it is an on-policy integral reinforce-ment learning(IRL).For online implementation of SPUA,the dis-turbance signals need to be adjustable,which is unrealistic.In this paper,an off-policy IRL algorithm based on SPUA is pro-posed without making use of any knowledge of the systems dynamics.Then,a neural-network based online adaptive critic implementation scheme of the off-policy IRL algorithm is pre-sented.Based on the online off-policy IRL method,a computa-tional intelligence interception guidance(CIIG)law is developed for intercepting high-maneuvering target.As a model-free method,intercepting targets can be achieved through measur-ing system data online.The effectiveness of the CIIG is verified through two missile and target engagement scenarios.
基金approved by the Institutional Review Board of General Hospital of Thessaloniki“G.Papanikolaou”(Protocol Code 77481-12 and 05-04-2024).
文摘BACKGROUND Osteoid osteoma is a benign bone tumor with characteristic clinical symptomatology.The selected method for its treatment is percutaneous radiofrequency ablation.However,percutaneous cryoablation is an alternative method with certain advantages.AIM To evaluate percutaneous computed tomography(CT)-guided cryoablation for the treatment of osteoid osteoma in young patients and adults.METHODS A total of 25 patients were treated with percutaneous CT-guided cryoablation for osteoid osteomas between October 2020 and March 2023 at a single institution.All patients were above 14-years-old(mean age,24-years-old),and all procedures were performed under local anesthesia.Of the 25 patients,8 were female and 17 were male.Tumor sites included the femur(n=9),medial malleolus(n=4),sacral ala(n=4),facets(n=4),humerus(n=3),and tibia(n=1).One cryoprobe was used in each procedure and,when possible,the lesion was covered by the ice-ball using an extraosseous position without penetrating the nidus.All necessary thermal protective techniques were used depending on the anatomical structure at risk.RESULTS All patients treated had complete response(100%clinical success rate)starting on the day of the procedure.Technical success was achieved in all cases.Visual analog scale(VAS)scores at 1 year were 0,compared to a mean VAS score of 8.5±1(SD)before the procedure.No recurrences were reported at the 1-year follow-up and no complications were observed.In 11/25 cases,an extraosseous position of the cryoprobe was used with less procedural time achieving technical and clinical success and no complications with less patient discomfort.All patients were discharged from the hospital on the same day as the procedure.CONCLUSION Cryoablation of osteoid osteomas is an efficacious and safe procedure with durable clinical results.Its greatest advantage is that the procedure can be performed under local anesthesia using an extraosseous position of the cryoprobe when possible.
基金Beijing You’an Hospital Affiliated to Capital Medical University Youth Talent Incubation Project(BJYAYYYN2022-25)
文摘Objective To explore the value of clinical application of a navigation system with three-dimensional(3D)imaging for thermal ablation of liver tumors.Methods The study cohort comprised 60 patients who underwent computer tomography-(CT)guided thermal ablation(radiofrequency or microwave ablation)of liver tumors in our department from August 2021 to October 2022.A random envelope method was used to allocate the study patients randomly to two groups of 30 patients each:a navigation and a control group.An intraoperative 3D imaging navigation system with CT guidance was used in the navigation group,whereas traditional CT guidance was used in the control group.During the thermal ablation process,the number of puncture needle adjustments,time to target puncture,and number of CT scans were recorded and compare between the two groups.Results The average number of punctures and needle adjustments was significantly lower in the navigation group(2.7±1.1 mins)than in the control group(4.9±3.7 mins).The average time taken to puncture the target was significantly shorter in the navigation group(11.3±4.2 mins)than in the control group(15.5±4.8 mins).There average number of CT scans was significantly smaller in the navigation group(4.5±1.6)than in the control group(8.4±4.5)(all P<0.05).Conclusion Use of an intraoperative 3D imaging navigation system in thermal ablation of liver tumors can improve the accuracy of tumor thermal ablation puncture and reduce the number of punctures,number of CT scans,and average puncture time.Such systems can play an important role in the clinic.
