震后多目标动态应急医疗设施选址-伤员转运问题研究

Multi-objective Dynamic Facility Location-transportation Problem in Emergency Humanitarian Logistics

地震等灾害的突发性和破坏性常导致部分伤员无法得到快速有效的救治,同时会给伤员造成一定的负面心理,影响救援效率。本文综合考虑救护车辆(救护车、直升机)和医疗设施容量的动态变化、各类伤员生存概率随时间动态变化以及伤员心理状况变化,构建了最大化伤员生存数量和最小化心理成本的震后伤员二级后送模式的医疗设施选址-伤员转运双目标动态规划模型。运用epsilon约束法有效处理双目标模型,以玉树地震后伤员后送问题为例,采用CPLEX对模型进行求解,通过分析医疗资源数量对伤员转运数量的影响,表明在伤员后送过程中,增加临时医院数量或容量与救护车数量比增加后方医院数量或容量与直升机数量更有效;考虑伤员的心理成本,为了提高伤员存活率,在灾害前期,可以通过增加救护车数量,转运更多的重伤员,而中后期提高临时医院容量,尽量优先转运轻伤员。

The sudden and destructive earthquake disasters often lead to some casualties cannot be transported quickly and timely, which will cause anxiety and panicto casualties andaffect the efficiency of emergency rescue. Transporting casualties from earthquake-affected areas to on-site clinics or general hospitals are vital after devastating earthquake strikes. On-site clinics are established near disaster areas such as racecourses or airports to provide simple treatment and general hospital can provide comprehensive treatment in EMS for casualties.At that time, not only the optimal locations of on-site clinics and general hospitals, butalso the scheme of casualty transportation should be decided. In this paper,a bi-objective dynamic mixed integer programming model combining emergency medical facilities location and casualty transportation for casualty response planningin various period safter earthquake is developed, in which all the casualties were transported to the on-site clinics by ambulance, then the more serious casualties in stable condition were transported to the general hospital for comprehensive treatment by helicopter. The dynamic change of the emergency medical resources, survival probability change and the psychological status of the various casualtiesover timeare considered. The objective is to maximize the survival quantity and minimize the psychological costof the casualties.The epsilon constraint method is used to transform bi-objective model effectively. Then CPLEX is used to solve the cases based on Yushu earthquake. Finally, sensitivity analysis shows that the capacity of on-site clinics and the number of the ambulances have greater effect on the objective value compared with the capacity of general hospitals and the number of the helicopters. The number of ambulances should be increased to transported more serious casualties in the early stage of the disaster and the capacity of temporary hospitals should be increased to transport more mild casualties in the middle and late period in order to improve the survival rate of casualties and decrease the psychological costs.The scientific decision-making basis for casualty response planning is provided and the basic theory of emergency medical rescue is developed.