基于并行结构的多种群粒子群优化算法

针对粒子群优化(PSO)算法中存在的多样性差、易早熟收敛和鲁棒性不强等缺点,提出一种基于并行结构的多种群PSO算法。并行多种群算法在基本粒子群算法的基础上,增加了分别能加速和减缓粒子移动的两种更新公式,既改善了粒子群算法种群多样性差的缺陷,又能保证算法的计算精度。采用十种典型的标准测试函数对提出的算法进行了仿真实验。测试结果表明:与基本粒子群优化算法相比,并行多种群粒子群算法收敛速度更快,运算时间更短。

虚拟正颌外科结合肋骨肋软骨移植治疗成人M3型半侧颜面短小

目的探讨以肋骨、肋软骨移植重建下颌支,同期采用计算机辅助虚拟手术设计行正颌手术,治疗成人M3型半侧颜面短小畸形的临床效果。方法2015年11月至2017年10月,上海第九人民医院收治M3型半侧颜面短小畸形患者共5例,男3例,女2例,年龄19~26岁,平均22岁。利用对侧第6或第7肋骨、肋软骨重建缺失下颌支,同期行上颌骨LeFortⅠ截骨术和健侧下颌骨矢状劈开截骨术,改善骨骼对称性和咬合关系。术后即刻以及术后3、6、12个月随访,检查面部对称性、张闭口功能及咬合关系;CT重建后测量面部对称性,评估手术效果。结果肋骨、肋软骨切取长度为47~67mm,移植修复下颌支后同期行正颌手术,术后移植肋骨、肋软骨均成活,5例患者创面一期愈合。患者均获得2~13个月随访,平均8个月,双侧下颌支患/健侧比例恢复至80%以上,咬合关系好,术后6个月面部对称性效果满意。结论下颌支重建同期正颌外科矫治成年M3型半侧颜面短小畸形,手术操作便捷,移植效果好,面型恢复满意,咬合关系稳定。

Primary Clinical Research of a Patient Specific Implant System for an Old Zygomaticomaxillary Complex Comminuted Fracture

The objective of this study was to expound a novel surgical management technique assisted by patient-specific implants(PSIs)for comminuted fractures of the zygomaticomaxillary complex(ZMC).The aim of this study was to explore the feasibility of using PSIs to accurately restore and fix comminuted fractures.A male patient with an old ZMC comminuted fracture was used to describe the workflow,technique,and method.Computerassisted surgical simulation was used to determine the optimal plan for the reduction of bone segments prior to surgery.The PSIs were used to accurately guide the surgeon’s position of the bone segments,as planned,during the operation.Oral panoramic films and cephalometric films were taken immediately at 1,3,6,and 12 months after the operation,while computed tomography images of the whole skull were taken immediately,half a year,and one year after the operation.The patient’s follow-up showed that the zygomatic symmetry recovered well post-surgery and the patient was satisfied with the outcome.This new surgical method greatly improved the facial symmetry of this patient.