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The moth-flame optimization( MFO) algorithm may show shortcomings such as the local optimum and convergence stagnation when solving the practical optimization problem.Therefore,aiming at the problem that MRI( magnetic resonance imaging) images are difficult to segment,this paper proposes a chaotic moth-flame optimization( CMFO) algorithm. In order to help doctors read the MRI films and improve the efficiency and accuracy of diagnosis,the knee MRI images are selected as research objects during the experiments. Then,CMFO algorithm and maximum threshold entropy are combined and applied into multi-threshold segmentation. In order to present the advantages of the CMFO algorithm proposed,SOA,BFOA and MFO algorithms are introduced under the same condition for comparative experiments. The experimental results show that CMFO can effectively improve the optimal performance of MFO,and has better applicability and advantages for knee MRI image segmentation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Accurate and minimally invasive surgery procedure has become the pursuit of the current surgical goals. With the rapid development of intelligent robots, the precise and minimally invasive treatment of fractures has become an irresistible trend. OBJECTIVE: To evaluate the clinical efficacy of robot-assisted percutaneous reduction and minimally invasive internal fixation for Schatzker II-III tibial plateau fractures. METHODS: Clinical data of patients with Schatzker II-III tibial plateau fractures who received robot- (n=22, robot-assisted group) and traditional fluoroscopy (n=26, traditional group)-assisted internal fixation at Tianjin Hospital from April 2017 to August 2018 were analyzed retrospectively. All patients suffered from unilateral, closed, and fresh tibial plateau fractures. Statistical indicators included: incision length, operation time, intraoperative blood loss, number of fluoroscopy, one-time success rate of screw, hospitalization time, fracture healing time, total weight-bearing time and postoperative complications. At the last follow-up, the range of motion of knee was recorded. The function of knee was evaluated by Rasmussen’s imaging and clinical score. RESULTS AND CONCLUSION: (1) There was no significant difference in the baseline data between two groups (P ＞ 0.05). (2) Compared with the traditional group, the robot-assisted group was better in the intraoperative blood loss, incision length, number of fluoroscopy, total number of drilled screws for fixation, average hospitalization time, fracture healing time, total weight-bearing time, and one-time success rate of fixation screw placement (P ＜ 0.05). There was no significant difference in the operation time between two groups (P=0.932). (3) The range of motion of knee and Rasmussen clinical function score in the robot-assisted group were superior to those in the traditional group (P ＜ 0.05). (4) There were fewer postoperative complications in the robot-assisted group compared with traditional group. (5) These results indicate that robot-assisted percutaneous reduction and minimally internal fixation for the treating Schatzker II-III tibial plateau fracture are satisfactory. It has obvious advantages in minimally invasive surgery, precise reduction, rigid fixation and accelerated postoperative rehabilitation. Key words: robot; tibial plateau fracture; Schatzker II; Schatzker III; percutaneous reduction; internal fixation. [ABSTRACT FROM AUTHOR]

The ankle is one of vulnerable parts of the low limb joints of the human body. Based on its structural characteristics， a 3-SPS/S parallel manipulator for ankle rehabilitation is built， and the inverse kinematics is solved by its dimensional characteristics. Then， the simulation platform of 3-SPS/S parallel manipulator for ankle rehabilitation is established by SimMechanics toolbox in Matlab software. A target trajectory is provided to produce input signals of actuating arms. Afterwards， the dynamics of parallel rehabilitation manipulator model are analyzed， and 3D rendering is generated. The experimental results show that it can provide the efficient and visual simulation platform to study the control strategy of parallel rehabilitation manipulator. [ABSTRACT FROM AUTHOR]