A method of lung puncture path planning based on multi-level constraint / 生物医学工程学杂志

Percutaneous pulmonary puncture guided by computed tomography (CT) is one of the most effective tools for obtaining lung tissue and diagnosing lung cancer. Path planning is an important procedure to avoid puncture complications and reduce patient pain and puncture mortality. In this work, a path planning method for lung puncture is proposed based on multi-level constraints. A digital model of the chest is firstly established using patient's CT image. A Fibonacci lattice sampling is secondly conducted on an ideal sphere centered on the tumor lesion in order to obtain a set of candidate paths. Finally, by considering clinical puncture guidelines, an optimal path can be obtained by a proposed multi-level constraint strategy, which is combined with oriented bounding box tree (OBBTree) algorithm and Pareto optimization algorithm. Results of simulation experiments demonstrated the effectiveness of the proposed method, which has good performance for avoiding physical and physiological barriers. Hence, the method could be used as an aid for physicians to select the puncture path.

A Novel Four-Degree-of-Freedom Upper Limb Rehabilitation Robot / 中国康复理论与实践

Objective:A novel four-degree-of-freedom upper limb rehabilitation robot was designed to overcome the shortcomings of the structure of the most of serial robots. Methods:The shoulder and elbow joint drive system and the information detection system were placed in the base. The synchronous belt drive system and the spiral bevel gear transmission system were designed to transmit power from the base to the shoulder and elbow joint of the arm. The cubic polynomial trajectory planning method based on the joint space was selected to accomplish the trajectory planning of the recovery movements of taking objects and drawing quadrilaterals, and the single-degree-of-freedom motion control experiment and multi-degree-of-freedom trajectory planning experiment were designed to verify the rationality and feasibility of the design. Results:Each joint of the rehabilitation robot reached the designed range of motion at the designed speed, and well completed the planned rehabilitation training movements. Conclusion:This robot can effectively reduce the volume and mass of the mechanical arm, overcome the influence of motor noise and radiation on patients' rehabilitation training, and assist patients to complete a variety of rehabilitation exercises.

Kinematic analysis and trajectory planning of serial robot / 医疗卫生装备

Objective To select a safe, flexible and lightweight manipulator and to execute its kinematic analysis and trajectory planning, so as to improve the application of serial robot in the treatment of hazardous biochemical products. Methods The kinematic modeling was carried out for the manipulator, and the kinematic and inverse kinematic formulas were deduced and verified.Differential transform method was used to obtain the Jacobian matrix of the manipulator,and the trajectory planning was implemented for the manipulator at joint and cartesian spaces.Results An ideal motion curve was formed by the trajectory planning of serial robot to realize its stable and high-efficiency motion at spaces.Conclusion Serial robot is facilitated to execute the treatment of hazardous biochemical products, and references are provided to other researches on serial robot.