A. Szilaghyi

Structural Analysis and Synthesis of Parallel Robots for Brachytherapy

Cancer represents one of the main causes of death nowadays, due to a complex set of uncontrollable natural and artificial factors. Huge efforts have been made by the entire scientific community to provide better cancer treatment solutions, all aiming to improve survival and life expectancy. An innovative option in the fight against cancer is brachytherapy (BT), called also internal radiation. BT enables to deliver higher doses of radiation to more-specific areas of the body, compared with the conventional form of radiation therapy that projects radiation from a machine outside the body. The paper presents the structural synthesis of suitable innovative parallel robots used in brachytherapy.

An Innovative Family of Modular Parallel Robots for Brachytherapy

Brachytherapy (BT) is an advanced form of radiation therapy enabling the concentration of high doses in specific target points, enabling the direct treatment of tumors without damaging the proximal healthy tissues. BT usage is limited by the insufficient accuracy of radioactive seeds placement in the body. For this purpose, the paper presents an innovative family of modular parallel robots designed specifically to overcome the limitations of current BT procedures. The robotic structures employ two distinct modules in conjunction, which result in a reduced number of moving parts and removal of unwanted motions.

Kinematics Simulation and Validation of a Medical Robot

A simulation model of a parallel medical robot is presented in this paper. The robot consists of two modules: the PARAMIS robot and an additional parallel module. The parallel module is used to obtain a mechanically fixed remote center of motion (RCM), enabling the structure to manipulate active instruments. The new structure provides the necessary motion control with respect to the particularities and restrictions of minimally invasive applications. A simulation based on the developed kinematic models is performed using the Simulink software from MATLAB. Another simulation of the imposed motion is performed using the CAD model of the structure. The numerical results obtained during the simulations are compared and show that the robotic structure is correctly modelled and reliable.

Kinematics Analysis of a Parallel Surgical Robot

The geometric and kinematic analysis of a surgical parallel robot, used for camera and active instruments positioning is presented in this paper. Its workspace is also illustrated. The robot structure consists of two modules: the PARAMIS robot and the new parallel positioning module. The use of this new parallel structure in surgery presents the following advantages: it releases some of the pressure on the abdominal wall in certain positions of the robot and the new robot may be used either as laparoscope holder or as manipulator of active instruments, used for cutting, suturing, grasping etc. The new robot provides the necessary control of motion to fulfil the imposed tasks in the case of surgical applications. Numerical results and conclusions from the performed simulations are described.

The Control System of a Parallel Robot for Brachytherapy

Huge efforts have been made by the entire scientific community to provide better solutions aiming to improve survival and life expectancy in the fight against cancer. Such an approach is brachytherapy (BT), the targeted irradiation of tumors achieved by placing radioactive cell inside or very close to the tumor itself. The paper presents the control system of a parallel robot designed specifically for brachytherapy. The PARA-BRACHYROB modular structure is capable to target multiple organs in the thoracic-abdominal area under CT-Scan real-time monitoring providing an accurate tool for the delivery of the BT seeds at the defined locations. The control system is designed according to a specific protocol covering both therapeutic and safety issues.

Workspace and Singularity Analysis for a Parallel Robot Used in Surgical Applications

The paper presents the workspace and singularity analysis of a parallel robot, which can handle both a laparoscope or an active instrument in minimally invasive surgery (MIS). Using the inverse geometric model of the robot the analytical workspace is achieved. The paper will demonstrate that with this parallel structure, one can obtain the necessary workspace required for a minimally invasive operation. Finally, an in-depth study of different types of singularity is performed and some conclusions are presented.