Bogdan Gherman

Kinematic modelling of a 5-dof hybrid parallel robot for laparoscopic surgery*

Robotic-assisted surgery is a continuously developing field because robots have demonstrated clear benefits in operating rooms. Until now, vast majority of robots used in surgery had serial structures. This paper presents the kinematic modelling of a 5-degree of freedom hybrid parallel architecture in two slightly different variants. The kinematics of this structure is determined, and following the analysis of singularities, the best variant is chosen. The robot workspace is computed and finally the experimental model and some simulation results are presented.

Singularities and workspace analysis for a parallel robot for minimally invasive surgery

The paper presents the singularity and workspace analysis of PARAMIS — the first parallel robot, for camera guidance in minimally invasive surgical procedures developed in Romania. The graphical workspace is achieved through a series of geometric constructions in modeling software. The analytical workspace is achieved through a simple method based on the geometric model of the robot. The paper will demonstrate that the use of a simple structure with the minimum number of degrees of freedom required by the application provides the necessary workspace without singularity points. Results and conclusions from the first experimental procedures are presented.

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.

Kinematical Analysis and Design of a New Surgical Parallel Robot

Robots in surgery are used because of their superior advantages: improved accuracy, tremor elimination etc, which exceeds human capabilities. Unlike serial robots, parallel robots offer higher stiffness, reduced masses in motion, higher rigidity, all of these leading more precise manipulations that fit medical applications. In this paper, a new innovative parallel structure for laparoscopy is presented. It is studied the forward and inverse kinematics, the singularities, it is generated the workspace and are presented some simulation results.

Development of a Voice Controlled Surgical Robot

In the paper the first developed voice-controlled parallel robot PARAMIS (PARAllel robot for Minimally Invasive Surgery) in Romania, used for laparoscope camera positioning in the minimally invasive surgery, is presented. The development of the structure focused on the achievement of a simple, lightweight, cheap solution, able to work alone or as part of a multiarm robotic system. The adopted solution for the voice commands interface is presented. Some experimental results are illustrated pointing out the behavior of the robot in a surgical procedure.

Kinematics and Design of a 5-DOF Parallel Robot Used in Minimally Invasive Surgery

Robotic assisted surgery is a continuously developing field, as robots have proved their utility in the operating rooms. Some of their advantages could be summed as follows: increased precision, the possibility of reaching positions and places that could prove difficulty in reaching using classical instruments, the replacement of medical personnel in the operating room, allowing for more space and cost saving etc. Until now, the vast majority of robots used in surgery, had serial structures. A new parallel hybrid architecture is proposed in this paper, the kinematics of this new structure is determined, the singularities are discussed and the design of the robot is presented.

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.

Optimal Planning of Needle Insertion for Robotic-Assisted Prostate Biopsy

Robotic systems used for prostate biopsy offer important advantages compared to the manual procedures. In the robotic assisted prostate biopsy procedure, an important problem is to identify the optimal needle trajectories that allow reaching the target tissue and avoiding vital anatomical organs (major blood vessels, internal organs etc.). The paper presents an algorithm for optimal planning of the biopsy needle trajectories, based on virtual reality technologies, using as case study a novel parallel robot designed for transperineal prostate biopsy. The developed algorithm has been tested in a virtual environment for the prostate biopsy robotic-assisted procedure and results are presented.

Application Oriented Design and Simulation of an Innovative Parallel Robot for Brachytherapy

The paper presents the design and simulation of a new 5-DOF parallel robot named PARA-BRACHYROB used for brachytherapy. Brachytherapy (BT) is an advanced cancer treatment technique, where radioactive seeds are delivered directly in the tumor without damaging the proximal healthy tissues. Due to the tremendous therapeutic potential of brachytherapy, many researches are encouraged to provide solutions for enhanced placement of BT devices inside the patient body, thus further developing brachytherapy robotic systems. Therefore the paper presents an innovative CT-Scan compatible robotic device for this application. The PARA-BRACHYROB system consists of a parallel robot with five degrees of freedom (DOF) for needle positioning and orientation up to the insertion point in the patient body and a 1-DOF mechanism for the needle insertion. The kinematic models of PARA-BRACHYROB are presented and validated through a multi-body simulation including a short description of the numerical and simulation results for the developed model.Copyright

A CT-Scan Compatible Robotic Device for Needle Placement in Medical Applications

Several medical applications require devices capable of placing different substances inside the human body. Due to the nature of the task it is desirable to perform these actions with visual feedback, whereas the most viable solution, especially for deep target points, is computer tomography (CT). The paper presents an innovative device, which can be fitted inside the CT gantry, and has decoupled motions to ensure maximum accuracy during the needle placement. It will be shown that for needle placement tasks 5 degrees of freedom (DOF) are sufficient to achieve the task. The geometric and kinematic model of the robot will be presented. The workspace and precision mapping are computed. Some simulation results will show the robot capabilities as well as its placement in the CT scan environment.