Showing papers by "Bogdan Gherman published in 2022"

Singularity Analysis and Geometric Optimization of a 6-DOF Parallel Robot for SILS

Abstract: The paper presents the singularity analysis and the geometric optimization of a 6-DOF (Degrees of Freedom) parallel robot for SILS (Single-Incision Laparoscopic Surgery). Based on a defined set of input/output constraint equations, the singularities of the parallel robotic system are determined and geometrically interpreted. Then, the geometric parameters (e.g., the lengths of the mechanism links) for the 6-DOF parallel robot for SILS are optimized such that the robotic system complies with an operational workspace defined in correlation with the SILS task. A numerical analysis of the singularities showed that the operational workspace is singularity free. Furthermore, numerical simulations validate the parallel robot for the next developing stages (e.g., designing and prototyping stages).

Design and Experimental Setup of a Robotic Medical Instrument for Brachytherapy in Non-Resectable Liver Tumors

Abstract: Simple Summary This paper presents an experimental study on a brachytherapy multi-needle insertion device, manipulated using a collaborative robot, to assess a set of characteristics: accuracy, needle deflection due to resistance forces, instrument and needle wear and the influence of insertion speed and rotation during needle manipulation inside the liver parenchyma. Abstract This paper presents a study regarding the design and the experimental setup of a medical robotic system for brachytherapy using tribology analysis. The robotic system is composed of a collaborative robotic arm and a multi-needle brachytherapy instrument controlled using a unified control system embedding a haptic device and force-feedback. This work is oriented towards identifying the technical characteristics of the system components to determine the accuracy of the procedure, as well as using different scenarios for needle insertion in ex vivo porcine liver tissue in order to determine the forces required for insertion and extraction of the needle and the friction coefficient that accompanies the previously mentioned forces. Subsequent to the computation of the friction forces, the normal forces and the wear during the needle insertion are determined with the scope of predicting the lifecycle of some components of the medical device.

Application Oriented Modelling and Simulation of an Innovative Parallel Robot for Single Incision Laparoscopic Surgery

Abstract: Single-incision laparoscopic surgery (SILS) is on the path of becoming a standard procedure in minimally invasive surgery due to the outstanding results obtained both during and after the medical act, these being defined by the reduced hospitalization time, the reduced recovery time, and the reduced visibility of the incision. The paper presents the modeling and simulation of a new parallel robot concept with 6 Degrees of Freedom (DOF), called PARA-SILSROB used for the single incision laparoscopic surgery. The paper focuses on the inverse kinematics, the preliminary design, and the robot control system architecture of PARA-SILSROB. A CAD motion simulation validates the mathematical model using Siemens NX.

Analysis of Dynamic Behavior of ParReEx Robot Used in Upper Limb Rehabilitation

Abstract: This paper presents a dynamic analysis of the ParReEx multibody mechanism, which has been designed for human wrist joint rehabilitation. The starting point of the research is a virtual prototype of the ParReEx multibody mechanism. This model is used to simulate the dynamics of the multibody mechanism using ADAMS in three simulation scenarios: (a) rigid kinematic elements without friction in joints, (b) rigid kinematic elements with friction in joints, and (c) kinematic elements as deformable solids with friction in joints. In all three cases, the robot is used by a virtual patient in the form of a mannequin. Results such as the connecting forces in the kinematic joints and the torques necessary to operate the ParReEx robot modules are obtained by dynamic simulation in MSC.ADAMS. The torques obtained by numerical simulation are compared with those obtained experimentally. Finite element structural optimization (FEA) of the flexion/extension multibody mechanism module is performed. The results demonstrate the operational safety of the ParReEx multibody mechanism, which is structurally capable of supporting the external loads to which it is subjected.

HRI Based Command System of a Modular Parallel Robot for Brachial Monoparesis

Abstract: The present paper focuses on the development of a command system based on different Human Robot Interaction (HRI) strategies for a parallel robot for medical rehabilitation of the wrist. The command system uses several predefined functions personalized to the medical rehabilitation task based on the torque control monitoring capabilities of the system. To validate the proposed command system several in-lab experimental tests are performed using healthy subject.

Experimental Investigations of Hydrogen Fuelled Pulsed Detonation Combustor

Abstract: Detonation combustion unveils avenues towards increased performances and efficiencies of classic deflagration architectures and enables opportunities for supersonic flight platforms. Furthermore, their primarily fuel candidate, Hydrogen, which is prone to detonation, has enormous potential in both industrial and mobility decarbonization. Nonetheless supersonic flame propagation is associated with disadvantages in terms of aerodynamic and thermal losses, which raises difficulties in achieving practical applications. Moreover, to achieve a safe and reliable energy conversion, Hydrogen combustion needs special attention. This paper addresses the analysis of a Hydrogen fuelled pulsed detonation combustor, to contribute to the understanding of the high-speed mixing performance and to improve the specific know-how regarding pressure gain combustors. By means of Z-type Schlieren visualization technique, the structure of the engine’s exhaust plume is determined to capture the intrinsic unsteady phenomena of the detonation process. Qualitative instantaneous static pressure results are presented and correlated to the Schlieren images to evaluate the cycle stages and its operating frequency.

An Innovative Recommendation System for a Knowledge Transfer Matchmaking Platform

Abstract: The phenomenon of aging, which has become more prevalent in our society in recent decades, has raised a number of concerns about the well-being of the elderly. Studies show that a significant percentage of retired seniors suffer from depression as a result of inactivity and a poor social environment. In order to provide seniors an opportunity to reintegrate into a healthy work environment, a knowledge transfer platform was created, with the goal of allowing seniors to share their knowledge with organizations that required the experience of a specialist. The paper presents a hybrid system that can recommend mentors for a certain assignment to companies, based on their abilities. Using AI agents, a combination of a matchmaking system and a collaborative filter calculates the similarity between the corporate profile and candidate profiles. The functionality of the system has been tested on different scenarios.