Virtual Reality Based Simulation of Hysteroscopic Interventions

Virtual reality based simulation is an appealing option to supplement traditional clinical education. However, the formal integration of training simulators into the medical curriculum is still lacking. Especially, the lack of a reasonable level of realism supposedly hinders the widespread use of this technology. Therefore, we try to tackle this situation with a reference surgical simulator of the highest possible fidelity for procedural training. This overview describes all elements that have been combined into our training system as well as first results of simulator validation. Our framework allows the rehearsal of several aspects of hysteroscopy—for instance, correct fluid management, handling of excessive bleeding, appropriate removal of intrauterine tumors, or the use of the surgical instrument

Evaluation of a new virtual-reality training simulator for hysteroscopy

BACKGROUND: To determine realism and training capacity of HystSim, a new virtual-reality simulator for the training of hysteroscopic interventions. METHODS: Sixty-two gynaecological surgeons with various levels of expertise were interviewed at the 13(th) Practical Course in Gynaecologic Endoscopy in Davos, Switzerland. All participants received a 20-min hands-on training on the simulator and filled out a four-page questionnaire. Twenty-three questions with respect to the realism of the simulation and the training capacity were answered on a seven-point Likert scale along with 11 agree-disagree statements concerning the HystSim training in general. RESULTS: Twenty-six participants had performed more than 50 hysteroscopies ("experts") and 36 equal to or fewer than 50 ("novices"). Four of 60 (6.6%) responding participants judged the overall impression as "7 - absolutely realistic", 40 (66.6%) as "6 - realistic", and 16 (26.6%) as "5 - somewhat realistic". Novices (6.48; 95% confidence interval [CI] 6.28-6.7) rated the overall training capacity significantly higher than experts (6.08; 95% CI 5.85-6.3), however, high-grade acceptance was found in both groups. In response to the statements, 95.2% believe that HystSim allows procedural training of diagnostic and therapeutic hysteroscopy, and 85.5% suggest that HystSim training should be offered to all novices before performing surgery on real patients. CONCLUSION: Face validity has been established for a new hysteroscopic surgery simulator. Potential trainees and trainers assess it to be a realistic and useful tool for the training of hysteroscopy. Further systematic validation studies are needed to clarify how this system can be optimally integrated into the gynaecological curriculum

Ilaptic Feedback Device for Needle Insertion

Tele-surgery is one of the emerging fields which combine engineering and medical sciences. Application of tole-surgery can be found in remote communities, war-zones and disasterstricken areas. One of the most complex and tedious issue in tele-surgery is needle insertion. The surgeon relies on haptic feedback during needle insertion. The force exerted on needle during insertion is measured and reproduced at surgeon's end is known as haptic feedback. The realistic force reproduction requires haptic feedback device which should be dynamically identical to needle. The haptic feedback device enables the surgeon to sense the needle insertion remotely. The basic objective of this thesis is to design a device used for needle insertions in soft tissue. The force information from needle insertions is measured by a sensor. The force feedback produced by the device can be used in robot-assisted needle insertion. A device is designed for reality-based data that results in more accurate representation of a needle insertion haptic feedback scenario. The device is modeled dynamically and it is clear from the model that the reactive force is reproduced by the friction forces which is controlled by the motors. The system is sensitive to mass of rollers, mass of the stick and friction between the stick and rollers. The needle insertion force is modeled in three parts; force due to capsule stiffness, friction, and cutting. The force due to capsule stiffness is modeled terms of three components namely diameter of needle, elasticity of tissue and deformation of tissue. The data from model is compared with real time force data. The haptic feedback device input and output forces are compared and the highest correlation factor is 82%. The sensitivity analysis of the device is performed. The capsule stiffness force for 0.9 millimeter diameter needle is 0.98 Newton, the stiffness force for 0.8 millimeter is 0.91 Newton and stiffness force for 0.6 millimeter diameter is 0.41 Newton. The capsule stiffness force for 0.6 millimeter needle is not following the capsule stiffness model. The insertion force data was collected on chicken skin and meat. The device designed in this work is having one degree of freedom; it only produces force feedback for vertical needle insertion. This design is not able to produce the force feedback for angular needle insertion. Graphical User Interface is designed for the visual haptic feedback. The data acquisition is done with the help of a PC sound card. Future work should include the design of a multidegree of freedom haptic feedback device and to advance the GUI for audio feedback that may be extended to accommodate the design of a simulator

Acquiring minimally invasive surgical skills

Many topics in surgical skills education have been implemented without a solid scientific basis. For that reason we have tried to find this scientific basis. We have focused on training and evaluation of minimally invasive surgical skills in a training setting and in practice in the operating room. This thesis has led to an enlarged insight in the organization of surgical skills training during residency training of surgical medical specialists.AT Hiemstra-Timmenga, NVEC, Simendo B.V., Maatschap Gynaecologie Haga Ziekenhuis, DSSH, BMA BV (Mosos), Memedis Pharma BV, Convedien BVUBL - phd migration 201

Haptic Feedback Device for Needle Insertion

Tele-surgery is one of the emerging fields which combine engineering and medical sciences. Application of tele-surgery can be found in remote communities, war-zones and disasterstricken areas. One of the most complex and tedious issue in tele-surgery is needle insertion. The surgeon relies on haptic feedback during needle insertion. The force exerted on needle during insertion is measured and reproduced at surgeon's end is known as haptic feedback. The realistic force reproduction requires haptic feedback device which should be dynamically identical to needle. The haptic feedback device enables the surgeon to sense the needle insertion remotely. The basic objective of this thesis is to design a device used for needle insertions in soft tissue. The force information from needle insertions is measured by a sensor. The force feedback produced by the device can be used in robot-assisted needle insertion. A device is designed for reality-based data that results in more accurate representation of a needle insertion haptic feedback scenario. The device is modeled dynamically and it is clear from the model that the reactive force is reproduced by the friction forces which is controlled by the motors. The system is sensitive to mass of rollers, mass ofthe stick and friction between the stick and rollers. The needle insertion force is modeled in three parts; force due to capsule stiffness, friction, and cutting. The force due to capsule stiffness is modeled terms of three components namely diameter of needle, elasticity of tissue and deformation of tissue. The data from model is compared with real time force data. The haptic feedback device input and output forces are compared and the highest correlation factor is 82%. The sensitivity analysis of the device is performed. The capsule stiffness force for 0.9 millimeter diameter needle is 0.98 Newton, the stiffness force for 0.8 millimeter is 0.91 Newton and stiffness force for 0.6 millimeter diameter is 0.4 I Newton. The capsule stiffness force for 0.6 millimeter needle is not following the capsule stiffness model. The insertion force data was collected on chicken skin and meat. The device designed in this work is having one degree of freedom; it only produces force feedback for vertical needle insertion. This design is not able to produce the force feedback for angular needle insertion. Graphical User Interface is designed for the visual haptic feedback. The data acquisition is done with the help of a PC sound card. Future work should include the design of a multidegree of freedom haptic feedback device and to advance the GUI for audio feedback that may be extended to accommodate the design of a simulator

Real-time hybrid cutting with dynamic fluid visualization for virtual surgery

It is widely accepted that a reform in medical teaching must be made to meet today's high volume training requirements. Virtual simulation offers a potential method of providing such trainings and some current medical training simulations integrate haptic and visual feedback to enhance procedure learning. The purpose of this project is to explore the capability of Virtual Reality (VR) technology to develop a training simulator for surgical cutting and bleeding in a general surgery

Development and Validation of a Hybrid Virtual/Physical Nuss Procedure Surgical Trainer

With continuous advancements and adoption of minimally invasive surgery, proficiency with nontrivial surgical skills involved is becoming a greater concern. Consequently, the use of surgical simulation has been increasingly embraced by many for training and skill transfer purposes. Some systems utilize haptic feedback within a high-fidelity anatomically-correct virtual environment whereas others use manikins, synthetic components, or box trainers to mimic primary components of a corresponding procedure. Surgical simulation development for some minimally invasive procedures is still, however, suboptimal or otherwise embryonic. This is true for the Nuss procedure, which is a minimally invasive surgery for correcting pectus excavatum (PE) – a congenital chest wall deformity. This work aims to address this gap by exploring the challenges of developing both a purely virtual and a purely physical simulation platform of the Nuss procedure and their implications in a training context. This work then describes the development of a hybrid mixed-reality system that integrates virtual and physical constituents as well as an augmentation of the haptic interface, to carry out a reproduction of the primary steps of the Nuss procedure and satisfy clinically relevant prerequisites for its training platform. Furthermore, this work carries out a user study to investigate the system’s face, content, and construct validity to establish its faithfulness as a training platform

Assessing Suturing Techniques using a Virtual Reality Simulator

Master'sMASTER OF ENGINEERIN

Patient Specific Systems for Computer Assisted Robotic Surgery Simulation, Planning, and Navigation

The evolving scenario of surgery: starting from modern surgery, to the birth of medical imaging and the introduction of minimally invasive techniques, has seen in these last years the advent of surgical robotics. These systems, making possible to get through the difficulties of endoscopic surgery, allow an improved surgical performance and a better quality of the intervention. Information technology contributed to this evolution since the beginning of the digital revolution: providing innovative medical imaging devices and computer assisted surgical systems. Afterwards, the progresses in computer graphics brought innovative visualization modalities for medical datasets, and later the birth virtual reality has paved the way for virtual surgery. Although many surgical simulators already exist, there are no patient specific solutions. This thesis presents the development of patient specific software systems for preoperative planning, simulation and intraoperative assistance, designed for robotic surgery: in particular for bimanual robots that are becoming the future of single port interventions. The first software application is a virtual reality simulator for this kind of surgical robots. The system has been designed to validate the initial port placement and the operative workspace for the potential application of this surgical device. Given a bimanual robot with its own geometry and kinematics, and a patient specific 3D virtual anatomy, the surgical simulator allows the surgeon to choose the optimal positioning of the robot and the access port in the abdominal wall. Additionally, it makes possible to evaluate in a virtual environment if a dexterous movability of the robot is achievable, avoiding unwanted collisions with the surrounding anatomy to prevent potential damages in the real surgical procedure. Even if the software has been designed for a specific bimanual surgical robot, it supports any open kinematic chain structure: as far as it can be described in our custom format. The robot capabilities to accomplish specific tasks can be virtually tested using the deformable models: interacting directly with the target virtual organs, trying to avoid unwanted collisions with the surrounding anatomy not involved in the intervention. Moreover, the surgical simulator has been enhanced with algorithms and data structures to integrate biomechanical parameters into virtual deformable models (based on mass-spring-damper network) of target solid organs, in order to properly reproduce the physical behaviour of the patient anatomy during the interactions. The main biomechanical parameters (Young's modulus and density) have been integrated, allowing the automatic tuning of some model network elements, such as: the node mass and the spring stiffness. The spring damping coefficient has been modeled using the Rayleigh approach. Furthermore, the developed method automatically detect the external layer, allowing the usage of both the surface and internal Young's moduli, in order to model the main parts of dense organs: the stroma and the parenchyma. Finally the model can be manually tuned to represent lesion with specific biomechanical properties. Additionally, some software modules of the simulator have been properly extended to be integrated in a patient specific computer guidance system for intraoperative navigation and assistance in robotic single port interventions. This application provides guidance functionalities working in three different modalities: passive as a surgical navigator, assistive as a guide for the single port placement and active as a tutor preventing unwanted collision during the intervention. The simulation system has beed tested by five surgeons: simulating the robot access port placemen, and evaluating the robot movability and workspace inside the patient abdomen. The tested functionalities, rated by expert surgeons, have shown good quality and performance of the simulation. Moreover, the integration of biomechanical parameters into deformable models has beed tested with various material samples. The results have shown a good visual realism ensuring the performance required by an interactive simulation. Finally, the intraoperative navigator has been tested performing a cholecystectomy on a synthetic patient mannequin, in order to evaluate: the intraoperative navigation accuracy, the network communications latency and the overall usability of the system. The tests performed demonstrated the effectiveness and the usability of the software systems developed: encouraging the introduction of the proposed solution in the clinical practice, and the implementation of further improvements. Surgical robotics will be enhanced by an advanced integration of medical images into software systems: allowing the detailed planning of surgical interventions by means of virtual surgery simulation based on patient specific biomechanical parameters. Furthermore, the advanced functionalities offered by these systems, enable surgical robots to improve the intraoperative surgical assistance: benefitting of the knowledge of the virtual patient anatomy