Virtual Suturing Simulation Based on Commodity Physics Engine for Medical Learning

Design and Testing of Two Haptic Devices Based on Reconfigurable 2R Joints

This paper presents the design and testing of two haptic devices, based on reconfigurable 2R joints: an active 2R spherical mechanism-based joint and a differential gear-based joint. Based on our previous works, in which the design and kinematic analysis of both reconfigurable joints were developed, the experimental setup and the various tasks intended to test the reconfigurability, precision, force feedback system and general performance, are presented herein. Two control modes for the haptic device operation are proposed and studied. The statistical analysis tools and their selection principles are described. The mechanical design of two experimental setups and the main elements are considered in detail. The Robot Operating System nodes and the topics that are used in the software component of the experimental setup are presented and explained. The experimental testing was carried out with a number of participants and the corresponding results were analyzed with the selected statistical tools. A detailed interpretation and discussion on of the results is provided.

A Novel Mixed Reality Solution Based on Learning Environment for Sutures in Minor Surgery

Minor Surgery Sutures is a fundamental skill for healthcare professionals. However, in the educational field, the practice of suturing is sometimes limited and reduced, with more theoretical than practical study. In order to facilitate learning, our goal is to develop an immersive and interactive educational tool that complements theoretical study, called Suture MR. This application could enhance suture procedural skills in the fields of nursing and medicine. Applying Mixed Reality techniques, we generate a 3D model of an arm with a full-scale wound. Realistically, the user will simulate the suture movements as part of the learning process. The application has surgical clamps and a needle holder that are virtually visualized in the user’s hands, allowing gestures and movements faithful to the real ones. In this article, we want to demonstrate the usability of our environment and the feasibility of using Mixed Reality learning experiences in clinical practical training as a complement to theoretical training. The results of the study reveal a greater perception of learning and the willingness of students to use this methodology.

Data-Driven Modeling and Rendering of Force Responses from Elastic Tool Deformation

This article presents a new data-driven model design for rendering force responses from elastic tool deformation. The new design incorporates a six-dimensional input describing the initial position of the contact, as well as the state of the tool deformation. The input-output relationship of the model was represented by a radial basis functions network, which was optimized based on training data collected from real tool-surface contact. Since the input space of the model is represented in the local coordinate system of a tool, the model is independent of recording and rendering devices and can be easily deployed to an existing simulator. The model also supports complex interactions, such as self and multi-contact collisions. In order to assess the proposed data-driven model, we built a custom data acquisition setup and developed a proof-of-concept rendering simulator. The simulator was evaluated through numerical and psychophysical experiments with four different real tools. The numerical evaluation demonstrated the perceptual soundness of the proposed model, meanwhile the user study revealed the force feedback of the proposed simulator to be realistic.

SutureHap

Haptic devices have been highly valued in virtual training environments in the medical field. Nevertheless, the principal challenges to develop these environments are the complexity to model the virtual elements and to provide proper haptic feedback during tasks. In this study, it was decided to take advantage of NVIDIA PhysX physics engine to produce a fast and effortless process in the creation of a virtual training environment for suturing tasks. Although PhysX correctly deploys collisions between solid and deformable objects in the graphical environment, it does not send this information to the developers environment to provide haptic rendering. Therefore, in this article, a “simplified method” was proposed to facilitate the detection of collisions between rigid and deformable bodies. This simplified method allows the calculation of haptic feedback to be displayed, and it avoids complexity and high computational costs. Additionally, an architecture to facilitate the integration of haptic devices was designed. The study case proposed in this work was the development of an application to perform a suturing task, SutureHap. The system was tested by volunteers from different areas and senior medical students. The latter pointed out that SutureHap is very promising, and it could be a useful tool to develop surgical skills. Finally, participants agreed that the use of the elements in the environment is reasonably intuitive, and all of them stated that they would recommend the simulator.

Virtual interactive suturing for the Fundamentals of Laparoscopic Surgery (FLS)

BACKGROUND

Suturing with intracorporeal knot-tying is one of the five tasks of the Fundamentals of Laparoscopic Surgery (FLS), which is a pre-requisite for board certification in general surgery. This task involves placing a short suture through two marks in a penrose drain and then tying a double-throw knot followed by two single-throw knots using two needle graspers operated by both hands. A virtual basic laparoscopic skill trainer (VBLaST©) is being developed to represent the virtual versions of the FLS tasks, including automated, real time performance measurement and feedback. In this paper, we present the development of a VBLaST suturing simulator (VBLaST-SS©). Developing such a simulator involves solving multiple challenges associated with fast collision detection, response and force feedback.

METHODS

In this paper, we present a novel projection-intersection based knot detection method, which can identify the validity of different types of knots at haptic update rates. A simple and robust edge-edge based collision detection algorithm is introduced to support interactive knot tying and needle insertion operations. A bimanual hardware interface integrates actual surgical instruments with haptic devices enabling not only interactive rendering of force feedback but also realistic sensation of needle grasping, which realizes an immersive surgical suturing environment.

RESULTS

Experiments on performing the FLS intracorporeal suturing task show that the simulator is able to run on a standard personal computer at interactive rates.

CONCLUSIONS

VBLaST-SS© is a computer-based interactive virtual simulation system for FLS intracorporeal knot-tying suturing task that can provide real-time objective assessment for the user's performance.

Characteristics of successful technological interventions in mental resilience training

In the last two decades, several effective virtual reality-based interventions for anxiety disorders have been developed. Virtual reality interventions can also be used to build resilience to psychopathology for populations at risk of exposure to traumatic experiences and developing mental disorders as a result, such as for people working in vulnerable professions. Despite the interest among mental health professionals and researchers in applying new technology-supported interventions for pre-trauma mental resilience training, there is a lack of recommendations about what constitutes potentially effective technology-supported resilience training. This article analyses the role of technology in the field of stress-resilience training. It presents lessons learned from technology developers currently working in the area, and it identifies some key clinical requirements for the supported resilience interventions. Two processes made up this research: 1) developers of technology-assisted resilience programs were interviewed regarding human-computer interaction and system development; 2) discussions with clinicians were prompted using technology-centered concept storyboards to elicit feedback, and to refine, validate and extend the initial concepts. A qualitative analysis of the interviews produced a set of development guidelines that engineers should follow and a list of intervention requirements that the technology should fulfill. These recommendations can help bridge the gap between engineers and clinicians when generating novel resilience interventions for people in vulnerable professions.