Study of interaction fidelity for two viewpoint changing techniques in a virtual biopsy trainer

International audienceVirtual Reality simulators are increasingly used for training novice surgeons. However, there is currently a lack of guidelines for achieving interaction fidelity for these systems. In this paper, we present the design of two navigation techniques for a needle insertion trainer. The two techniques were analyzed using a state-of-the-art fidelity framework to determine their levels of interaction fidelity. A user study comparing both techniques suggests that the higher fidelity technique is more suited as a navigation technique for the needle insertion virtual trainer

Effets de la fidélité dans les simulateurs de réalité virtuelle sur l'apprentissage des compétences techniques en chirurgie

The reform of medical studies in France attributes an important role to simulation in healthcare professionals' training. In this context, virtual reality simulators can be very useful. However, the fidelity of these systems remains an open question with a lack of guidelines for determining their appropriate levels of fidelity to support effective training. In this thesis, we are interested in the fidelity of immersive simulators for the training of technical skills in surgery. More particularly, we investigate how the fidelity of interactions and artifacts to perform certain tasks in the simulator could affect the efficiency of these systems. From a theoretical perspective, we propose an articulation of the concepts of simulator fidelity through a model based on the various fidelity components identified in our literature review, and the various interfaces and interactions used in virtual simulators for the training of technical skills. Two experimental studies were conducted to explore the factors of simulator fidelity associated with a navigation task and a tool handling task and their impacts on the learning of two technical skills in virtual reality. The results show that the simulator's interaction techniques and artifacts with a moderate fidelity can support the completion of secondary tasks for effective training. The designers of virtual simulators can rely on the recommendations resulting from our work in order to avoid including certain devices and fidelity components, which can be cumbersome and expensive without a real impact on the efficiency of these simulators.La réforme des études médicales en France réserve une place importante à la simulation dans la formation des professionnels de santé. Dans ce contexte, les simulateurs en réalité virtuelle peuvent jouer un rôle important. Cependant, la fidélité de ces systèmes reste une question ouverte avec un manque de lignes directrices pour déterminer les niveaux appropriés de leur fidélité pour une formation efficace. Dans cette thèse, nous nous intéressons à la fidélité des simulateurs immersifs pour l'apprentissage des compétences techniques en chirurgie. Plus particulièrement, nous cherchons à comprendre comment la fidélité des interactions et artefacts pourrait affecter l'efficacité de certaines tâches effectuées dans le simulateur. Sur le plan théorique, nous proposons une articulation des notions de fidélité des simulateurs à travers un modèle basé sur les différents composants de la fidélité identifiés dans notre revue de littérature, et des différentes interfaces et interactions utilisées dans les simulateurs virtuels pour la formation des compétences techniques. Deux études expérimentales ont été réalisées pour explorer les facteurs de la fidélité du simulateur associés à une tâche de navigation et à une tâche de manipulation d'un outil et leurs impacts sur l'apprentissage de deux gestes techniques en réalité virtuelle. Les résultats montrent que des techniques d'interaction et artefacts du simulateur avec une fidélité modérée peuvent supporter la réalisation de tâches secondaires pour une formation efficace. Les concepteurs des simulateurs virtuels peuvent s'appuyer sur les recommandations issues de nos travaux afin d'éviter d'inclure certains dispositifs et composants de la fidélité qui peuvent être encombrants et coûteux sans avoir un réel impact sur l'efficacité de ces simulateurs

Effects of fidelity in virtual reality simulators on learning technical surgical skills

La réforme des études médicales en France réserve une place importante à la simulation dans la formation des professionnels de santé. Dans ce contexte, les simulateurs en réalité virtuelle peuvent jouer un rôle important. Cependant, la fidélité de ces systèmes reste une question ouverte avec un manque de lignes directrices pour déterminer les niveaux appropriés de leur fidélité pour une formation efficace. Dans cette thèse, nous nous intéressons à la fidélité des simulateurs immersifs pour l'apprentissage des compétences techniques en chirurgie. Plus particulièrement, nous cherchons à comprendre comment la fidélité des interactions et artefacts pourrait affecter l'efficacité de certaines tâches effectuées dans le simulateur. Sur le plan théorique, nous proposons une articulation des notions de fidélité des simulateurs à travers un modèle basé sur les différents composants de la fidélité identifiés dans notre revue de littérature, et des différentes interfaces et interactions utilisées dans les simulateurs virtuels pour la formation des compétences techniques. Deux études expérimentales ont été réalisées pour explorer les facteurs de la fidélité du simulateur associés à une tâche de navigation et à une tâche de manipulation d'un outil et leurs impacts sur l'apprentissage de deux gestes techniques en réalité virtuelle. Les résultats montrent que des techniques d'interaction et artefacts du simulateur avec une fidélité modérée peuvent supporter la réalisation de tâches secondaires pour une formation efficace. Les concepteurs des simulateurs virtuels peuvent s'appuyer sur les recommandations issues de nos travaux afin d'éviter d'inclure certains dispositifs et composants de la fidélité qui peuvent être encombrants et coûteux sans avoir un réel impact sur l'efficacité de ces simulateurs.The reform of medical studies in France attributes an important role to simulation in healthcare professionals' training. In this context, virtual reality simulators can be very useful. However, the fidelity of these systems remains an open question with a lack of guidelines for determining their appropriate levels of fidelity to support effective training. In this thesis, we are interested in the fidelity of immersive simulators for the training of technical skills in surgery. More particularly, we investigate how the fidelity of interactions and artifacts to perform certain tasks in the simulator could affect the efficiency of these systems. From a theoretical perspective, we propose an articulation of the concepts of simulator fidelity through a model based on the various fidelity components identified in our literature review, and the various interfaces and interactions used in virtual simulators for the training of technical skills. Two experimental studies were conducted to explore the factors of simulator fidelity associated with a navigation task and a tool handling task and their impacts on the learning of two technical skills in virtual reality. The results show that the simulator's interaction techniques and artifacts with a moderate fidelity can support the completion of secondary tasks for effective training. The designers of virtual simulators can rely on the recommendations resulting from our work in order to avoid including certain devices and fidelity components, which can be cumbersome and expensive without a real impact on the efficiency of these simulators

Fidélité d'interaction dans les simulateurs : deux techniques de navigations pour un simulateur virtuel de biopsie

International audienceVirtual Reality simulators are increasingly used for training novice surgeons. However, there is currently a lack of guidelines for how to go about achieving the appropriate levels of interaction fidelity for these systems. In this paper, we present two navigation techniques for a needle insertion trainer. The first technique is based on tracking the user’s head position and represents a high-fidelity interaction metaphor. The second technique is touch-based and represents a medium-fidelity interaction metaphor. Our objective is to present the design rational of these techniques, our research questions and a discussion about the experimental study that will be used to compare them.Les simulateurs virtuels sont de plus en plus utilisés pour former des chirurgiens débutants. Cependant, il y a actuellement un manque de lignes directrices pour définir les niveaux appropriés de fidélité d’interaction pour ces systèmes. Dans ce papier, deux techniques de navigation pour un simulateur virtuel d’insertion d’aiguille sont présentées. La première technique est basée sur le suivi de la position de la tête de l'utilisateur et représente une métaphore d’interaction haute-fidélité. La seconde technique est basée sur l’interaction tactile et représente une métaphore d'interaction moyenne-fidélité. Notre objectif est de présenter la logique de conception de ces techniques, nos questions de recherche et une discussion sur le protocole expérimental qui servira à les comparer

Comparing touch-based and head-tracking navigation techniques in a virtual reality biopsy simulator

International audienceRecently, virtual reality (VR) technologies started gaining momentum in surgical simulation-based training by allowing clinicians to practice their skills before performing real procedures. The design of such simulators is usually focused on the primary operative tasks to be taught, but little attention is paid to secondary tasks that the user needs to perform, such as changing his/her point of view when manipulating the surgical instruments. More particularly, it is not clear how to design appropriate interaction techniques for those tasks, and how the fidelity of these interactions can impact the user’s performance on such systems. In this paper, we compare two viewpoint changing techniques having two different levels of interaction fidelity during needle insertion in a semi-immersive VR (SIVR) biopsy trainer. These techniques were designed based on observing clinicians performing actual biopsy procedures. The first technique is based on tracking the user’s head position (high interaction fidelity), while the second technique is touch-based with the user utilizing his/her non-dominant hand fingers to manipulate the point of view on a touch screen (moderate interaction fidelity). A user study was carried out to investigate the impact of the interaction fidelity of the viewpoint changing task (secondary task) on the user’s performance during the needle insertion task (main task). Twenty-one novice participants were asked to perform several trials of a needle insertion task while using the navigation techniques (within-subject design). Objective and subjective measures were recorded to compare the task performance (time to accomplish the task, precision of the tumor sampling, and errors) and user experience for both techniques. The results show that the touch-based viewpoint changing technique improves the users’ task completion performance during needle insertion while maintaining a similar level of needle manipulation accuracy as compared to the head-tracking technique. These results suggest that high interaction fidelity is not always necessary when designing surgical trainers. This also highlights the importance of designing appropriate interactions for secondary tasks because they can influence the user’s primary task performance in VR simulators

Influence of hand visualization on tool-based motor skills training in an immersive VR simulator

International audienceImmersive VR technologies offer versatile training tools by recreating real-world situations in a virtual and safe environment andallowing users to have a first-person experience. The design of such training systems requires defining the most critical components tosimulate, and to what extent they can be simulated successfully. One open research question for designing such systems is how torepresent the user in the virtual environment, and which is the added value of this representation for training purposes. In this work, wefocus on how the user’s hand representation in an immersive virtual environment can impact the training of tool-based motor skills.To investigate this question, we have designed a VR trainer for a simple tool-based pick and place task. A user experiment wasconducted to evaluate how the movements of the users’ real hand representation influence their performance and subjective experiencein the virtual environment. For that purpose, the participants performed the task on the VR simulator with two conditions: thepresence or absence of their animated virtual hands representation. The results of this study show that, although users prefer to havea visual representation of their hands, they achieved similar and correlated performance in the VR system regardless of the handrepresentation condition. These results suggest that the presence of the user’s hand representation is not necessary when performing atool-based motor skill task in a VR trainer. These findings have practical implications for the design of VR simulators for training motorskills tasks since adding users’ hand representation may require cumbersome and expensive additional devices

The influence of hand visualization in tool-based motor-skills training, a longitudinal study

International audienceIn this work, we study how the user's hand representation impacts the training of tool-based motor skills in immersive VR. We created a VR trainer for a tool-based task, and conducted a user study (N=26) to evaluate how the hand visualization can influence participants' learning performance. Two groups of participants were trained in the simulator under one of the two experimental conditions: presence/absence of their virtual hands' representation, while a control group received no training. The results show that while both training groups improve their performance compared to the control group, no significant impact of the hand visualization is observed

Study of self-avatar's influence on motor skills training in immersive virtual environments

International audienceImmersive virtual reality simulators are increasingly being used in different domains. One open research problematic of such systems is the user’s representation inside the environment, what is called, the self-avatar representation. Our research focus on using immersive virtual environments (IVEs) for training motor skills. In this case, the typical self-avatar representation is the user’s hand. Researchers have focused on studying the influence of hand appearance and structure on the user’s sense of presence and embodiment, but little is known about the role it plays in learning motor skills. In this paper we present the design and implementation of a virtual reality (VR) training simulator for a basic motor task, as well as the design of an experiment to investigate this research problematic

Study of communication modalities for teaching distance information

International audienceWe present an exploratory study to compare the haptic, visual, and verbal modalities for communicating distance information in a shared virtual environment. The results show that the visual modality decreased the distance estimation error while the haptic modality decreased the completion time. The verbal modality increased the sense of copresence but was the least preferred modality. These results suggest that a combination of modalities could improve communication of distance information to a partner. These findings can contribute to improving the design of collaborative VR systems and open new research perspectives on studying the effectiveness of multimodal interaction

Classic3D and Single3D: Two unimanual techniques for constrained 3D manipulations on tablet PCs

International audienceStandard 3D widgets are used for object manipulation in desktop CAD applications but are less suited for use on touchscreens. We propose two 3D constrained manipulation techniques for Tablet PCs. Using finger identification, the dominant hand's index, middle and ring fingers are mapped with the X, Y and Z axes. Users can then trigger different manipulation tasks using specific chording gestures. A user study to assess usability and efficiency permitted to identify the gestures that are the most suitable for each manipulation task. Some design recommendations for an efficient 3D constrained manipulations technique are presented