An immersive educational tool for dental implant placement: A study on user acceptance.

BACKGROUND: Tools for training and education of dental students can improve their ability to perform technical procedures such as dental implant placement. Shortage of training can negatively affect dental implantologists' performance during intraoperative procedures, resulting in lack of surgical precision and, consequently, inadequate implant placement, which may lead to unsuccessful implant supported restorations or other complications. OBJECTIVE: We designed and developed IMMPLANT a virtual reality educational tool to assist implant placement learning, which allows users to freely manipulate 3D dental models (e.g., a simulated patient's mandible and implant) with their dominant hand while operating a touchscreen device to assist 3D manipulation. METHODS: The proposed virtual reality tool combines an immersive head-mounted display, a small hand tracking device and a smartphone that are all connected to a laptop. The operator's dominant hand is tracked to quickly and coarsely manipulate either the 3D dental model or the virtual implant, while the non-dominant hand holds a smartphone converted into a controller to assist button activation and a greater input precision for 3D implant positioning and inclination. We evaluated IMMPLANT's usability and acceptance during training sessions with 16 dental professionals. RESULTS: The conducted user acceptance study revealed that IMMPLANT constitutes a versatile, portable, and complementary tool to assist implant placement learning, as it promotes immersive visualization and spatial manipulation of 3D dental anatomy. CONCLUSIONS: IMMPLANT is a promising virtual reality tool to assist student learning and 3D dental visualization for implant placement education. IMMPLANT may also be easily incorporated into training programs for dental students.

Touchless interaction with medical images based on 3D hand cursors supported by single-foot input: A case study in dentistry.

Feet input can support mid-air hand gestures for touchless medical image manipulation to prevent unintended activations, especially in sterile contexts. However, foot interaction has yet to be investigated in dental settings. In this paper, we conducted a mixed methods research study with medical dentistry professionals. To this end, we developed a touchless medical image system in either sitting or standing configurations. Clinicians could use both hands as 3D cursors and a minimalist single-foot gesture vocabulary to activate manipulations. First, we performed a qualitative evaluation with 18 medical dentists to assess the utility and usability of our system. Second, we used quantitative methods to compare pedal foot-supported hand interaction and hands-only conditions next to 22 medical dentists. We expand on previous work by characterizing a range of potential limitations of foot-supported touchless 3D interaction in the dental domain. Our findings suggest that clinicians are open to use their foot for simple, fast and easy access to image data during surgical procedures, such as dental implant placement. Furthermore, 3D hand cursors, supported by foot gestures for activation events, were considered useful and easy to employ for medical image manipulation. Even though most clinicians preferred hands-only manipulation for pragmatic purposes, feet-supported interaction was found to provide more precise control and, most importantly, to decrease the number of unintended activations during manipulation. Finally, we provide design considerations for future work exploring foot-supported touchless interfaces for sterile settings in Dental Medicine, regarding: interaction design, foot input devices, the learning process and camera occlusions.

On the utility of 3D hand cursors to explore medical volume datasets with a touchless interface.

Analyzing medical volume datasets requires interactive visualization so that users can extract anatomo-physiological information in real-time. Conventional volume rendering systems rely on 2D input devices, such as mice and keyboards, which are known to hamper 3D analysis as users often struggle to obtain the desired orientation that is only achieved after several attempts. In this paper, we address which 3D analysis tools are better performed with 3D hand cursors operating on a touchless interface comparatively to a 2D input devices running on a conventional WIMP interface. The main goals of this paper are to explore the capabilities of (simple) hand gestures to facilitate sterile manipulation of 3D medical data on a touchless interface, without resorting on wearables, and to evaluate the surgical feasibility of the proposed interface next to senior surgeons (N=5) and interns (N=2). To this end, we developed a touchless interface controlled via hand gestures and body postures to rapidly rotate and position medical volume images in three-dimensions, where each hand acts as an interactive 3D cursor. User studies were conducted with laypeople, while informal evaluation sessions were carried with senior surgeons, radiologists and professional biomedical engineers. Results demonstrate its usability as the proposed touchless interface improves spatial awareness and a more fluent interaction with the 3D volume than with traditional 2D input devices, as it requires lesser number of attempts to achieve the desired orientation by avoiding the composition of several cumulative rotations, which is typically necessary in WIMP interfaces. However, tasks requiring precision such as clipping plane visualization and tagging are best performed with mouse-based systems due to noise, incorrect gestures detection and problems in skeleton tracking that need to be addressed before tests in real medical environments might be performed.