## 3 Results
### Outcomes and Examples of Student Projects
This project also has applications in occupational safety and health, as it can be used for monitoring the vibration exposure of workers operating different types of machines in various environments, in order to assess the risks of vibration-related conditions such as Hand-Arm Vibration Syndrome (HAVS) [47] and identify preventive measures. One student developed an augmented reality surgical simulation, where users control a virtual scalpel using a gamepad to perform dissection tasks and learn about human anatomy. In this example, the resistance of different tissues during dissection and surgical interventions is represented through different haptic stimuli, providing feedback on how deeply the scalpel has cut (Figure 11). The scalpel is controlled along the horizontal axis using the left stick of the gamepad, while the height control, i.e., cutting depth, is  
Figure 10: Simulation of working with a jackhammer on a construction site. User is provided with a stronger haptic stimulus because their avatar is not wearing protective gloves. controlled via the right stick. Cutting pressure is regulated by the right trigger, bumper buttons are used for switching between instruments (scalpel, scissors, forceps, etc. ), and camera adjustments are performed using the D-pad. As the scalpel traverses different tissue layers, haptic feedback dynamically adjusts based on the scalpel's position and movement within the tissue and applied pressure. The haptic feedback generated during tissue interaction is also influenced by the density and texture of the tissue. Denser tissues, such as muscle and bone, produce a stronger and sharper haptic feedback, whereas fatty tissues provide a weaker, softer, and \"squishier\" feedback. Transitions between haptic feedback of different levels are smooth, allowing users to feel the difference in texture and resistance. When retracting the scalpel from the tissue, haptic feedback decreases with an inverse curve reflecting the reduction in resistance as the scalpel exits the tissue. This transition is smoothly blended with the feedback of the overlaying tissue layer and a slight drag resistance effect is applied. When the scalpel is positioned within multiple tissue types simultaneously, the resulting haptic feedback is determined by its overall position, movement, tissue properties, and the specific action being performed. Prototype curves for haptic effects based on the density and texture of the tissue are shown in Figure 11b. Such simulations foster education and training, allowing users to experience potentially dangerous environments and situations without physical risk. They also overcome the challenge of finding appropriate equipment and examples for demonstrations, giving students the opportunity to feel haptic stimuli and gain information and experiences that are valuable for learning. During the research, it was observed that the gamepad provided a particularly immersive experience when the virtual object resembled the shape of the gamepad, and the positioning of the user's hands during the activity aligned with the position of their hands holding the gamepad. This was evident in scenarios like the motorcycle simulation, where users grip the handlebars, or the jackhammer simulation, where users hold the handles of the tool. Figure 11: Surgical augmented reality simulation for learning anatomy and dissection: **(a)** Haptic zones marked on different tissue layers of a 3D model, with each tissue type providing distinct haptic feedback when the virtual scalpel interacts with it. **(b)** Prototype curves for haptic effects based on density and texture of the tissue.