## 4 Discussion  
This study evaluated the performance of AngioSim, a novel augmented-reality angiography simulation system combined with a vascular silicone simulator, in enhancing neurointerventional training. The results demonstrate that AngioSim provides realistic and valuable training experiences. All physicians who participated in the study (100%) rated AngioSim as useful for neurointerventional training. Our findings showed that 93% of physicians who had prior experience with camera-based silicone simulators preferred AngioSim, suggesting that the augmented-reality features significantly improve the training experience by providing more realistic imaging without the need for ionizing radiation. Although only 48% preferred AngioSim over computer simulators, this is still a promising result, especially considering that AngioSim is a prototype and lacks features to simulate the movement of the C-arm or table and multi-plane imaging. Notably, AngioSim was rated significantly more essential for neuroendovascular training than computer simulators (\(p<0.05\)). This perceived necessity may stem from AngioSim's ability to facilitate hands-on training with real devices within a realistic anatomical model, providing more authentic haptic feedback, a critical component for achieving realistic simulation experiences [13]. Our finding that 72% of the physicians favor in vivo models over AngioSim aligns with previous studies, where 77% of the physicians indicated a desire for more training time with in vivo models, compared to just 7% for the silicone model [14]. This might be due to the usage of real angiography rooms in animal experiments. Nevertheless, the necessity of the AngioSim was rated significantly higher (\(p<0.05\)) than that of in vivo models. This could be due to the ethical concerns of medical in vivo training [15]. The lack of a significant difference in necessity ratings between AngioSim and clinical training with human subjects (\(p=1\)) highlights its potential as a complementary tool that can prepare trainees before they perform procedures in angio-suits on patients, thereby improving patient safety and trainee confidence [16]. While AngioSim adequately displays catheters and guidewires sufficiently, 24% of participants still considered the simulation unrealistic, underscoring the need for further improvements. Future enhancements should focus on controlling the camera via a joystick, enabling camera rotation around the silicone model and incorporating a second camera for biplanar imaging. However, these upgrades may not fully resolve the issue of overlapping vascular structures, as the system relies on light-based imaging instead of the penetrating capabilities of radiation. Additionally, the grayscale display makes it challenging to distinguish between microcatheters and microwires without markers for ionizing radiation as depicted in Figures 2b and 3d and to identify the exact position and orientation of other medical devices such as stent retrievers. Due to its low cost, modular architecture and reliance on commonly available hardware, AngioSim is highly scalable and easily adaptable to various training environments. Its straightforward setup allows for implementation not only in institutional settings but also in workshops. As a radiation-free solution, it aligns well with modern simulation-based training curricula [16] and could serve as a valuable component in structured neurointerventional education programs for residents, fellows, and continuing education initiatives. This study represents a proof-of-concept evaluation of the AngioSim system, aimed at assessing its feasibility, realism, and acceptance among physicians in a training context. Rather than focusing on technical performance or skill acquisition, we prioritized initial user impressions and perceived value. These early insights provide a foundation for future, more extensive evaluations involving objective performance metrics and multi-center participation.