Influence of anatomic landmarks in the virtual environment on simulated angled laparoscope navigation

Background - The aim of this study is to investigate the influence of the presence of anatomic landmarks on the performance of angled laparoscope navigation on the SimSurgery SEP simulator. Methods - Twenty-eight experienced laparoscopic surgeons (familiar with 30º angled laparoscope, >100 basic laparoscopic procedures, >5 advanced laparoscopic procedures) and 23 novices (no laparoscopy experience) performed the Camera Navigation task in an abstract virtual environment (CN-box) and in a virtual representation of the lower abdomen (CN-abdomen). They also rated the realism and added value of the virtual environments on seven-point scales. Results - Within both groups, the CN-box task was accomplished in less time and with shorter tip trajectory than the CN-abdomen task (Wilcoxon test, p0.05). In both groups, the CN tasks were perceived as hard work and more challenging than anticipated. Conclusions - Performance of the angled laparoscope navigation task is influenced by the virtual environment surrounding the exercise. The task was performed better in an abstract environment than in a virtual environment with anatomic landmarks. More insight is required into the influence and function of different types of intrinsic and extrinsic feedback on the effectiveness of preclinical simulator training.Industrial DesignIndustrial Design Engineerin

CakeVR: A social virtual reality (VR) tool for co-designing cakes

Cake customization services allow clients to collaboratively personalize cakes with pastry chefs. However, remote (e.g., email) and in-person co-design sessions are prone to miscommunication, due to natural restrictions in visualizing cake size, decoration, and celebration context. This paper presents the design, implementation, and expert evaluation of a social VR application (CakeVR) that allows a client to remotely co-design cakes with a pastry chef, through real-time realistic 3D visualizations. Drawing on expert semi-structured interviews (4 clients, 5 pastry chefs), we distill and incorporate 8 design requirements into our CakeVR prototype. We evaluate CakeVR with 10 experts (6 clients, 4 pastry chefs) using cognitive walkthroughs, and fnd that it supports ideation and decision making through intuitive size manipulation, color/favor selection, decoration design, and custom celebration theme fitting. Our fndings provide recommendations for enabling co-design in social VR and highlight CakeVR’s potential to transform product design communication through remote interactive and immersive co-design

Measuring and understanding photo sharing experiences in social virtual reality

Millions of photos are shared online daily, but the richness of interaction compared with face-to-face (F2F) sharing is still missing. While this may change with social Virtual Reality (socialVR), we still lack tools to measure such immersive and interactive experiences. In this paper, we investigate photo sharing experiences in immersive environments, focusing on socialVR. Running context mapping (N=10), an expert creative session (N=6), and an online experience clustering questionnaire (N=20), we develop and statistically evaluate a questionnaire to measure photo sharing experiences. We then ran a controlled, within-subject study (N=26 pairs) to compare photo sharing under F2F, Skype, and Facebook Spaces. Using interviews, audio analysis, and our questionnaire, we found that socialVR can closely approximate F2F sharing. We contribute empirical findings on the immersiveness differences between digital communication media, and propose a socialVR questionnaire that can in the future generalize beyond photo sharing

Do Basic Psychomotor Skills Transfer Between Different Image-based Procedures?

Background - Surgical techniques that draw from multiple types of image-based procedures (IBP) are increasing, such as Natural Orifice Transluminal Endoscopic Surgery, fusing laparoscopy and flexible endoscopy. However, little is known about the relation between psychomotor skills for performing different types of IBP. For example, do basic psychomotor colonoscopy and laparoscopy skills interact? Methods - Following a cross-over study design, 29 naïve endoscopists were trained on the Simbionix GI Mentor and the SimSurgery SEP simulators. Group C (n = 15) commenced with a laparoscopy session, followed by four colonoscopy sessions and a second laparoscopy session. Group L (n = 14) started with a colonoscopy session, followed by four laparoscopy sessions and a second colonoscopy session. Results - No significant differences were found between the performances of group L and group C in their first training sessions on either technique. With additional colonoscopy training, group C outperformed group L in the second laparoscopy training session on the camera navigation task. Conclusions - Overall, training in the basic colonoscopy tasks does not affect performance of basic laparoscopy tasks (and vice versa). However, to limited extent, training of basic psychomotor skills for colonoscopy do appear to contribute to the performance of angled laparoscope navigation tasks. Thus, training and assessment of IBP typespecific skills should focus on each type of tasks independently. Future research should further investigate the influence of psychometric abilities on the performance of IBP and the transfer of skills for physicians who are experienced in one IBP type and would like to become proficient in another type of IBP.Industrial DesignIndustrial Design Engineerin

Game feature and expertise effects on experienced richness, control and engagement in game play

The extent to which game play is experienced as engaging is an important criterion for the playability of video games. This study investigates how video games can be designed towards increased levels of experienced engagement over time. For this purpose, two experiments were conducted in which a total of 35 participants repeatedly played a video game. Results indicate that experienced engagement is based on the extent to which the game provides rich experiences as well as by the extent to which the game provides a sense of control. In view of the influence of both game features and players’ expertise on the levels of experienced richness and control, it is concluded that game features should be modified over time to maintain optimal levels of engagement

A ratio scale for brightness perception derived from difference and ratio judgments

The often observed nonlinearity between magnitude estimations and category ratings has raised the question whether subjects can judge sensation differences as well as sensation ratios when instructed to do so. For brightness this will be shown to be the case; the rank order of difference judgments differs from the rank order of ratio judgments. Nonmetric analysis of these rankings yields a ratio scale for brightness perception that is (1) a power function of luminance (power: 0.13), (2) linearly related to direct category ratings, (3) nonlinearly related to direct magnitude estimations. Implications for the nonlinearity between magnitude estimations and category ratings are discussed

Comparison of combination rules for digital-image-coding impairments

At high compression ratios, digitally-coded images usually comprise several coding artifacts, each impairing perceptual image quality to a greater or lesser extent. In this paper, two possible rules for combining such digital-image-coding impairments are presented and tested experimentally, viz., Annatt's 'law of subjective addition' and a rule based on the Minkowski p-metric. AllnaU's rule assumes a reciprocal relation between quality and impairment and a linear addition of impairments. The rule using the Minkowski p-metric assumes a linear relation between quality and impairment and a nonlinear addition of impairments. Two experiments are presented in which these rules are tested. In the first experiment, the stimuli consisted of a set of scale-space-coded images in which the sharpness of the image was systematically varied. Both image quality and impairment were assessed by means of numerical category scaling. In the second experiment, subjects rated image quality of scale-space-coded colour images comprising one to three perceptually different impairments, namely, 'unsharpness', 'phantoms' (dark/bright patches in bright/dark regions) and 'colour desaturation'. The results of the first experiment show a linear relation between quality and impairment. The combined results of the first and second experiment indicate the Minkowski p-metric as the most suitable rule for describing the observed accumulation of digital-image-coding impairments. Exponent p was found to be about two