89 research outputs found
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
Bone mineral density in children and adolescents: relation to puberty, calcium intake, and physical activity
The association of height, weight, pubertal stage, calcium intake, and
physical activity with bone mineral density (BMD) was evaluated in 500
children and adolescents (205 boys and 295 girls), aged 4-20 yr. The BMD
(grams per cm2) of lumbar spine and total body was measured with dual
energy x-ray absorptiometry. Lumbar spine volumetric BMD was calculated to
correct for bone size. BMD and volumetric BMD increased with age. During
puberty, the age-dependent increment was higher. After adjustment for age,
the Tanner stage was significantly associated with all three BMD variables
in girls and with spinal BMD in boys. In boys, positive correlations were
found between BMD and both calcium intake and physical activity after
adjustment for age. Stepwise regression analysis with weight, height,
Tanner stage, calcium intake, and physical activity as determinants with
adjustment for age resulted in a model with Tanner stage in girls and
weight in boys for all three BMD variables. The major independent
determinant of BMD was the Tanner stage in girls and weight in boys
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
Usability problem reports for comparative studies: consistency and inspectability
The present study explores issues of consistency and inspectability in
usability test data analysis processes and reports. Problem reports resulting
from usability tests performed by three professional usability labs in three
different countries are compared. Each of the labs conducted a usability test
on the same product, applying an agreed test protocol that was collaboratively
developed by the labs. Each lab first analyzed their own findings as they
always do in their regular professional practice. A few weeks later, they again
analyzed their findings but then everyone applied the same method
(SlimDEVAN: a simplified version of DEVAN, a method developed for
facilitating comparison of findings from usability tests in an academic setting).
It was found that levels of agreement between labs did not improve when they
all used SlimDEVAN there was inherent subjectivity in their analyses. It was
found that consistency of single analysts in analyzing their data can be
improved by using a method like SlimDEVAN. Such methods can also help in
making the analysis process and findings more inspectable. Inspectability is
helpful in comparative studies based on identified usability problems because
it allows for the traceability of findings to original observations, as well as for
laying bare the subjective parts of the data analysis
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
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