Creating a 3D Learning Tool for the Growth and Development of the Craniofacial Skeleton.

Advances in technology are facilitating wider access to delicate, and often irreplaceable, anatomy specimens for teaching. Moreover, 3-dimensional (3D) models and interactive applications may help students to understand the spatial arrangement of complex 3D anatomical structures in a way not afforded by the 2-dimensional (2D) textbook images of traditional teaching.Historical specimens from the University of Glasgow's Museum of Anatomy were digitised for the creation of a 3D learning tool to help students better understand the growth and development of the juvenile skull. The overarching goal of this project was to assess whether interactive 3D applications can provide a useful tool for teaching more complex, non-static, anatomy subjects such as growth and development.The application received positive feedback from the small test group of 12 anatomy students. The majority of participants strongly agreed that the application helped them learn more about the human skull and they positively rated the use of 3D models in helping them learn about the position and structure of anatomical features, and in comparing skulls at different stages of development. Following on from this positive feedback, further tests could be conducted to assess if this 3D application confers an advantage in student learning over traditional teaching methods.

Operative Digital Enhancement of Macular Pigment during Macular Surgery.

PURPOSE: To describe the feasibility of intraoperative digital visualization and its contribution to the enhancement of macular pigmentation visualization in a prospective series of macular surgery interventions. MATERIALS AND METHODS: A prospective, single-center, single-surgeon study was performed on a series of 21 consecutive cases of vitrectomy for various types of macular surgery using a 3D visualization system. Two optimized filters were applied to enhance the visualization of the macular pigment (MP). For filter 1, cyan, yellow, and magenta color saturations were increased. Filter 2 differed from filter 1 only in having a lower level of magenta saturation for the green-magenta color channel. RESULTS: Optimized digital filters enhanced the visualization of the MP and the pigmented epiretinal tissue associated with the lamellar and macular holes. In vitreomacular traction surgery, the filters facilitated the assessment of MP integrity at the end of surgery. Filter 1 enhanced MP visualization most strongly, with the MP appearing green and slightly fluorescent. Filter 2 enhanced MP visualization less effectively but gave a clearer image of the retinal surface, facilitating safe macular peeling. CONCLUSION: Optimized digital filters could be used to enhance MP and pigmented epiretinal tissue visualization during macular surgery. These filters open new horizons for future research and should be evaluated in larger series and correlated with intraoperative OCT.

Use of Digital Methods to Optimize Visualization during Surgical Gonioscopy.

Purpose: The aim of this study was to evaluate the efficacy of digital visualization for enhancing the visualization of iridocorneal structures during surgical gonioscopy. Methods: This was a prospective, single-center study on a series of 26 cases of trabecular stent implantation performed by the same surgeon. Images were recorded during surgical gonioscopy, and before stent implantation, with standard colors and with the optimization of various settings, principally color saturation and temperature and the use of the cyan color filter. Subjective analyses were performed by two glaucoma surgeons, and objective contrast measurements were made on iridocorneal structure images. Results: The surgeons evaluating the images considered the optimized digital settings to produce enhanced tissue visibility for both trabecular meshwork pigmentation and Schlemm's canal in more than 65% of cases. The mean difference in the standard deviation of the pixel intensity values was 37.87 (±4.61) for the optimized filter images and 32.37 (±3.51) for the standard-color images (p < 0.001). The use of a cyan filter provided a good level of contrast for the visualization of trabecular meshwork pigmentation. Increasing the color temperature highlighted the red appearance of Schlemm's canal. Conclusions: We report here the utility of optimized digital settings including the cyan filter and a warmer color for enhancing the visualization of iridocorneal structures during surgical gonioscopy. These settings could be used in surgical practice to enhance the visualization of the trabecular meshwork and Schlemm's canal during minimally invasive glaucoma surgery.

Use of Black-and-White Digital Filters to Optimize Visualization in Cataract Surgery.

PURPOSE: To evaluate the effect of a black-and-white (BW) filter on the optimization of visualization at each stage of cataract surgery. METHODS: Prospective, single-center, single-surgeon, consecutive case series of 40 patients undergoing cataract surgery with BW filter. Surgical images and videos were recorded with and without the BW filter at each stage of cataract surgery. Contrast measurements of surgical images and subjective analysis of video sequences were performed. RESULTS: The surgeons assessed the BW filter to optimize the tissue visibility of capsulorhexis contours, hydrodissection fluid wave perception, the contrast of instruments through a nucleus during phaco-chop, and subincisional cortex contrast through the corneal edema. Despite the higher contrasts' value obtained with BW filter images during nucleus removal, posterior capsular polishing and viscous removal, the surgeons subjectively reported no significant advantage of using a BW filter. Standard color images were found to be better for localizing the limbal area during incision and for nucleus sculpture to assess groove depth. CONCLUSIONS: In conclusion, we describe here the potential indications for BW filter use at particular stages in cataract surgery. A BW filter could be used, with caution, in cases of poor visualization.

Early corneal pachymetry maps after cataract surgery and influence of 3D digital visualization system in minimizing corneal oedema.

PURPOSE: To describe the early topography of corneal swelling occurring after cataract surgery and to evaluate the impact of the three-dimensional (3D) digital visualization system in minimizing corneal oedema. METHODS: Prospective observational, single-centre, consecutive case series of 134 patients undergoing cataract surgery performed by the same surgeon, with either 3D or conventional visualization systems. Eyes were assigned to two groups based on their anterior chamber depth (group ACD ≤3 mm and group ACD >3 mm). Optical coherence tomography was performed to evaluate postoperative corneal swelling. RESULTS: Three corneal swelling profiles were identified on the first postoperative day type 1, limited corneal oedema near peripheral corneal incisions; type 2, dome-shaped corneal swelling spreading from the principal corneal incision and reaching the paracentral cornea; type 3, continuous oedema spreading from the principal incision to central cornea, with a generalized oedema predominating in the upper part of the cornea. On the first day after surgery, in group ACD ≤3 mm, visual acuity was significantly better in patients undergoing surgery with 3D visualization (0.023 vs 0.072 logMar, p = 0.014) with reduced central corneal thickening 17.3 µm (±3.2) in comparison with conventional visualization 44.0 µm (±9.3) (p = 0.0082). In group ACD >3 mm, no significant association was found between the use of the 3D system and pachymetry changes and early visual rehabilitation. On day 21 after surgery, no significant differences in corneal pachymetry values were observed between the two surgical approaches in both groups. CONCLUSIONS: We describe early postoperative corneal map profiles providing insight into the pathogenesis of postoperative corneal swelling and possible prevention strategies. By improving visualization of the narrow surgical space in patients with shallow anterior chambers, the 3D system could help to minimize postoperative corneal oedema.

True colours or red herrings?: colour maps for finite-element analysis in palaeontological studies to enhance interpretation and accessibility.

Accessibility is a key aspect for the presentation of research data. In palaeontology, new data is routinely obtained with computational techniques, such as finite-element analysis (FEA). FEA is used to calculate stress and deformation in objects when subjected to external forces. Results are displayed using contour plots in which colour information is used to convey the underlying biomechanical data. The Rainbow colour map is nearly exclusively used for these contour plots in palaeontological studies. However, numerous studies in other disciplines have shown the Rainbow map to be problematic due to uneven colour representation and its inaccessibility for those with colour vision deficiencies. Here, different colour maps were tested for their accuracy in representing values of FEA models. Differences in stress magnitudes (ΔS) and colour values (ΔE) of subsequent points from the FEA models were compared and their correlation was used as a measure of accuracy. The results confirm that the Rainbow colour map is not well suited to represent the underlying stress distribution of FEA models with other colour maps showing a higher discriminative power. As the performance of the colour maps varied with tested scenarios/stress types, it is recommended to use different colour maps for specific purposes.

The use of photogrammetric fossil models in palaeontology education.

Photogrammetry allows overlapping photographs of fossils to be taken and converted into photo-realistic three-dimensional (3-D) digital models. These models offer potential advantages in teaching palaeontology: they are cheap to produce, can be easily shared and allow the study of rare and delicate specimens. Here I describe approaches for using photogrammetric models in the teaching and learning of palaeontology. Little is known about how students perceive these models and whether they find them valuable in their learning. To address this, first-year university students taught using both fossil specimens and digital models were surveyed about their experience through an anonymous online survey. Most students found that the digital models were easy to use, helped them understand anatomy and were more useful than studying photographs. However, most did not see the models as a substitute for studying real fossils and felt they could learn more from physical models. Digital models are a useful addition to palaeontological education that can supplement real fossils and allow palaeontological education to take place in circumstances where handling of specimens is not possible.

Simulation-Based Estimation of the Number of Cameras Required for 3D Reconstruction in a Narrow-Baseline Multi-Camera Setup.

Graphical visualization systems are a common clinical tool for displaying digital images and three-dimensional volumetric data. These systems provide a broad spectrum of information to support physicians in their clinical routine. For example, the field of radiology enjoys unrestricted options for interaction with the data, since information is pre-recorded and available entirely in digital form. However, some fields, such as microsurgery, do not benefit from this yet. Microscopes, endoscopes, and laparoscopes show the surgical site as it is. To allow free data manipulation and information fusion, 3D digitization of surgical sites is required. We aimed to find the number of cameras needed to add this functionality to surgical microscopes. For this, we performed in silico simulations of the 3D reconstruction of representative models of microsurgical sites with different numbers of cameras in narrow-baseline setups. Our results show that eight independent camera views are preferable, while at least four are necessary for a digital surgical site. In most cases, eight cameras allow the reconstruction of over 99% of the visible part. With four cameras, still over 95% can be achieved. This answers one of the key questions for the development of a prototype microscope. In future, such a system can provide functionality which is unattainable today.

Virtual Reality and Simulation in Neurosurgical Training.

Recent biotechnological advances, including three-dimensional microscopy and endoscopy, virtual reality, surgical simulation, surgical robotics, and advanced neuroimaging, have continued to mold the surgeon-computer relationship. For developing neurosurgeons, such tools can reduce the learning curve, improve conceptual understanding of complex anatomy, and enhance visuospatial skills. We explore the current and future roles and application of virtual reality and simulation in neurosurgical training.

A virtual world of paleontology.

Computer-aided visualization and analysis of fossils has revolutionized the study of extinct organisms. Novel techniques allow fossils to be characterized in three dimensions and in unprecedented detail. This has enabled paleontologists to gain important insights into their anatomy, development, and preservation. New protocols allow more objective reconstructions of fossil organisms, including soft tissues, from incomplete remains. The resulting digital reconstructions can be used in functional analyses, rigorously testing long-standing hypotheses regarding the paleobiology of extinct organisms. These approaches are transforming our understanding of long-studied fossil groups, and of the narratives of organismal and ecological evolution that have been built upon them.