A study of the visual symptoms in two-dimensional versus three-dimensional laparoscopy

Aim: There are reports of visual strains and associated symptoms when operating in a 3D laparoscopic environment. We aimed to study the extent of visual symptoms seen in 3D versus conventional 2D imaging in volunteers performing laparoscopic tasks and study the effect of eye exercises on 3D laparoscopy.Methods: Twenty four consented laparoscopic novices were required to undergo a visual acuity test (Snellen chart) and eye deviation test (Maddox Wing). A battery of specific isolated laparoscopic tasks lasting 30 min was developed to test their ability to detect changes in 2D and 3D environments separately. Before and after the 2D and 3D laparoscopic tasks, subjects were asked to complete a standardised questionnaire designed to scale (from 0 to 10) their visual symptoms (blurred vision, difficulty in refocusing from one distance to another, irritated or burning eyes, dry eyes, eyestrain, headache and dizziness). Participants who underwent 3D laparoscopic tasks were randomized into two groups, those who received two minutes eye exercises before performing the tasks and those who didn't. Independent t-test was used for the statistical analysis of this study.Results: Visual symptoms and eye strain were significant in 2D (p &lt; 0.01) and difficulty in refocusing from one distance to another was significant in 3D laparoscopic imaging (p &lt; 0.05). There was no significant effect of the simple eye exercises on relieving the visual symptoms in the 3D group.Conclusion: Visual symptoms were present in both 2D and 3D imaging laparoscopy. Eye strain was prominent in 2D imaging, while difficulty in refocusing from one distance to another was prominent in 3D. Eye exercises for 3D visual symptoms did not bring any significant improvement.</p

A Comparative Study of Generic Visual Components of Two-Dimensional Versus Three-Dimensional Laparoscopic Images

Aims: There is a strong evidence to suggest that 3D imaging improves the laparoscopic task performance when compared against 2D. However, to date, no study has explained why that might be. We identified six generic visual components during laparoscopic imaging and aimed to study each component in both 2D and 3D environments for comparison.Methods: Twenty-four consented laparoscopic novices performed specific isolated tasks in a laparoscopic Endo Trainer in 2D and 3D separately. The six endpoints were the accuracy in detecting changes in the laparoscopic images in the following components: distance, area, angle, curvature, volume and spatial coordinates. All the components except the spatial coordinates were assessed by creation, measurement and comparison. Each component was analysed between 2D and 3D groups and within each group at different values. Tests of spatial coordinates were video-recorded and analysed for error number and error types by human reliability analysis technique. Errors types included past-pointing, not reaching the object and touching the wrong object. The results were statistically analysed with independent T test.Results: There was no statistically significant difference between 2D and 3D accuracy in the angle, area, distance and curvature. 3D performed more accurately in comparing volumes (p = 0.05). In spatial coordinates, there were a statistically significant higher number of errors in 2D as compared to 3D (p &lt; 0.001). Past-pointing and touching the wrong objects were significantly higher in 2D (p &lt; 0.05).Conclusion: Between all the visual components, detecting change in volume and the spatial coordinates showed significant improvement in 3D environment when compared to 2D.</p

Preparation and Characterization of Chitosan from Perna viridis (Linnaeus, 1758) shell waste as raw material

Chitosan is extracted from Perna viridis as the staring source via the cycle of chitin deacetylation, which is conducted at 90°C for 6 hours using 40% NaOH. Physiochemical properties such as yield (18%), ash content (0.626%), moisture content (2.9%), and solubility, degree of deacetylation (55), fat binding capability (209%) and water binding ability (254 %) revealed that P.viridis is an important alternative source of chitosan. Fourier transforms infrared spectroscopy (FTIR) analysis showed the characteristic peaks of OH at 3400cm-1 and amine at 1660cm-1, the X-ray diffraction (XRD) analysis suggested two critical characteristic peaks at 18° and 34° at (2θ). Scanning electron microscope (SEM) was used to evaluate the surface morphology of isolated chitosan. Thermogravimetric analysis (TG/DTA) was also used to describe the thermal stability of P.viridis chitosan. The procoagulant capacity, plasma recalcification time assays and minimal bactericidal activity verified the hemocompatibility and antibacterial activity of the preparation of chitosan.</jats:p