User max/ User min - defines the minimum and maximum range value when using the user range option for range type.Legen Orientation: sets the orientation of the legend bar (horizontal or vertical).Show legend - allows you to toggle the displaying of the legend bar in the Graphics View.Range divisions - changes the number of fringes that PostView will draw on the model.The user can use this option to select a dynamic range (range is updated for each state independently), a static range (range is calculate over all the states) or user range (user defines the minimum and maximum values). Range type - PostView keeps track of the range of the selected data field (that is the minimum and maximum values).This will produce a discretized drawing of the data, but will be truer to the actual data since the element data is not interpolated before displaying. However, when this option is turned of, element data will be displayed by using a single color for each element. Glyph color - allows the user to set how PostView will determine the color of each glyph. This option allows the user to select the glyph. When displaying element data, PostView will first project the element data to the nodes to produce a smooth rendering of the data. Glyph - a small graphic that PostView will draw at each node to represent the vector. Nodal values - PostView defines nodal data and element data.Color map: defines the color map that PostView will use to color the model.When this option is off, a discrete set of colors is used instead. When gradient smoothing is on, the fringe colors are smoothed to produce a continuous transition between fringes. Gradient smoothing - PostView colors the material by drawing a fringe plot of the selected data field.The color of the model is defined by the data field and the color gradient (see below). Data field - allows the user to select the data field that PostView will use to define the color of the model.The following properties are defined for the color map. The properties will then be listed in the Properties Window below. The Color Map’s properties can be accessed by selecting the item in the Model Viewer entitled Color Map. To employ a finite element (FE) stress model to simulate laser in situ keratomileusis (LASIK) surgery and its biomechanical consequences.The Color Map defines how PostView will calculate the color that is used to display the model in the Graphics View. The basic geometrical model we used for the cornea was patient-specific on which we manually incorporated seven simulations: three simulations evaluating the effect of a 120, 140 and 180 μm flap (without ablation) three simulations evaluating ablation depths of 40, 80 and 120 μm (with a 120 μm flap) and one control model, without any simulated surgical intervention. In all simulations, stress values were greatest in the centre of the cornea. Furthermore, when comparing the different treatments, stress values were highest in the cornea with the deepest ablation, and were lowest in the non-treated cornea. Specifically, peak effective stresses were 0.031, 0.028 and 0.025 MPa in 120, 80 and 40 µm ablation depths, respectively. In our model, the depth of tissue penetration using ablation or flap creation was correlated with tissue loads-the thinner the residual stromal bed is, the greater are the stresses occurring as a result of the same IOP. We based our model geometry on patient specific scans, allowing for customisation of the treatment to the patient’s corneal structure. Post-laser-assisted in situ keratomileusis (LASIK) ectasia, in which the cornea progressively becomes weaker after the surgery, is a major concern in refractive surgery as it degrades the vision and can severely affect the visual prognosis. Therefore, a large portion of preoperative screening is focused on detecting refractive surgery candidates that may be at high risk for this complication. Post LASIK ectasia is defined as a reduction in biomechanical integrity to below the threshold required to maintain corneal shape and curvature.
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