# Left Ventricular Geometric Fit (simplified)

### Description

• These step-by-step instructions will guide you through fitting a more complicate data set in 3D space
• The data set is obtained from 4 long-axis slices of left ventricle
• Initial truncated elipsoidal geometry is created in order to fit with the data set
• An automated script that runs this tutorial up to the point of changing to 3D is included in the Continuity installation: examples\data07\fittingLeftVentricle.py. To run it, click File→Scripts→Read script…

### Start Continuity

• Launch the Continuity Client
• check the fitting box under Use Modules:

• Click OK to bring up the main window

### Setup intial mesh

• Select prolate spheriodal in the Global Coordinates: pop-up menu4

• Enter 3.75 next to the Focus Position field

• Click OK to submit Coordinate Form

• Choose Lagrange Basis Function→2D→Linear-Linear

• Choose Hermite Basis Function→2D→Cubic-Cubic

• Verify that the list of basis functions now contains:
• Linear-Linear Lagrange 3*3*
• Cubic-Cubic Hermite 3*3
• Click OK to submit Basis Form

• Click Import/Export/Graph button to open Continuity Table Manager

• Select tab-delimited nodes file ( nodes.xls )

• You should now have nodes numbered 1-40
• Select Cubic-Cubic Hermite under Coordinate 1, Coordinate 2 and under Coordinate 3

• Click OK to submit Node Form

• Click Import/Export button to open Continuity Table Manager

• Select tab-delimited elements file ( elems.xls )

• You should now elements numbered 1-32 in the list
• Click OK to submit Element Form

• Select fitting and click OK

• The menu bar should now show the Fitting command
• Click Import/Export/Graph button to open Continuity Table Manager

• Select tab-delimited data file ( data.xls )

• You should now have Data numbered 1-686 in the list
• Click OK to submit Data Form

• For all three coordinates, fill in the values according to the table below (use these as a starting guide)
 s(1) s(1)s(1) s(2) s(1)(2) s(2)(2) s(3) s(1)s(3) s(2)s(3) s(3)s(3) 0.5 0.5 0.01 0.02 0.01 0.0 0.0 0.0 0.0
• Click the lines radio button

• Click Render

• Click OK

• Click on datapoints2 in the list on the left

• Go to the Properties tab

• Drag the Quality value to 4

• Close the window by click the X button

• The mesh should now look similar to the first screenshot

### Fit prolate in lambda

• In the Cooridinates tab, select coord_1, coord_2, coord_3 for the three coordinates

• In the Xi Projections tab, enter 1-343 for Data list and 1-16 for Use points in element list

• In the Fitting Variables tab, deselect all three coordinates

• Click the Fit button on the bottom

• Go back to the Xi Projections tab. Enter 344-686 for Data list and 17-32 for Use points in element list

• Go back to the Fitting Variables tab and againdeselect all three coordinates

• Click the Fit button on the bottom again

• In the Fitting Variables tab, select only Coordinate 1

• Click the Fit button one more time

• Close the window by click the X button

• Click the lines radio button

• Click Render

• Click on elements lines3 in the list on the left

• Click on the Colors tab

• Change the R,G,B color field to 1, 0, 0 to change the color to the brightest red and then hit Enter

• The mesh should now look similar to the second screenshot

### Convert to 3D

• Click Import/Export button to open Continuity Table Manager

• Select the second tab-delimited elements file ( elems2.xls )

• You should now have elements 1-16 in the list
• Click OK to submit Element Form

• Remove the two basis functions currently in the list by selecting each and then clicking the Subtract button.

• Choose Hermite Basis Function→3D→Cubic-Cubic-Linear

• Choose Hermite Basis Function→3D→Cubic-Cubic-Cubic

• Choose Lagrange Basis Function→3D→Linear-Linear-Linear

• Verify that the list of basis functions now contains:
• Cubic-Cubic-Linear Hermite 3*3*3
• Cubic-Cubic Hermite 3*3
• Cubic-Linear Hermite 3*3
• Linear-Cubic Hermite 3*3
• Cubic-Cubic-Cubic Hermite 3*3*3
• Linear-Linear-Linear Lagrange 3*3*3
• Linear-Linear Lagrange 3*3
• Click OK to submit Basis Form

• Select Cubic-Cubic-Linear under Coordinate 1

• Select Linear-Linear-Linear under Coordinate 2 and Coordinate 3

• Select Cubic-Cubic-Linear under Field Variable 1 in the Field Vector 1 tab

• Click OK to submit Node Form

• Enter 1 for xi1, 1 for xi2, and 1 for xi3 under New Element per old element in

• Click OK to submit

• Select Cubic-Cubic-Cubic under Coordinate 1, Coordinate 2, and Coordinate 3

• Select Cubic-Cubic-Cubic under Field Variable 1 in the Field Vector 1 tab

• Click OK to submit Node Form

• Click Render to display mesh

• Click on elements lines4 in the list on the left

• Click on the Colors tab

• Change the R,G,B color field to 0, 0.5, 0.5 to change the color to the brightest red and then hit Enter

• Close the window by click the X button

• The mesh should now look similar to the third screenshot

### Pre-built model

This cont6 file contains all data and parameters for this problem prior to changing it to 3D: fit2_a.cont6 This cont6 file contains all data and parameters for this problem after changing to 3D: fit2_b.cont6 The model is also loaded into the Continuity database (ID: 1303) with run scripts in the script manager.