Shape Generator

This window provides the means to generate, display, and store a shaped RF pulse or PFG.

  1. Shapes: This pull-down button provides a menu of standard shapes (select OTHER to define your oun shape).
  2. Other: Displays the analytical expression of the selected shape function and allows the user to enter/edit a user-defined shape. Use this edit box so specify your own shape function (use Matlab conventions, i.e. a squared sine function should be written here as sin(x).^2 . In order to use this box, first select "OTHER" in the Shapes window (1). If a stored shape function is loaded, its analytical expression is shown in this box.
  3. Shape Display: A plot of the selected shape. The abscissa axis is the time axis.
  4. Excitation Profile: A plot of the Fourier transformation of the selected shape. The abscissa axis displays frequency in Hz or ppm.
  5. Data Analysis Box: Displays the integral (area under the graph) of the selected shape funstion and the ratio of this integral to that for a rectangular pulse of the same duration.
  6. Defaults: Click to set the default parameter values for a stadand shape function.
  7. EXIT button: Click to exit the Shape Generator and close the Window.
  8. LOAD button: Click to activate the load window in order to load shape function stored earlier.
  9. DRAW button: CLick to plot the selected shape function and its Furier Transformation.
  10. SAVE button: Click to activate the save window to save the selected shape for further use in the "experiment".
  11. Frequency units: Select frequency units (Hz or ppm) for the graph of the Fourier Transform. After the desired unit has been selected, click on the DRAW button to update the graphs.
  12. Pulse length [ms]: Specify the duration of the shaped pulse. The value of 0 will be interpreted as a value from the lower to the upper bounds, in ms.
  13. Upper bound: Specify the abscissa for the rightmost point (upper limit for x value) for the selected shape function.
  14. Lower bound: Specify the abscissa for the leftmost point (lower limit for x value) for the selected shape function.
  15. Number of points: Specify the number of data points to represent the selected shape.


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Page designed by David Fushman. Modified 11/26/2002.