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- # -*- coding: utf-8 -*-
- """
- A subroutine to add FS block.
- Requires the params structure as input.
- Need to think of the reequired output (pulse sequence variable itself?)
- @author: petrm
- """
- #imports
- from MRI_sequences.pypulseq.make_gauss_pulse import make_gauss_pulse
- from MRI_sequences.pypulseq.make_trapezoid import make_trapezoid
- from MRI_sequences.pypulseq.calc_rf_center import calc_rf_center
- from MRI_sequences.pypulseq.calc_duration import calc_duration
- import numpy as np
- def FS_CHESS_block(params, scanner_parameters, gz90):
- #function creates CHESS saturation block with accompanied gx and gy spoiled gradients
- flip_fs = round(110 * np.pi / 180, 3) #TODO ad parameter to GUI
- params['B0'] = 1.5 # TODO add to GUI
- #params['FS_sat_ppm'] = -3.30 # TODO add to GUI
- #params['FS_pulse_duration'] = 8e-3 # TODO add to GUI
- FS_sat_frequency = params['B0'] * 1e-6 * params['FS_sat_ppm'] * params['gamma']
- g_rf_area = gz90.area * 10
- rf_fs = make_gauss_pulse(flip_angle=flip_fs, system=scanner_parameters, duration=params['FS_pulse_duration'],
- bandwidth=abs(params['BW_sat']), freq_offset=FS_sat_frequency)
- #TODO
- #rf_fs.phaseOffset=-2*pi*rf_fs.freqOffset*mr.calcRfCenter(rf_fs)
- gx_fs = make_trapezoid(channel="x", system=scanner_parameters, delay=calc_duration(rf_fs),
- area= 4*g_rf_area, rise_time=params['dG'])
- gy_fs = make_trapezoid(channel="y", system=scanner_parameters, delay=calc_duration(rf_fs),
- area= 4*g_rf_area, rise_time=params['dG'])
- return rf_fs, gx_fs, gy_fs
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