VTOFG: Vibration Test Object Function Generator

Introduction

A function generator that uses the audio output (3.5mm port, speaker, or usb-c) on a computer, for use with a vibration test object (VTO) for testing of doppler ultrasound. This can be used as a general function generator if plot is set to False.

When the function generator is ran it has the following inputs: -- Master amplitude: the overall amplitude of the signal (essentially the volume when played through a speaker)

• Generator frequency: the frequency of the audio frames in the signal
• Resolution: the resolution of each audio frame
• Buffer time: the length of each segment that is calculated/played (the next segment is calculated while the previous one is being played)
• Transducer Frequency: The ultrasound wave frequency in kHz
• Pulse Repetition Frequency: The Pulse Repetition Frequency that the scanner is using in Hz
• Display Time: The time period displayed
• Display Samples: The number of lines per time period
• Wall Filter: The wall filter frequency used (A simple cutoff mask is used)
• Gain: Arbitrary value use to scale the displayed signal
• Display Speed: used to control the display speed if it is out of sync with the signal
• For each sweep wave:
  • Wave amplitude: relative to each other, changing this will not change the overall signal amplitude
  • Start Frequency: the frequency to start the sweep
  • End Frequency: the frequency to end the sweep
  • Sweep Time: the period of the sweep

Installation Instructions

Windows

Use pip to install the vtofg package:

pip install vtofg

Run the following python script:

import vtofg

gen = vtofg.FunctionGenerator(plot=True)
gen.mainloop()

Set plot to False if you don't want the plotter.

See Example.PNG for expected output when ran with settings shown in image.

Mac and others

Installation of the package is largely the same, except you will need to run pip3 install vtofg instead of pip install vtofg. You may also need to manually install a version of python through your package manager which includes tkinter, as the default version of python3 preloaded onto your system may not contain this.

Python Version

An installation of python 3.7.9 is recommended, other versions have not been tested.

Roadmap

• Adding functionality to save/load waves
• Add functionaality to run .wav files

Contributing

Contributions are welcome

Contributors

• Zack Ravetz

License

This project is licensed under the BSD license.