Parameters

Discussion in 'XeThru Explorer' started by Hanna Hebestreit, Feb 16, 2016.

  1. Hanna Hebestreit

    Hanna Hebestreit New Member

    What do the different parameters in the settings mean?
    For example: For what stands an RPM history of 120? What changes if we set the value higher or lower?
    Or where do I find these Information?
    Greetings
    Hanna
     
  2. Hanna Hebestreit

    Hanna Hebestreit New Member

    I found out, that it influences the scale of the x-axis of the corresponding value. It defines the length of the x-axis.
    Is there any other meaning of the Settings?
     
  3. kjetil

    kjetil New Member

    You are correct, this is part of the User Interface settings noted as UI in the XeThru Explorer, and lets you define the length of data history you want to display. You will find a short description of the UI history sliders if you press the "?" in the top right corner. One thing you made me notice is that there is no information saying that the unit is seconds. We will add that in a future release. Thanks for your feedback.
     
  4. Hanna Hebestreit

    Hanna Hebestreit New Member

    Maybe it would also be good to offer, that al three Parameters pass trough the UI with the same velocity. So that the time is equivalent for all.
    Thanks for your help, i have never klicked on the "?" :D
     
  5. Hanna Hebestreit

    Hanna Hebestreit New Member

    What is the unit of the ObjectMovement in the resulting excel document? And how is the breathing pattern defined?
     
    Last edited: Feb 19, 2016
  6. Olav Liseth

    Olav Liseth Administrator Staff Member

  7. Hanna Hebestreit

    Hanna Hebestreit New Member

    I saw that, but then I get really weird results. I was measuring the movement of a pendulum, with a movement of round about 1cm. My results are attached.
    For the ObjectMovement I get then more than 100mm and that is impossible.
    What could be the problem?
     

    Attached Files:

  8. Olav Liseth

    Olav Liseth Administrator Staff Member

    I agree that the amplitude/pattern looks weird.

    1. What is the frequency of the pendulum?
    2. Is the pendulum movement +/- 1 cm?
    The system is designed to detect normal breathing ( typically less than +/- 5 mm) and a larger movement might result in wrong detection.

    Olav
     
  9. Hanna Hebestreit

    Hanna Hebestreit New Member

    1. The frequency is 0.7Hz
    2. The movement was around 1cm in total, so around +/- 5mm. I attach another data set, where I am sure that the movement is less than +/- 5mm. The same problem appears...
    Greetings
    Hanna
     

    Attached Files:

  10. Olav Liseth

    Olav Liseth Administrator Staff Member

    Hanna,

    I had some problems with your latest pdf, can you upload the csv file? In addition, can you record and upload a breathing sequence?

    Olav
     
  11. Hanna Hebestreit

    Hanna Hebestreit New Member

    The one that ends with 11 is the breathing, the one with 29 is the pdf as csv-file.

    It could be possible that the proplem is only with decimal places.
     
  12. Olav Liseth

    Olav Liseth Administrator Staff Member

    I plotted the one that ended with 29, that's the pendulum right? It looks good now, seems like the pdf conversion was the problem.
    xethru_log_Respiration_XeThruModuleX2M1000_20160222_105429.csv.png
     
  13. Hanna Hebestreit

    Hanna Hebestreit New Member

    I think then there is a Problem with my Excel-Settings. Because I get the pdf values. Maybe something about comma and point settings
     
  14. Hanna Hebestreit

    Hanna Hebestreit New Member

    How is the Signal Quality defined? Is it like a Signal-to-Noise-Ratio?
     
  15. Olav Liseth

    Olav Liseth Administrator Staff Member

    Exactly, signal to noise in a scale from 0-10. A correct rpm can be measured with low signal quality, but the breathing pattern requires a certain level of signal quality. The example above gives a pretty good breathing pattern with a signal quality of 6. I guess the setup and movement is quite clean.
     
  16. Hanna Hebestreit

    Hanna Hebestreit New Member

    And what is the area, which is detected by the sensor? If I have a plate of 5x5cm, does the sensor detect the whole plate? Because it can also detect smaller objects (I tried with a 2x2 metal plate). So I am not sure how it works, if he only analyzes part of the plate, or the whole...
     
  17. IngarH

    IngarH Moderator Staff Member

    What is detected is the effective area facing the sensor (referred to as the radar cross section). When using a plate or a flat object the angel of the object relative to the radar is important. Check out this document (page 2) http://www.microwaves101.com/encyclopedia/Navy handbook/4.11 Radar Cross-Section (RCS).pdf
    Internally we rather use metal spheres for testing because these have the same radar cross section from all angels. If there are many objects moving the radar will use the reflector generating the strongest return signal.
     
  18. Hanna Hebestreit

    Hanna Hebestreit New Member

    Okay, thanks!
    Just to be sure: the XeThru Explorer uses the whole radar crosssection of one "moving object" to get the breathing pattern?
    And what how high is the spatial resolution of the sensor? I couldn't find that information yet
     
    Last edited: Mar 14, 2016
  19. IngarH

    IngarH Moderator Staff Member

    A human body is a very complex reflector. What part of the body that will give the strongest signal is different from person to person. The part with the strongest signal is what the sensor is using.
    The spacial resolution of the radar itself is about 4mm (given by the ~40GHz sampling rate) but this is interpolated so we can detect periodic movements below 1mm
     
  20. Olav Liseth

    Olav Liseth Administrator Staff Member