How "Real Time" is the Respiration Pattern? Suitability for Measuring Standing Person?

Discussion in 'Respiration Sensor' started by embedded-creations, Feb 7, 2019.

  1. embedded-creations

    embedded-creations New Member

    Hi, I'm trying to understand if the X4M200 Respiration Sensor is suitable for my application, and after reviewing the data sheet and demo videos, I'm still not sure if it is suitable.

    1. I need to give real-time visual feedback on the user's breath, so the latency of the respiration pattern output from the module is important. The only spec on latency I can find is that the output of the respiration pattern is in "real time". However, this video demo shows the respiration pattern significantly out of sync with the person's
    XeThru X4M200 Respiration Sensor Demonstration

    This demo of the previous version of the module shows respiration pattern is more in sync with the breath

    XeThru Respiration Monitoring Demo

    Is the respiration pattern output actually real time without significant delays that would be obvious to someone comparing their own breath and the respiration pattern output?

    2. Ideally I want my users to be standing to interact with my device, not sitting, and definitely not lying down. As I understand, the sensor is just measuring distance to the closest person, and detecting the slight changes in distance when the person's body moves due to breathing. If the user is standing, they will be swaying slightly, which I assume would interfere with the correlation of the respiration pattern output to their actual breathing, and could interfere with the RPM count.

    As I don't yet have a sensor here to test myself, could someone tell me if slight movements while standing are likely to significantly reduce the quality of the respiration pattern output?

    Is the RPM count likely to stay accurate even if there are slight movements from standing while the sensor is counting respirations?
  2. Charlie Shao

    Charlie Shao Moderator Staff Member

    Hi, according to your description. I believe the X4M200 cannot meet your requirements. The X4M200 is more designed for respiration record during sleep instead of real-time respiration monitoring. For your application, the wearable monitoring device might be a good choice.
  3. embedded-creations

    embedded-creations New Member

    Hi Charlie,

    Thank you for your feedback. What specifically makes you think that the X4M200 cannot meet my requirements?

    Since I posted, I found these projects that use XeThru respiration sensors to provide realtime feedback to a user, one seated, one standing:

    If the X4M200 cannot meet my requirements, how can it meet the requirements of these projects?

  4. Charlie Shao

    Charlie Shao Moderator Staff Member

    Hi Louis,

    I saw your first post pay much attention to respiration pattern, so I reckoned your application has high requirement on this. X4M200 datasheet defines Breathing pattern of closest breathing target as detected respiratory movement in mm perpendicular to the X4M200. Since X4M200 is a non-connect sensor and respiratory movement on the human body is quite small, people need to keep completely still to get good breathing pattern output.

    RPM output is another topic, X4M200 using the pulse-doppler algorithm to extract the RPM signal. Normally you will see RPM output even when breathing pattern is poor.

    For the above two projects, please pay attention that they are not use breathing pattern to control light directly. I am not sure the detail on how they use XeThru sensors, but it is able to use RPM output or radar raw data as output to control lights, there are other messages from XeThru sensor that can be used for custom DSP. I can see people are at fixed positions in the two projects, this also makes this custom algorithm easier.

    Anyway, I strongly suggest you evaluate X4M200 with experiments, then you will be able to understand how to use X4M200 in a better way. Please feel free to ask if you meet any problems.

  5. embedded-creations

    embedded-creations New Member

    Thank you Charlie for the detailed response.

    > please pay attention that they are not use breathing pattern to control light directly

    Thanks for pointing that out, I just assumed that must be how they were controlling the lights.

    Sounds like my next step is to get a module, thank you for your help.