Wearable Strain Gauge Sensor

Discussion in 'The Projects Forum' started by LED Man, Dec 3, 2008.

  1. LED Man

    Thread Starter Active Member

    Jan 15, 2008
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    Hey guys,

    I am wondering if anyone out there happens to know of any good sensors that are wearable. I'm thinking a strain gauge sensor would work best for my application. I'd like to put the sensor on a part of the body in an attempt to model what position that part of the body is in over time. The idea is that the change in position of the body part would vary the strain gauge producing a voltage specific to various positions of the body part. Anyone know of any good sensors for this? Thanks.
     
  2. leftyretro

    Active Member

    Nov 25, 2008
    394
    2
    Not going to be an easy solution for that. A strain gauge(s) will only tell you the force being applied to it, but that does not translate well to a specific body position. Possibly an array (one for each movable body part! $$$) of 3 axis accelerometers could be useful but thinking of the math needed to convert that array of readings into body position hurts my head ;)
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
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    Hard to get to to work. The maximum compression/elongation a typical resistive gauge can handle before the foil breaks is about 5%. And they report strain, not position.

    I have heard of using a frame attached to arms and legs with a potentiometer at the joints that was used to resolve joint angles.
     
  4. KL7AJ

    AAC Fanatic!

    Nov 4, 2008
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    I think I could have used a strain gauge belt for Thanksgiving. :D
     
  5. davebee

    Well-Known Member

    Oct 22, 2008
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    A lot of people have made sensor gloves for measuring everything from golf club swing, to detecting sign language, or as a replacement for the computer mouse.

    Why not see how they have been designed?
     
  6. LED Man

    Thread Starter Active Member

    Jan 15, 2008
    62
    0
    That's a good idea. This idea is to make this as non-invasive as possible. I've found an option for a polymer type paste which would, through literally painting the material on another material, would convert any type of surface in to a workable variable resistance sensor.

    What do people think of having a few micro transmitters embedded in to a wearable material which communicate with a main hub located at, say, your belt. Based on distance away from the central "reference" point, you would be able to tell which position the other transmitters are in and then be able to reconstruct a 3-d image corresponding to the actual position of, say, your arm?
     
  7. beenthere

    Retired Moderator

    Apr 20, 2004
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    If you can do the programming and have the computer to crunch the numbers, then that might work.

    The one advantage to using pots and jointed followers is that an initial calibration may be good for any number of uses. The paint on paste sounds as if it would give a different result every time, and require lengthy calibration sessions each time.
     
  8. LED Man

    Thread Starter Active Member

    Jan 15, 2008
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    0
    Feasible to do in a few months?

    What do other people think of the idea?
     
  9. bertus

    Administrator

    Apr 5, 2008
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