• JupiterJupiter September 2016
    I've been doing a lot of thinking lately (to be clear, I usually do a lot of thinking, lately I've been doing a lot of thinking about the following topics) and have decided that certain implantable technologies are either too complicated for me to get into at the moment or too expensive for me to get into for the moment. So I've been thinking about a wearable project. To be specific a sort of clothing (to start I want to just make like a 6-8 inch sleeve for my forearm to try the technology, but eventually the idea is that it could be worn anywhere).

    I want to be able to feel through said fabric, but in an augmented way, that is, it should be a tough and durable material (part of the goal here is that it's protective), but in order to not lose the ability to feel through it I was thinking that TENS-like pulses could be used to signal pressure or contact on the "fabric". For the moment, let's not worry about how the fabric detects said contact.

    I intend to do some testing myself, but i thought other opinions would be nice.

    Obviously a high resolution on the feedback is helpful so I'd like to know your opinions on how close TENS contacts can be and still be effective.
    Also, I'm aware there a certain places (such as over the spine) where strong pulses shouldn't be used (correct me if that's wrong). Any other places I should know about?
    For those hardware tinkers, I intend on modifying one slightly to run off a rechargeable Lithium Ion battery (if anyone else wants to do the same, I'd love feedback from that). I also intend on attempting to microsize the contacts (again, for the resolution) (and again with feedback), I've never seen what the contacts may look like without the soft, adhesive pads, but I assume that the size of the pads has little to do with the pulse strength.
  • MeanderpaulMeanderpaul September 2016
    Ok so I know you didn't want input right away on the whole contact thing but I happen to be thinking about that for other projects I've been writing up/planning.

    Flexible resistors would work for knowing if pressure was applied. Say space them with 1inch gap between each going around the arm (lengthwise)

    I'll try and clarify. Run the resistors from shoulder to elbow then place another 1inch (or however far based on your arm) from that and continue until you are back where you started.

    Best thing is I believe they make machine washable versions which are apart of an electronics category called etextiles. They are specificly made for clothing integration. Snap a handy dandy arduino to it (also an etextiles and machine washable) and you could have a real prototype rocking out. Off the top of my head the arduino I can think of by name is lilypad but I'm not sure if it's going to work but take a look.
  • MeanderpaulMeanderpaul September 2016
    Right sorry forgot the link to the things I'm talking about.

    Take a look I'm sure you could find them cheaper elsewhere but It will give you some ideas.

    https://www.sparkfun.com/categories/204
  • JupiterJupiter September 2016
    I like the idea, as you seem to be aware, that step is a little premature, but I like the idea just the same. I think I'm going to want a higher resolution than an inch, optimally I was hoping for square centimeters, my thoughts were that the first build would not be so wearable, that is, the "sleeve" would be wired to a larger than wearable computer (something with lots of connection points for the TENS contacts and whatever detects contact. I've thought previously about used for Arduino's Lilypad device. Ultimately though I think it just doesn't have enough connectors for what I need.

    I'm curious, have you used the resistors you mentioned before? I'm curious to know what the minimum pressure that can be detected is. I like the idea, since they'd be able to basically detect anything that applied enough pressure, but if it requires so much pressure that I can easily feel it with my actual skin, through the sleeve, then it's not the most useful.
  • TheGreyKnightTheGreyKnight September 2016
    Maybe experiment with some dry mesh electrodes. If you don't want burns, higher voltage is a must. Depending on what you use for the sleeve, you could definitely look into getting some conductive thread and sewing little conductive patches and traces into the sleeve.
  • MeanderpaulMeanderpaul September 2016
    I haven't used it yet but I believe you need to apply enough pressure to flex it but that also isn't much pressure.

    What are you expecting to have touch you that you wouldn't be able to feel normally?
  • JupiterJupiter September 2016
    Haven't settled on a specific material. Still trying to come up with a good compromise between tight, form fitting, something latex-like, and the other side of things where I also want it to be breatheable, and cool. I swear very easily and can picture my skin sweating under the sleeve. In my experience, skin doesn't tend to sweat significantly when tightly wrapped (I figure it's because the sweat literally can't properly ooze out of pores), however I live in a (what I consider) warm climate (currently it's still high 80 degrees during the day) (on the bright side it's getting down to high 60s at night).

    Anyways, if you know of a material that's like latex, but breathes like cotton, let me know.

    The whole "feeling" thing is more for light touches, I've noticed that (in the winter when I get to wear long sleeves, which I think looks and feels nicer, but I can't wear that sort of thing most of the year) things tend to get snagged on my sleeves, and I generally can't feel things so much, (earbud cords as an example). The whole project is a small thing, ultimately it's a secondary thing on the sleeve. I still want some sort of embedded, flexible display.

    EDIT: I do plan on getting Apple's new AirPods when they come out in a month or so, and getting only wireless earbuds from then on. But they might not always be Apple's.
  • MeanderpaulMeanderpaul September 2016
    Well I can tell you the under armor shirts are very good at keeping moisture away and are breathable just don't get the winter wear version.

    Check out this wearable I want to get them.

    https://www.liveathos.com/shop?s=89083efee6e5a6890365258766da3cfe

    Clarifying:
    A screen built in adds complexity. So what your looking for more is a jacket that has sensors not a tight fitting shirt for the winter?

    If so have the sensors on the jacket and have the compression shirt have the "notifications".

    New problem:
    Speaking between the two wearables

    Solution:
    simple plug at base of jacket and compression shirt?

    Please let me know how accurate my assumptions are. Also more info about what you'd like it to do would be helpful.
  • JupiterJupiter October 2016
    That all sounds about right, I had strongly considered doing it in two layers, however the outer layer would be more like a long sleeve shirt, not a jacket, that is, it wouldn't be terribly thick or heavy. Not sure if that's what you were thinking of.

    As for that link, I had considered eventually adding body monitoring pieces to it. Primarily a heart rate monitor around the wrist (seems to be a fairly typical location these days) and some sort of orientation tracker (probably a couple to determine sitting, standing, or laying down (though that would go more in a whole body suit not just a sleeve).

    Anyways, assuming I don't purchase any specific material to do my first version of the TENS system in a sleeve, I think I have a good material. I bought it several months (might be over a year now) for a different project, I bought a few different kinds of fabric, I can't remember what this one is called though so I may check my purchase history to see if I can find it so I can let you know, it's not as "breatheable" as I'd like, but is a bit stretchy so I think I'm going to go with that for my first prototype.

    As for the connection, yes, probably some small cable when I get to that point. A 3.5mm cable, like what's used for headphones, I believe would be simple, depends if there's a separate computer in each half or just in one.
  • MeanderpaulMeanderpaul October 2016
    I personally don't wear jackets but rather sweat shirts. I imagine your in the same boat being from warmer climates. But yes that is what I was talking about.

    I would cation trying to add every feature right away because you may need to back track to find some issues. Perfect one feature at a time. I wouldn't go with the 3.5mm cable simply because of how simple it is to unplug and you could run into it just "popping" out.