The Electronette (EMS)

Introduction: The Electronette (EMS)

About: Twitter: @4Eyes6Senses. Chris Hill is a PhD student in Creative Technology and Design advised by Ann Eisenberg and Daniel Leithinger. He is a McNair Scholar, a Google CS Research Mentorship participant, and h…

The purpose of this project was to focus on the creation of novel, computationally-enriched “sensory extension” for educational purposes, the intent is to enable students to design and build their own sensory applications, and in doing so will learn about various computer science and neuroscience topics. The HCI device created is called the Electronette. The Electronette is an arm-mounted electrical muscle stimulation device for extending a sense using electrodes and responding with a tactile output for the user.

This material is based upon work supported by the National Science Foundation under Grant No. 1736051.

The project was developed in the Craft Tech Lab at the University of Colorado Boulder.

I think the best way to start this Instructable is with the applications of the Electronette, which can be seen in the video above. With the Electronette, I wanted to allow for the user to customize finger movements with the goal of allowing the user to play instruments they've never encountered before, to give those with a paraplegic hand the ability to have pre-programmed finger calisthenics routines, learn different baseball pitching finger positions, as well as have the device be a tactile output device similar to vibration motors. While these are all very lofty goals, I believe that the Electronette has the ability to achieve some of them.

As an EMS/TENS device, the Electronette completes a circuit using the human body, which depending on the voltage, can cause muscle groups to contract involuntarily; causing fingers to twitch, arms to move, hands to grasp, and more. The Electronette is a relatively customizable device that takes an electric current from either a TENS unit or a hand made EMS unit (If you use your own device make sure to start at a very low current and always use AC current). You then split that signal into two channels, one will be (+) and the other (-). Based on the number of electrodes you want you'll connect the channels into relays. The relays will be controlled by an Arduino. Finally, you connect the electrodes to the other terminals on the relays and implement the code.

If you have any questions, want to keep up with my work, or just toss around ideas, please do so on my Twitter: @4Eyes6Senses.

WARNING: Please read the safety warning sheet found -here- before using any type of device that sends voltage through your body, definitely read if you have any implanted electronic devices or similar medical concerns and determine if you should avoid, I think EMS is cool but not that cool. Note that this Instructable is for the arm only. I am in no way responsible for any damage or issues you receive from using this device, please be safe by reading up on EMS and see if there are any dangers that would prevent you from using this device.

Supplies

A TENS/EMS device (This could be any TENS or EMS unit just make sure that it has a "Normal" mode and come with lead wires)

Multi-channel relay module (For this Instructable I used a 16 channel relay which can be found here)

Arduino UNO or Mega (depends on the number of relays)

2 breadboard buses

Red and blue ribbon cable

Dupont pin and housing kit

DC-DC boost step-up converter (To power the relays)

Step 1: Setup the Relays and Cables

Step 1: After you've selected an EMS/TENS unit (for this Instructables I'm using the TENS 7000, but I've used alternatives as well), replace the ends of the TENS lead wire with male housing connectors. Do this again with any additional TENS cable you have, but this time cut the TENS unit plug side, not the pin connectors, you'll use them later on.

Step 2: Plug the new connectors into one bus each, plug one pin into the "+" and the other into "-". It doesn't matter which cable you choose for VCC or GND (figure 2).

Step 3: Plug cables into the "+" and "-" sides of the bus (figures 2, 3, & 4).

Step 2: Divide the Current Into Two Channels

Step 1: Select a relay that you want to use (for this Instructable I'm using a16 channel relay) (figure 1).

Step 2: Plug the "+" bus cables into the relay's common terminal (middle terminal), then repeat with the "-" bus cables on the relays located on the other side.

Step 3: Using the additional 2mm pin connectors that you've cut from the TENS cables, connect them to the NO terminal (right terminal) (figure 2 & 3). You can connect to the NC terminal (left terminal) you'll just need to change the code later on.

Step 3: Connect Arduino to Relays

Step 1: Connect the relay unit pins to the Arduino using a rainbow cable, feel free to choose your own pin placement, just remember to change the code to reflect this.

Step 2: If you are using the 16 channel relay you'll need an additional power source for the relay unit. connect the Arduino 5V and GND (figure 2) to the "in" side fo the DC booster. Set the output of the booster to 12V, then connect the booster to the relay board (figure 2).

Step 4: Implement Code & Electrode Placement

Included is some beginner code to show how to control the Electronette with a sensor. If you changed the relay terminals you'll need to reverse the HIGH and LOW statements. While the Arduino is off, I'd suggest that you turn on the TENS unit and see what level works best for either you or the person wearing the Electronette. Please be careful not to activate all multiple pads at once as it may be too much for you to handle, I recommend only activating one or two sets of pads at once.

After uploading the code on the Arduino, you'll want to start to add the electrodes that will be controlling your arm. I suggest that you read up on human arm physiology to see what arm muscle groups you want to control (figure 1). I've also included pictures of places where I've placed electrodes pads (figures 2, 3, & 4). Make sure that the pair of "+" and "-" pad stay on the same arm, do not split them up between multiple parts of the body.

You can also use the Electronette strictly as a tactile output device. If you set your TENS unit low enough you should feel a sensation similar to a vibration motor, try it out!

Step 5: Done!

You now have your very own Electronette!

If you have any in-depth questions, want to learn about human augmentation, want to keep up with my work, or just toss around ideas, please do so on my Twitter:

@4Eyes6Senses Thanks!

Sensors Contest

Participated in the
Sensors Contest

Be the First to Share

    Recommendations

    • 3D Printed Student Design Challenge

      3D Printed Student Design Challenge
    • Unusual Uses Contest

      Unusual Uses Contest
    • Tiny Things Speed Challenge

      Tiny Things Speed Challenge

    8 Comments

    0
    prl22tcrvths
    prl22tcrvths

    Question 1 day ago

    What should I use for my if statement in the code?

    0
    4Eyes6Senses
    4Eyes6Senses

    Answer 9 hours ago

    it's not necessary, that's only there if you want to connect a sensor and have the conditional control the relays.

    0
    prl22tcrvths
    prl22tcrvths

    Question 13 hours ago

    Sorry if I'm being too inquisitive, but I would like to know how to make it so the pads will connect to the device? I think I have some ideas, but I'm not sure if they'll work the way I want them to.

    0
    4Eyes6Senses
    4Eyes6Senses

    Answer 9 hours ago

    Assuming you're talking about the wire that connects the pads to the relay, you strip one end of the wire and that goes into the relay, the other end plugs into the electrode.

    0
    prl22tcrvths
    prl22tcrvths

    Question 4 days ago

    Another question: do you think you could upload each of these steps in motion, so I can know exactly what I'm supposed to do? The before and after pictures aren't exactly 100% helpful on their own.

    0
    4Eyes6Senses
    4Eyes6Senses

    Answer 3 days ago

    Unfortunately no, I made this project 2-3 years ago.

    0
    prl22tcrvths
    prl22tcrvths

    Question 4 days ago on Introduction

    Would it be okay to use an Auvon TENS device instead of a 7000? I'm building this for my Senior Project, and I didn't check what I was ordering specifically.

    0
    4Eyes6Senses
    4Eyes6Senses

    Answer 3 days ago

    Yes, any TENS device should work in this configuration. One warning is that you may want a device that has a "normal" or "standard" mode, some devices only have preprogrammed patterns or ramp-ups that don't work very well with EMS applications (e.g. they only actuate a muscle for a second then stop). Best of luck!