Control Stuff With Your Muscles

circuit boards

[David Nghiem] has been working with circuitry designed to read signals from muscles for many years. After some bad luck with a start-up company, he didn’t give up and kept researching his idea. He has decided to share his innovations with the hacker community in the form of a wearable suit that reads muscle signals.

It turns out that when you flex a muscle, it gives off a signal called a Surface ElectroMyographic signal, or SEMG for short. [David] is using an Arduino, digital potentiometer and a bunch of op amps to read the SEMG signals. LEDs are used to display the signal levels.

The history behind [David’s] project dates back to the late twentieth century, which he eloquently points out – “Holy crap that was a long time ago”. He worked with the MIT Aero Astro Lab and the Boston University Neuromuscular Research Center where he worked on a robotic arm for astronauts. The idea being to apply an opposing force to the arm to help prevent muscle deterioration.

Be sure to check out [David’s] extensive and well documented work, along with the several videos showing his projects at various stages of completion. If this gives you the electromyography bug, check out this guide on detecting the signals and an application of the concept for robotic prosthesis.

17 thoughts on “Control Stuff With Your Muscles

  1. Random thought, somewhat lighthearted but actually genuine. Maybe more appropriate for Arse Elektronika instead. Could you use this to read the SEMG from (male or female) ejaculation? You could call it a Surface ElectroMyographic Actualization signal or SEMGMA signal for short.

    1. Why would you want to read the muscles during ejaculation? Wouldn’t it be much, much easier to just use a basic pressure sensor to detect such things? For men, a simple ring that measures pressure form the urethra would more than suffice (And since such rings are common accessories it would not look out of place).

      For women would be a little more difficult, as there isn’t much to connect to. I suppose you’d have to attach a moisture sensor with either an expanding ring inside the vagina, or some kind of belt that hold it from the outside. Of course you would need to figure out some way of measuring the quantity of fluid to ensure you don’t get false positives off of standard vaginal secretions or unintentional release of urine. Further complicated by the fact that vaginal secretions can easily out-mass that of ejaculate (What you are seeing in pornography is really just urine). It’d be much easier to measure neurological activity.

      Although I have to wonder why would need such information anyway given that an orgasm can occur, in both genders, without ejaculation and vice-versa (See semen collection in the agriculture industry for more details on how to cause ejaculation without and orgasm)

      1. A basic pressure sensor would not do it. Nor would a moisture sensor. Maybe something more akin to a GC/MS sensor would, in theory, be able to at least differentiate materials but that’s largely impractical until somebody invents a surface mount GC/MS sensor and I don’t know exactly what you would do with that information exactly? Or some kind of portable MRI unit, which also sounds extremely impractical with current technology. And you raise a good point too, that ejaculation and orgasm are not necessarily linked. Not sure exactly how granular of a control system one could achieve here and then what exactly one would want to do with it? Chastity applications seems like the low hanging fruit but outside of that, I am not entirely sure what commercial or otherwise applications there would be. The accurate, granular detection problem seems like it has to be overcome first before any applications would be developed and that’s a rather, um, hard problem to solve seeing as nobody seems to have done it yet.

    2. Hmm, the requirement for accurately placed, multiple skin contact electrodes is a bit of an issue. What about noise from other things, like voluntary contractions? I could see something like this possibly coupled with a digital chastity belt technology, such as a male version at as they are already in contact with the skin and don’t tend to shift around much. Could be an interesting avenue of research and there are reasonably significant commercial opportunities. It also reminds me a bit of this: that “maps out” touch using one electrode and high frequency signals. Maybe the two could be combined? Just throwing ideas out there, seems like a really neat tech.

  2. Cool stuff. It would be great to see applications for Parkinson’s (lack of dopemine in the brain, so I constantly work with Physical Therapist on muscle movement) and also Dystonia (unwanted muscle movements). At night, when most people go into REM sleep, my muscles are alive and working, so my spouse calls me the Tasmanian Devil at night (sigh I get three hours of sleep, but feels like I just got out of a gym!)

      1. Thanks. Working with a MDS (Neuro who specializes in Motor Disorder Specialist). I average from 60 to 120 PLMD per hour when sleeping. Life with Parkinsons makes it interesting.

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