Using A Theremin For Medical Applications

[Eswar] is not an ordinary 16 years old boy. He figured out a noninvasive way to measure breathing in hospitals for less than $50. He is using a theremin to measure the rise and fall of a patient’s chest. For our curious readers, this touch-less instrument was invented back in 1929 by the Russian inventor [Leon Theremin]. It uses the heterodyne principle and two oscillators to generate an audio signal. One electronic oscillator creates an inaudible high pitch tone while another variable oscillator is changed by adding capacitance to an antenna.

As you can guess the space between the patient’s chest and the antennas placed around the bed forms a tiny capacitor which varies when exhaling. With three simple TTL chips and a little guessing [Eswar] had a working prototype ready to be implemented in the real world. If you’re interested in theremin, we invite you to see one of our previous articles on how to make one in a few minutes with a soda can.

30 thoughts on “Using A Theremin For Medical Applications

  1. Two thoughts: 1) Would a second person in the room cause false readings? 2) He mentions measuring heart rate. I wonder if this could be used to measure heart rates of mother and fetus.

    1. Filtering.

      There is a code to detect heart rate through a webcam, picking the signal out of the noise in this application seems pretty easy in comparison.

      Brilliant idea though, someone is going to make a bucketload fitting these to baby’s cots.

  2. Seems so ideal, that I wonder if it hasn’t been tried before. And forgotten because it has some issue. Could the AC field couple into ECG and EKG leads, for example? Could two being used in close proximity cause beat frequencies that would be difficult to filter out?

  3. Just some food for thought… Please don’t kill me guys! Due to the fact that he is of such a young age, he should look into getting some kind of Intellectual Property on the product (more of the concept than the hardware it self) The medical field would eat this up, and to be honest, this would be a great way to put his name out into the world. Even if he never does any thing with it, having “Patent Owner” on a resume helps. A LOT.

      1. In the US it’s multiple thousands of dollars. And then having enough money to enforce your patent is even more expensive. Getting a patent is great, in some cases. In other cases its a terrible financial decision. Big Medicine(TM) will either counter sue you when you try to enforce it, forcing you to withdraw(and lose) since you don’t have millions of dollars and hundreds of lawyers, Or they’ll just design their own protocol.

  4. Just some food for thought… Please don’t kill me guys! Due to the fact that he is of such a young age, he should look into getting some kind of Intellectual Property on the product (more of the concept than the hardware it self) The medical field would eat this up, and to be honest, this would be a great way to put his name out into the world. Even if he never does any thing with it, having “Patent Owner” on a resume helps. A LOT.

    1. Firstly I am sorry I went to reply and clicked report >,<
      I'm used to reply being where Hackaday has report T___T
      And then there was no prompt just "We'll look into it" so when and if you look into it please ignore it, thank you and sorry again.

      As far as claiming ownership of the concept …… NO. Just no …. I'm sick to death of patents (admittedly primarily software) that do little more than claim ownership of a vague concept with little more than a nebulous description presented in the broadest possible terms that could apply to most anything.

      Kid wants to apply for a specific method of doing X that is totally fine.

      1. You have a valid point, Ive been through the process my self, and it is a ton of hoops and bull. But, College inst cheap, and sticking out of the pack be cause you had a great idea and the initiative to actually go out and pursue it makes you look like a go getter compared to the other person waiting for the interview. And no worries about the report hahaha stuff happens.

  5. I dispute his conclusions.

    He just puts a graph up with no labeling of the axes and zero context.
    I have no idea if that represents breathing or not.

    Second he has not done a ‘null’ test with a non-breathing individual.
    A corpse of any mammalian species would work.

    This research is poorly executed and any claims about its efficacy as a medical device are outright fraudulent until he has proper proof.

    1. Dude, he’s 16 years old.

      You could excite and encourage by pointing out how to extend and complete his research, or you could dishearten and demoralize by pointing out how poorly executed it is.

      And apropos of nothing, endless disparagement is seen as a negative in social interactions. Such people are shunned as a downer, loser, or wet blanket.

      Learn how to encourage, how to give advice, and how to foster interest. It’ll serve you well when you have children of your own.

      1. Served you well. You can’t even deal with negative criticism directed toward someone else. Negative criticism is a fact of life and most people don’t learn to deal with it. Instead they try to create “safe zones” and impose them on everyone else.

        1. I feel that unbridled enthusiasm, while helpful to receive, isn’t always helpful at actually getting to the root of the actual issues. It’s a balance. If the project has major flaws, pointing out only the positives doesn’t make the flaws go away. Still, a certain degree of “he’s 16” tempering should be employed here as well.

        2. Mark your words, if you have children one day, they will be unsure of themselves, and have major intellectual impairments, rarely speak up for themselves, rarely defend anything of their own. You will be like a demon that will haunt them in everything they do. Your kids will amount to nothing, because they are never able to fail without thinking something bad will happen to them. Plus you completely missed the point of Okian’s comment. It wasn’t to say never say someone got something wrong, its the how and why you say it. He was pointing out to provide an atmosphere to children that promotes innovation, risk, and failure, not just a berating and megalomania with no room for failure as you think is best. Your a fool even amongst fools.

    1. Are you kidding me? He didn’t photograph or even videotape his experimental setup (instead he took the time to put together some CAD models). The last thing the kid needs is an unjustified ego boost from bad reporting.

  6. As the lurking physician, 2 things:

    1. Congrats to Eswar.
    2. Probably not as useful as many of you think. If I am worried about a patient’s respiratory rate, I am probably also worried about their oxygenation. This would require placing an O2 sat on a patient’s finger, which will also measure resp rate for me. What’s more, I can simply look at my patient to evaluate their resp rate. Different, clinically, from monitoring a patient’s heart rate & rhythm.

  7. This is a great idea. Any ideas and innovation that moves in the direction of non-invasive diagnostics is a huge step. Where one day we might be able to have star trek like tricorders that can detect things without any need of touch. Pretty neat. Keep up the great work and thinking, don’t let people get you down because they hate themselves so much, they have to hate you too for doing something good, like the NotArduino guy. Here is some famous quotes of failure;
    Adam Savage, failure is always an option.
    Theodore Roosevelt, Far better is it to dare mighty things, to win glorious triumphs, even though checkered by failure… than to rank with those poor spirits who neither enjoy nor suffer much, because they live in a gray twilight that knows not victory nor defeat.
    Michael Jordan, I can accept failure, everyone fails at something. But I can’t accept not trying.
    Steve Jobs, Remembering that I’ll be dead soon is the most important tool I’ve ever encountered to help me make the big choices in life. Because almost everything – all external expectations, all pride, all fear of embarrassment or failure – these things just fall away in the face of death, leaving only what is truly important.
    Ralph Waldo Emerson, The greatest glory in living lies not in never falling, but in rising every time we fall.
    Albert Einstein, The true sign of intelligence is not knowledge but imagination.

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