Safe power source for iontophoresis device?

Discussion in 'Power Electronics' started by talco92, Aug 10, 2016.

  1. talco92

    Thread Starter New Member

    Jul 15, 2013
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    So I searched this forum and it seems like there have been a few previous threads on this, but not much in the way of the answers I'm seeking.
    Iontophoresis is a treatment in which current is passed through a body part (typically the hands) to either deliver a drug or push ions into the skin (to disrupt sweat glands and stop sweating [hyperhidrosis]).

    These iontophoresis devices sell for ridiculous amounts of money, for what looks like a relatively simple device. I'm assuming the bulk of the money goes towards the R&D/compliance and regulation side of the businesses. Anyway, I would like to know if anyone here thinks that it would be possible to make one of these.

    Here is some information from the website of Iontoderma, a company that makes one of the many devices on the market (the cheapest at the moment).
    https://iontoderma.com/products/iontoderma-id-1000?variant=15322682564
    "device is mains powered. It converts AC to DC." (note: most of the other devices on the market are battery powered, I'd prefer wall)
    Universal wall power (100V-240V AC, 50-60Hz).
    Variable tension, adjustable voltage: 12V, 15V, 16V, 18V, 19V, 20V, 24V.
    Maximum output: 25mA at 1kΩ.

    I'm in Australia, so mains voltage is 230V, 50Hz

    EDIT: If you watch the video on their website, its clear that all of the 'technology' is in the power supply. It must be DC (according to many studies) and the rest of the device is just a glorified plastic document case, some metal plates and material... hence why the focus is on the power specs only.
     
    Last edited: Aug 10, 2016
  2. AlbertHall

    Well-Known Member

    Jun 4, 2014
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    I would suggest that I would not a DIY designed and built mains powered unit in intimate contact with my skin.
    Stick with battery power.
     
  3. talco92

    Thread Starter New Member

    Jul 15, 2013
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    There's no reason not to if the design is safe
     
  4. AlbertHall

    Well-Known Member

    Jun 4, 2014
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    Indeed that is the case. A commercial unit should be correctly designed and built and should have been tested to the required standards (though that might depend on where in the world it was made).
    If you have sufficient knowledge to design and build a mains powered skin contact unit with suitable safety precautions, you would not need to ask in here how to make what amounts to a simple DC power supply.
     
  5. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
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    It looks like nothing more than a variable DC power supply with a 1k resistor in series with the output, the user even has to stop and switch polarity, although, I don't know why he didn't just walk around to the other side of the table.

    The current draw is likely to be so small that a battery operated unit would be entirely practical without the risk of death. Simply hook 8 x AA cells together and put it to the test, the 1k resistor is optional but will provide protection if the probes are shorted.
     
    Last edited: Aug 10, 2016
  6. hp1729

    Well-Known Member

    Nov 23, 2015
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    How does this system stop sweating much less deliver a drug?
     
  7. AlbertHall

    Well-Known Member

    Jun 4, 2014
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    Whether it does anything useful is a whole new can of worms.
     
  8. ian field

    Distinguished Member

    Oct 27, 2012
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    A double-insulated wall-wart should tick all the boxes - you don't want to earth the patient in case they touch something *ELSE* that's live.
     
  9. ian field

    Distinguished Member

    Oct 27, 2012
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    I seriously doubt it stops sweating - the word; "ion" is a clue to the second bit.
     
  10. ian field

    Distinguished Member

    Oct 27, 2012
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    There are commercial products on the market - the one I know of is for removing cellulite (sort of blotchy fat deposits).
     
  11. ian field

    Distinguished Member

    Oct 27, 2012
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    The commercial unit I reverse engineered used the textbook 2 transistor constant current circuit, which was fed by narrow pulses at around 30V.

    You can also make the current limiter with a single JFET and a resistor. The resistor is in the source lead and the gate goes to the bottom - current through that resistor develops the pinch off voltage.

    Can't remember the correct current level - but its very low if you want to avoid permanent scarring.
     
  12. #12

    Expert

    Nov 30, 2010
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    Here's an idea:
    If you want pulses, that will need a TL555
     
  13. talco92

    Thread Starter New Member

    Jul 15, 2013
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    The efficacy of the treatment is highly documented in peer reviewed journals. Feel free to look it up. Keywords are iontophoresis and hyperhidrosis
     
  14. ian field

    Distinguished Member

    Oct 27, 2012
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    The commercial unit I reverse engineered had a CMOS hex inverter, a couple of the gates were the oscillator and those left over were paralleled to drive a TO92 MOSFET flyback converter. The master frequency was somewhere around 20 -30kHz with a CMOS divider to produce the lower frequency therapy pulses.
     
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