Poopable Cameras

Pill cameras, devices for ‘capsule endoscopy’, or in much cruder terms, ‘poopable cameras’, are exceedingly cool technology. They’re astonishingly small, communicate through a gastrointestinal tract to the outside world, and have FDA certification. These three facts also mean pill cameras are incredible expensive, but that doesn’t mean a hardware hacker can’t build their own, and that’s exactly what [friarbayliff] is doing for his entry into The Hackaday Prize.

First things first: [friarbayliff] is not building one of these for human consumption. That’s a morass of regulatory requirements and ethical issues. This pill camera is only being built as an experiment, because it would be fun to build one. The pill cams swallowed by patients every day have millions of dollars in R&D behind them before human trials. That said, given a good food-safe enclosure, I’d down one of these as an experiment.

This pill camera will use a simple, off-the-shelf 2 megapixel image sensor that can be bought on eBay for less than five dollars. With a small 32-bit micro, these cameras are easy to drive and capture images from. Power is provided from a single silver oxide button cell battery and a boost converter. In total, [friarbayliff] estimates the total PCB area to be just under one square inch, making this a relatively inexpensive device to build. There will be a radio transceiver in there somewhere, but [friar] hasn’t figure that part out yet.

Pill cameras are some amazing technology, but relatively inaccessible unless you get a used one. Ew. [Mike Harrison] tore one of these pill cams apart a few years ago, and it really is an incredible device. Building one for fun – even if it won’t be used in a human – is a fantastic learning experience and a great entry for the 2016 Hackaday Prize.

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51 thoughts on “Poopable Cameras

  1. Given the number of deaths from kids swallowing coin cells (the reaction in their stomachs leading to a horrible demise), I’d be a little more wary of swallowing such a project. Any problem with the enclosure could spell game over for the swallower.

    1. Precisely. There’s a reason medical devices are so expensive. They are designed and tested to ensure there are no unexpected adverse biological reactions in the body.

      Plus the manufacturers have INSURANCE to cover the consequences of their activities. (Sorry about the SHOUT, but that point should not be missed!)

      I hope any amateur hacker is similarly well prepared.

    2. I doubt that the coin cells are fatal today. Might have been fatal in the days when mercury oxide/zinc cells were common but the zinc air or lithium batteries that are used today are hardly fatal because the ingredients are fairly harmless. Lithium might cause some slight burns but that probably is all that happens.

      1. It’s not just the chemical reaction that is the concern but also physical obstruction. It is possible (although I do admit much less likely) that the cell can get jammed somewhere in the digestive track which then causes all sorts of problems, such as at the appendix for one example.

        1. What doctors do to prevent this is they have the patient swallow a dissolving capsule the same size as the camera. If it passes, they assume the camera will also pass unobstructed. If it gets stuck, after a certain period if time it dissolves and passes anyway.

      2. I think it is not a question of the chemical ingredients only. At least Li-Cells with their higher voltage can do electrolysis. This can generate corrosive/toxic substances. So perhaps with bad luck the burn is not only slight.

      3. See, that’s why this can be so dangerous. You’ve only addressed the chemical aspect. The next person addressed the physical obstruction. Let me throw in a third: electrical.

        Everyone’s touched a 9V battery to their tongue. Even a1.5V or 3V coin or button cell gives a similar reaction. In a child that swallows a coin cell that electrical “burn” can do some serious damage (especially to esophagus or small intestine).

        A child that swallows a coin cell may require emergency surgery. In a third world country that could be a death sentence.

    3. The primary cause of death in button cell swallowing is not poisoning through case failure, but getting stuck in the esophagus where generation of hydroxide through hydrolysis can erode tissue. If the battery makes it to the stomach, destruction of the case is actually safer.

      18 children in the US have died 1985-2014 due to button battery ingestion out of 73,647 reported events to the National Poison Data System, mostly children under the age of 6 who weren’t able to completely swallow the cell. http://www.poison.org/battery/stats
      I think there were 5 in 2015, but I don’t have a source handy.

      I’d strongly recommend using 1.5V cells instead of 3V cells and a gasket to increase the distance between terminals. Maybe plasti-dip the cell except for where the battery holder touches the faces..

  2. Coin cell deaths are mostly caused by the electric current through the tissues of the gut causing a buidup of sodium hydroxide (caustic Soda) in the tissues which then etches those tissues away.

    This is why swallowing anything capable of generating an electric current through the tissues of the gut can be problematical.

    It’s a nice design exercise though! I never cease to be impressed by the ambition and capabilities of the hacker community.

      1. Honestly? I don’t think it would be too bad. Consider what ordinary surgical tools go through — they could be dipped in a vat of ricin, and they’d probably be safe to use after the proper cleaning procedure. If one of these cameras can survive e.g. an autoclave, I would be fine re-swallowing it.

        1. Crazy! They were able to include a real high-voltage vacuum x-ray tube into this pill. But I can’t imagine how the supply the energy – 1-2V at 0,5 to 1A alone for the heated cathode and no idea how much for the high voltage supply.

  3. typo:
    ” but [friar] hasn’t figure that part out yet. ”
    suggest either
    but [friar] hasn’t figured that part out yet.
    but [friar] hasn’t managed to figure that part out yet.

  4. It is ashame these things are so incredibly expensive. The cameras used in normal butt / throat cam procedures are virtually impossible to clean. It is a well known thing that they can become infected with those super bugs and then anyone who gets scoped has a chance to contract the bug. As someone about to roll the dice it sure would be swell to swallow a 20$ camera that was not previously used instead.
    Google “super bug endoscope impossible to clean”

    1. They’re not virtually impossible to clean, cleaning them are labour intensive and require attention to detail by someone who understands and respects the potential implications of doing a bad job. That sort of dedication is difficult to find at the sort of wages such a task commands.

      1. actually it was just a bad design and impossible to clean
        A number of people died and dozens of others were infected by a superbug that medical experts believe is linked to a particular endoscope. The medical device, which was re-designed by Olympus to make surgeries more efficient, was never approved by the FDA. In January 2016, Olympus issued a recall for thousands of these scopes.


        1. Exactly, where I work there was a huge deal about this, with everyone running around testing all the scopes for damage, indications of improper cleaning, signs of contamination, etc. And the pill cameras are disposable and intended for single use only, partly due to the concern regarding contamination and partly as it is just about impossible to replace the battery and re-seal them to prevent internal contamination. In fact the contamination issue is the bigger concern, as there is a whole department here that deals with Hospital Acquired Infections called (appropriately) Infection Control.

          1. No doubt bob, i skipped out on my first apt 4 yrs ago because of it , 6 months later it was in the news the exact place i was going to for it killed a bunch of people the month i was gonna go. I guess i will roll the dice now but still figure its better chance of getting hosed than not.

  5. When physicians prescribe this treatment, they always follow it up with an abdominal X-ray a week later to ensure it has passed through the GI tract. Without also building an X-ray machine, do not swallow any metal, plastic, glass, or batteries that may cause massive infection if they are not expediently pooped (as the title of this article indeed mandates)

    1. I would NOT recommend building an x-ray machine to use it on yourself. So either use bucket until positive evidence that the camera left the body – because you found it – or get a normal x-ray.

      1. I have two books containing explaining how to do just that.

        “Something to Make” by Eric Wood has one chapter “An XRay Apparatus” and another “A Fluoroscope”.

        “The Boy Electrician”, which I can’t instantly locate, has a chapter things you can do with your XRay machine. It does suggest that you are using it too much if your skin becomes red.

    2. You could sort-of solve for this by including an RFID tag in the capsule. If it passes successfully, you can detect it in the stool. If you don’t detect it by Day 2, go to the hospital and have them do an X-ray.

      Assuming you have a magical RFID tag that works in water (and fecal matter), of course. Most cheap RFID tags are stymied by water (which has been one of the problems at implementing RFID grocery stores.)

      Another thing is the doctors require a thorough cleansing of the GI tract before doing a visual inspection; it would be no different than preparing for a colonoscopy. It’s two days of fasting and drinking various cleansing products. Anything you pass after that process is basically smelly water, so recovering the capsule should be very evident.

      1. Could be solved by non magnetic pipes with embedded rfid tags say every meter or position markings printed on the inside, and a pill with its own storage memory. You let go he pill and wait for it to reach the sewer, then download all data with associated position.

  6. The most complicated problem I can see is getting the information out. A radio doesn’t work because RF is not able to leave the body. What is done in the existing cameras is to have two electrodes trough these electrodes the signal is transmitted modulated at a few megahertz. However the whole bandwidth available when doing this is a couple of Mbps. Look it up you can easily find the paper by searching on google. On the outside, you have the receptor connected to the body with two electrodes. So the problem is to send high-quality video trough this low bandwidth channel. For this, you need to encode the video signal to compress it enough to fit the communications channel.

    1. nope, see the answers above. The main danger, though chemical in nature is caused by an electric current through the tissues causing a buildup of sodium hydroxide. It doesn’t matter where the current comes from.

  7. I could use a tiny camera like this for a multitude of things that they were never intended for (checking wire conduits for obstructions, getting into engine cylinders without tearing them apart, etc.)

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