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It's easy to find a bedside monitor in a hospital in the developing world, but it's harder to find one in use. Western hospitals replace their electrocardiogram machines every few years and donate their used equipment. The second-hand machines work fine, with one glaring exception: They don't come with pads. The pads are disposable and often in short supply in impoverished regions.
The solution is to make ECG pads (link to E4C's how-to) from easy-to-find materials such as snap buttons and bottle caps. Robert Malkin and students at Duke University invented the trick, and our friends at Engineering World Health travel the world and demonstrate that making ECG pads and conductive gel is fun for the whole family. The materials required are bottle caps (read: beer and soft drinks) and the conductive gel is a gooey mess that kids enjoy. Incidentally, the gel is two ingredients and some changed proportions shy of homemade Playdough (another Instructable), which may also also go over well in the pediatric ward.
Electrocardiogram (ECG, sometimes EKG for the German name) machines measure the heart rate and rhythm and indirectly assess the blood flow to the heart. They monitor electrical activity through the pads stuck to the patients' skin.
Here's how to make the the pads, and see the last step for directions for use.
The solution is to make ECG pads (link to E4C's how-to) from easy-to-find materials such as snap buttons and bottle caps. Robert Malkin and students at Duke University invented the trick, and our friends at Engineering World Health travel the world and demonstrate that making ECG pads and conductive gel is fun for the whole family. The materials required are bottle caps (read: beer and soft drinks) and the conductive gel is a gooey mess that kids enjoy. Incidentally, the gel is two ingredients and some changed proportions shy of homemade Playdough (another Instructable), which may also also go over well in the pediatric ward.
Electrocardiogram (ECG, sometimes EKG for the German name) machines measure the heart rate and rhythm and indirectly assess the blood flow to the heart. They monitor electrical activity through the pads stuck to the patients' skin.
Here's how to make the the pads, and see the last step for directions for use.
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Signing UpStep 1Materials
Pad materials:
1. Bottle caps
2. Nickel-plated brass sewing snap buttons, size 3
3. Flathead screwdriver
4. Utility knife (boxcutter, X-Acto or another sharp-bladed, small knife)
5. Pot, water and a stove
6. Optional: tweezers/forceps
1. Bottle caps
2. Nickel-plated brass sewing snap buttons, size 3
3. Flathead screwdriver
4. Utility knife (boxcutter, X-Acto or another sharp-bladed, small knife)
5. Pot, water and a stove
6. Optional: tweezers/forceps
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I bet a lot of these have been thrown out, when they might have gone with the ecg machines to better homes.
If you cook the flour water mix, you'll need a lot less flour to get the same texture.
Great work!
Jennifer
It sound like donated equipment needs to be "de-Americanized" for use without disposables.
I could also see where there maybe safety and proprietary features that are useful in the developed would, but would present a significant barrier to use elsewhere.
Is there ever an opportunity to modify the equipment before it is shipped off?
I also wanted to add that if you have disposable diapers, you can make electrode gel from the water absorbing crystals by removing them from the diaper and adding salt and water. One diaper will make a cup or so of gel. It is like ultrasound gel.
A disposable diaper with salt and water should work as an ES ground pad as well.
Of course, that is if you have disposable diapers.
I like the 'play-dough' solution better.
Do you think the pads and conductive gel will work well for use with a wearable TENS unit for pain management? I could try making the pads bigger like mine, which are some sort of black conductive rubbery stuff, about 40 mm across. But the best gel I've been able to buy is usually only good for a few hours before it dries out and needs to be re-applied to the pads, and new skin tape.
A long time ago I tried some self-stick conductive pads coated with a thick conductive gel made with (I think) agar. They were marketed for people with sensitive skin. They worked well, since I have trouble with the glue on skin tapes, and they lasted for several days of application, removal, and re-application, but they were disposable and quite expensive. Any ideas on how to make your pads & gel self-stick? It could radically reduce the need for all the tape needed to keep the pads in place, especially if the gel doesn't dry out too fast without needing tape around the pads.
I'm delighted to see this excellent and important contribution on Instructables! Thank you!
After cleaning be sure to dry the skin. Ironic as it might be; Don't use wipes with alcohol at all since it may cause excessive drying of the skin. And go over the skin once or twice with a fine abrasive, just be sure it's clean and doesn't cause any skin damage. Fine sandpaper generally does well. All of the above is essentially what makes those "ECG Prep Pads" so special (and expensive). Especially the latter step might seem weird, but it reduces the skin contact resistance significantly.
Also be sure to not leave the wire hanging if the person the pad is applied to is able to move. Movement causes a lot of noise. Attach the wire to the skin with some extra tape.
There is also an abundance of scratched prepaid phone cards that are discarded in Africa everyday. Do you think they would make a suitable substrate?
Great post!
And Engineering World Health is also trying to spread the word through training courses it offers in developing countries.