Introduction: Quick Release for Medical Air Tubing
Many people need an oxygen air supply to breathe, which involves long cords of oxygen tubing hooked up between an oxygen supply unit and the user's face and nose. If the user is moving around, the tubes can easily get caught on something, yielding to painful and dangerous yanks.
This instructable shows an easy to build, inexpensive magnetic quick release that attaches to standard size medical air tubing. When subjected to a hard pull, the disconnect breaks at the magnet connection. It can be rejoined easily just by putting the two magnet ends near each other. The inspiration is the Apple magnetic power cords.
Please note, by its nature this device is not 100% air-tight (though it should be reasonably close with proper assembly), nor medically sterile, nor has it been cleared by the FDA. No warranty is given or implied. This has however been successfully used by people with oxygen air tubes.
Public OnShape CAD workspace - you are welcome to remix, please send us a link to your new version!
YouTube video of assembly - this video demos tubing without the connectors, we recommend using tubing with connectors but otherwise the steps are identical.
- Neodynium ring magnets (2), about 3/4" outer diameter. Available at Home Depot and elsewhere.
- Spare air tubing with standard connectors
- Superglue or epoxy
- Wire cutters or scissors able to cut the air tubing. Please clean them before using!
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Step 1: Cut the Tubing
Using a clean pair of cutters, snip off one end of the medical tubing. You should have the connector plus a few inches of tube, the exact length is up to you.
Repeat for the other end of the tubing so you have two pieces.
Step 2: Print the Tube Holders
This project requires two 3d-printed tube holders. The STL file is attached here, the units are millimeters. Find a friend with a 3d printer or use third-party service. We used PLA for our version, but other materials should work as well. It will take about 40 minutes to print both parts.
Since 3d printed parts can vary slightly in dimension, it's a good idea to press-fit everything, especially the tubing, before adding any glue.
If you would like to make your own version, you are welcome to use the public OnShape CAD files listed in the intro. OnShape is free for personal use.
Step 3: Glue the First Magnet to a Tube Holder
Remember: do a sanity check of your 3d-printed tube holders and confirm that the tubing will fit in them (see step 5) before gluing the magnets on!
Place one of the tube holders as shown in the drawing. There is a vertical slit in the tube holder; have the slightly wider section of the slit towards the bottom.
Apply superglue to the top semi-circle of the tube holder.
Place magnet on the top semi-circle, centering carefully. You will have a very limited time to make any adjustments.
Step 4: Glue the Second Magnet to the Other Tube Holder
In gluing the second piece, we need to be sure that the magnets are oriented properly relative to one another. If they aren't, the two ends will repel each other instead of attracting!
Neodynium magnets are fairly strong -- they can come together and pinch your fingers if you are not careful. If the small discs get stuck together before assembly, sliding them apart is the safest way to disconnect them.
Once you've confirmed which side of the magnet should be facing up, move it away from the other magnet for now. Position the remaining tube holder as in the previous step. Add superglue and center the magnet on top as before.
Keep the magnets well away from each other until the superglue has a chance to dry. The force between them is powerful and can pull pieces off center or apart.
Step 5: Connect the Tubing
For this step, you may want to look at the video at the beginning.
We press fit the tubing first. Pinch the end and slide that tiny section into the wider portion of the slit in the tube holder. Once the tubing is in the center, it can be slid inward towards the magnet. It should go in deep, but not beyond the magnet.
If your 3d printed part came out too small or has some extra material on the inside, a file may help.
Once you've confirmed that the tubing can slide in correctly, take it out. Put a small amount of superglue in the tube holder opposite the vertical slit. Then put the tubing in as before. Superglue dries quickly, so again you will have limited time to get everything seated properly.
Repeat for the other tube holder.
Step 6: Use Your Release
Once everything is dry, bring the two magnets near each other -- they will snap together. To test the release function, give a hard yank at both ends. It needs to be a hard pull -- our users told us that they did not want it to release under light pressure.
The connectors can go directly onto any device with the proper fitting, and can be attached to other tubing by using a standard coupler.