Weekend Project: TENS Case Project

The two enemies of human happiness are pain and boredom.

Arthur Schopenhauer

One of the projects that has been in my queue for a while is to make fabric pouches that my friend, M, can wear to hold her TENS machine. She has chronic back pain, and the TENS unit sends a small current through electrodes on her back. Apparently pain is primarily an electrical transmission along nerve endings and this small current disrupts the pain cycle and may bring some relief.

This is one pattern that I completely made up on my own, using the measurements of her TENS unit that she emailed me. It was a bit of a challenge, because I didn't have an actual unit that I could test myself, and she lives in the UK! But, with some iterations, we worked out a pattern that suits her reasonably well.

She visited last May and we went shopping for some fabric for more pouches. Here she is in Joann's:

Here is the basic pattern. I cut two of the main piece to make it lined, and the small piece is a flap that gets doubled over. It's a pretty standard approach to making a fabric pouch, but I'll show you some pictures and discuss the special features that we added due to our preliminary experiments.

Originally I put in 2 windows - one for the on/off switch on the side and one to allow her to read the digital display on the front. But she decided that she doesn't really need to see the digital display, so I've quit putting that window in. Putting the switch window in is a bit of a nuisance - I cut it kind of like a bound buttonhole and iron it open.

My original version didn't have a flap - her belt attached through the back of the main pouch. But she felt that it was insecure, and was afraid that if she leaned down to pick something up, the TENS unit might fall out. So, we ended up adding this flap (for the belt to pass through) above the pouch itself. That puts the center of mass of the unit lower and allows it to swing forward if/when she leans over.

Making the flap:

This shot shows where the flap gets added to the pouch:

This shot shows the flap, inserted between the outer layer and the lining:

In addition to adding the flap, another detail of this pouch that we had to work out over time is the top stitching. This top stitching isn't just for appearance's sake. The original pouch didn't hold its shape well, and the TENS unit tended to slide around inside of it. This was a problem because often the switch didn't line up with the window. I got the idea to "force" the shape of the pouch into a rectangle by adding the top stitching, and it works!

And the third feature that we worked out over time was adding an elastic strip along the outside back of the pouch, to hold the extra length of wires between the unit and the electrodes, so that they don't dangle all over the place.

Here are the three new cases that I made over my Christmas holiday:


Note the buttonholes in the flap, to allow a belt to be threaded through... Here she is modeling one of the pouches that I made during her visit last Spring:




And here she shows off the back, with the extra wires tucked into the elastic:

I dropped the new ones in the mail on Monday (5 Jan) as a belated Christmas present. And another project from my queue is complete! Yay! :)