Hand Osteoarthritis Exercise Glove – Stretch Sensor Switch

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This is my grandmother who washed my cloth diapers by hand during the cold winter when I was a baby.  Because of all the chores and hard work she did, she developed sever osteoarthritis, especially in her hand.  During the cold weather, it gets very painful for her to even bend her fingers. This personal story inspired me to make gloves that will facilitate hand exercises needed for osteoarthritis patients.

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There are hand osteoarthritis exercising gloves and physical therapy gloves in the market, but most of them are very rigid and “machine-like.” So I wanted to explore the possibility of soft gloves that are inviting for patients to use.

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I started experimenting with conductive thread and made different thickness of single crochet chains. But, the thread I used was too conductive and didn’t work. The numbers on the multimeter changed when stretched, but arduino’s serial port was just floating.

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After my intensive Google search and YouTube videos, I learned that I need to mix regular yarn with con5. uctive thread / yarn and knit a tube using a method called spool knitting.  I ended up using three small hook screws and an empty thread spools to make my own three pin knitting spool.  And it worked in arduino serial port! The key was to divide the analogRead by  4 so that the arduino only reads from 0 – 256.

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The knitting spool I made was really shitty, so Eden and I made knitting spools in four different sizes! After many try and error, I learned that the mix of conductive thread / thin yarn with regular yarn, and the size of spools and pin numbers on the spool can change the conductivity. So far, the best thin conductive yarn I found is 316L stainless this conductive yarn / thick conductive thread from adafruit.

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I used stronger and more conductive thread to sew the my stretchy knit on to the glove, and sew them down to the bottom to connect to wires. I made sure that each line won’t touch each other.

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I cleaned up the alligator clips and made a cover to hide all the wiring.

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Each finger is programmed to one LED out put.  But… I found one issue after all the work… the glove itself is stretchy and depending on how you sew the knitting parts to the glove changes how well it works when you bend your fingers. So it works the best when you actually hold on to the bottom of the glove to let the finger parts stretch all the way. Otherwise, the LEDs won’t turn on even though the number passes the threshold way enough.

For the next future step of the project, I want explore the construction of the glove itself. I wonder if I can knit a glove and have the finger parts knitted with conductive yarn. Also, I want make the output of the bending more fun. For example, 10 different colored LED as the output to create light illuminations or have 10 piano key board sounds as output to make piano gloves. That way, it is more fun to do the exercise. If I can make one pair of gloves that works well, I would love to send it to my grandmother.

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