Year
2023-24
Role
Designer: research, concept, 3D model and fabric prototypes
Context
Research project, IIT Hyderabad
Duration
2023 to Jan 2024
Team
Individual project
Status
Concept and fabric prototypes. Not tested on patients.
The problem
Elephantiasis blocks the lymph channels and the leg swells again and again. Bandages and pump sleeves help, but the need was a portable wrap that drains the fluid and keeps the swelling down.
The outcome
A 3D concept, three fabric prototypes, and a clear list of what is still unmeasured.
4
families of soft actuator compared
Pneumatic networks, fiber-reinforced, knit textile, artificial muscle
3
fabric prototype versions, the first one failed
Inflated at +200 mmHg
20-50
mmHg, the usual compression range for leg edema
My literature review
Overview
Elephantiasis, or lymphatic filariasis, starts when a parasite spread by mosquitoes blocks the lymph channels. Fluid builds up in the leg, the leg swells, and the swelling keeps coming back. Today's answers are manual drainage, crepe bandages, compression wraps and air-pump sleeves.
I looked for a portable, wearable device that drains the fluid from the swollen site and reduces how often the swelling returns. The idea I settled on is a bandage that does the squeezing itself.
From my research deck: swollen legs from elephantiasis (photos: Institute of Applied Dermatology) and the need I wrote from them.
DISCOVER
What exists, and which muscle
Care today is manual drainage, crepe bandages and garments, manual compression wraps, and air-pump sleeves that inflate in sequence or by gradient. I wanted a wrap that is portable and light and still controls how hard it squeezes.
I compared four families of soft actuator: pneumatic networks, fiber-reinforced actuators, knit-textile actuators and artificial muscles. I picked the thin McKibben muscle, a rubber tube inside a braided sleeve that gets shorter and wider when air goes in. It is strong, can be knitted into fabric, breathes, is cheap and light, and is safe to wear.
The pressure targets came from the literature, not from my own tests. For leg edema, 20 to 50 mmHg is the usual range, with cycles of 15 to 30 seconds of compression and 40 to 60 seconds of rest.
The solutions I reviewed, from manual wrapping to pneumatic sleeves, and the actuator families I chose between. Product photos belong to their makers.
DEVELOP
The idea: weave the muscle into the bandage
The muscles run one way and threads cross over and under them, like cloth. When air goes in, the muscles get thicker, the threads are pulled into tighter curves, and the fabric gets shorter across its width. That squeeze is exactly what a bandage has to do. The weave principle follows published work on active textiles made of thin McKibben muscles.
My aim was a wrap that goes on and off easily, is flexible and breathable, can be made at scale, and controls how hard it squeezes. It would also save the repeated cost of crepe bandages.
Left: my concept sketch, tube and sleeve woven into a band, loose when empty and tight when inflated. Right: how a McKibben muscle shortens under pressure.
DELIVER
Prototypes
I built fabric prototypes to see whether the weave works. Version 1 failed. A nylon thread with a PET sleeve barely inflated even at 250 mmHg, because the tube was too hard and the nylon and PET did not grip each other.
Version 3 inflated at +200 mmHg and worked as a thin, flat muscle sheet: a 1 up 1 down weave with 19 warps and 34 wefts, which expands along the warps. A second weave (1 down 2 up, 14 warps and 45 wefts) curves instead. I have not measured the pressure it puts on a limb, and nobody with lymphedema has tried it.
Left: version 1, which failed. Right: version 3, a flat woven muscle sheet.
Key takeaway
Weave the muscle into the bandage, so the bandage itself does the squeezing.
Reflection
It moves, and that is all I can claim. I did not measure the pressure on skin, the prototypes are small swatches, and no patient has tested it. A working bandage needs all three.
Grounded in
Weave principle: Kurumaya, S., Nabae, H., Endo, G., & Suzumori, K. (2019). Active textile braided in three strands with thin McKibben muscle. Soft Robotics, 6(2), 250-262. https://doi.org/10.1089/soro.2018.0076. The therapy ranges and the full literature review are in the Behance project.
