Scientists at the University of Waterloo, in partnership with Myant Inc., have developed an inexpensive robotic sleeve designed to treat lymphedema through precisely-controlled compression via a microfluidic chip.
A common side-effect of breast cancer surgery, lymphedema causes fluid and proteins to build up in the tissues of the arm. Pneumatic or hydraulic compression sleeves are a common treatment, squeezing and releasing the arm to restore normal flow — but the devices are both expensive and cumbersome, leaving considerable room for improvement in the state-of-the-art.
"My definition of wearable is you can wear it and do whatever you want, and not be plugged into a wall," explains Carolyn Ren, co-author of the paper detailing a much lower-cost and more portable version of a robotic compression sleeve. "Bringing in the microfluidics field, we wanted to make the system battery-powered but without compromising the performance."
The microfluidic chip, built using a 3D-printed mold, has 16 individual channels, designed to offer varying resistance to create a timing delay as each chamber of the sleeve is inflated — inflating the ones lower down the arm first, in order to push fluid up and out of the arm. A traditional compression sleeve, the researchers claim, would require eight expensive valves to achieve the same — and cost thousands of dollars, where the team's prototype costs an order of magnitude less.
There are other advantages to the team's work beyond a dramatic reduction in cost, too. The sleeve is powered by a single 3.7V lithium-ion battery, making it portable, and its control system weighs less than an iPhone.
The team has proven the approach in concept using a 3D-printed forearm model and off-the-shelf hardware: 16 Adafruit pressure sensors connected to an Arduino Uno microcontroller, while the prototype control box uses an Adafruit air pump, SparkFun motor driver, two-way solenoid valves, and an Arduino Nano Every. Results proved promising, but human trials have not yet taken place.
The team's work has been published under open-access terms in the journal Biomicrofluidics, under open-access terms; patient recruitment is underway for human testing, with a view to patenting the technology and bringing it to market as a commercial product.