Diabetes patients often suffer from nerve and circulation problems in the feet, which can reduce their perception of pain. Whereas in healthy individuals the nerve pathways ensure that weight is automatically transferred from one foot to the other during prolonged standing, diabetics may not notice that their toes, heels or the balls of their feet are too heavily loaded. This could lead to the foot not receiving the relief, and pressure sores may develop unnoticed.
To ensure that poorly healing wounds don’t occur in the first place, researchers at the Fraunhofer Institute for Silicate Research ISC in Würzburg with support from industry partners and colleagues from the Fraunhofer Institute for Integrated Circuits IIS in Erlangen have developed a special stocking with integrated sensors. In total, 40 very fine, dielectric elastomer sensors measure compression load and distribution for diabetes patients, taking over the job usually performed by the nerves in their feet.
“Existing systems on the market measure the pressure distribution only on the bottom of the foot using shoe inserts,” explains Fraunhofer ISC research scientist Dr. Bernhard Brunner. “Our sensors are attached to the stocking’s sole, at the heel, the top of the foot and the ankle, so they can take readings in three dimensions.”
A pair of these smart stockings should cost no more than 250 Euros because the measuring system can be cost-effectively manufactured in series.
In total, 40 very fine, dielectric elastomer sensors measure compression load and distribution for diabetes patients.The technology used to in these stockings collects the measurement data and the controller transmits it wirelessly to a smartphone or tablet, which then informs the diabetes patient that it is time to change foot position or weight distribution. The prototype device has the electronics attached to the end of the stocking, and going forward the plan is to relocate them to a small, button-sized housing that can be detached with a hook-and-loop fastening strip. Moreover, the sensors must be made resistant to water and detergent.
The stockings themselves are made from a blend of cotton and synthetic fibers, making the fabric is breathable, moisture wicking and extremely comfortable to wear.
Beyond diabetics, this product could be used in sports and fitness, with joggers using it to analyze their running style and foot positioning. The researchers have already filed a patent application for their invention and will be presenting a prototype device at the forthcoming SENSOR+TEST 2015 Measurement Fair in Nuremberg (May 19-21).