Now, smart cushioning to prevent bedsores, postural defects
Scientists have now developed a smart cushioning sensor mat that will do away with the discomforts of lying and sitting by equalizing pressure selectively.
Anyone confined to a wheelchair or a bed has to deal with numerous complications. Frequently, they suffer from bedsores or decubitus ulcers as physicians call them. Bony prominences, such as the sacrum, coccyx and ischium, are especially endangered spots. Unrelieved pressure can lead to tissue necrosis. Damage can extend into the periosteum and, at the worst, into bones themselves. The ulcers are entryways for germs, which can trigger sepsis.
While hitherto available passive aids such as air, gel or vacuum cushions relieve pressure, they do not relieve the affected area optimally. Some patients are also unable to actively control the distribution of pressure and alleviate their own suffering. They are dependent on others for help.
Researchers at the Fraunhofer Institute for Factory Operation and Automation IFF in Magdeburg are endowing textile cushions with the capability to “feel” by outfitting them with smart sensor systems.
“Every person has a unique build, which must withstand differing compressive loads,” said Martin Woitag, research manager at the Fraunhofer IFF.
“Our sensor mat made of ordinary foam and conductive threads automatically detects how a person is sitting or lying, and automatically equalizes the pressure at endangered points by activating an actuator. One hundred measured points on a typical seat suffice to do this.”
The trick is that the tactile sensor mat functions based on the principle of a parallel-plate capacitor. Instead of plates, two textile components are employed, which form sensor cells arranged in a matrix. Conductive thread functions as an electrode. Sensor cells are mounted in commercially available foam at intervals of four centimeters.
The compression of a single cell varies the voltage and produces an electrical impulse. Measurement electronics connected to the sensor system analyze the data in real time, evaluate them and regulate air cushions located beneath the sensor system.