"Smart patch" will prevent the formation of pressure sores
Engineers at the University of California at Berkeley, together with colleagues from the University of San Francisco, have developed a "smart patch" that uses an electric current to detect tissue damage invisible to the eye that precedes the formation of bedsores.
The head of the study, Associate Professor Michael Maharbiz, explains the principle of operation of a smart patch that allows detecting pressure sores at the early stages of formation.
Bedsores occur in cases where prolonged pressure interferes with the normal blood supply to the skin. The areas of skin that cover protruding bones, such as the heels, the lateral surfaces of the pelvis and the coccyx, are most susceptible to the formation of pressure sores. Patients who are unable to move independently for various reasons are at the greatest risk of developing bedsores. Bedsores are associated with fatal septic infections and increase the likelihood of death of patients by 2.8 times. In many cases, the appearance of signs of bedsore on the surface of the skin indicates the irreversibility of the process.
Researchers working under the guidance of Associate Professor Michael Maharbiz have developed a device capable of detecting changes in the electrical conductivity of tissues that occur at the initial stages of the death of healthy cells. Elimination of chronic pressure at this stage is sufficient to prevent the development of bedsores.
The device is a thin flexible film superimposed on the surface of the skin, on the surface of which dozens of gold electrodes are applied. Weak electrical discharges emitted by the electrodes create a spatial map of the underlying tissue. This map is visualized using a technology that registers differences in the frequency of electric current pulses and is known as impedance spectroscopy.
The researchers explain that the membrane of a normally functioning cell is relatively impervious to electric current and acts as an insulating shell for the cell contents conducting electricity. However, the integrity of the membrane of a dying cell is violated, which allows electrical signals to penetrate into the intracellular space.
To test the effectiveness of the smart patch, the researchers simulated pressure sores by gently squeezing the bare skin of rats between two magnets. The magnets were left on the skin of animals conducting normal activity for one or three hours. The restoration of blood flow after the removal of magnets led to the development of local inflammation and oxidative damage, increasing cell death.
The smart patch was used to obtain data on the condition of the damaged area once a day for at least three days. It made it possible to register changes in the electrical resistance of tissues corresponding to an increase in the permeability of cell membranes, indicating massive cell death. As expected, one hour of pressure resulted in moderate reversible tissue damage, whereas a three-hour period of pressure caused more serious irreversible damage.
The researchers exerted pressure on the skin of rats of different duration, which led to the formation of pressure sores of varying severity. An orange hexagon corresponds to a smart patch applied to the skin, while a circle drawn with a dotted blue line corresponds to a zone subject to pressure. The figure shows examples from top to bottom: A – irreversible damage, B – reversible, when, thanks to the sensitivity of the smart patch, it is possible to detect the beginning of the pathological process before visible changes appear on the surface of the skin, and C – the normal condition of the skin.
The authors are very optimistic about the future of their development. They note that the miniaturization of technologies and the deepening of knowledge about the body's reactions to diseases and injuries make it possible to create very useful devices in the form of patches. It is quite possible that in the future, to obtain important information about the patient's health status, it will be enough for the doctor to stick a "smart patch" on his skin.
Article by Sarah L. Swisher et al. The impedance sensing device enables early detection of pressure ulcers in vivo published in the journal Nature Communications.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on UC Berkeley materials:
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