چكيده به لاتين
The appropriate body support in both sitting and lying positions, due to the long contact periods during day and night, is an important issue. This becomes even more important for patients or people who are bound to chairs and beds because of various conditions. For these individuals, in addition to comfort, the risk of developing pressure sores is a decisive factor.Tissues in the gluteal region are susceptible to this type of wound due to the anatomy of this region and especially due to the thrust of the bony parts in weight bearing positions. Cushions, as the surfaces in direct contact with the body play a major role in the best possible distribution of tissue stress and hence their design and selection is of great importance. One of the cushion types that are currently attracting attention are air cell based cushions.
Here we have employed the finite element method as a suitable tool for solving internal tissue stresses and strains during tissue-cushion interaction. The interaction between a slice of gluteal tissue around the sacral region in a decubitus position and different types of cushions was studied through 7 tissue-cushion finite element models in a semi-2d analysis. 3 of these 7 models had different types of foam as cushions and the rest contained air cell cushions. This problem was simulated in CAE and solved by the explicit dynamic solver of Abaqus. Stresses and strains were computed as part of the solution in addition to the final deformed configuration and a comparison between all models was performed. The figures show a better tissue stress distribution and lower maximum stress and strain up to 83% and 34%, respectively, in models with air cell cushions. This finding, considering the correlation between pressure ulcers and tissue stresses, means longer safe periods without the occurrence of ulcers.
