80 - Mechanical Properties of the Support Surfaces Used in Intraoperative Period
Description: Problem /
Purpose: There is a range of materials with viscoelastic properties such as polymers, polyurethanes, polyethylenes that are used in the fabrication of support surfaces (SS). However, little is known about its mechanical behavior. Literature Review: There is no evidence in the literature comparatively evaluating such devices for durability and mechanical characteristics to select lower-cost, high-quality polymer equivalent materials. Also, the lack of specification of the SSs used in the studies becomes a limitation on their replication in clinical practice. Hypothesis: Viscoelastic polymer has higher durability, creep resistance, indentation strength, fatigue strength compared to other materials.
Objective: To compare the mechanical properties (permanent compression deformation, indentation force, dynamic fatigue, and durability) of the support surfaces. Conceptual Framework: The characteristics of a product, which matches a consumer good intended for human use, are determined by specific tests. In the case of flexible foam mattresses, these standards are governed by the Brazilian Association of Technical Standards (ABNT). International standards also determine these parameters, such as the standards described by the American Society for Testing and Materials (ASTM). Methodology: experimental laboratory research. SSs (sealed foam at densities 28, 33 and 34; soft foam at densities 18 and 28 and viscoelastic polymer) were characterized for density, hardness, permanent compression deformation, indentation force and dynamic fatigue. Data Analysis: Assays were performed following ABNT Standards 8797, 9176, 9177 and ASTM D 395-97.
Results: Soft foam showed higher deformations compared to sealed foam and viscoelastic polymer. The viscoelastic polymer showed deformation similar to sealed foam D45. Soft D18 and sealed D28 foams showed lower resistance to force application in the indentation force test. Viscoelastic polymer and sealed foam D45 showed less loss of indentation strength when performing the fatigue test, indicating that these SSs are more resistant to use according to the standards used. The most durable SSs were viscoelastic polymer and foam sealed. Conclusions /
Discussion: Viscoelastic polymer and sealed foam D45 showed less deformation, higher strength to the application of force and less loss of indentation force when performing the fatigue test, indicating that these SSs were more resistant to use. Perioperative Nursing Implications: The results found may support further discussions about the best material to be used to make low cost, more wear-resistant support surfaces.
Co-Authors: Karoline Faria deOliveira, Cleudmar Amaral deAraujo, Maria Helena Barbosa