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R. Reihsner, R. Beer, J. Eberhardsteiner, H. Millesi:
"Neuentwicklung einer Prüfmaschine für zweiachsige Festigkeitsuntersuchungen an anisotropen weichen biologischen Geweben mit Anwendungsbeispielen";
ÖIAZ - Österreichische Ingenieur- und Architektenzeitschrift, 143 (1998), 6; 262 - 266.

Wound healing after incisions of human skin depends on their orientation to the 'Langer cleavage lines' which are often described as lines of minimal estensibility of the skin. In order to investigate the correlation between the biomechanical anisotropy, parametrized by extensibility and direction dependent strength, and, on the other hand, clinical experience of the wound healing process depending on the design of incisions performed for example for skin grafts, a testing device for the determination of two-dimensional biomechanical behavior of skin specimens was developed. This testing equipment allows the determination of the biomechanical anisotropy of human skin with the aid of twelve loading axes being designed to apply displacements in radial and tangential orientation to the sample circumference. This original circumference - before excision of the sample - has been chosen as a circle with a diameter of 30 mm. Agter excision the sample circumference shrinks nearly immendiately (practical elasticity) to a ellipse with its long acis coinciding with the orientation of the 'Langer line'. After extending the sample to its in-vivo configuration (first test step) and the determination of the corresponding loads which are regarded as a measure of the in-vivo acting forces, a strain controlled program is applied (second test step). As an example, in this paper a comparison of biomechanical behavior of specimens from the sulcus genitofemuralis region originating from different sites was based on radial strains.

Keywords: mechanische Anisotropie, menschliche Haut, weiche Gewebe