J025014 マットレスに押し付けられた骨突起部軟組織の体積変化による微小血管の変形解析([J02501]生命体統合シミュレーション(1))

Abstract

Effects of volume reduction of the soft tissues, i.e., skin and subcutaneous tissue, at a bone prominence on the deformation of microvessels were investigated by finite element method. A hyperfoam model with viscoelasticity with Poisson's ratio of 0.1 or 0.2 was postulated to simulate a volume reduction of the soft tissues with vascular deformations under compression and stress relaxation. For the model with Poisson's ratio of 0.1, a load on the bone corner was adjusted so that the skin surface pressure on the mattress was near 10 kPa. The cross sectional area of the vessels decreased largely with a volume reduction by 75% near the midpoint of the circumference for the microvessel in the subcutaneous tissue and by 60% for that in the skin. Regional volume reduction was at most 30%. A model with Poisson's ratio of 0.2 obtained a relatively smaller deformation of microvessels. Compared with small deformations of the vascular cross sections for an incompressible hyperelastic model with viscoelasticity, it is concluded that the volume reduction of the soft tissues may play an important role to cause a pressure ulcer.