Medical & Biological Engineering & Computing

, Volume 55, Issue 1, pp 79–88 | Cite as

Skin stiffness determined from occlusion of a horizontally running microvessel in response to skin surface pressure: a finite element study of sacral pressure ulcers

  • Hiroshi Yamada
  • Yoshiaki Inoue
  • Yuki Shimokawa
  • Keisuke Sakata
Original Article
First Online:
Received:
Accepted:

Abstract

Pressure ulcers occur following sustained occlusion of microvessels at bony prominences under skin surface pressure (SSP). However, the mechanical conditions of the surrounding soft tissue leading to microvascular occlusion are not fully understood. This study determined the stiffness of homogenized skin with microvasculature at the sacrum that occludes microvessels at an SSP of 10 kPa (consistent with a standard mattress) and recovers from occlusion at 5 kPa (consistent with a pressure-redistribution mattress). We conducted two-dimensional finite element analyses under plane stress and plane strain conditions to determine the stiffness of the skin. The results for plane stress conditions show that the microvessel was occluded with a Young’s modulus of 23 kPa in response to an SSP of 10 kPa at the center of the sacrum and that the circulation recovered following a reduction in the SSP to 5 kPa. The resulting Young’s modulus is consistent with reported data. Our study indicates that the critical value of the SSP for microvascular occlusion is determined not only by the stiffness of homogenized skin with microvasculature but also by the intraluminal pressure, microvascular wall stiffness, and body support conditions.

Keywords

Capillary closure Finite element method Neo-Hookean material Pressure ulcer Young’s modulus 
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Copyright information

© International Federation for Medical and Biological Engineering 2016

Authors and Affiliations

  • Hiroshi Yamada
    • 1
  • Yoshiaki Inoue
    • 1
  • Yuki Shimokawa
    • 1
  • Keisuke Sakata
    • 1
  1. 1.Department of Biological Functions Engineering, Graduate School of Life Science and Systems EngineeringKyushu Institute of TechnologyKitakyushuJapan

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