Optical assessment of skin blood content and oxygenation.

The alteration of blood flow in the skin and subcutaneous tissue due to mechanical loading is of great importance in the prevention of decubitus ulcers. A technique is described for assessing changes in blood content optically. The results indicate that such changes occur after loading even though the deformation is maintained constant.

Biomechanical concepts and effects.

Superficial tissue ulceration can be caused by the effect of mechanical loads acting on localised areas of skin and subcutaneous tissues. Be they low sustained loads applied for long periods or higher loads intermittently applied, the importance of the time factor has been recognised clinically by doctors and nurses. The significance of the type of loading and its magnitude in the damage of tissue is, however, not well agreed.