A Digital Model for Determining Oxygen Consumption in Tissue

Abstract

Tissue oxygenation models based on the Krogh cylinder geometry have often been used to determine oxygen distribution in various tissues, especially brain and muscle. Often, the quantity of interest is the partial pressure of oxygen (pO2) at the point in the tissue farthest from the arterial end of the capillary. This point is designated the “lethal corner” since it corresponds to the least oxygenated point in the tissue and is therefore theoretically at the greatest risk of becoming anoxic. Generally, assumptions are made regarding the dynamics of oxygen transport within such a geometry and appropriate partial differential equations are written to describe the system. Given a set of values, including tissue cylinder radius, length of capillary, metabolic rate and others, a solution can be obtained by programming the equations on a digital and/or analog computer. The solution to the equations is the pO2 at any point in the tissue or capillary cylinder.