Apparatus for the polarographic measurement of oxygen

Abstract

Abstract The oxygen concentration (partial pressure) in a perfused medium, such as man tissue through which blood is perfused, is measured polarographically. The polarographic measurement process itself consumes oxygen, and tends to yield a read-out lower than the true concentration. Non-zero perfusion tends to replenish the consumed oxygen, thus counteracting the too low read-out, but the read-out is still lower than the true concentration. The uncorrected oxygen measurement is corrected by one factor to simulate a condition wherein perfusion is zero but oxygen consumption is non-zero, and by a second factor to simulate a condition in which the perfusion has its actual value but oxygen consumption is zero, thereby yielding an accurate oxygen read-out. A switchover device connects a polarography electrode and a reference electrode across a hydrogen-generating unit, and then a polarograhic hydrogen-measuring unit, and then a polarographic oxygen-measuring unit, in succession. The information concerning the wash-out of the generated hydrogen is converted into a corrective factor compensating for the non-zero perfusion. The other corrective factor is introduced to compensate for the effect of the non-zero perfusion upon the rate at which oxygen is consumed during the polarographic measurement, by taking into account the diffusion resistance of the type of tissue involved.

Inventors

• 👤 Manfred Kessler

Bibliographic Details