Apparatus for the polarographic measurement of oxygen

US4120770A · kind A · utility

Assignee

• Max-Planck-Gesellschaft zur Föderung der Wissenschaften e.V. · US

Inventor

• Manfred Kessler · Dortmund, DE

Key dates

• Filing date: Jul 21, 1977
• Grant date: Oct 17, 1978
• Expiry date: Jul 21, 1997

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/48
• WIPO field: Measurement
• WIPO sector: Instruments

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 …