pH electrodes, ion-selective electrodes, and oxygen sensors: Electrochemical sensors used in the medical field

Current blood analyzer can combine pH sensor, ion-selective electrodes for potassium, calcium, sodium, carbon dioxide, and other ions and oxygen sensor with other type of sensors for blood. Several are hand-held with a disposable cartridge containing the blood sample. The tendency is to further miniaturize sensors and replace PVC in the ion-selective electrodes with biocompatible polymers for in situ and long-term monitoring, and to miniaturize the blood analyzers for faster determinations. A basic knowledge of common electrochemical sensors is necessary in order to understand the strengths and limitations of the methods. While pH electrodes is a mature field, the possibilities of new sensors from polymer membrane ISEs is still not as developed. With combinations of sensors, new understanding of the techniques will occur.