A METHOD AND A SYSTEM FOR THE IN VIVO DETERMINATION OF AN ELECTRICAL POTENTIAL DIFFERENCE

摘要

The in vivo determination of an electrical potential difference across a human or animal membrane of a fluid-containing cavity, such as the stomach (200), is performed by arranging (e.g. via an endoscope (201)) a measuring half cell (20) (electrode and electrolyte) in its entirety within the cavity and in contact with the cavity fluid, and arranging a reference half cell (50) in contact with a human or animal fluid outside the cavity, typically the blood, suitably via a catheter (87). The concentration of a species such as a H<+> concentration in gastric juice contributing significantly to a liquid junction potential between the measuring electrolyte and the cavity fluid is measured, preferably by means of a sensor such as a pH sensor (110), preferably arranged within the cavity, and a relevant correction of the potential difference measured is based on said concentration measurement.