Catheter system for potassium measurements in medical application

In critical care the blood potassium concentration is an important parameter to characterise the patients condition. To switch from the common ex situ determination of potassium (mostly in serum) to the in vivo monitoring of it in whole blood opens new dimensions in the diagnostics but produce a number of problems to be solved. For the task a new potassium sensitive microsensor was developed using silicon technology. The abstract will discuss the manufacture and performance of the catheter-chip in respect to slope, reproducibility, reliability and long time stability in biological fluids.