The individual metabolic liver condition is of utmost importance for liver surgery, drug dosing, operation planning, and chemotherapy. Standard routines to assess information of the liver status are serum parameters and biopsys. Serum parameters provide unspecific and delayed information of the liver status, and biopsys provide only local information and are risky.

In collaboration with Prof. Stockmann we developed a system comprising of the LiMAx-test and a medical device (FLIP) to precisely assess the metabolic power of the liver from exhaled breath within minutes at bedside.

More than 10,000 LiMAx-tests were perfomed up to now (and growing every day).

The FLIP/LiMAx system consists of a metabolic test, the LiMAx-test, and a device, the FLIP device, that is developed for the LiMAx-test. Since a single exhaled breath provides changing concentrations and temperatures manipulation of the breath or selection of specific parts of the breath alters the outcome of measurements significantly on a high sensitivity level. The FLIP/LiMAx system solved all problems associated with breath handling and high-sensitivity gas detection, and allows for detection and analysis of a single breath in real-time.

Thus, the outcome of the FLIP/LiMAx system is realiable and reproducible, and is market by Humedics GmbH. The FLIP/LiMAx system measures the additionally exhaled 13CO2 due to metabolization of 13C-labelled methacetin in the liver cells. The typical 13CO2 curves show a fast increase upon 13C-methacetin application, followed by a maximum and a decrease of the signal or a plateau region on a time scale up to 60 minutes. The signal shape is indicative for the liver condition. The liver condition is the basis for liver therapy, clinical pathways, drug dosing, operations, etc.

Optimal liver condition shows the fastest increase accompanied by a high maximum, and a decrease of the signal. Reduced liver conditions show delayed signal increases with lower maxima and a plateau region. Thus, the rising of the signal and the maximum are indicative for the liver metabolic function.

Here, we show a statistical analysis of more than 10,000 measurements and the accompanied signal shapes.

There are other devices (cyan dots) that show different signal shapes than the FLIP/LiMAx system. These devices cannot be used to measure the LiMAx-test, since their outcome will deviate significantly from the published literature.