Can We Measure Visceral Fat With Bioimpedance Spectroscopy Now?
INTRO
Non-invasive measurement of visceral fat tissue with bioimpedance spectroscopy. Definition of bioimpedance spectroscopy.
Bioimpedance spectroscopy description
Bioimpedance spectroscopy (BIS) is a non-invasive measurement method. The aim is to measure the complex, frequency-dependent impedance in a spectrum. Between typically 1 kHz and 1 MHz, for example, to determine body composition.
Bioimpedance spectroscopy measurement methods
The BIS uses the established four-point measurement. In which a small, harmless alternating current is fed in between two electrodes. And the resulting voltage drop is measured at two further electrodes. In this way, it is possible to eliminate the electrode-skin impedance. And determine only the body impedance.
Body tissues Impedance
In general, the impedance of body tissues is frequency-dependent. This can be described by modeling body tissue. As a suspension of cells in a conductive fluid. The so-called extracellular space. The cells themselves are modeled. By the intracellular space and a double lipid layer, the cell membrane.
Extracellular and intracellular space higher frequencies
Electrotechnically, this can be transferred to the Cole model. This results in a different current path depending on the frequency. While the current flows primarily through the extracellular space at low frequencies.
The current flows through both. The extracellular and intracellular space at higher frequencies. This results in a semicircular impedance curve.
Application of bioimpedance spectroscopy
The BIS is usually used when the composition of visceral fat tissue is to be inferred. An example from everyday life is the body fat scale. Current research areas are, for example, in the field of lung monitoring.
It is assumed that the analysis of BIS data can be used to draw conclusions about existing diseases. Such as pulmonary edema or pneumonia (inflammation). Especially for seriously ill patients, non-invasive detection of these diseases would be desirable.
CONTENT:
- Bioimpedance spectroscopy description
- Bioimpedance spectroscopy measurement methods
- Body tissues Impedance
- Extracellular and intracellular space higher frequencies
- Application of bioimpedance spectroscopy