Abstract
The paper deals with possibility to measure vital reaction of a driver using reaction force of a seat. It is very useful, if the vital reaction can be measured without driver's consciousness. At first step of this research, driver's breath is examined as an example. The heart beat, breath, and the seat pressure are measured at steady state condition of driver on board. The relation between the seat pressure and driver's breath is examined using the frequency analysis result. Finally, it is shown that driver's breath can be measured using the seat pressure, and also shown the measuring position which is easy to identify.
