The invention is directed to a prediction device for use in combination with a human being where the human being issues data. The prediction device comprisesa means to acquire the data from inside or outside the human being for one or more time periods located in a time interval from a moment in the past to the present moment to obtain an acquired data set,a means to model the acquired data set as a geometric Brownian motion random process model to obtain a fitted random process model, anda means to predict a state of the human being using the fitted random process model to obtain a predicted state of the human being.
