[Let's study exponential function related to anesthesiology by using computer graphics--Part I: Wash-out exponential function].

A computer simulation is used to analyze physical or biophysical changes related to anesthesiology mostly by computer oriented experts. Recent development in a personal computer and its program, however, has made it possible for more anesthesiologists to have an experience of computer analysis. For example, graphic expression of exponential functions can easily be obtained by using a computer program, such as "Graphnote" by Fukutake Pub. Co. In this literature, the author first explained the wash-out exponential function. Then estimation of changes in the hematocrit and serum protein concentration associated with blood loss during surgery was given as an example of biophysical phenomena related to anesthesiology, to which the wash-out exponential function is applicable for mathematical simulation. Besides, the author demonstrated the way to draw exponential function curves by using "Graphnote", so that the readers can express the curves by themselves.