Conclusions From the analyses and considerations, the conclusions of this paper are followings; u (1) We measured I/O responses of human system, states of human systems like amounts of grouped a waves, cardiac rhythms and winking under a simple HCI task. (2) The all measured data are changing dynamically. (3) It is possible to represent the response of human systems as a function of factors indicating states of human systems. (4) Amounts of grouped a waves, cardiac rhythms, and numbers of winking are one of the good factors to determine the states of human systems. (5) A results of (4) show the importance of studies about human states to design a suitable method to future HCI. (6) A flexibility or fluctuation is one of important characteristics of future HCI.