PURPOSE: To obtain a physiological effect, to reduce blood pressure rise just after start of bathing, and to promote blood circulation in a shortest time by stopping a micro bobble generator and starting up an ordinary bobble generator when the face that change quantity of a skin surface temperature is made smaller than a reference value is decided.
CONSTITUTION: At a definite time interval set by a timer, a difference between the skin surface temperature measured one time ago and the skin surface temperature measured at present is obtained. In such a way, a change quantity detecting means is composed of the timer, a voltage holding circuit 23 and a subtracting circuit 24. An output voltage ΔT of the subtracting circuit 24 is inputted to a comparator 25 which is a deciding means, and a largeness relation between a reference voltage ΔT0 set by a reference value setting part 26 and the voltage ΔT is compared. While the reference voltage ΔT0 is higher than the output voltage ΔT of the subtracting circuit 24, a micro bobble generator 11 is selected by a switching device 13, and when the output voltage ΔT of the subtracting circuit 24 is made smaller than the reference voltage ΔT0, the switching device 13 selects an ordinary bobble generator 12 instead of the micro bubble generator 11.
YAMADA HAJIME
SHIMADA YUKO
