In the figure, a circulatory-organ-relating-information obtaining means 70 iteratively obtains, as a sort of information relating to circulatory organ of a living subject, a degree of sharpness KL of a low-frequency peak L of a frequency spectrum obtained from the heart rate values HR determined based the ECG signal SM2 supplied from the ECG device 34, and/or a degree of sharpness KH of a high-fre