Biological state eliminating apparatus and method

Abstract

A biological state estimating apparatus includes a pair of electrocardiographic electrodes, a photoplethysmographic sensor, and a controller that includes a peak detecting section, a pulse transmission time measuring section, a correlation information storing section, and a biological state estimating section. The electrocardiographic electrodes detect an electrocardiogram signal and the photoplethysmographic sensor, which has light-emitting and light-receiving elements, detects a photoplethysmogram signal. The controller detects peaks of the electrocardiogram and photoplethysmogram signals and determines a pulse transmission time from the time difference between the respective peaks of the photoplethysmogram and the electrocardiogram signal. Memory stores information determined in advance based on the relationship between pulse transmission time and biological state. The controller further estimates the biological state of the user on the basis of the pulse transmission time, and the correlation information stored in the correlation information storing section.