Biofeedback training for respiratory fluctuation of pupil diameter

Abstract

  Pupil diameter is known to be fluctuated by respiration as well as heart rate, and to be correlated to physiological and psychological state in human. Paying attention to this, we have proposed a new biofeedback training utilizing respiratory pupil-diameter fluctuation. Pupil diameters of subjects are measured by an eye-mark recorder and the values are feed-backed to the subjects. Along with the feedback, in the first step, ask the subject to control his/her own pupil diameters by his/her respiration voluntarily. In the next step, ask the subject to breathe coincidently to flushing of the LED arrays to evoke his/her convergence reflex to confirm whether the synchronization training between pupil diameter and respiration can be achieved or not. As results, by the feedback, pupil dimeters can be controlled partly by respiration and synchronization between pupil diameter and respiration can be achieved. For our future development, statistical study with a larger number of subjects should be scheduled both in physiological and psychological aspects.