Eye tracking technology has been continuously researched for application in various fields. In the past, studies have been conducted to interpret eye movements in 3D space in order to solve the problem of not being able to find the centre of rotation of the eye. In this paper, we propose a novel pre-processing method for eye-gaze tracking by monitoring the front of the face with a camera. Our method works regardless of the distance between the eye and the camera. The proposed method includes an analysis technique that simplifies conventional three-dimensional space analysis to two dimensions. The contribution this work presents is a method to simplify gaze direction detection. The errors in our model’s estimations appear to be under 1 pixel. In addition, our approach has an execution time of less than 1 s, enabling an adaptive model that responds to user movements in real time. The proposed method was able to overcome various problems that methods in existing studies still suffer from, including accurately finding the rotational centre of the user’s eye-ball. Moreover, even when a user’s pupil can only be monitored from a distance, our approach still makes it possible to produce accurate estimations.

The purpose of this study is to suggest sound biofeedback, which is a new technique of early stress relief effect by observing change in the heart rate variability (HRV). The sound biofeedback imitating heart rate of the comfortable and stress state is termed parasympathetic stimulation sound (PSS) and sympathetic stimulation sound (SSS), respectively. Twelve subjects were selected without previous history of cardiovascular diseases and mental illness, such as arrhythmia, myocardial infarction, depression and panic disorder. To confirm the changes in the low-frequency (LF), high-frequency (HF) and LF/HF values of HRV as stress evaluation indicators, the HRV of subjects was measured by photoplethysmogram. Signals were processed using the peak detect algorithm, and fast Fourier transform. Results were obtained using power specific densities. During the PSS stimulation, the LF/HF tended to decrease generally. On the other hand, during the SSS stimulation, LF/HF tended to increase. The LF/HF Mean change value ([Formula: see text]) using the PSS stimulation is similar to the effect of Transcutaneous Vagal Nerve Stimulation (tVNS). In addition, the quantitative effect of sound biofeedback was confirmed by judging changes in the parasympathetic and sympathetic nerves in the autonomic nervous system (ANS) through [Formula: see text]-score normalized data. These experimental results suggest that sound biofeedback has the same stimulation location and clinical applicability as tVNS. As a result, sound biofeedback may be used as a new method for stress reduction.

No abstract

No abstract

No abstract