Method for Psychological Status Monitoring with Line of Sight Vector Changes (human Eye Movements) Detected with Wearing Glass

—Method for psychological status monitoring with line of sight vector changes (human eye movement) detected with wearing glass is proposed. Succored eye movement should be an indicator of humans' psychological status. Probability of succored eye movement, therefore, is measured. Through experiments with simple and complicated documents, relation between psychological status measured with eeg signals and the probability of succored eye movements is clarified. It is found that there is strong relation between both results in psychological status can be estimated with eye movement measurements.


INTRODUCTION
The number of blink increases in accordance with angrily nevus, excitations while it decreases in accordance with concentration, cares.In accordance with Asher & Ort (1951), fixed eye status is affected by emotional words stimulating human brain with eye jerk movement in horizontal direction, frequent blink, and eye close [1].Antrobus et al. (1964) said that eye movement when human actively think about something is much active than that when human think about something passively [2].Stoy (1930) also said that eye movement when human look at spatial materials is much active than that when human look at non spatial materials [3].Meanwhile, Greenberg (1970) said that optokinetic nystagmus increases when human calculation by heart for complicated calculations in comparison to that when human calculate by heart for simple calculations [4].These studies are conducted with users who do not move at all.As mentioned above, there is strong relation between psychological status and eye movement.In particular, succored movement has a strong relation to psychological status.Eye movements can be detected and tracked with camera images even if users are moving.By using glass mounting near infrared camera with near infrared light sources, acquired images do not affect by illumination condition changes and also it allows users' movements [5]- [10].Therefore, eye movement detection and tracking can be done through users' movement results in estimation of psychological status monitoring during users' movement.
The proposed method and system allows such this functionality of psychological status monitoring under users' movement conditions.Through experiments with simple and complicated documents, relation between psychological status measured with eeg signals and the probability of succored eye movements is clarified.It is found that there is strong relation between both results in psychological status can be estimated with eye movement measurements.
The following section describes the proposed method and system followed by experiments.Then final section describes conclusion with some discussions.

II. PROPOSED METHOD AND SYSTEM
A. System Architecture The proposed system consists of the glass which mounts near infrared camera with near infrared LED: Light Emission Diodes which are aligned surrounding to the optical entrance of near infrared camera.Figure 1 shows outlook of the glass while major specification is shown in Table 1.Outlook of the glass mounting near infrared camera with near infrared LEDs The glass is mounting two cameras, one is for acquiring human eye and the other camera is for acquiring the image at which user looks.As shown in Table1, camera has LED of light source so that eye movement can be detected and tracked without influence due to illumination condition changes Also, the glass moves in accordance with head movements so that the proposed system allows users' movement.www.ijarai.thesai.org

C. Preliminary Experimental Results on Gaze Estimation Accuracy
System starts with find the location of pupil.After pupil location is found, next is converts into gaze angle.As we see in Figure 3, the single camera is used and the position is mounted on user's glass.It means that between camera and display is separated each others.Because of this, should has the connector that will connect between camera mounted on user's glass and display monitor in order to obtain that what user's look is same position with pointer in display.In order to connect them, the calibration is required.After user wearing the glass, user looks at four corners on display.By using the adjustment method, the user's gaze output will correlate with the pointer.
Gaze estimation accuracy is measured at the middle center to horizontally aligned five different locations with the different angles as shown in Figure 4.The experimental result shows the gaze estimation error at the center middle (No.1) shows zero while those for the angle ranges from -5 to 15 degrees is within 0.2 degree of angle estimation error as shown in Table 3..Because the user looks at the center middle with 5 degree allowance results in 0.2 degree of gaze estimation accuracy.5 (a) and (b).Four students read the two documents in almost same conditions.students read two documents, eeg signals are acquired.The frequency components are analyzed with FFT: Fast Fourier Transformation.Then maximum frequency component is used for characterization of psychological status.

E. Preliminary Experimental Results of Maximum Frequency of eeg Signals
Eeg signals are acquired when a student is taking a rest and learn hard with e-learning contents.Maximum frequency of eeg signals are calculated at the same time.Figure 6 (a) shows an example of maximum frequency at when the student is taking a rest while Figure 6 (b) shows that at when the student is learning with e-learning contents, respectively.As shown in Figure 6, maximum frequency at when the student is learning is much higher than that at when the student is taking rest, obviously.

F. Experimental Results
Figure 7 shows eeg signals of the students A to D when they are reading the relatively simple document.Meanwhile, Figure 8 shows those for the students A to D when they read the comparatively complicated document.Each student shows a little bit different trend of the maximum frequency.Namely, each student feels difficultness or easiness of the document differently.The maximum frequency for the relatively simple document is below 10 Hz while that for the comparatively complicated document shows more than 10Hz in particular more than 15Hz for three students.Alpha frequency ranged from 8 to 13 Hz.Averaged maximum frequencies over the time for reading the relatively simple documents for the student A to D are 6, 7, 9, and 10, respectively.On the other hand, averaged maximum frequencies over the time for reading the relatively complicated documents for the student A to D are 23, 20, 15, and 14.Therefore, difference of maximum frequencies between relatively simple and comparatively complicated documents is significant.
Therefore, most students read the relatively simple document in a relax situation while most students read the comparatively complicated document in a irritated situation because their maximum frequency component shows beta frequency dominantly.Figure 9 shows the maximum frequency of eeg signal when the students read the two documents.Figure 10 shows the number of succored eye movement a second when the students are reading the two documents.Succored movements are detected with the acquired students' eye images through image analysis based on template matching.The number of succored movements for the relatively simple document is less than that for the comparatively complicated document, obviously.Furthermore, the difference of the number of succored movement between the two documents is dependent on each student.Furthermore, Figure 11 shows the remarkable moments of the maximum frequency when the students are reading the comparatively complicated document.In the figure, the first red circle is situated when the students read the word "Electroencephalogram" while the second red circle is situated when the students read the word of "ナルコレプシー" and the third red circle indicates at when the students read the word of " 双極子推定法", respectively.These words are totally new for the students so that they had to read again the words.The first red circle is situated when the students read the word "Electroencephalogram" while the second red circle is situated when the students read the word of "ナルコレプシー" and the third red circle indicates at when the students read the word of "双極子推定法", respectively.. IV.CONCLUSION Method for psychological status monitoring with line of sight vector changes (human eye movement) detected with wearing glass is proposed.Succored eye movement should be an indicator of humans' psychological status.Probability of succored eye movement, therefore, is measured.Through experiments with simple and complicated documents, relation between psychological status measured with eeg signals and the probability of succored eye movements is clarified.It is found that there is strong relation between both results in psychological status can be estimated with eye movement measurements.

Fig. 1 .
Fig. 1.Outlook of the glass mounting near infrared camera with near infrared LEDs

Fig. 2 .
Fig. 2.Outlook of the eeg signal acquisition sensor of brain catcher manufactured by Noroku Kaihatsu Co. Ltd. is used.

Fig. 5 .
Fig. 5. Two documents used for the experiments Fig. 7. Maximum frequency during the students read the relatively simple document Fig. 9.Maximum frequency of eeg signal when the students read the two documents

Fig. 11 .
Fig. 11.The remarkable moments of the maximum frequency when the students are reading the comparatively complicated document.

TABLE I .
SPECIFICATION OF NEAR INFRARED: NIR CAMERA Experimental Method The experiments are conducted with eeg sensor.Eeg sensor of brain catcher manufactured by Noryoku Kaihatsu Co. Ltd. is used.Outlook of the eeg sensor is shown in Figure 2. Major specification of eeg sensor is shown in Table2.

TABLE II .
SPECIFICATION OF EEG SENSOR

TABLE III .
GAZE ESTIMATION ACCURACY AT THE DESIGNATED VIEWING ANGLES