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TRANSCRIPT
VSN/1
Performance evaluation of voluntary blinking detection of versatile single switch VSN/1 using
a photo-reflective sensor
○
JALSA JALSA
IT
Daisuke YAJIMA, Niigata University Toyohiko HAYASHI, Niigata University Yoshinobu MAEDA, Niigata University
Tetsuya WATANABE, Niigata University Yuko WAKABAYASHI, Japan ALS Association Prefecture branch in Niigata
Takashi ODA, Japan ALS Association Prefecture branch in Niigata Satoshi WATANABE, Ftech company limited
Akira ABE, Ftech company limited Toshimitsu YAMAGUCHI, Niigata IT Support Center for Persons with Disabilities
Key Words: communication support, ALS, photo-reflective sensor, blink, single switch
1.
ALS
(1)
ALS
(2) (3)
VSN/1(4)-(6)
(4)
ALS
2. VSN/1
3. ALS
4. 5.
2. VSN/1
2-1
Fig. 2 Positioning of the sensor array relative to one of the
subject’s eyes by means of a 3-DOF sensor
attachment secured to an eye-glass
Fig. 1 Photo-reflective sensor array of VSN/1 for blinking
detection fixed on an eye-glass lens, consisting of
three sensors denoted as CH1, CH2 and CH3
CH1
CH2
CH3
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LED
LED
3[mm] 4[mm]
2[mm] NJL5197K-F25(4)-(6)
3
Fig.
1 Fig. 1 3
1 3 CH1 3
3 Fig. 2
12[g](3) 26[g]
2-2
(4)
Fig. 3 CH2
a
b, d, e
c
Fig. 3
Fig. 4
±Vt
2
VRMS 3 Vt = 3×
VRMS
Vt t1 -Vt
t2 tb = t2 - t1
tb
10 3
0.5[s]
tb tmin tb≦tmax
tb
tmin tmin = 0.5[s]
tmax tmax = 3.0[s] tb
tmin tb≦tmax t2
Fig. 4
2-3
2-2 3
3 1
2
Vp Vt
3 Vp
Vp
3 Vp
Vmax
Vpth
Vt tb
Vt
Vt
Vp
Vpth Vpth Vmax
Vpth = Vmax / 2 Vt
Vp≧Vpth
3. ALS
3-1
ALS
VSN/1
(4)
ALS
Fig. 3 An example of signal waveform obtained from the
photo-reflective sensor
Fig. 4 A waveform obtained by differentiating the original
one shown in Fig. 2 and temporal parameter tb defined
by using an amplitude threshold Vt: Other thresholds
Vpth, tmin and tmax are used for distinguishing voluntary
blink from other ones.
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ALS
3-2 3-4
3-2
Fig. 5 ALS 76
1 2
CH2
15[Hz]
20
3-3
3-1
Fig. 6
→ → →
5 10
Visual C++ Microsoft
1 1
12 1
3 3
3 9 3
5
4 1 1
2 1
3
4 1 2
Fig. 6 1
12
3
Fig. 2
3-4
3
2
6
Table 1 n1 n6
n6 n1 n5
5
1 {(n1+n4) (n1+n2+n3+n4+n5)}×100[%]
2 {(n3+n5) (n1+n2+n3+n4+n5)}×100[%]
3 {n2 (n1+n2+n3+n4+n5)}×100[%]
4 {n1 (n1+n2)}×100[%]
5 {n4 (n3+n4)}×100[%]
12
1
4.
3-4 3
Fig. 5 Experimental setup
Fig. 6 Visual stimulation for triggering the voluntary blink
displayed on a computer screen: The color of a
circular region changes from red to green as a trigger
to start the blink.
Table 1 Counting of several events defined as a combination
of input motion and output of the switch
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97.3±0.28[%] 2.2±0.47[%]
0.5±0.33[%] 95.4±3.21[%]
97.5±0.53[%]
t
Fig. 7
Fig. 7-(a) a, c, d
1 b
(b) Fig. 7-(a)
b
5.
VSN/1(4) 94.9±2.05[%]
1.8±1.56[%] 3.3±1.30[%]
97[%]
95[%]
VSN/1 ALS
4.
Fig. 7-(a) b
Fig. 7-(b)
tb
1
2
Vp Vp Vpth
0.5[%]
VSN/1 ALS
(7) VSN/1
(6) VSN/1
ALS
ALS
(1) e-AT , -
-, pp. 21-22, 73-95, , 2003.
(2) , , , ,
, , no. 62, pp. 253-259, 2009.
(3) ,
, 8
, vol. 3 K-007, pp. 533-539, 2009.
(4) , , , , ,
, , ,
VSN/1
, 7
, pp. 63-64, 2009.
(5) , , , , ,
ALS
, WIT2006-125,
vol. 106, no. 612, pp. 115-120, 2007.
(6) , , , , ,
, MBE2007-123, vol. 107, no. 541,
pp. 73-76, 2008.
(7) , , , , ,
ALS ,
, vol. 43, no. 12, pp. 1298-1305, 2009.
(a) An example of signal waveforms caused by periodic
blinks, observed in periods from “a” to “d”
Fig. 7 An example of malfunction resulted from a signal
waveform caused by a periodic blink
(b) The waveforms obtained by differentiating the original
one shown in (a)
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