iSonar: an obstacle warning device for the totally blind

Figures & data

Figure 1.  The obstacle detection with ultrasonic pulse.

Figure 2.  The ultrasonic echo pulse (left), the iSonar coverage area (right).

Figure 3.  The embedded software overview flowchart.

Figure 4.  The device's main component (left), iSonar's outside with a neck strap (right).

Figure 5.  A totally blind person with the device attached to his body (left), the volunteer in the simulated test field (right).

Table 1. The collision percentage and total travel time

	Collision percentage (%) (n=15)
Obstacle level	Only standard white cane	Standard white cane with iSonar	Difference
Overhead	73.33	13.33	+60.00
Chest	26.67	0.00	+26.67
Above waist	33.33	6.67	+20.00
Below waist	13.33	13.33	0.00
Whole body	20.00	0.00	+20.00
Total	33.33	6.67	+26.66
The average of total travel time	1:21.57	0:57.27	+0:24.30

Table 2. The iSonar performance satisfaction score

Evaluation items	Average Likert scale (Total=5)
Distance detection	3.87
Tactile feedback	3.53
Convenience	4.13
Accuracy	4.33
Shape and size	4.67
Product cost	4.27
Total	4.13