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Brief Review of Existing Travel Aids for the Blind
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Most successful and widely used travel aid to date
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Detect obstacles on the ground, uneven surfaces, holes, steps, and puddles
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Very inexpensive, lightweight, small
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Disadvantages: Limited reach, no protection above waist.
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Electronic Travel Aids (ETAs)
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Laser Cane: optical triangulation with 3 laser diodes
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Disadvantage: requires active scanning by user
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Mowat Sensor: one sonar, handheld like flashlight
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Disadvantage: requires active scanning by user
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Common disadvantages of these ETAs:
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user must actively scan environment to detect obstacles
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user must actively “measure” obstacle to circumnavigate.
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SonicGuide: Mounted on spectacle frames
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One sonar transmitter between spectacle lenses, One receiver on each side
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Audio feedback indicates obstacles
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Disadvantage: acoustic feedback masks environmental cues, no protection from floor-level obstacles, downsteps, etc.
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