Researchers have a real challenge trying to construct any sort of
theoretical model when the building blocks are, at the very least,
divergent ideas. Having said that, I'm going to make the job even more
challenging.
First, I think that it would be a real mistake to model any future travel
aid too closely to dog guides, or canes for that matter. The real
questions that must be answered are these: What information do we already
get from canes, dogs, and from other sources; what information are we
not getting that would significantly enhance our ability to travel
perhaps with less training, and what would we be willing to pay in terms
of money, inconvenience and appearance to get that information. There
are probably other, more specific questions, questions that need to be
answered as well, but these would be a good start.
What information do we get from canes and dogs? Since I am a cane user,
I'm going to confine my comments to that. The obvious information
includes change in surface (grass to cement), change in level (stairs,
curbs, hills), and whether the path ahead is clear. What is less obvious
is the role of the cane as a sound source. The experienced blind
traveler can use the echos that result from the tapping of a cane and
other sounds to extract more information from the environment. I rarely
need my cane to locate a flight of three or more ascending stairs,
because I can usually hear them. Open or deeply set doors in a hallway
can usually be heard as well as detected by the cane. One can usually
tell whether one is entering a door leading to stairs because the general
lack of carpeting results in a great deal of echo. Since the ability to
hear some of these effects is dependent upon one's hearing, not all
travelers get the same information. These techniques can use
improvement. However, it should be understood that a travel aid that can
find an open door will not necessarily be seen as a major breakthrough.
What information do we need that we do not currently get? I feel that
the ability to locate objects at a greater distance than the length of my
cane would be useful but generally not essential. Most of us who use
canes have likely experienced the annoyance of having our faces "washed"
by a wet leaf suspended from a low-hanging branch, but I'm not sure how
much I'd pay to avoid this situation. It would be nice to get a detailed
enough image of a large hotel lobby to locate stairs that are located out
in the middle somewhere, but I am in hotel lobbies of this type so seldom
that I probably wouldn't pay much for it. In short, a travel aid that
would do the things I mentioned above would be useful but not essential
to many of us, unless it were low in cost.
What about cost, convenience and appearance? If an electronic travel aid
were to be intended to replace a cane, it would have to be extremely
reliable. That means that its power source would need to be stable over
a wide temperature range, -25 to 110 F. Since I live in Minnesota, any
such aid would need to function during all seasons reliably or it just
wouldn't be worth it. This also means that the mechanical construction
would have to be very strong as well. It was mentioned elsewhere that
some kind of track would have to be used to handle stairs and the like.
I question whether ar such a track would work for long with the slush and
salt that we often have on our sidewalks. I also would not want to worry
about leaving a track width of salt and other dirt as a trail when I went
in-doors. It may be that the earlier observation about feeding and
cleaning up after an electronic dog guide was incorrect. It may well be
more difficult to clean up after a device using a track. {grin}
Maintenance must be a consideration. The original cost of many devices
is far surpassed by the cost of maintenance. Could a person on a low
income afford to pay for maintenance?
I feel that the best approach would be to develop a device that is
primarily handheld. This would eliminate the need for wheels, tracks, and
the associated power-hungry drive motors. Beyond that, though, I am not
certain that the question of what information would make traveling
simpler has really been answered here or anywhere else. By that I
don't mean what would be nice, but rather what would really make a
difference. That is probably where our discussion really needs to center.
--
Steve Jacobson
National Federation of the Blind
3M Company
Internet: SOJACOBSON@MMM.COM
This archive was generated by hypermail 2b29 : Sun Dec 02 2012 - 01:30:03 PST