Hi,
I am assisting a a student with a project. He wants to create sort of a proximinity sensor for the "blind". That would assist vision impaired indiviual, who cant afford a seeing eye dog. It would be in addtion to the specialezed walking cane.
Any idea where to begin?
--- How about an ultrasonic SONAR which he wears on a hat which beeps one audible tone when it transmits and another when it receives? The blind guy will get an idea of range to a "target" by the time between the two different beeps and he won't get confused by which is which.
Ya might even call it the BatHat and send me $1 for each one you sell. Want a schematic?
-- John Fields Professional Circuit Designer
20 or 30 years ago "wireless world" magazine held a competition for electronic gadjets to help the disabled. The winner was an ultra sound transmitter/reciever array built into specticle frames the output was audio into earpieces on the frame legs.
Do I take it theat these proved no use in service, as I've never seen or heard of a blind person using one?
Paul Burke
They take some getting used to, and at least one user has complained that the old SonicGuide was heavy enough to hurt the ears if worn for any length of time.
Have a look at
IIRR one of my ex-girl-friends did a masters degree with Kay in New Zealand, back in the early 1960's, and the relatively bulky and primnitive device that her blind subjects used worked remarkably well.
Whether the OP could usefully get into competition with Kay is an open question - there is obviously some kind of problem with his device, and somebody coming at it from outside might conceivably be able to see some way of avoiding a problem that Kay hasn't be able to solve in some forty years of trying.
Kay ought to know about polyvinylidene fluoride as an ultrsound transducer - it's been around for at least thrity years - so that probably won't offer any breakthroughs.
-- Bill Sloman, Nijmegen
I would guess that a blind person has a highly developed sense of hearing and uses that hearing to navigate the environment. So any device that beeps and interferes with "hearing" the environement might be counter-productive...
But an ultasonic ranging device that created some kind of tactile or other output might be helpful...
Mark
My wife has tried a few of them on, and finds that they all driver her crazy. The high tones, constantly shifting and changing, hurts her ears, and most of them are pretty bulky and heavy.
Charlie
Hello,
This is a very challenging area that interested me some twenty-five years ago as my uncle who inspired my electronic gadget making from an early age was also blind and going deaf as the years progressed. But that's another story. Today Lev Termen a great thinker from the early twentieth century influences my experimentation in the area of proximity detection. A novel approach of what you're attempting to do might just be hidden in my current research. What ever path you choose let the project guide you and don't force it into a preconceived box.
RS Theremin
Good Luck,
Temecula CA.USA
The device Kay has developed illuminates the area in front of the user with ultrasound, and detects the reflected signal with two separate (and separated) receivers. The receiver outptus are combined to produce audio-frequency difference signals which the useres can learn to process to acquire quite a good image of the area in front of them.
Charlie Edmondson's wife would seem to be representative of the people who can't or won't learn to process the noise into images. The claim that the units are bulky and awkward also comes up in the comments of people who like the devices, and would seem to be something that modern electronics could do a lot about.
-- Bill Sloman, Nijmegen
I had occasion to handle a blind guy's stick one time, and the end wasn't just a plain stick - there was a flat washer mounted to the end of the stick with some sort of rivet, loosely, so that when the tip hit stuff it made more noise than just a stick tip hitting something. I believe they actually hear that, and do a form of echolocation. Heck, I could close my eyes, and _I_ could navigate reasonably well by listening to the stick.
Cheers! Rich
Hello Rich,
I agree, nothing could replace the cain for simple effectiveness. I think what many blind people want in a navigational aid is not identifying that a block wall is 10 feet in front of them rather a person about two feet away in the Shopping Mall is about to get their leg tapped. Listening is another effect personal tool so adding noisy navigational gadgets are going to interfere with this.
Such a challenging project and all these engineers ARE holding back... hum
Temecula CA.USA
Unfair and innaccurate. John Fields was right there in the very first reply and asked the OP if he wanted a schematic.
It has been 8 days, and the OP has not responded. If anyone is holding back, it's the OP, who has not seen fit either to give John the courtesy of a reply or to comment on any of the other respondent's posts. But for all you or I know, the OP and John may be working merilly away at this via Email.
You owe Fields an apology. He was right there, 22 minutes after the OP, with an offer to help. And if you've followed the various threads, you'd know that the circuits John provides are *good*.
Ed
Hello Ed,
I apologize John, your stamina and knowledge in these electronic newsgroups is legendary. I noticed this immediately when I arrived two weeks ago.
When I made my statement it was to gather other methods or ideas from this vast news knowledge base that might be practical for this type of application. I am always hunting for a better idea. It's personal. (:
Kind regards,
Temecula CA.USA
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