Prosthetic Senses

[SaxonViolence]

I was reading about a new gadget a few years ago.

 

Diabetics, Lepers and other folks with Neuropathy in their feet have a problem.....

 

They walk awkwardly, because the soles of their feet are numb, and they can'y feel pain. A small rock in a shoe, or even a fold in a stocking, blithely ignored all day, can result in some serious damage. Give it a couple or three days to fester unnoticed, and the numb-footed may be facing amputation.

 

But you know when you have a rock digging into your foot, or your stocking has bunched uncomfortably. Even if you don't immediately pause to remove the shoe, a strategic stomp or two will generally take care of the problem.....But first you have to be aware that there is a problem.

 

Okay, I saw this device--it is essentially a Doctor Shoals pad with eight or ten pressure sensors on it. Each sensor is connected via a wire, to an elastic garter about halfway up one's calf.

 

You may not get the garter on precisely the same way every time, so it is important that it be asymetrical--so your body can index it instictively.

 

Each pressure sensor causes one spot on the garter to give one tiny area on the leg, a tiny electrical shock--proportional to the pressure.

 

Well you would think that just a handful of sensors (I don't remember precisely how many) would give a rather crude approximation of what was going on with the sole of the foot. You would also think that you'd really have to concentrate very hard on the garter, and it would take a fair while to learn.

 

Wrong on all counts. Wear it for a couple days, and you will no longer consciously feel electrical tingles on your calf. It will feel to you exactly as if you were feeling your feet once again.

 

The Brain recognizes right off that the sensations on the ankle are causally connected with pressure to the feet, and it effortlessly decodes it.

 

One of the hardest feats of balance and flat-out athletic agility, is for someone with two above-knee amputations to learn to ride a bicycle.

 

It takes long training, but it can be done--though probably not by everyone.

 

With the addition of just two dime-sized pressure sensors--one on the Ball of the Foot, the other on the Heel--Riding a bicycle becomes trivial. Driving a car, using the prosthetic on the accelerator and brake is no problem.

 

In fact, it feels to the amputee, as if he had feeling in the whole foot. It also eliminates most phantom limb pain.

 

Most prosthetic arms are simply a pair of pliers--grippers. They can make much more elaborate hands, but sensation and control are the big problems.

 

At any rate, the prosthetic is delicate enough to pick an egg up, but since there is no feedback, one must stare very intently at the egg--and sometimes it ends up broken anyway.

 

One dime-sized sensor gives very good feedback to the hand.

 

Finally, they now have temperature sensors for prosthetic hands--in addition to pressure sensors. They use those odd semi-conductors that get hot and cold depending on which way current flows through them. They get hot or warm in proportion to how hot or cold the sensor is.

 

The folks on the show that I watched said that the temperature sensor made the prosthetic feel much more alive.

 

Do you know that you use prosthetic senses regularly?

 

Imagine trying to unscrew a screw that is out of reach, and out of sight in a deep hole. Imagine that you're probing with a long bladed screw-driver.

 

As the blade edge of the screw driver slides across the hidden screw, you can tell that it is a round-headed screw, and that it has a pretty big burr un the front. You can "Feel" all sorts of things with a footlong screw driver.

 

Forty years ago, a coach at a Wrestling Clinic showed me this:

 

"You don't need to see the man, if you are touching him."

 

"If I have him "Here....."

 

He was cupping the man's left triceps in his right hand--like the arm half of a fireman's carry.

 

"If I have his arm 'Here' " At this point he tightly closed his eyes. "Then you know that his ankle is 'Here'--has to be.If it were anywhere else, he'd be off balance and in the process of falling down."

 

Its a hard thing to explain, but even after all these years--if you blindfold me, and let me contact just one bony place on your skeleton, and I'll know to within fractions of the inch, where every other macroscopic bone is.

 

Well, lots of gadgets come to mind--but one in particular stands out.

 

Find some pressure sensors the size of Indian Beads. Put about thirteen on the bottom of the rubber tip to my cane--one in the center; a half diameter hexagon, and a full diameter hexagon, rotated 30 degree in relation to the first hexagon.

 

Put me a couple temperature sensors on the bottom, and one on the side.

 

And I just now thought of it--but maybe include a couple of the mercury-filled tilt sensors in the cane too.

 

Route them wireless (So I can freely swap hands) to a high-riding arm band.

 

Imagine walking through a dark Winters Night, with your cane feeling alive, feeling even relatively minor features of the pavement underneath--and even sensing the coldness of the sidewalk, and the air.....

 

Well, in all likelihood I'll never get around to building it....

 

But I'd sure like to have one.

 

Saxon Violence

[Turtle]

I was reading about a new gadget a few years ago.

 

...

Well, lots of gadgets come to mind--but one in particular stands out.

 

Find some pressure sensors the size of Indian Beads. Put about thirteen on the bottom of the rubber tip to my cane--one in the center; a half diameter hexagon, and a full diameter hexagon, rotated 30 degree in relation to the first hexagon.

 

Put me a couple temperature sensors on the bottom, and one on the side.

 

And I just now thought of it--but maybe include a couple of the mercury-filled tilt sensors in the cane too.

 

Route them wireless (So I can freely swap hands) to a high-riding arm band.

 

Imagine walking through a dark Winters Night, with your cane feeling alive, feeling even relatively minor features of the pavement underneath--and even sensing the coldness of the sidewalk, and the air.....

 

Well, in all likelihood I'll never get around to building it....

 

But I'd sure like to have one.

 

Saxon Violence

 

sounds cool. :Glasses: i found something similar, but it is an auditory feedback and not your muscular nerve interface. still, you might like it. i'd sure like to have a gadget cane of some kind, hardened for hiking; i think it would be great day or night. shove it down that hole you're thinking of reaching into and virtually feel first the lay of the land. yeah; i want one.

 

anyway...

 

full article: Developing a 'smart cane' for the blind

 

For the past several years, various research institutions and organizations have been experimenting with electronic “white canes” for the blind. One of these was the ultrasound-enabled UltraCane, which we profiled five years ago. Now, however, an associate professor of applied science at the University of Arkansas is working on something more advanced – a white cane that utilizes laser technology to give users the lay of the land.

 

U Arkansas’ Dr. Cang Ye and his colleagues plan to use a Flash LADAR (laser detection and ranging) three-dimensional imaging sensor to create a detailed model of the user’s environment. Unlike other laser ranging systems that require the laser to mechanically scan back and forth across the environment, Flash takes everything in at once, within sequential floodlit exposures that typically lasts less than a nanosecond each – this is particularly well-suited to people on the move.

 

The Flash system obtains two images per exposure, one that measures the physical range (or distance away) of each pixel, and one that measures their intensity. Ye’s team has created an algorithm called VR-Odometry (VRO), that uses this data to calculate the user’s position within their environment....