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A Humanitarian Engineering Problem
zrosener asks: "A have a friend who has ALS (Stephen Hawking's ailment), a particularly nasty disease in which her motor neurons deteriorate over time, slowly waylaying her. She is in pretty bad shape now, and her movement is restricted to moving her eyes, and very limited (1 inch in each direction) hand movement. She has very light bell that she uses to wake up her husband when she needs assistance, but as her strength wanes it is becoming less and less effective. She is afraid at night now that if something were to go wrong she would not be able to rouse her husband. My challenge to you is to design a noise-making-husband-alerting device cheaply and quickly assembled from strip mall parts (Radioshack, Walmart, etc.) that she could use with her extremely restricted movement. Buttons are out of the questions, as are anything that requires gripping. Analog answers are encouraged too! Please email all suggestions or post them."
Oi! Oi! The first cool Askslashdot question in a long time!
An idea, that is sort of like a button but not quite is to use those touch-sensetive lightswitch panels (the on/off kind, not dimmer kind) so you only need a very light touch to trigger the switch.
Hilary Rosen's speech was about her love of money and her desire to roll around naked in a pile of money.
I have seen this before, just set it up so there is an air tube that the person can blow some of their breath through to activate a button that could sound something.
I know some people do morse code this way because they can't move their hands or legs.
Simple. Get a small lightbulb and arrange it to shine on a photodetector. Hook it up so that a buzzer will sound if the detector output drops.
Then all she has to do is move her hand to cover the detector and the buzzer will sound.
For slightly more technical than Rat Shack, use an IR LED with corresponding detector.
Two metal plates that are only several inches apart and near her hand. Her hand alwas rests on one plate with her fingers just shy of the second plate.
When she needs help she moves that tiny distance and her hand touches both plates and completes the circut which is then wired to any bell and whistle you might choose.
Simple but effective and easy.
Puto
The Revolution Will Not Be Televised
Possibly even easier, depending on teh reliability of her muscle control, is a pair of finger cymbals. Each is connected to one side of the wire - tap them together, on it goes.
When the wife becomes nervous her heart rate probably goes up. Get a heart rate monitor that has an upper target rate alarm. Set it to a reasonable value through trial and error.
The middle mind speaks!
Why not have a small IR beam sensor (you can buy the parts at most ratshacks) and have that set off a buzzer/siren. Position the beam sensor pair within range of motion of her hand so all she needs to to is interrupt the beam with her fingertip.
Ratshack even used to sell a larger-scale version of this as a door entry bell. You placed the unit and a reflector on either side of a doorway and anytime someone walks through the beam a chime sounds. Most ratshacks had these set up and operating to alert the salespeople to incoming customers during off-hours.
You might be able to find a pre-made version of this device on a small scale for detecting cabinet openings, or as a small portable "hotel room alarm" but most of these kinds of devices will not use this mode of sensing. (most cabinet alarms sense the light pouring in from the room into the cabinet, and most hotel alarms hang on the doorknob and sense being rocked around with a mercury switch.)
-Matt
Would she be able to use a light switch panel that has the large, flat switch (as opposed to a regular light switch)?
Also, a sensitive motion detector? It might be able to pick up blinking or other movements she could make moving an object like a pencil.
How about a handicapped-helper dog?
Another idea is a button she could bite on that triggers a noisemaker.
Advice: I hope you find something. Be creative. Use functions of her body which are not affected by ALS, i.e. respiration or heart rate. If either vital signs drop or accelerate to a certain point, a simple breathing monitor or heart monitor would make noise.
Take a piezo buzzer or Sonaralert (if you want something LOUD) and wire it to a standard-issue microswitch. You can get microswitches with actuators that are a short piece of metal about the size of a ball-point-pen clip. Actuation force can be VERY tiny (grams) with motion as little as 1/8 to 1/4 inch.
Some versions with cat-whisker actuators are also avaiable, just a bit of wire sticking straight up that you give a push in any direction. You can build something similar out of a couple of paper clips if you want REAL cheap.
You could add a latch/time circuit so you wouldn't have to keep the switch depressed, ie: a quick press would sound the alarm for some set period of time.
There are also preassembled photosensors with a light source and sensor and a gap between the two, stick a finger between them and it triggers, zero force required.
I've also seen the microswitch thing work as a blink/squint sensor. You stick the wire actuator to the skin above/below the eye and a good squint will trigger it.
One last idea, shine a low-power IR led at the corner of the eye, read the reflection brightness with a photocell. Now looking to that side causes the colored part of the eye to reduce the reflected light, triggering the sensor.
The biggest problem with running something off the eyebrow or eye look/blink is usually preventing it from going off by accident, or if the person goes to sleep.
There are also devices that actuate by sucking/blowing on a straw or pushing with the toung or chin...though these don't work so well if you're on a respirator.
Milo from Kangaroo Koncepts
you could work in some extra circuitry to make certian very quick brushes don't trigger the sound, but that's optional.
Ad in classifieds: Pandora's Box (no box) $5
I work on a spinal cord injury unit at a VA hospital. We work with people of all levels of disability, including advanced ALS patients.
Can she move her tounge? There are simple switching devices that can be placed in a person's mouth that can be tripped with a tounge movement.
Can she breathe (i.e. not on a ventilator). There are all kind of "sip-and-puff" devices out there that can generate several signals based on whether or not the person is sipping or blowing.
You said she can see, and has some eye movement. We have patients who are trained using eye gaze computers.
A search on google for adaptive devices, adaptive technology, a call to a local rehab hospital should all be able to provide you with information with regard to devices already available. Even if this person can't afford these things, it may give you ideas as to what you can build for her. I'm sorry I can't provide specific info, as our rehab staff/prosthetics department takes care of actual building and ordering.
When you work with people with a serious impairment, in a rehab setting, its truly remarkable what can be built/developed to take advantage of even the slightest behavior a person can elicit.
hth,
jeff
Having done some work with the disabled, here are some suggestions for sensors.
Touch (Capactive switches)
Beam (light, ultrasound, IR triggers)
Magentic (Reed switches)
Tilt (Mercury switches)
I'll only touch on Magnetic and Tilt switches, as the others have adequately been covered by a number of people.
Magnetic switches are easily and cheaply bought anywhere you can get house alarm parts. They are very simple, last a lifetime, and work really well. Using a tiny magnet strapped to a finger allows you to use a number of reed switches so there is a choice of "what to do".
Tilt switches are easily worn on the finger, or on the head. Some care must be taken to encase the deadly mercury as the glass container may be easily broken, and mercury is poisonous. The way I would encase such switches would be by first finding a glue that is capable of sticking to GLASS and plastic, and coating the glass covered mercury switch in it. This way, if the glass cracks, the pieces will usually stay together. Let it dry, then dip it in hot plastic a number of times. You can then put it inside a piece of dense foam rubber (use a glue that sticks to rubber and plastic to keep it in place). The goal is that if you accidently stand on it, it won't break.
I've used both methods before to provide something that a disabled child can use, usually to encourage them to make some sort of movement. One Example: Mercury tilt sensor attached to a head strap with velcro (for position adjustment), to encourage the child to 'lift' their head (helps build up the neck muscles and train the brain). The mercury switch was usually wired into a radio or tape deck, switching it on or off. It also provided some real insight into what sort of music some of the kids liked, as after a little training, they would drop their head when something they didn't like would come on, and then every now and then raise their head to "check" what was playing now.
Good luck.
I suggest a portable biofeedback monitor. My GF uses one for muscle problems. They have a light, relatively small sensor that can be taped to the skin. When the muscle underneath is tensed, the alarm goes off - and the trigger level is widely adjustable.
The device she uses is walkman sized and cost about $500 from a company in Canada. The brand name is Myotrac.
Any working muscle will do and the thing is very sensitive, with gain as well as level controls. And very easy to use. Google turns up lots of hits, here's the manufacturers URL: http://www.thoughttechnology.com/myotrac.htm
As a bonus, the engineers answer the phone and will gladly discuss your intended use.