Need Help With Circuit For My Brain Damaged Son

[trench58]

Hello, I am John. I love electronics and am able to build circuits from a schematic. However I am disabled with limited cognitive ability and unable to understand most electronic theory. My 19 year old son Chris was in a horrible car crash in January and suffered very severe traumatic brain injury, he can only move his right hand a little but does squeeze my finger for a yes to questions. I am trying to figure out how to make a switch for his right hand that will light a different color LED each time the switch makes contact, so that maybe green comes on first and equals YES. Then maybe red next squeezze for NO. And so on,blue,yellow,white,orange, whatever I can figure out and train him to do. I am not good at explaining things and usually stay out of things because of that, but I want to try and make something to help my boy.The simpler the better. Any help from those with the knowledge to figure out such a circuit would be more than appreciated. All I can do is barely figure out a squeeze switch that can sense a very small, light pulse from one of any of the fingers. I can not do any PICs. Thanks for the time.

 

[Mosaic]

I hope your son is on the road to recovery. Once there is life there is hope.
What you ask is not too complex but a little more info can help make a more useful appliance aid.

1) Can your son control how fast he squeezes? Perhaps once per second vs twice per second?
2) Can he control how hard he squeezes?
3) Can he control what he squeezes or presses, can he select from buttons?

For instance, I have a colleague at work who broke his jaw and cannot speak. He uses a Kindle to say basic word responses .

These data will help guide what can be done.

On the matter of PICs, they are probably a very good way of proceeding since the s'ware can decide how to respond to the signals from your son. If the forum were to provide the actual s'ware hex file would u be able to assemble the circuit and download the program into a PIC with a programmer like PICKIT 2 or 3?

 

[Sceadwian]

Skip electronics altogether, simply give him something long and flexible but light, like a longer piece of styrefoam that will deform if a hand around it squeezes think of something like the material pool noodles are made out of. You still have to watch for the twitches but it will mechanically augment them so you can see them outside of physical contact.

 

[Mosaic]

Perhaps using an LCD device that converts long & short squeezes (Morse code) into letters might be the way to go, so he can ask his own questions or originate statements rather than have to be prompted.
You can decide on a simplified 'Morse code' just to create a vocabulary of words to start., rather than having to read Morse from a chart (He can see?) and then spell out his requests.

If that can work it is also possible to permit the handheld squeeze interface to uplink to a tablet or PC to permit him to read his msg as he 'types' and even trigger e-mail (& respond to email) from his bedside.

 

[OlPhart]

There are flexible-resistive components that may well address a limited input situation.

 

[trench58]

Hello again. Chris is very minimally responsive and is expected to never do much better. He does have some cognitive ability. He can hear, can only see up close now and the only thing he can do on command is squeezzee my finger with his right hand. It has to be opened manually. Sometimes it is a very very light pulse, sometimes strong. Which finger varies and sometime no response at all. I am in the hope that I will be able to train and improve him to some level of consistency. I am trying to teach him basic colors and single digit numbers now. If I could just start with 3 colors of LEDs and get him consistent with recognizing them assosiated with a definition or meaning. I think I have figured out a switch that will measure weak and strong pulses from any finger. It seems the switch should be momentary on? But really it gets complicated really quick for me. I have been ill past ten years and things are quite challenging mentally and physicaly. Not whinning just please understand who you are dealing with. Which I appreciate so very much. To Mosiac's 3 questions . It is no to all 3. John

 

[DerStrom8]

Hi John. I am very sorry about your son's situation. I imagine that must be very hard on the both of you, and I admire what you are doing for him

The simplest solution I can think of is a decade counter (perhaps a 4017). For each input clock pulse, it will turn on the next output in a 10-output sequence. The input clock would be the switch your son would press, which should probably be debounced so that it doesn't cause unwanted "jumps". That can be done with a simple 555, or even a capacitor circuit.

For the main part, I think this will achieve what you are describing:

View attachment 63525

You can see the switch on the left, connected to the "CLK" input to the 4017. That is the switch your son would operate, though it would require the debouncing circuitry to be added in.

If you decide this is what you'd like to do, I can work out a schematic, if you're interested.

Good luck to you and Chris. I hope you can get this solved very soon

Kind regards,
Der Strom

 

[bountyhunter]

I work at an animal shelter as a volunteer: I wonder if he might start training with some kind of slender flexible toy that squeaks when squeezed. The noise would provide feedback indicating when he was successfully squeezing it.

 

[crosslakeguy]

I ask, if you speak to him, and ask him to do something, say chris....... move hand/finger is there a response? how about his eyes? can he move them freely? say move eyes up. down, left, right. It is important to know more specificaly what he is capable of to know what may work for his needs. If he cannot physicaly move freely but can blink or move his eyes, then other options could be possible? something you could start with, without the confusion of a machine. If you move something in front of his eyes does he follow it. I know you are looking for the best solution, but it is difficult to give sound help without knowing exactly what his capabilities are, I am aware of people spelling, and communicating with their eyes.....If he can move a finger a little bit one way, then the other....... even a little consistanly. an optical finger mouse with a specific program could work too.....for simple pre-programmed commands.

 

[pilko]

Hi John,
I am so sorry about your situation.
The first thing we need to do is find a switch that your son is able to operate. Have you googled "squeeze switch" or "grip switch".
Here is one such link http://www.abledata.com/abledata.cfm?pageid=19327&ksectionid=19327&top=11357
When you have found a switch that he can operate, we can make it do things like light LED's or make sounds.
Another cheaper option is to use conductive foam, google that also and try some.

pilko

 

[alec_t]

I'm also sorry to hear of your situation and hope it has a good outcome. Hats off to you for your dedication under difficult circumstances.
I think the most challenging part of this project will be finding a reliable switch. Would you son be able to blow into a tube to operate a pressure switch?

 

[trench58]

Hello Again: First thank you all for the kind words. Der Strom, I really like your idea. If you would draw a schematic, I cannot say the level of appreciation I would feel. Is it possible to not use a bar graph and only some LEDs? I have studied debounce and think that is a wise addition. Bountyhunter, that is a spectacular idea with the squeek toy for training untill the project is completed, thank you much. Crosslakequy, yes Chris will squeeze my hand if I ask him, most of the time. That is pretty much it though, he does not follow with his eyes and has no response in speech therapy. He does not have any controll at all other than the right hand and that is very eratic. Pilko, I am trying to make a switch myself, to keep cost down. Which is quite a challenge. But I think the hand switch and LEDs are the best idea, at least for now. I truly appreciate this help, otherwise I would just have to give up. Thanks so very very much. John

 

[trench58]

Alec_t, Thanks you. Chris is on a trach to breath through. If he gets off of that , then I will try to get a breath response from him. Good idea and yes the switch is quite a challenge. John

 

[DerStrom8]

Hello Again: First thank you all for the kind words. Der Strom, I really like your idea. If you would draw a schematic, I cannot say the level of appreciation I would feel. Is it possible to not use a bar graph and only some LEDs? I have studied debounce and think that is a wise addition.

Yes, using individual LEDs shouldn't be a problem. The concept will remain the same regardless.

There are a couple of different types of debouncers. The simplest would probably be just a capacitor, but I'm not sure if that will work properly for a clock input to the 4017. Personally, I'd recommend a 555 timer debouncer, since the output is a cleaner square wave. I'll get right to work on the schematic for you

Kind regards

 

[DerStrom8]

Okay, here's the basic idea:

View attachment 63563

I apologize for the sloppiness--I haven't used EAGLE in a little while

Anyway, the circuitry on the left is the debouncer circuit. S1 is the main switch. This is the switch that will change which LED is on. S2 is the reset switch. After each question, you'll need to "clear" everything. This is why there is no LED on Q0 (first output). Normally, when you reset it, Q0 would switch on. Normally, you wouldn't want an LED on, so by leaving out the LED the entire array will be clear. From then on, every time you would ask your son a question, he'd be able to press the switch and each time a different LED would light up. He could stop at the one corresponding to his answer. After you get the answer, you'd want to reset it using S2, and you're ready for the next time.

It also wouldn't be a bad idea to have an audio indicator that the button is pressed, as I believe someone suggested already. You should be able to attach a buzzer or beeper to the "Q" pin of the 555. Just make sure it's the type with a built-in oscillator.

I realize it looks a little complicated. I'm sure someone who's been using EAGLE recently would be able to do a much better job with the circuit and make it look neater and easier

Good luck!

[EDIT] Please ignore the second attachment under "Attached Thumbnails", below. That is the wrong circuit and I can't seem to figure out how to remove it

 

[alec_t]

Regarding the switch, how much/little finger movement (in mm) is there to operate it?

 

[trench58]

Hello All, Der Strom , no need for applologies, it looks great to me. I can follow that and get it put together. I have a question of something I am not sure of. Will the previous LED stay on or go out when the next one is lighted and at the end they are all on or only the last one? Great idea about the audio indicator also. So long as the beeper/buzzer will activate with power alone, it should mean it has an oscillator? I really can't say thanks enough! Alec_t, In mm I am going to say a weak pulse is only about 3mm distance. Maybe not the same finger all the time and sometime quite a bit of pressure, not sure of the stronger distance as I feel the pressure, but a lot stronger. he is usually lightly holding my finger or fingers. I have been trying different amounts of fingers to try and determine what size works best for him and I seem to think 3 may be the best fit. I have medium sized hands. I thank you all so much for your help, interest, time, everything, it means a great deal to me and my family, thanks so much. I have had a long day and must sleep on this information and start anew tomorrow. By for now. John

 

[alec_t]

I've just been experimenting with a piezo disc as a possible input device. A light touch on it with a finger gives an output pulse of about +1V which decays to 0V in a fraction (I guess < 0.5) of a second. Removing finger pressure gives an output pulse of about -1V which likewise decays. A 3-finger-wide bar could be attached to it and requires virtually zero movement to operate. A lever with small movement (~1mm) could be used to apply greater pressure to the disc and so increase the output signal if required. Thus the disc could make the basis of a slim switch with no contact-bounce; although some signal conditioning would probably be needed to overcome any 'jitter' in the applied pressure.

 

[DerStrom8]

Hello All, Der Strom , no need for applologies, it looks great to me. I can follow that and get it put together. I have a question of something I am not sure of. Will the previous LED stay on or go out when the next one is lighted and at the end they are all on or only the last one? Great idea about the audio indicator also. So long as the beeper/buzzer will activate with power alone, it should mean it has an oscillator? I really can't say thanks enough!

When one output of the 4017 turns on, the previous one should turn off. There should only be one LED on at any given time. This is an animation of an automated one, just to show how the 4017 works:

View attachment 63584

The only difference is that you'll be using all but the first output, and it will only go to the next LED if the switch is pressed.

Yes, if a buzzer/beeper activates just by connecting to power, it has a built-in oscillator. You could build an oscillator yourself and use a speaker, but that requires a little extra circuitry. It's up to you.

Regards

 

[trench58]

Hello, Alec_t, I will have to experiment with the piezo disc. I would have no clue how to conditions the signal though. Der Strom , I have 9 outputs I believe, could it be, by useing some outputs to reset have it so it would start off go green then red then off then green then red then off the green then red and back to off as the cycle. it would only be 2 colors then off in a cycle but would be yes and no and just go in a circle. Amazing how fast you drew that circuit. or may it is as simple as leaving every third output unhooked. I don't know. Thank you all for you superior knowledge, it is a huge help for us. John