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  • Author Author: jw0752
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Power Straw

jw0752

For several years my Mom has been in a Nursing Home with Parkinson's disease. As she has lost function of her muscles I have attempted to use technology to assist her. I have posted a couple of my attempts to assist her in my Blog on E-14.

 

https://www.element14.com/community/people/jw0752/blog/2015/07/07/hacking-a-lift-chair

 

https://www.element14.com/community/people/jw0752/blog/2016/01/15/building-an-led-amplifier-for-mom

 

Recently on her bad days she has been too weak to draw the thickened water she has to drink up a straw. This causes her to become dehydrated and quickly affects her health. She is very stubborn and will not allow herself to be fed by other than by herself. To help her in the days that she is too weak to drink through a straw  I have constructed this little device to assist her. I call it a Power Straw. It is very light on electronics so perhaps it does not have much application to our electronics site but since I had published previous projects I though a few of the guys would be interested.

 

Here is a schematic of the project:

 

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I began the project by collecting a variety of potential components. My Goal was to draw her thickened water from a reservoir and pump it up a line and into her mouth. She is accustomed to using a push button call switch when she needs help from an attendant so I decided to use a very similar switch to actuate the pump.

 

The water line would run axially with the switch and its wiring. The switch could be held in her hand and the water feed line would continue past the switch by about 4 inches.

 

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Picture of Hand Switch

 

I decided to try a small 12 volt water pump, that is usually used in small fountains, to pump the water from the reservoir.

 

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Picture of Pump in the Reservoir

 

My first prototype did not include an in line solenoid. This created a problem if the cord accidentally fell to the floor as gravity would siphon the water from the reservoir and create a big mess on the floor. My final prototype needed a solenoid.

 

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Solenoid Picture

 

Since space and weight were not a particular problem I decided to use two 6 volt 4.5 Ahr Lead Acid Gel Cells for the batteries.

 

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Battery Picture

 

A small Volt Meter circuit was incorporated in the control box so I could check the level of the battery and recharge it when needed.

 

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Control Box Picture

 

The control box is very simple with the Volt Meter and a momentary switch to activate it, a single P Channel MOSFET, Jacks for: Batteries, Charger, Pump, Solenoid, and actuation switch.

 

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Pictures on inside the Control Box

 

The Reservoir is an lightly insulated hospital drinking cup that I brought home after a past overnight adventure.

 

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Picture of the Reservoir.

 

Here is a picture of the finished project before I took it to Mom's room and nylon strapped it to the back of her wheel chair.

 

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Picture of completed assembly

 

I can see room for many improvements. The parts that I ordered and received did not meet my imagined specifications. For example the pump could have a little more power and the solenoid draws too much current. While the batteries will be heavy enough to deal with the present solenoid, ideally, I should be able to find one that uses 200 mA or less instead of the current 400+ mA. I have made the reservoir and hand cord easy to disassemble for cleaning but improvements can be made. The plugs that were used on the pump and the solenoid were not polarized. While this will not affect the solenoid it is important the the pump spin in the correct direction for maximum efficiency. I have marked the non-polarized plugs but someone other than me might miss this detail. For the time being however Mom is happy and after the newness wears off she too will have some good suggestions for her sonny boy on how he can make it better.

Parents

  • ERRATA :

    I have discovered that I made a mistake and published incorrect information reference the mA draw of the peristaltic pump. If one looks closely at the picture of the Fluke Meter in my last post you will see that I had the meter set on mA AC. I do not usually use the Fluke to test mA and forgot that besides setting the function switch it is also necessary to push the orange mode button to switch from the default AC to DC mA. Experience and common sense should have triggered a "somethings wrong" warning in my head but it didn't until tonight. It is funny how often in my life I have made an obvious mistake and not realized it until a later time. Suddenly the realization just pops into my head that something isn't right. In this case a test using a meter set to mA gave a more common sense 300 mA draw.

    John

Comment

  • ERRATA :

    I have discovered that I made a mistake and published incorrect information reference the mA draw of the peristaltic pump. If one looks closely at the picture of the Fluke Meter in my last post you will see that I had the meter set on mA AC. I do not usually use the Fluke to test mA and forgot that besides setting the function switch it is also necessary to push the orange mode button to switch from the default AC to DC mA. Experience and common sense should have triggered a "somethings wrong" warning in my head but it didn't until tonight. It is funny how often in my life I have made an obvious mistake and not realized it until a later time. Suddenly the realization just pops into my head that something isn't right. In this case a test using a meter set to mA gave a more common sense 300 mA draw.

    John

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