I need to pump up to 30psi then hold for 1.5 minutes;then release the pressure for 0.5 min and start the cycle over. As the muscle in the neck relax the pressure goes down. Since I'll have a micro controller running this I'll set a upper psi and a lower psi and let the controller keep the pressure in that range. I'm finding pressure sensors are not cheap. I need to find a surplus store that has good deals !!
Love the comments here ! Blood pressure machine that cuts off your arm - what a product liability lawsuit that would be.
Hard to believe the traction unit mfg doesn't have an option for an electric pump. How do the 80 year old grandmothers who get this via medicare use it? If not, Dave needs to take his final design and sell it. I can see the television info-commercials now for the "Traction Pump Store".
Blood pressure monitors provide the capbility to pump up to 160 psi in 15 seconds. I would suspect that they can generate 40 psi within seconds. They are typically turned on/off with membrane switches which could be stripped out and replaced by some external digital signal, thus automating the psi cycle.
As another approach for consideration... Might an air tank work? They're basically just like the pressure tank on an air compressor-- just without the pump.
You 'fill' it from an air compressor (they're usually 5-10gallon sized) and then you have a nice, silent source of pressurized air.
A little 4V110 sized air valve (solenoid controlled ~$10 on eBay) and you've got an electrically controlled fill/exhaust air control.
The tank would just get around the noisy little compressor motor blasting away nearby (at the expense of having to fill it occasionally depending on the air volume required).
Harbor Freight sells the air tanks for ~$25-40.
"something that had a pressure gauge with BCD outputs..." - you don't want much, do you? ;-)
It should not be difficult to plumb in a commercial pressure sensor if you can't find one like this, or if you need a fixed pressure, just get a pressure switch (nice easily interface-able 1 bit input...
Sorry guys but you're are both correct ... air pump is all I need. From Dave's last comment sounds like my Sleep Number bed pump wouldn't drive to 30 psi. I'll check out the local auto supply around town and see what they have. It would be really cool if I could find something that had a pressure gauge with BCD outputs (of course it's going to cost more) I could hack.
Blog Make a Frequency Plan Tom Burke 17 comments When designing a printed circuit board, you should develop a frequency plan, something that can be easily overlooked. A frequency plan should be one of your first steps ...