My mother's external catheter causes bruising, because the pump always runs so she won't use it. I want to put a temperature sensor in the external catheter to turn on the pump milliseconds after the urine begins to flow.
Here's what the external catheter consists of:
Using an Arduino of some sort, an air pump, some container, tubing, and I'm thinking a fast acting temperature sensor (or any sensor you guys would think is better suited) to make a pump that turns on the second it's required and turns off when it's not is something I'm hoping is feasible. Please help me figure out the best way to go about this. Im somewhat familiar with raspberry pi. I've used raspberry putting together a pen testing platform and flashed different kernels of Kali Linux and other sorts of similar stuff onto it. I've only had the one raspberry pi 3 not sure which off the top of my head and I'm sure that's not relevant anyway. I have limited experience using terminals to run programs and messing around in directories and with files. This is the first time I've ever posted any question on any forum so if I suck(I'm sure I do I suck at everything) I apologize. Productive input would be very appreciated and you'll be helping an old woman regain some dignity. Thank you.
PS I only used raspberry pi for my purposes because it seemed to require less technical competence than arduino not because I prefer one to the other.
Having some light knowledge in this subject, but too less....
Using a catheter the tube usually goes into a bag collecting the urine. At intervals the bag is checked and emptied or changed.
The use of a pump is new to me.
Can You explain that "solution"?
I don't really understand the details of the pump catheter. However for a sensor I would use a small NTC resistor. It would have to be liquid proof as urine is rather conductive.
Can you adjust the air flow by venting the suction line a bit? That may help. Also contact the manufacture about this problem, they should help as those things are expensive.
I think a thermocouple is the only temperature sensor that will give you usable response time. I can see where milliseconds will matter based on how the system works.
If you look at the part that catches the urine, you see that quite a lot would have to be absorbed without leakage before any flow measurement in the tube could occur. That's probably why the pump runs all the time in the current setup.
Pee on your hand and get back with me.
The moisture sensor would probably do the trick but would have to be very low current to not be terribly uncomfortable. Run a few microamps through some sensitive area and note the effect.
I think there are too many problems associated with insulating a thermocouple and maintaining the response time to make it a practical approach.
So you don't think there will be a current path between the wet conducting pad and the skin it is directly against? It's safely doable but the current will have to be limited and isolating the rest of the device from the body will have to be carefully considered.
I do not see any intermittent systems in the market.
What pressure are you currently running in the collector?
I would think that you would be more successful trying to minimize the suction pressure required by placing the collector below your mother, and using a precision regulator instead of what comes standard on the device.
I believe what you have is a PureWick™ System Products or simply put an external urine collection system. They use what they call a External Catheter along with a pump as part of the whole urine collection system.
The pump runs 24/7 to make sure there is vacuum on the tube, less that vacuum the urine is not going into the collection tube so the pump needs to run 24/7.
From the looks of that machine it seems like a conductive probe in the absorbing material would be the only way. One problem is once moist it would stay that way for a while. Another problem is there would be wires that would have to be routed as not to interfere with it's main purpose. An alternative is that Musk has a chip that is implanted in the brain which probably could control it.
With all this discussion I searched for "external catheter" and have a feel for what is going on.
Unfortunately I don't think stopping the vacuum until urine is detected in the tube will work.
My understanding is that the "wick" of the urine pickup is under vacuum all the time. When urine is released the existing vacuum will suck the urine into the container.
If the pump we to be stopped, when urine was released it would just sit in the wick and leak our around the wick assembly. There would be no force to move the urine through the wick for sensing further on.
I do not know the possibility of sensing temperature at the wick for pump control. If somehow the wick saturation level could be determined the I believe controlling the pump would be possible.
I wonder if a compromise would be good enough that your mother would be comfortable using the device? Since an automatic switch would be most helpful when your mother is sleeping, instead let the pump run constantly then and have a manual switch to activate it when she needs it when she is awake. Hopefully that would reduce the bruising.
