Catheter Balloon Inflation
Catheter Balloon Inflation
(OP)
Hi
I'm new to bioengineering but I've been asked to calculate the theoretical inflation time for a catheter balloon. Can any one point me in the right direction? Any guidance appreciated.
I'm new to bioengineering but I've been asked to calculate the theoretical inflation time for a catheter balloon. Can any one point me in the right direction? Any guidance appreciated.





RE: Catheter Balloon Inflation
V = volume, Q is flowrate, t is time.
What would you be doing, if you knew that you could not fail?
RE: Catheter Balloon Inflation
RE: Catheter Balloon Inflation
RE: Catheter Balloon Inflation
RE: Catheter Balloon Inflation
RE: Catheter Balloon Inflation
Thanks for your help.
RE: Catheter Balloon Inflation
I need to calculate the time to fill and then deflate a catheter balloon. This consists of a hand pump connected to a long tube which then widens out to the balloon vessel. I need to reach a certain pressure in the balloon. The balloon is already expanded and it is assumed no further expansion of the material will occur.
I know the volumetric flow rate (Q) from the hand pump. The length (L) of the tube is 1400mm. I have calculated the pressure drop across the tube (delP).
How to I determine how long it will take to fill both the tube and the balloon from vacuum to a given pressure and then how long to pull a vacuum on the system? Any help appreciated.
I previously used Pressure = mass*Gas Constant*Temperature/Volume. I did this at intervals until the pressure in the vessel equaled the pressure required, giving me the time required. However I found that this did not match my experiment. (The calculated times were much greater than the actual)
RE: Catheter Balloon Inflation
As general rule, you should refrain from double posting: thread755-322700: Balloon Inflation/Deflation Times However, given that no one else replied to the other thread, going here is probably reasonable.
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RE: Catheter Balloon Inflation
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RE: Catheter Balloon Inflation
In the code (which is not giving me the correct answers) I have used the mass flow rate and to calculate the mass in the balloon and from that calculate the pressure in the balloon. I have converted the 1ml/sec to 1000mm3/sec and I am checking this model with water but need to ultimately do it with saline.
RE: Catheter Balloon Inflation
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RE: Catheter Balloon Inflation
RE: Catheter Balloon Inflation
I have a pump, which will pump water through a long length of pipe ( long in relation to its diameter) into a tank. it is a closed system. there will initially be a vacuum in the pipe and tank. i want to find out how long it will take to fill the tank to a prescribed pressure.
Thanks for your feedback.
RE: Catheter Balloon Inflation
Patricia Lougheed
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RE: Catheter Balloon Inflation
RE: Catheter Balloon Inflation
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RE: Catheter Balloon Inflation
RE: Catheter Balloon Inflation
In any case, you've not stipulated anything that resembles a resistance to inflation
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RE: Catheter Balloon Inflation
Since we don't know if the cathetar is going to be placed inside the body and we also don't know the properties of the "balloon" fabric -- which really does play a role -- there's only so much that can be done. We can't really teach sph99 fluid flow over these forums -- and to be honest, he couldn't teach me (at least) structural engineering either. The book will give him a practical starting point. Between that, his test data, and his coworkers, hopefully it will be enough to solve his problem. If not, well, then the usual advice is to hire the right expertise, isn't it?
Patricia Lougheed
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RE: Catheter Balloon Inflation
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RE: Catheter Balloon Inflation
Just thought you'd want to know. :)
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Catheter Balloon Inflation
Crane was helpful in getting to grips with what I should be looking for and I have made progress since starting to read it.
However, while I am getting closer to solving the problem, I think the long tube with an diameter of less than 1mm is affecting my results. I have a hand pump which feeds into the long tube. The tube widens out into the balloon. I have called it a balloon but it does not display the properties of a balloon. It is already expanded into shape and then a vacuum is pulled on the whole system.
I would like to initially solve the problem assuming that there are no forces acting on the outside other than atmospheric pressure, and the balloon does not resist inflation. When I get this much done I will then have to look at the case where the balloon begins to expand as the pressure increases.
RE: Catheter Balloon Inflation
I admit you are well outside my area of expertise. My only "experience" with catheter balloons is when nuclear medicine procedures go wrong and a catheter balloon is somehow involved ... and one of the inspectors draws me a diagram to explain how someone ended up receiving a dose of radionuclides in this area here instead of where it was planned over here ... <I think my profile mentions I no longer do engineering for a living and I come here for sanity's sake.>
I'm glad Crane put you on the right track. There is a description in Section 1 (I think) about long thin tubes that might bear reading. It affects the formula that you use.
Patricia Lougheed
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