Fluid question: Detecting Blood Pressure in Mice

[magic_castle32]

Need some help regarding fluid flow and pressure detection:To detect blood pressure in a mouse, we usually insert a small pipe with a refined tip into the artery that is connected to a blood pressure detector. However, the problem we have been getting is that the detected blood pressure is lower than it actually should be.

Why is this the case?

Would changing the pipe diameter, or 'pointiness' of the tip, be of help in getting a more accurate reading?

 

[Andy Resnick]

Without more information, it's hard to diagnose the problem:

How is the detector calibrated? What is your control condition? How do you know the readings are incorrect?

For example, do you also take a reading in the tail vein?

 

[magic_castle32]

Without more information, it's hard to diagnose the problem:

How is the detector calibrated? What is your control condition? How do you know the readings are incorrect?

For example, do you also take a reading in the tail vein?

The experimental setup is properly calibrated.

I just want to know if the pipe diameter, or the 'pointiness' of the tip of the pipe, could influence the pressure. Otherwise we'd have to look into other variables, or other aspects of the set-up.

 

[Andy Resnick]

It's easy to imagine viscous losses which would give low pressure readings. But again, without any information about your setup, it's hard to say anything definitive.